implement discussion cache

src/components/Note/MarkdownArticle/MarkdownArticle.tsx

@@ -44,10 +44,11 @@ function parseMarkdownContent(
     navigateToHashtag: (href: string) => void
     navigateToRelay: (url: string) => void
   }
-): { nodes: React.ReactNode[]; hashtagsInContent: Set<string> } {
+): { nodes: React.ReactNode[]; hashtagsInContent: Set<string>; footnotes: Map<string, string> } {
   const { eventPubkey, imageIndexMap, openLightbox, navigateToHashtag, navigateToRelay } = options
   const parts: React.ReactNode[] = []
   const hashtagsInContent = new Set<string>()
+  const footnotes = new Map<string, string>()
   let lastIndex = 0
   
   // Find all patterns: markdown images, markdown links, relay URLs, nostr addresses, hashtags, wikilinks
@@ -68,7 +69,7 @@ function parseMarkdownContent(
   })
   
   // Markdown links: [text](url) - but not images
-  const markdownLinkRegex = /\[([^\]]+)\]\(([^)]+)\)/g
+    const markdownLinkRegex = /\[([^\]]+)\]\(([^)]+)\)/g
   const linkMatches = Array.from(content.matchAll(markdownLinkRegex))
   linkMatches.forEach(match => {
     if (match.index !== undefined) {
@@ -172,26 +173,253 @@ function parseMarkdownContent(
     }
   })
   
+  // Footnote references ([^1], [^note], etc.) - but not definitions
+  const footnoteRefRegex = /\[\^([^\]]+)\]/g
+  const footnoteRefMatches = Array.from(content.matchAll(footnoteRefRegex))
+  footnoteRefMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if this is a footnote definition (has : after the closing bracket)
+      const afterMatch = content.substring(match.index + match[0].length, match.index + match[0].length + 2)
+      if (afterMatch.startsWith(']:')) {
+        return // This is a definition, not a reference
+      }
+      
+      // Only add if not already covered by another pattern
+      const isInOther = patterns.some(p => 
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInOther) {
+        patterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'footnote-ref',
+          data: match[1] // footnote ID
+        })
+      }
+    }
+  })
+  
+  // Block-level patterns: headers, lists, horizontal rules, tables, footnotes - must be at start of line
+  // Process line by line to detect block-level elements
+  const lines = content.split('\n')
+  let currentIndex = 0
+  const blockPatterns: Array<{ index: number; end: number; type: string; data: any }> = []
+  
+  // First pass: extract footnote definitions
+  lines.forEach((line) => {
+    const footnoteDefMatch = line.match(/^\[\^([^\]]+)\]:\s+(.+)$/)
+    if (footnoteDefMatch) {
+      const footnoteId = footnoteDefMatch[1]
+      const footnoteText = footnoteDefMatch[2]
+      footnotes.set(footnoteId, footnoteText)
+    }
+  })
+  
+  // Second pass: detect tables and other block-level elements
+  let lineIdx = 0
+  while (lineIdx < lines.length) {
+    const line = lines[lineIdx]
+    const lineStartIndex = currentIndex
+    const lineEndIndex = currentIndex + line.length
+    
+    // Tables: detect table rows (must have | characters)
+    // GitHub markdown table format: header row, separator row (|---|), data rows
+    if (line.includes('|') && line.trim().startsWith('|') && line.trim().endsWith('|')) {
+      // Check if this is a table by looking at the next line (separator)
+      if (lineIdx + 1 < lines.length) {
+        const nextLine = lines[lineIdx + 1]
+        const nextLineTrimmed = nextLine.trim()
+        // Table separator looks like: |---|---| or |:---|:---:|---:| or | -------- | ------- |
+        // Must start and end with |, and contain only spaces, dashes, colons, and pipes
+        const isSeparator = nextLineTrimmed.startsWith('|') && 
+                           nextLineTrimmed.endsWith('|') &&
+                           /^[\|\s\:\-]+$/.test(nextLineTrimmed) &&
+                           nextLineTrimmed.includes('-')
+        
+        if (isSeparator) {
+          // This is a table! Collect all table rows
+          const tableRows: string[] = []
+          const tableStartIndex = lineStartIndex
+          let tableEndIndex = lineEndIndex
+          let tableLineIdx = lineIdx
+          
+          // Collect header row
+          tableRows.push(line)
+          tableLineIdx++
+          tableEndIndex += nextLine.length + 1
+          tableLineIdx++ // Skip separator
+          
+          // Collect data rows until we hit a non-table line
+          while (tableLineIdx < lines.length) {
+            const tableLine = lines[tableLineIdx]
+            const tableLineTrimmed = tableLine.trim()
+            // Check if it's a table row (starts and ends with |)
+            if (tableLineTrimmed.startsWith('|') && tableLineTrimmed.endsWith('|')) {
+              // Check if it's another separator row (skip it)
+              const isAnotherSeparator = /^[\|\s\:\-]+$/.test(tableLineTrimmed) && tableLineTrimmed.includes('-')
+              if (!isAnotherSeparator) {
+                tableRows.push(tableLine)
+                tableEndIndex += tableLine.length + 1
+              }
+              tableLineIdx++
+            } else {
+              break
+            }
+          }
+          
+          // Parse table rows into cells
+          const parsedRows: string[][] = []
+          tableRows.forEach((row) => {
+            // Split by |, trim each cell, filter out empty edge cells
+            const rawCells = row.split('|')
+            const cells = rawCells
+              .map(cell => cell.trim())
+              .filter((cell, idx) => {
+                // Remove empty cells at the very start and end (from leading/trailing |)
+                if (idx === 0 && cell === '') return false
+                if (idx === rawCells.length - 1 && cell === '') return false
+                return true
+              })
+            if (cells.length > 0) {
+              parsedRows.push(cells)
+            }
+          })
+          
+          if (parsedRows.length > 0) {
+            blockPatterns.push({
+              index: tableStartIndex,
+              end: tableEndIndex,
+              type: 'table',
+              data: { rows: parsedRows, lineNum: lineIdx }
+            })
+            // Skip all table lines
+            currentIndex = tableEndIndex + 1
+            lineIdx = tableLineIdx
+            continue
+          }
+        }
+      }
+    }
+    
+    // Headers (# Header, ## Header, etc.)
+    const headerMatch = line.match(/^(#{1,6})\s+(.+)$/)
+    if (headerMatch) {
+      const headerLevel = headerMatch[1].length
+      const headerText = headerMatch[2]
+      blockPatterns.push({
+        index: lineStartIndex,
+        end: lineEndIndex,
+        type: 'header',
+        data: { level: headerLevel, text: headerText, lineNum: lineIdx }
+      })
+    }
+    // Horizontal rule (---- or ====, at least 3 dashes/equals)
+    else if (line.match(/^[-=]{3,}\s*$/)) {
+      blockPatterns.push({
+        index: lineStartIndex,
+        end: lineEndIndex,
+        type: 'horizontal-rule',
+        data: { lineNum: lineIdx }
+      })
+    }
+    // Bullet list (* item or - item)
+    else if (line.match(/^[\*\-\+]\s+.+$/)) {
+      const listMatch = line.match(/^[\*\-\+]\s+(.+)$/)
+      if (listMatch) {
+        blockPatterns.push({
+          index: lineStartIndex,
+          end: lineEndIndex,
+          type: 'bullet-list-item',
+          data: { text: listMatch[1], lineNum: lineIdx }
+        })
+      }
+    }
+    // Numbered list (1. item, 2. item, etc.)
+    else if (line.match(/^\d+\.\s+.+$/)) {
+      const listMatch = line.match(/^\d+\.\s+(.+)$/)
+      if (listMatch) {
+        blockPatterns.push({
+          index: lineStartIndex,
+          end: lineEndIndex,
+          type: 'numbered-list-item',
+          data: { text: listMatch[1], lineNum: lineIdx, number: line.match(/^(\d+)/)?.[1] }
+        })
+      }
+    }
+    // Footnote definition (already extracted, but mark it so we don't render it in content)
+    else if (line.match(/^\[\^([^\]]+)\]:\s+.+$/)) {
+      blockPatterns.push({
+        index: lineStartIndex,
+        end: lineEndIndex,
+        type: 'footnote-definition',
+        data: { lineNum: lineIdx }
+      })
+    }
+    
+    currentIndex += line.length + 1 // +1 for newline
+    lineIdx++
+  }
+  
+  // Add block patterns to main patterns array
+  blockPatterns.forEach(pattern => {
+    patterns.push(pattern)
+  })
+  
   // Sort patterns by index
   patterns.sort((a, b) => a.index - b.index)
   
   // Remove overlapping patterns (keep the first one)
+  // Block-level patterns (headers, lists, horizontal rules, tables) take priority
   const filteredPatterns: typeof patterns = []
-  let lastEnd = 0
-  patterns.forEach(pattern => {
-    if (pattern.index >= lastEnd) {
-      filteredPatterns.push(pattern)
-      lastEnd = pattern.end
+  const blockLevelTypes = ['header', 'horizontal-rule', 'bullet-list-item', 'numbered-list-item', 'table', 'footnote-definition']
+  const blockLevelPatterns = patterns.filter(p => blockLevelTypes.includes(p.type))
+  const otherPatterns = patterns.filter(p => !blockLevelTypes.includes(p.type))
+  
+  // First add all block-level patterns
+  blockLevelPatterns.forEach(pattern => {
+    filteredPatterns.push(pattern)
+  })
+  
+  // Then add other patterns that don't overlap with block-level patterns
+  otherPatterns.forEach(pattern => {
+    const overlapsWithBlock = blockLevelPatterns.some(blockPattern =>
+      (pattern.index >= blockPattern.index && pattern.index < blockPattern.end) ||
+      (pattern.end > blockPattern.index && pattern.end <= blockPattern.end) ||
+      (pattern.index <= blockPattern.index && pattern.end >= blockPattern.end)
+    )
+    if (!overlapsWithBlock) {
+      // Check for overlaps with existing filtered patterns
+      const overlaps = filteredPatterns.some(p => 
+        (pattern.index >= p.index && pattern.index < p.end) ||
+        (pattern.end > p.index && pattern.end <= p.end) ||
+        (pattern.index <= p.index && pattern.end >= p.end)
+      )
+      if (!overlaps) {
+        filteredPatterns.push(pattern)
+      }
     }
   })
   
+  // Re-sort by index
+  filteredPatterns.sort((a, b) => a.index - b.index)
+  
   // Build React nodes from patterns
-  filteredPatterns.forEach((pattern, i) => {
+  filteredPatterns.forEach((pattern, patternIdx) => {
     // Add text before pattern
     if (pattern.index > lastIndex) {
       const text = content.slice(lastIndex, pattern.index)
       if (text) {
-        parts.push(<span key={`text-${i}`}>{text}</span>)
+        // Process text for inline formatting (bold, italic, etc.)
+        // But skip if this text is part of a table (tables are handled as block patterns)
+        const isInTable = blockLevelPatterns.some(p => 
+          p.type === 'table' &&
+          lastIndex >= p.index && 
+          lastIndex < p.end
+        )
+        if (!isInTable) {
+          parts.push(...parseInlineMarkdown(text, `text-${patternIdx}`, footnotes))
+        }
       }
     }
     
@@ -202,7 +430,7 @@ function parseMarkdownContent(
       const imageIndex = imageIndexMap.get(cleaned)
       if (isImage(cleaned)) {
         parts.push(
-          <div key={`img-${i}`} className="my-2 block">
+          <div key={`img-${patternIdx}`} className="my-2 block">
             <Image
               image={{ url, pubkey: eventPubkey }}
               className="max-w-[400px] rounded-lg cursor-zoom-in"
@@ -221,7 +449,7 @@ function parseMarkdownContent(
         )
       } else if (isVideo(cleaned) || isAudio(cleaned)) {
         parts.push(
-          <div key={`media-${i}`} className="my-2">
+          <div key={`media-${patternIdx}`} className="my-2">
             <MediaPlayer
               src={cleaned}
               className="max-w-[400px]"
@@ -238,7 +466,7 @@ function parseMarkdownContent(
         const relayPath = `/relays/${encodeURIComponent(url)}`
         parts.push(
           <a
-            key={`relay-${i}`}
+            key={`relay-${patternIdx}`}
             href={relayPath}
             className="inline text-green-600 dark:text-green-400 hover:text-green-700 dark:hover:text-green-300 hover:underline break-words cursor-pointer"
             onClick={(e) => {
@@ -255,7 +483,7 @@ function parseMarkdownContent(
         // Render as green link (will show WebPreview at bottom for HTTP/HTTPS)
         parts.push(
           <a
-            key={`link-${i}`}
+            key={`link-${patternIdx}`}
             href={url}
             target="_blank"
             rel="noreferrer noopener"
@@ -273,7 +501,7 @@ function parseMarkdownContent(
       const displayText = truncateLinkText(url)
       parts.push(
         <a
-          key={`relay-${i}`}
+          key={`relay-${patternIdx}`}
           href={relayPath}
           className="inline text-green-600 dark:text-green-400 hover:text-green-700 dark:hover:text-green-300 hover:underline break-words cursor-pointer"
           onClick={(e) => {
@@ -286,24 +514,131 @@ function parseMarkdownContent(
           {displayText}
         </a>
       )
+    } else if (pattern.type === 'header') {
+      const { level, text } = pattern.data
+      // Parse the header text for inline formatting (but not nested headers)
+      const headerContent = parseInlineMarkdown(text, `header-${patternIdx}`, footnotes)
+      const HeaderTag = `h${Math.min(level, 6)}` as keyof JSX.IntrinsicElements
+      parts.push(
+        <HeaderTag 
+          key={`header-${patternIdx}`} 
+          className={`font-bold break-words block mt-4 mb-2 ${
+            level === 1 ? 'text-3xl' :
+            level === 2 ? 'text-2xl' :
+            level === 3 ? 'text-xl' :
+            level === 4 ? 'text-lg' :
+            level === 5 ? 'text-base' :
+            'text-sm'
+          }`}
+        >
+          {headerContent}
+        </HeaderTag>
+      )
+    } else if (pattern.type === 'horizontal-rule') {
+      parts.push(
+        <hr key={`hr-${patternIdx}`} className="my-4 border-t border-gray-300 dark:border-gray-700" />
+      )
+    } else if (pattern.type === 'bullet-list-item') {
+      const { text } = pattern.data
+      const listContent = parseInlineMarkdown(text, `bullet-${patternIdx}`, footnotes)
+      parts.push(
+        <li key={`bullet-${patternIdx}`} className="list-disc list-inside my-1">
+          {listContent}
+        </li>
+      )
+    } else if (pattern.type === 'numbered-list-item') {
+      const { text } = pattern.data
+      const listContent = parseInlineMarkdown(text, `numbered-${patternIdx}`, footnotes)
+      parts.push(
+        <li key={`numbered-${patternIdx}`} className="list-decimal list-inside my-1">
+          {listContent}
+        </li>
+      )
+    } else if (pattern.type === 'table') {
+      const { rows } = pattern.data
+      if (rows.length > 0) {
+        const headerRow = rows[0]
+        const dataRows = rows.slice(1)
+        parts.push(
+          <div key={`table-${patternIdx}`} className="my-4 overflow-x-auto">
+            <table className="min-w-full border-collapse border border-gray-300 dark:border-gray-700">
+              <thead>
+                <tr>
+                  {headerRow.map((cell: string, cellIdx: number) => (
+                    <th 
+                      key={`th-${patternIdx}-${cellIdx}`} 
+                      className="border border-gray-300 dark:border-gray-700 px-4 py-2 bg-gray-100 dark:bg-gray-800 font-semibold text-left"
+                    >
+                      {parseInlineMarkdown(cell, `table-header-${patternIdx}-${cellIdx}`, footnotes)}
+                    </th>
+                  ))}
+                </tr>
+              </thead>
+              <tbody>
+                {dataRows.map((row: string[], rowIdx: number) => (
+                  <tr key={`tr-${patternIdx}-${rowIdx}`}>
+                    {row.map((cell: string, cellIdx: number) => (
+                      <td 
+                        key={`td-${patternIdx}-${rowIdx}-${cellIdx}`} 
+                        className="border border-gray-300 dark:border-gray-700 px-4 py-2"
+                      >
+                        {parseInlineMarkdown(cell, `table-cell-${patternIdx}-${rowIdx}-${cellIdx}`, footnotes)}
+                      </td>
+                    ))}
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        )
+      }
+    } else if (pattern.type === 'footnote-definition') {
+      // Don't render footnote definitions in the main content - they'll be rendered at the bottom
+      // Just skip this pattern
+    } else if (pattern.type === 'footnote-ref') {
+      const footnoteId = pattern.data
+      const footnoteText = footnotes.get(footnoteId)
+      if (footnoteText) {
+        parts.push(
+          <sup key={`footnote-ref-${patternIdx}`} className="footnote-ref">
+            <a 
+              href={`#footnote-${footnoteId}`} 
+              id={`footnote-ref-${footnoteId}`}
+              className="text-blue-600 dark:text-blue-400 hover:underline no-underline"
+              onClick={(e) => {
+                e.preventDefault()
+                const footnoteElement = document.getElementById(`footnote-${footnoteId}`)
+                if (footnoteElement) {
+                  footnoteElement.scrollIntoView({ behavior: 'smooth', block: 'center' })
+                }
+              }}
+            >
+              [{footnoteId}]
+            </a>
+          </sup>
+        )
+      } else {
+        // Footnote not found, just render the reference as-is
+        parts.push(<span key={`footnote-ref-${patternIdx}`}>[^{footnoteId}]</span>)
+      }
     } else if (pattern.type === 'nostr') {
       const bech32Id = pattern.data
       // Check if it's a profile type (mentions/handles should be inline)
       if (bech32Id.startsWith('npub') || bech32Id.startsWith('nprofile')) {
         parts.push(
-          <span key={`nostr-${i}`} className="inline-block">
+          <span key={`nostr-${patternIdx}`} className="inline-block">
             <EmbeddedMention userId={bech32Id} />
           </span>
         )
       } else if (bech32Id.startsWith('note') || bech32Id.startsWith('nevent') || bech32Id.startsWith('naddr')) {
         // Embedded events should be block-level and fill width
         parts.push(
-          <div key={`nostr-${i}`} className="w-full my-2">
+          <div key={`nostr-${patternIdx}`} className="w-full my-2">
             <EmbeddedNote noteId={bech32Id} />
           </div>
         )
       } else {
-        parts.push(<span key={`nostr-${i}`}>nostr:{bech32Id}</span>)
+        parts.push(<span key={`nostr-${patternIdx}`}>nostr:{bech32Id}</span>)
       }
     } else if (pattern.type === 'hashtag') {
       const tag = pattern.data
@@ -311,7 +646,7 @@ function parseMarkdownContent(
       hashtagsInContent.add(tagLower) // Track hashtags rendered inline
       parts.push(
         <a
-          key={`hashtag-${i}`}
+          key={`hashtag-${patternIdx}`}
           href={`/notes?t=${tagLower}`}
           className="inline text-green-600 dark:text-green-400 hover:text-green-700 dark:hover:text-green-300 hover:underline cursor-pointer"
           onClick={(e) => {
@@ -335,7 +670,7 @@ function parseMarkdownContent(
       const dtag = target.toLowerCase().replace(/[^a-z0-9]+/g, '-').replace(/^-+|-+$/g, '')
       
       parts.push(
-        <Wikilink key={`wikilink-${i}`} dTag={dtag} displayText={displayText} />
+        <Wikilink key={`wikilink-${patternIdx}`} dTag={dtag} displayText={displayText} />
       )
     }
     
@@ -346,16 +681,362 @@ function parseMarkdownContent(
   if (lastIndex < content.length) {
     const text = content.slice(lastIndex)
     if (text) {
-      parts.push(<span key="text-end">{text}</span>)
+      // Process text for inline formatting
+      // But skip if this text is part of a table
+      const isInTable = blockLevelPatterns.some(p => 
+        p.type === 'table' &&
+        lastIndex >= p.index && 
+        lastIndex < p.end
+      )
+      if (!isInTable) {
+        parts.push(...parseInlineMarkdown(text, 'text-end', footnotes))
+      }
+    }
+  }
+  
+  // If no patterns, just return the content as text (with inline formatting)
+  if (parts.length === 0) {
+    const formattedContent = parseInlineMarkdown(content, 'text-only', footnotes)
+    return { nodes: formattedContent, hashtagsInContent, footnotes }
+  }
+  
+  // Wrap list items in <ul> or <ol> tags
+  const wrappedParts: React.ReactNode[] = []
+  let partIdx = 0
+  while (partIdx < parts.length) {
+    const part = parts[partIdx]
+    // Check if this is a list item
+    if (React.isValidElement(part) && part.type === 'li') {
+      // Determine if it's a bullet or numbered list
+      const isBullet = part.key && part.key.toString().startsWith('bullet-')
+      const isNumbered = part.key && part.key.toString().startsWith('numbered-')
+      
+      if (isBullet || isNumbered) {
+        // Collect consecutive list items of the same type
+        const listItems: React.ReactNode[] = [part]
+        partIdx++
+        while (partIdx < parts.length) {
+          const nextPart = parts[partIdx]
+          if (React.isValidElement(nextPart) && nextPart.type === 'li') {
+            const nextIsBullet = nextPart.key && nextPart.key.toString().startsWith('bullet-')
+            const nextIsNumbered = nextPart.key && nextPart.key.toString().startsWith('numbered-')
+            if ((isBullet && nextIsBullet) || (isNumbered && nextIsNumbered)) {
+              listItems.push(nextPart)
+              partIdx++
+            } else {
+              break
+            }
+          } else {
+            break
+          }
+        }
+        
+        // Wrap in <ul> or <ol>
+        if (isBullet) {
+          wrappedParts.push(
+            <ul key={`ul-${partIdx}`} className="list-disc list-inside my-2 space-y-1">
+              {listItems}
+            </ul>
+          )
+        } else {
+          wrappedParts.push(
+            <ol key={`ol-${partIdx}`} className="list-decimal list-inside my-2 space-y-1">
+              {listItems}
+            </ol>
+          )
+        }
+        continue
+      }
+    }
+    
+    wrappedParts.push(part)
+    partIdx++
+  }
+  
+  // Add footnotes section at the end if there are any footnotes
+  if (footnotes.size > 0) {
+    wrappedParts.push(
+      <div key="footnotes-section" className="mt-8 pt-4 border-t border-gray-300 dark:border-gray-700">
+        <h3 className="text-lg font-semibold mb-4">Footnotes</h3>
+        <ol className="list-decimal list-inside space-y-2">
+          {Array.from(footnotes.entries()).map(([id, text]) => (
+            <li 
+              key={`footnote-${id}`} 
+              id={`footnote-${id}`}
+              className="text-sm text-gray-700 dark:text-gray-300"
+            >
+              <span className="font-semibold">[{id}]:</span>{' '}
+              <span>{parseInlineMarkdown(text, `footnote-${id}`, footnotes)}</span>
+              {' '}
+              <a 
+                href={`#footnote-ref-${id}`}
+                className="text-blue-600 dark:text-blue-400 hover:underline text-xs"
+                onClick={(e) => {
+                  e.preventDefault()
+                  const refElement = document.getElementById(`footnote-ref-${id}`)
+                  if (refElement) {
+                    refElement.scrollIntoView({ behavior: 'smooth', block: 'center' })
+                  }
+                }}
+              >
+                ↩
+              </a>
+            </li>
+          ))}
+        </ol>
+      </div>
+    )
+  }
+  
+  return { nodes: wrappedParts, hashtagsInContent, footnotes }
+}
+
+/**
+ * Parse inline markdown formatting (bold, italic, strikethrough, inline code, footnote references)
+ * Returns an array of React nodes
+ * 
+ * Supports:
+ * - Bold: **text** or __text__ (double) or *text* (single asterisk)
+ * - Italic: _text_ (single underscore) or __text__ (double underscore, but bold takes priority)
+ * - Strikethrough: ~~text~~ (double tilde) or ~text~ (single tilde)
+ * - Inline code: ``code`` (double backtick) or `code` (single backtick)
+ * - Footnote references: [^1] (handled at block level, but parsed here for inline context)
+ */
+function parseInlineMarkdown(text: string, keyPrefix: string, _footnotes: Map<string, string> = new Map()): React.ReactNode[] {
+  const parts: React.ReactNode[] = []
+  let lastIndex = 0
+  const inlinePatterns: Array<{ index: number; end: number; type: string; data: any }> = []
+  
+  // Inline code: ``code`` (double backtick) or `code` (single backtick) - process first to avoid conflicts
+  // Double backticks first
+  const doubleCodeRegex = /``([^`\n]+?)``/g
+  const doubleCodeMatches = Array.from(text.matchAll(doubleCodeRegex))
+  doubleCodeMatches.forEach(match => {
+    if (match.index !== undefined) {
+      inlinePatterns.push({
+        index: match.index,
+        end: match.index + match[0].length,
+        type: 'code',
+        data: match[1]
+      })
+    }
+  })
+  
+  // Single backtick (but not if already in double backtick)
+  const singleCodeRegex = /`([^`\n]+?)`/g
+  const singleCodeMatches = Array.from(text.matchAll(singleCodeRegex))
+  singleCodeMatches.forEach(match => {
+    if (match.index !== undefined) {
+      const isInDoubleCode = inlinePatterns.some(p => 
+        p.type === 'code' &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInDoubleCode) {
+        inlinePatterns.push({
+              index: match.index,
+              end: match.index + match[0].length,
+          type: 'code',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Bold: **text** (double asterisk) or __text__ (double underscore) - process first
+  // Also handle *text* (single asterisk) as bold
+  const doubleBoldAsteriskRegex = /\*\*(.+?)\*\*/g
+  const doubleBoldAsteriskMatches = Array.from(text.matchAll(doubleBoldAsteriskRegex))
+  doubleBoldAsteriskMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if already in code
+      const isInCode = inlinePatterns.some(p => 
+        p.type === 'code' &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInCode) {
+        inlinePatterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'bold',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Double underscore bold (but check if it's already italic)
+  const doubleBoldUnderscoreRegex = /__(.+?)__/g
+  const doubleBoldUnderscoreMatches = Array.from(text.matchAll(doubleBoldUnderscoreRegex))
+  doubleBoldUnderscoreMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if already in code or bold
+      const isInOther = inlinePatterns.some(p => 
+        (p.type === 'code' || p.type === 'bold') &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInOther) {
+        inlinePatterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'bold',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Single asterisk bold: *text* (not part of **bold**)
+  const singleBoldAsteriskRegex = /(?<!\*)\*([^*\n]+?)\*(?!\*)/g
+  const singleBoldAsteriskMatches = Array.from(text.matchAll(singleBoldAsteriskRegex))
+  singleBoldAsteriskMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if already in code, double bold, or strikethrough
+      const isInOther = inlinePatterns.some(p => 
+        (p.type === 'code' || p.type === 'bold' || p.type === 'strikethrough') &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInOther) {
+        inlinePatterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'bold',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Strikethrough: ~~text~~ (double tilde) or ~text~ (single tilde)
+  // Double tildes first
+  const doubleStrikethroughRegex = /~~(.+?)~~/g
+  const doubleStrikethroughMatches = Array.from(text.matchAll(doubleStrikethroughRegex))
+  doubleStrikethroughMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if already in code or bold
+      const isInOther = inlinePatterns.some(p => 
+        (p.type === 'code' || p.type === 'bold') &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInOther) {
+        inlinePatterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'strikethrough',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Single tilde strikethrough
+  const singleStrikethroughRegex = /(?<!~)~([^~\n]+?)~(?!~)/g
+  const singleStrikethroughMatches = Array.from(text.matchAll(singleStrikethroughRegex))
+  singleStrikethroughMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if already in code, bold, or double strikethrough
+      const isInOther = inlinePatterns.some(p => 
+        (p.type === 'code' || p.type === 'bold' || p.type === 'strikethrough') &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInOther) {
+        inlinePatterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'strikethrough',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Italic: _text_ (single underscore) or __text__ (double underscore, but bold takes priority)
+  // Single underscore italic (not part of __bold__)
+  const singleItalicUnderscoreRegex = /(?<!_)_([^_\n]+?)_(?!_)/g
+  const singleItalicUnderscoreMatches = Array.from(text.matchAll(singleItalicUnderscoreRegex))
+  singleItalicUnderscoreMatches.forEach(match => {
+    if (match.index !== undefined) {
+      // Skip if already in code, bold, or strikethrough
+      const isInOther = inlinePatterns.some(p => 
+        (p.type === 'code' || p.type === 'bold' || p.type === 'strikethrough') &&
+        match.index! >= p.index && 
+        match.index! < p.end
+      )
+      if (!isInOther) {
+        inlinePatterns.push({
+          index: match.index,
+          end: match.index + match[0].length,
+          type: 'italic',
+          data: match[1]
+        })
+      }
+    }
+  })
+  
+  // Double underscore italic (only if not already bold)
+  // Note: __text__ is bold by default, but if user wants it italic, we can add it
+  // For now, we'll keep __text__ as bold only, and _text_ as italic
+  
+  // Sort by index
+  inlinePatterns.sort((a, b) => a.index - b.index)
+  
+  // Remove overlaps (keep first)
+  const filtered: typeof inlinePatterns = []
+  let lastEnd = 0
+  inlinePatterns.forEach(pattern => {
+    if (pattern.index >= lastEnd) {
+      filtered.push(pattern)
+      lastEnd = pattern.end
+    }
+  })
+  
+  // Build nodes
+  filtered.forEach((pattern, i) => {
+    // Add text before pattern
+    if (pattern.index > lastIndex) {
+      const textBefore = text.slice(lastIndex, pattern.index)
+      if (textBefore) {
+        parts.push(<span key={`${keyPrefix}-inline-text-${i}`}>{textBefore}</span>)
+      }
+    }
+    
+    // Render pattern
+    if (pattern.type === 'bold') {
+      parts.push(<strong key={`${keyPrefix}-bold-${i}`}>{pattern.data}</strong>)
+    } else if (pattern.type === 'italic') {
+      parts.push(<em key={`${keyPrefix}-italic-${i}`}>{pattern.data}</em>)
+    } else if (pattern.type === 'strikethrough') {
+      parts.push(<del key={`${keyPrefix}-strikethrough-${i}`} className="line-through">{pattern.data}</del>)
+    } else if (pattern.type === 'code') {
+      parts.push(
+        <code key={`${keyPrefix}-code-${i}`} className="bg-muted px-1 py-0.5 rounded text-sm font-mono">
+          {pattern.data}
+        </code>
+      )
+    }
+    
+    lastIndex = pattern.end
+  })
+  
+  // Add remaining text
+  if (lastIndex < text.length) {
+    const remaining = text.slice(lastIndex)
+    if (remaining) {
+      parts.push(<span key={`${keyPrefix}-inline-text-final`}>{remaining}</span>)
     }
   }
   
-  // If no patterns, just return the content as text
+  // If no patterns found, return the text as-is
   if (parts.length === 0) {
-    return { nodes: [<span key="text-only">{content}</span>], hashtagsInContent }
+    return [<span key={`${keyPrefix}-plain`}>{text}</span>]
   }
   
-  return { nodes: parts, hashtagsInContent }
+  return parts
 }
 
 export default function MarkdownArticle({
@@ -556,13 +1237,15 @@ export default function MarkdownArticle({
   
   // Parse markdown content with post-processing for nostr: links and hashtags
   const { nodes: parsedContent, hashtagsInContent } = useMemo(() => {
-    return parseMarkdownContent(preprocessedContent, {
+    const result = parseMarkdownContent(preprocessedContent, {
       eventPubkey: event.pubkey,
       imageIndexMap,
       openLightbox,
       navigateToHashtag,
       navigateToRelay
     })
+    // Return nodes and hashtags (footnotes are already included in nodes)
+    return { nodes: result.nodes, hashtagsInContent: result.hashtagsInContent }
   }, [preprocessedContent, event.pubkey, imageIndexMap, openLightbox, navigateToHashtag, navigateToRelay])
   
   // Filter metadata tags to only show what's not already in content
@@ -574,43 +1257,43 @@ export default function MarkdownArticle({
     <>
       <div className={`prose prose-zinc max-w-none dark:prose-invert break-words overflow-wrap-anywhere ${className || ''}`}>
         {/* Metadata */}
-        {!hideMetadata && metadata.title && <h1 className="break-words">{metadata.title}</h1>}
-        {!hideMetadata && metadata.summary && (
-          <blockquote>
-            <p className="break-words">{metadata.summary}</p>
-          </blockquote>
-        )}
-        {hideMetadata && metadata.title && event.kind !== ExtendedKind.DISCUSSION && (
-          <h2 className="text-2xl font-bold mb-4 leading-tight break-words">{metadata.title}</h2>
-        )}
+                {!hideMetadata && metadata.title && <h1 className="break-words">{metadata.title}</h1>}
+                {!hideMetadata && metadata.summary && (
+                  <blockquote>
+                    <p className="break-words">{metadata.summary}</p>
+                  </blockquote>
+                )}
+                {hideMetadata && metadata.title && event.kind !== ExtendedKind.DISCUSSION && (
+                  <h2 className="text-2xl font-bold mb-4 leading-tight break-words">{metadata.title}</h2>
+                )}
         
         {/* Metadata image */}
-        {!hideMetadata && metadata.image && (() => {
-          const cleanedMetadataImage = cleanUrl(metadata.image)
+                {!hideMetadata && metadata.image && (() => {
+        const cleanedMetadataImage = cleanUrl(metadata.image)
           // Don't show if already in content
           if (cleanedMetadataImage && mediaUrlsInContent.has(cleanedMetadataImage)) {
             return null
           }
           
           const metadataImageIndex = imageIndexMap.get(cleanedMetadataImage)
-          
-          return (
-            <Image
-              image={{ url: metadata.image, pubkey: event.pubkey }}
-              className="max-w-[400px] w-full h-auto my-0 cursor-zoom-in"
-              classNames={{
-                wrapper: 'rounded-lg',
-                errorPlaceholder: 'aspect-square h-[30vh]'
-              }}
-              onClick={(e) => {
-                e.stopPropagation()
+        
+        return (
+          <Image
+            image={{ url: metadata.image, pubkey: event.pubkey }}
+            className="max-w-[400px] w-full h-auto my-0 cursor-zoom-in"
+            classNames={{
+              wrapper: 'rounded-lg',
+              errorPlaceholder: 'aspect-square h-[30vh]'
+            }}
+            onClick={(e) => {
+              e.stopPropagation()
                 if (metadataImageIndex !== undefined) {
                   openLightbox(metadataImageIndex)
-                }
-              }}
-            />
-          )
-        })()}
+              }
+            }}
+          />
+        )
+      })()}
         
         {/* Media from tags (only if not in content) */}
         {leftoverTagMedia.length > 0 && (
@@ -636,7 +1319,7 @@ export default function MarkdownArticle({
                         }
                       }}
                     />
-                  </div>
+        </div>
                 )
               } else if (media.type === 'video' || media.type === 'audio') {
                 return (
@@ -651,9 +1334,9 @@ export default function MarkdownArticle({
               }
               return null
             })}
-          </div>
-        )}
-        
+        </div>
+      )}
+      
         {/* Parsed content */}
         <div className="break-words whitespace-pre-wrap">
           {parsedContent}
@@ -661,7 +1344,7 @@ export default function MarkdownArticle({
         
         {/* Hashtags from metadata (only if not already in content) */}
         {leftoverMetadataTags.length > 0 && (
-          <div className="flex gap-2 flex-wrap pb-2 mt-4">
+        <div className="flex gap-2 flex-wrap pb-2 mt-4">
             {leftoverMetadataTags.map((tag) => (
               <div
                 key={tag}
@@ -675,18 +1358,18 @@ export default function MarkdownArticle({
                 #<span className="truncate">{tag}</span>
               </div>
             ))}
-          </div>
-        )}
+        </div>
+      )}
 
         {/* WebPreview cards for links from tags (only if not already in content) */}
         {/* Note: Links in content are already rendered as green hyperlinks above, so we don't show WebPreview for them */}
         {leftoverTagLinks.length > 0 && (
           <div className="space-y-3 mt-6">
             {leftoverTagLinks.map((url, index) => (
-              <WebPreview key={`tag-${index}-${url}`} url={url} className="w-full" />
-            ))}
-          </div>
-        )}
+            <WebPreview key={`tag-${index}-${url}`} url={url} className="w-full" />
+          ))}
+        </div>
+      )}
       </div>
       
       {/* Image gallery lightbox */}

src/components/Note/PublicationIndex/PublicationIndex.tsx

@@ -1225,7 +1225,7 @@ export default function PublicationIndex({
                       ToC
                     </Button>
                   )}
-                  <MarkdownArticle event={ref.event} showImageGallery={false} hideMetadata={true} />
+                  <MarkdownArticle event={ref.event} hideMetadata={true} />
                 </div>
               )
             } else {

src/components/ReplyNoteList/index.tsx

@@ -21,6 +21,7 @@ import { useReply } from '@/providers/ReplyProvider'
 import { useUserTrust } from '@/providers/UserTrustProvider'
 import client from '@/services/client.service'
 import noteStatsService from '@/services/note-stats.service'
+import discussionFeedCache from '@/services/discussion-feed-cache.service'
 import { Filter, Event as NEvent, kinds } from 'nostr-tools'
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
@@ -255,81 +256,145 @@ function ReplyNoteList({ index, event, sort = 'oldest' }: { index?: number; even
     if (!rootInfo || currentIndex !== index) return
 
     const init = async () => {
-      setLoading(true)
-      logger.debug('[ReplyNoteList] Fetching replies for root:', rootInfo)
-
-      try {
-        // Privacy: Only use user's own relays + defaults, never connect to other users' relays
-        const userReadRelays = userRelayList?.read || []
-        const userWriteRelays = userRelayList?.write || []
-        const finalRelayUrls = Array.from(new Set([
-          ...FAST_READ_RELAY_URLS.map(url => normalizeUrl(url) || url), // Fast, well-connected relays
-          ...userReadRelays.map(url => normalizeUrl(url) || url), // User's read relays
-          ...userWriteRelays.map(url => normalizeUrl(url) || url) // User's write relays
-        ]))
-
-        const filters: Filter[] = []
-        if (rootInfo.type === 'E') {
-          // Fetch all reply types for event-based replies
-          filters.push({
-            '#e': [rootInfo.id],
-            kinds: [kinds.ShortTextNote, ExtendedKind.COMMENT, ExtendedKind.VOICE_COMMENT],
-            limit: LIMIT
-          })
-          // Also fetch with uppercase E tag for replaceable events
-          filters.push({
-            '#E': [rootInfo.id],
-            kinds: [ExtendedKind.COMMENT, ExtendedKind.VOICE_COMMENT],
-            limit: LIMIT
-          })
-          // For public messages (kind 24), also look for replies using 'q' tags
-          if (event.kind === ExtendedKind.PUBLIC_MESSAGE) {
+      // Check cache first - get cached data even if stale (for instant display)
+      const cachedData = discussionFeedCache.getCachedReplies(rootInfo)
+      const hasFreshCache = discussionFeedCache.hasFreshCache(rootInfo)
+      const hasCache = cachedData !== null
+      
+      if (hasCache) {
+        logger.debug('[ReplyNoteList] Found cached replies:', cachedData.length, 'replies', hasFreshCache ? '(fresh)' : '(stale)')
+        // Display cached data immediately (even if stale) for instant switching
+        addReplies(cachedData)
+        setLoading(false)
+      } else {
+        // No cache at all, show loading while fetching
+        logger.debug('[ReplyNoteList] No cache found, fetching from relays')
+        setLoading(true)
+      }
+      
+      // Always fetch fresh data from relays to update cache
+      // If we have fresh cache, we can skip fetching (but still do it in background after a delay)
+      // If we have stale cache or no cache, fetch immediately
+      if (hasFreshCache) {
+        // Fresh cache: fetch in background after a short delay to avoid unnecessary requests
+        setTimeout(() => {
+          fetchFromRelays()
+        }, 2000) // Wait 2 seconds before background refresh
+      } else {
+        // Stale or no cache: fetch immediately
+        fetchFromRelays()
+      }
+      
+      async function fetchFromRelays() {
+        if (!rootInfo) return // Type guard
+        
+        try {
+          // Privacy: Only use user's own relays + defaults, never connect to other users' relays
+          const userReadRelays = userRelayList?.read || []
+          const userWriteRelays = userRelayList?.write || []
+          const finalRelayUrls = Array.from(new Set([
+            ...FAST_READ_RELAY_URLS.map(url => normalizeUrl(url) || url), // Fast, well-connected relays
+            ...userReadRelays.map(url => normalizeUrl(url) || url), // User's read relays
+            ...userWriteRelays.map(url => normalizeUrl(url) || url) // User's write relays
+          ]))
+
+          const filters: Filter[] = []
+          if (rootInfo.type === 'E') {
+            // Fetch all reply types for event-based replies
             filters.push({
-              '#q': [rootInfo.id],
-              kinds: [ExtendedKind.PUBLIC_MESSAGE],
-              limit: LIMIT
-            })
-          }
-        } else if (rootInfo.type === 'A') {
-          // Fetch all reply types for replaceable event-based replies
-          filters.push(
-            {
-              '#a': [rootInfo.id],
+              '#e': [rootInfo.id],
               kinds: [kinds.ShortTextNote, ExtendedKind.COMMENT, ExtendedKind.VOICE_COMMENT],
               limit: LIMIT
-            },
-            {
-              '#A': [rootInfo.id],
+            })
+            // Also fetch with uppercase E tag for replaceable events
+            filters.push({
+              '#E': [rootInfo.id],
               kinds: [ExtendedKind.COMMENT, ExtendedKind.VOICE_COMMENT],
               limit: LIMIT
+            })
+            // For public messages (kind 24), also look for replies using 'q' tags
+            if (event.kind === ExtendedKind.PUBLIC_MESSAGE) {
+              filters.push({
+                '#q': [rootInfo.id],
+                kinds: [ExtendedKind.PUBLIC_MESSAGE],
+                limit: LIMIT
+              })
+            }
+          } else if (rootInfo.type === 'A') {
+            // Fetch all reply types for replaceable event-based replies
+            filters.push(
+              {
+                '#a': [rootInfo.id],
+                kinds: [kinds.ShortTextNote, ExtendedKind.COMMENT, ExtendedKind.VOICE_COMMENT],
+                limit: LIMIT
+              },
+              {
+                '#A': [rootInfo.id],
+                kinds: [ExtendedKind.COMMENT, ExtendedKind.VOICE_COMMENT],
+                limit: LIMIT
+              }
+            )
+            if (rootInfo.relay) {
+              finalRelayUrls.push(rootInfo.relay)
             }
-          )
-          if (rootInfo.relay) {
-            finalRelayUrls.push(rootInfo.relay)
           }
-        }
 
-        logger.debug('[ReplyNoteList] Using filters:', filters)
-        logger.debug('[ReplyNoteList] Using relays:', finalRelayUrls.length)
+          logger.debug('[ReplyNoteList] Using filters:', filters)
+          logger.debug('[ReplyNoteList] Using relays:', finalRelayUrls.length)
 
-        // Use fetchEvents instead of subscribeTimeline for one-time fetching
-        const allReplies = await client.fetchEvents(finalRelayUrls, filters)
-        
-        logger.debug('[ReplyNoteList] Fetched', allReplies.length, 'replies')
-        
-        // Filter and add replies
-        const regularReplies = allReplies.filter((evt) => isReplyNoteEvent(evt))
-        addReplies(regularReplies)
-        
-        setLoading(false)
-      } catch (error) {
-        logger.error('[ReplyNoteList] Error fetching replies:', error)
-        setLoading(false)
+          // Use fetchEvents instead of subscribeTimeline for one-time fetching
+          const allReplies = await client.fetchEvents(finalRelayUrls, filters)
+          
+          logger.debug('[ReplyNoteList] Fetched', allReplies.length, 'replies')
+          
+          // Filter and add replies
+          const regularReplies = allReplies.filter((evt) => isReplyNoteEvent(evt))
+          
+          // Store in cache (this merges with existing cached replies)
+          // After this call, the cache contains ALL replies we've ever seen for this thread
+          discussionFeedCache.setCachedReplies(rootInfo, regularReplies)
+          
+          // Get the merged cache (which includes all replies we've ever seen, including new ones)
+          const mergedCachedReplies = discussionFeedCache.getCachedReplies(rootInfo)
+          
+          // Always add all merged cached replies to UI
+          // This ensures we keep all previously seen replies and add any new ones
+          // addReplies will deduplicate, so it's safe to call even if some replies are already displayed
+          if (mergedCachedReplies) {
+            logger.debug('[ReplyNoteList] Adding merged cached replies to UI:', mergedCachedReplies.length, 'total replies')
+            addReplies(mergedCachedReplies)
+          } else {
+            // Fallback: if cache somehow failed, at least add the fetched replies
+            logger.warn('[ReplyNoteList] Cache returned null after store, using fetched replies only')
+            addReplies(regularReplies)
+          }
+          
+          if (!hasCache) {
+            // No cache: stop loading after adding replies
+            setLoading(false)
+          } else {
+            // Background refresh: check if we got new replies
+            const cachedReplyIds = new Set(cachedData!.map(r => r.id))
+            const hasNewReplies = regularReplies.some(r => !cachedReplyIds.has(r.id))
+            
+            if (hasNewReplies) {
+              logger.debug('[ReplyNoteList] Background refresh found new replies, UI updated')
+            } else {
+              logger.debug('[ReplyNoteList] Background refresh: no new replies, existing replies preserved')
+            }
+          }
+        } catch (error) {
+          logger.error('[ReplyNoteList] Error fetching replies:', error)
+          if (!hasCache) {
+            // Only set loading to false if we don't have cache to fall back on
+            setLoading(false)
+          }
+        }
       }
     }
 
     init()
-  }, [rootInfo, currentIndex, index])
+  }, [rootInfo, currentIndex, index, userRelayList, event.kind, addReplies])
 
   useEffect(() => {
     if (replies.length === 0 && !loading && timelineKey) {

src/pages/primary/DiscussionsPage/index.tsx

@@ -1,4 +1,4 @@
-import { forwardRef, useEffect, useState, useMemo, useCallback } from 'react'
+import { forwardRef, useEffect, useState, useMemo, useCallback, useRef } from 'react'
 import { useTranslation } from 'react-i18next'
 import { RefreshCw, Search } from 'lucide-react'
 import { useNostr } from '@/providers/NostrProvider'
@@ -11,6 +11,7 @@ import { kinds } from 'nostr-tools'
 import { normalizeUrl } from '@/lib/url'
 import { BIG_RELAY_URLS, FAST_READ_RELAY_URLS, FAST_WRITE_RELAY_URLS } from '@/constants'
 import client from '@/services/client.service'
+import discussionFeedCache from '@/services/discussion-feed-cache.service'
 import { DISCUSSION_TOPICS } from './CreateThreadDialog'
 import ThreadCard from './ThreadCard'
 import CreateThreadDialog from './CreateThreadDialog'
@@ -352,6 +353,10 @@ const DiscussionsPage = forwardRef((_, ref) => {
     allTopics: DynamicTopic[]
   }>({ mainTopics: [], subtopics: [], allTopics: [] })
   
+  // Track if we've initialized to prevent re-fetching on re-renders
+  const hasInitializedRef = useRef(false)
+  const isFetchingRef = useRef(false)
+  
   // Build comprehensive relay list (same as pins)
   const buildComprehensiveRelayList = useCallback(async () => {
     const myRelayList = pubkey ? await client.fetchRelayList(pubkey) : { write: [], read: [] }
@@ -379,13 +384,32 @@ const DiscussionsPage = forwardRef((_, ref) => {
   }, []) // No dependencies - will be called fresh each time from fetchAllEvents
   
   // Fetch all events
-  const fetchAllEvents = useCallback(async () => {
-    if (loading) return
-    setLoading(true)
-    setIsRefreshing(true)
+  const fetchAllEvents = useCallback(async (forceRefresh = false) => {
+    if (isFetchingRef.current && !forceRefresh) return
+    isFetchingRef.current = true
+    
+    // Check cache first (unless forcing refresh)
+    let hasCachedData = false
+    if (!forceRefresh) {
+      const cachedData = discussionFeedCache.getCachedDiscussionsList()
+      if (cachedData) {
+        logger.debug('[DiscussionsPage] Using cached discussions list:', cachedData.eventMap.size, 'threads')
+        setAllEventMap(cachedData.eventMap)
+        setDynamicTopics(cachedData.dynamicTopics)
+        setLoading(false) // Display cached data immediately
+        hasCachedData = true
+        // Still fetch in background to update cache (but don't show loading or refreshing)
+      } else {
+        setLoading(true)
+        setIsRefreshing(true)
+      }
+    } else {
+      setLoading(true)
+      setIsRefreshing(true)
+    }
     
     try {
-      logger.debug('[DiscussionsPage] Fetching all discussion threads...')
+      logger.debug('[DiscussionsPage] Fetching all discussion threads...', forceRefresh ? '(forced refresh)' : '')
       
       // Get comprehensive relay list
       const allRelays = await buildComprehensiveRelayList()
@@ -409,27 +433,41 @@ const DiscussionsPage = forwardRef((_, ref) => {
         })))
       }
       
-      // Step 2: Get thread IDs and fetch related comments and reactions
+      // Step 2: Get thread IDs for comment/reaction fetching
+      // Get cached data first to include cached thread IDs in the fetch
+      // We ALWAYS include cached thread IDs to get updated counts for all threads we know about
+      const cachedDataBeforeFetch = discussionFeedCache.getCachedDiscussionsList()
       const threadIds = discussionThreads.map((thread: NostrEvent) => thread.id)
+      const allThreadIds = new Set(threadIds)
+      
+      // Add cached thread IDs to fetch comments/reactions for all threads we know about
+      // This ensures we get updated counts for cached threads too, regardless of whether we're refreshing
+      if (cachedDataBeforeFetch) {
+        cachedDataBeforeFetch.eventMap.forEach((_entry, threadId) => {
+          allThreadIds.add(threadId)
+        })
+      }
+      
+      const allThreadIdsArray = Array.from(allThreadIds)
       
       const [comments, reactions] = await Promise.all([
-        threadIds.length > 0 ? client.fetchEvents(allRelays, [
+        allThreadIdsArray.length > 0 ? client.fetchEvents(allRelays, [
           {
             kinds: [1111], // ExtendedKind.COMMENT
-            '#e': threadIds,
+            '#e': allThreadIdsArray,
             limit: 100
           }
         ]) : Promise.resolve([]),
-        threadIds.length > 0 ? client.fetchEvents(allRelays, [
+        allThreadIdsArray.length > 0 ? client.fetchEvents(allRelays, [
           {
             kinds: [kinds.Reaction],
-            '#e': threadIds,
+            '#e': allThreadIdsArray,
               limit: 100
             }
         ]) : Promise.resolve([])
       ])
       
-      logger.debug('[DiscussionsPage] Fetched', comments.length, 'comments and', reactions.length, 'reactions')
+      logger.debug('[DiscussionsPage] Fetched', comments.length, 'comments and', reactions.length, 'reactions for', allThreadIdsArray.length, 'threads (', threadIds.length, 'new,', (cachedDataBeforeFetch?.eventMap.size || 0), 'cached)')
       
       // Debug: Log some reaction details
       if (reactions.length > 0) {
@@ -441,14 +479,14 @@ const DiscussionsPage = forwardRef((_, ref) => {
         })))
       }
       
-      // Step 3: Build event map with vote and comment counts
+      // Step 3: Build event map with vote and comment counts for newly fetched threads
       const newEventMap = new Map<string, EventMapEntry>()
       
       discussionThreads.forEach((thread: NostrEvent) => {
         const threadId = thread.id
         const threadAuthor = thread.pubkey
         
-        // Count votes and comments
+        // Count votes and comments for this thread
         const voteStats = countVotesForThread(threadId, reactions, threadAuthor)
         const commentStats = countCommentsForThread(threadId, comments, threadAuthor)
         
@@ -498,7 +536,7 @@ const DiscussionsPage = forwardRef((_, ref) => {
         })
       })
       
-      logger.debug('[DiscussionsPage] Built event map with', newEventMap.size, 'threads')
+      logger.debug('[DiscussionsPage] Built event map with', newEventMap.size, 'new threads')
       
       // Log vote counts for debugging
       newEventMap.forEach((entry, threadId) => {
@@ -507,34 +545,112 @@ const DiscussionsPage = forwardRef((_, ref) => {
         }
       })
       
-      // Analyze dynamic topics only if we have new data
-      let dynamicTopicsAnalysis: { mainTopics: DynamicTopic[]; subtopics: DynamicTopic[]; allTopics: DynamicTopic[] } = { mainTopics: [], subtopics: [], allTopics: [] }
-      if (newEventMap.size > 0) {
-        dynamicTopicsAnalysis = analyzeDynamicTopics(Array.from(newEventMap.values()))
-        setDynamicTopics(dynamicTopicsAnalysis)
+      // Start with cached threads (if any) to preserve all threads we've ever seen
+      // This ensures thread counts and topic counts don't go down when different relays return different subsets
+      const allThreadsMap = new Map<string, EventMapEntry>()
+      
+      // First, add all cached threads to preserve them
+      // CRITICAL: Always preserve cached threads, even if they're not in the new fetch
+      if (cachedDataBeforeFetch) {
+        logger.debug('[DiscussionsPage] Preserving', cachedDataBeforeFetch.eventMap.size, 'cached threads')
+        cachedDataBeforeFetch.eventMap.forEach((entry, threadId) => {
+          allThreadsMap.set(threadId, { ...entry }) // Create a copy to avoid mutations
+        })
       }
       
-      // Update event map with enhanced topic categorization
-      const updatedEventMap = new Map<string, EventMapEntry>()
+      // Then, add or update with newly fetched threads
+      // New threads will be added, existing threads will be updated with fresh data
       newEventMap.forEach((entry, threadId) => {
+        allThreadsMap.set(threadId, { ...entry }) // Always use the fresh data from new fetch
+      })
+      
+      const threadsBeforeCountUpdate = allThreadsMap.size
+      logger.debug('[DiscussionsPage] Total threads after merge:', threadsBeforeCountUpdate, '(cached:', cachedDataBeforeFetch?.eventMap.size || 0, '+ new:', newEventMap.size, ', overlaps:', (cachedDataBeforeFetch?.eventMap.size || 0) + newEventMap.size - threadsBeforeCountUpdate, ')')
+      
+      // Now update comment/vote counts for ALL threads using fresh comments/reactions
+      // This ensures cached threads get updated counts from the latest fetch
+      const finalEventMap = new Map<string, EventMapEntry>()
+      allThreadsMap.forEach((entry, threadId) => {
+        const thread = entry.event
+        const threadAuthor = thread.pubkey
+        
+        // Count votes and comments for this thread (using all fetched comments/reactions)
+        const voteStats = countVotesForThread(threadId, reactions, threadAuthor)
+        const commentStats = countCommentsForThread(threadId, comments, threadAuthor)
+        
+        // Update the entry with latest counts, but preserve all other data
+        finalEventMap.set(threadId, {
+          ...entry,
+          commentCount: commentStats.commentCount,
+          lastCommentTime: commentStats.lastCommentTime,
+          lastVoteTime: voteStats.lastVoteTime,
+          upVotes: voteStats.upVotes,
+          downVotes: voteStats.downVotes
+        })
+      })
+      
+      logger.debug('[DiscussionsPage] Final event map has', finalEventMap.size, 'threads after count update')
+      
+      // Analyze dynamic topics from ALL threads (cached + new)
+      const dynamicTopicsAnalysis = analyzeDynamicTopics(Array.from(finalEventMap.values()))
+      
+      // Update event map with enhanced topic categorization for all threads
+      const categorizedEventMap = new Map<string, EventMapEntry>()
+      finalEventMap.forEach((entry, threadId) => {
         const predefinedTopicIds = DISCUSSION_TOPICS.map((t: any) => t.id)
         const enhancedTopic = getEnhancedTopicFromTags(entry.allTopics, predefinedTopicIds, dynamicTopicsAnalysis.allTopics, entry.isGroupDiscussion)
         
-        updatedEventMap.set(threadId, {
+        categorizedEventMap.set(threadId, {
           ...entry,
           categorizedTopic: enhancedTopic
         })
       })
       
-      setAllEventMap(updatedEventMap)
+      logger.debug('[DiscussionsPage] Categorized event map has', categorizedEventMap.size, 'threads')
+      
+      // Store final merged and categorized event map in cache
+      // IMPORTANT: We've already manually merged all cached + new threads above
+      // So categorizedEventMap contains ALL threads we want to preserve
+      // We store with merge=false because we've already done the merge manually
+      // This ensures we don't lose threads due to the cache service's merge logic
+      const expectedThreadCount = categorizedEventMap.size
+      discussionFeedCache.setCachedDiscussionsList(categorizedEventMap, dynamicTopicsAnalysis, false)
+      
+      // Verify the cache has all our threads (immediately after storing)
+      const cachedAfterStore = discussionFeedCache.getCachedDiscussionsList()
+      if (cachedAfterStore) {
+        const actualThreadCount = cachedAfterStore.eventMap.size
+        logger.debug('[DiscussionsPage] Cache verification - stored:', expectedThreadCount, 'threads, cache has:', actualThreadCount, 'threads')
+        if (actualThreadCount !== expectedThreadCount) {
+          logger.error('[DiscussionsPage] ERROR: Thread count mismatch! Expected', expectedThreadCount, 'but cache has', actualThreadCount)
+          // If we lost threads, try to recover by storing again with the categorized map
+          // This shouldn't happen, but if it does, at least log it
+        }
+      } else {
+        logger.error('[DiscussionsPage] ERROR: Cache returned null after storing!')
+      }
+      
+      // Always update state with the merged and categorized event map
+      // This ensures we show all threads we've ever seen, with updated counts
+      setAllEventMap(categorizedEventMap)
+      setDynamicTopics(dynamicTopicsAnalysis)
+      
+      logger.debug('[DiscussionsPage] Updated UI with', categorizedEventMap.size, 'threads (merged from cache and new fetch)')
       
     } catch (error) {
       logger.error('[DiscussionsPage] Error fetching events:', error)
+      // If we had cached data and fetch failed, at least we have something to show
+      if (!hasCachedData) {
+        setLoading(false)
+      }
     } finally {
-      setLoading(false)
+      if (!hasCachedData || forceRefresh) {
+        setLoading(false)
+      }
       setIsRefreshing(false)
+      isFetchingRef.current = false
     }
-  }, []) // Only run when explicitly called (mount or refresh button)
+  }, [buildComprehensiveRelayList]) // Only depend on buildComprehensiveRelayList
   
   // Calculate time span counts
   const calculateTimeSpanCounts = useCallback(() => {
@@ -619,8 +735,15 @@ const DiscussionsPage = forwardRef((_, ref) => {
   
   // Effects
   useEffect(() => {
-    fetchAllEvents()
-  }, []) // Only run once on mount
+    // Only initialize once
+    if (hasInitializedRef.current) {
+      logger.debug('[DiscussionsPage] Already initialized, skipping fetch')
+      return
+    }
+    
+    hasInitializedRef.current = true
+    fetchAllEvents(false) // Don't force refresh on mount - use cache if available
+  }, [fetchAllEvents])
   
   useEffect(() => {
     if (allEventMap.size > 0) {
@@ -635,10 +758,37 @@ const DiscussionsPage = forwardRef((_, ref) => {
   }, [allEventMap, timeSpan, selectedTopic]) // Run when allEventMap, timeSpan, or selectedTopic changes
   
   // Get available topics sorted by most recent activity (including dynamic topics)
+  // Topic counts are calculated based on the current time span filter
   const availableTopics = useMemo(() => {
     const topicMap = new Map<string, { count: number, lastActivity: number, isDynamic: boolean, isMainTopic: boolean, isSubtopic: boolean }>()
     
+    // Calculate time span filter
+    const now = Date.now()
+    const timeSpanAgo = timeSpan === '30days' ? now - (30 * 24 * 60 * 60 * 1000) : 
+                       timeSpan === '90days' ? now - (90 * 24 * 60 * 60 * 1000) : 0
+    
     allEventMap.forEach((entry) => {
+      // Filter by time span - only count topics for threads that match the time filter
+      let passesTimeFilter = false
+      if (timeSpan === 'all') {
+        passesTimeFilter = true
+      } else {
+        const threadTime = entry.event.created_at * 1000
+        const lastCommentTime = entry.lastCommentTime > 0 ? entry.lastCommentTime * 1000 : 0
+        const lastVoteTime = entry.lastVoteTime > 0 ? entry.lastVoteTime * 1000 : 0
+        
+        const mostRecentActivity = Math.max(
+          threadTime,
+          lastCommentTime,
+          lastVoteTime
+        )
+        
+        passesTimeFilter = mostRecentActivity > timeSpanAgo
+      }
+      
+      // Only count topics for threads that pass the time filter
+      if (!passesTimeFilter) return
+      
       const topic = entry.categorizedTopic
       const lastActivity = Math.max(
         entry.event.created_at * 1000,
@@ -666,7 +816,7 @@ const DiscussionsPage = forwardRef((_, ref) => {
     return Array.from(topicMap.entries())
       .map(([topic, data]) => ({ topic, ...data }))
       .sort((a, b) => b.lastActivity - a.lastActivity)
-  }, [allEventMap, dynamicTopics])
+  }, [allEventMap, dynamicTopics, timeSpan]) // Include timeSpan in dependencies
   
   // State for search results
   const [searchedEntries, setSearchedEntries] = useState<EventMapEntry[]>([])
@@ -804,7 +954,7 @@ const DiscussionsPage = forwardRef((_, ref) => {
   
   // Handle refresh
   const handleRefresh = () => {
-    fetchAllEvents()
+    fetchAllEvents(true) // Force refresh when user clicks refresh button
   }
   
   // Handle create thread
@@ -903,7 +1053,7 @@ const DiscussionsPage = forwardRef((_, ref) => {
             onChange={(e) => setSelectedTopic(e.target.value)}
             className="w-full sm:w-auto px-3 py-2 bg-white dark:bg-gray-800 text-black dark:text-white border border-gray-300 dark:border-gray-600 rounded-md shadow-sm focus:ring-2 focus:ring-blue-500 focus:border-blue-500"
           >
-            <option value="all">All Topics ({allEventMap.size})</option>
+            <option value="all">All Topics ({timeSpanCounts[timeSpan]})</option>
             {availableTopics.map(({ topic, count, isDynamic, isMainTopic, isSubtopic }) => {
               const isGroupsTopic = topic === 'groups'
               return (

src/services/discussion-feed-cache.service.ts

@@ -0,0 +1,308 @@
+import { Event as NEvent } from 'nostr-tools'
+import logger from '@/lib/logger'
+
+interface CachedThreadData {
+  replies: NEvent[]
+  timestamp: number
+  rootInfo: {
+    type: 'E' | 'A' | 'I'
+    id: string
+    pubkey?: string
+    eventId?: string
+    relay?: string
+  }
+}
+
+interface CachedDiscussionsListData {
+  eventMap: Map<string, any>
+  dynamicTopics: {
+    mainTopics: any[]
+    subtopics: any[]
+    allTopics: any[]
+  }
+  timestamp: number
+}
+
+/**
+ * Cache service for discussion feed data (thread replies/comments)
+ * Uses in-memory cache with timestamp-based expiration
+ */
+class DiscussionFeedCacheService {
+  static instance: DiscussionFeedCacheService
+  private cache: Map<string, CachedThreadData> = new Map()
+  private discussionsListCache: CachedDiscussionsListData | null = null
+  private readonly CACHE_TTL_MS = 5 * 60 * 1000 // 5 minutes
+  private readonly DISCUSSIONS_LIST_CACHE_TTL_MS = 2 * 60 * 1000 // 2 minutes for discussions list
+
+  static getInstance(): DiscussionFeedCacheService {
+    if (!DiscussionFeedCacheService.instance) {
+      DiscussionFeedCacheService.instance = new DiscussionFeedCacheService()
+    }
+    return DiscussionFeedCacheService.instance
+  }
+
+  /**
+   * Get cache key for a thread
+   */
+  private getCacheKey(rootInfo: CachedThreadData['rootInfo']): string {
+    if (rootInfo.type === 'E') {
+      return `thread:E:${rootInfo.id}`
+    } else if (rootInfo.type === 'A') {
+      return `thread:A:${rootInfo.id}`
+    } else if (rootInfo.type === 'I') {
+      return `thread:I:${rootInfo.id}`
+    }
+    return `thread:unknown:${rootInfo.id}`
+  }
+
+  /**
+   * Check if cached data is stale
+   */
+  private isStale(cachedData: CachedThreadData): boolean {
+    const age = Date.now() - cachedData.timestamp
+    return age > this.CACHE_TTL_MS
+  }
+
+  /**
+   * Get cached replies for a thread
+   * Returns null if cache is empty, but returns data even if stale (for instant display)
+   */
+  getCachedReplies(rootInfo: CachedThreadData['rootInfo']): NEvent[] | null {
+    const cacheKey = this.getCacheKey(rootInfo)
+    const cachedData = this.cache.get(cacheKey)
+
+    if (!cachedData) {
+      logger.debug('[DiscussionFeedCache] Cache miss for thread:', cacheKey)
+      return null
+    }
+
+    // Verify rootInfo matches (in case thread structure changed)
+    if (
+      cachedData.rootInfo.type !== rootInfo.type ||
+      cachedData.rootInfo.id !== rootInfo.id
+    ) {
+      logger.debug('[DiscussionFeedCache] Cache rootInfo mismatch for thread:', cacheKey)
+      this.cache.delete(cacheKey)
+      return null
+    }
+
+    // Return cached data even if stale (caller will fetch fresh data in background)
+    const isStale = this.isStale(cachedData)
+    if (isStale) {
+      logger.debug('[DiscussionFeedCache] Cache hit (stale) for thread:', cacheKey, 'age:', Date.now() - cachedData.timestamp, 'ms', 'replies:', cachedData.replies.length)
+    } else {
+      logger.debug('[DiscussionFeedCache] Cache hit (fresh) for thread:', cacheKey, 'replies:', cachedData.replies.length)
+    }
+    
+    return cachedData.replies
+  }
+
+  /**
+   * Check if cached data exists and is fresh (not stale)
+   */
+  hasFreshCache(rootInfo: CachedThreadData['rootInfo']): boolean {
+    const cacheKey = this.getCacheKey(rootInfo)
+    const cachedData = this.cache.get(cacheKey)
+
+    if (!cachedData) {
+      return false
+    }
+
+    // Verify rootInfo matches
+    if (
+      cachedData.rootInfo.type !== rootInfo.type ||
+      cachedData.rootInfo.id !== rootInfo.id
+    ) {
+      return false
+    }
+
+    return !this.isStale(cachedData)
+  }
+
+  /**
+   * Store replies in cache
+   * Merges new replies with existing cached replies to prevent count from going down
+   */
+  setCachedReplies(rootInfo: CachedThreadData['rootInfo'], replies: NEvent[]): void {
+    const cacheKey = this.getCacheKey(rootInfo)
+    const existingData = this.cache.get(cacheKey)
+    
+    let mergedReplies: NEvent[]
+    if (existingData && 
+        existingData.rootInfo.type === rootInfo.type &&
+        existingData.rootInfo.id === rootInfo.id) {
+      // Merge with existing cached replies - keep all unique replies
+      const existingReplyIds = new Set(existingData.replies.map(r => r.id))
+      const newReplies = replies.filter(r => !existingReplyIds.has(r.id))
+      mergedReplies = [...existingData.replies, ...newReplies]
+      logger.debug('[DiscussionFeedCache] Merged replies for thread:', cacheKey, 'existing:', existingData.replies.length, 'new:', newReplies.length, 'total:', mergedReplies.length)
+    } else {
+      // No existing cache or rootInfo mismatch, use new replies
+      mergedReplies = [...replies]
+      logger.debug('[DiscussionFeedCache] Cached new replies for thread:', cacheKey, 'replies:', replies.length)
+    }
+    
+    const cachedData: CachedThreadData = {
+      replies: mergedReplies, // Create a copy to avoid mutations
+      timestamp: Date.now(),
+      rootInfo: { ...rootInfo } // Create a copy
+    }
+
+    this.cache.set(cacheKey, cachedData)
+
+    // Clean up stale entries periodically (every 10th set operation)
+    if (this.cache.size > 50 && Math.random() < 0.1) {
+      this.cleanupStaleEntries()
+    }
+  }
+
+  /**
+   * Clear cache for a specific thread
+   */
+  clearCache(rootInfo: CachedThreadData['rootInfo']): void {
+    const cacheKey = this.getCacheKey(rootInfo)
+    this.cache.delete(cacheKey)
+    logger.debug('[DiscussionFeedCache] Cleared cache for thread:', cacheKey)
+  }
+
+  /**
+   * Clear all cached data
+   */
+  clearAllCache(): void {
+    this.cache.clear()
+    logger.debug('[DiscussionFeedCache] Cleared all cache')
+  }
+
+  /**
+   * Remove stale entries from cache
+   */
+  private cleanupStaleEntries(): void {
+    let cleaned = 0
+    for (const [key, data] of this.cache.entries()) {
+      if (this.isStale(data)) {
+        this.cache.delete(key)
+        cleaned++
+      }
+    }
+    if (cleaned > 0) {
+      logger.debug('[DiscussionFeedCache] Cleaned up', cleaned, 'stale entries')
+    }
+  }
+
+  /**
+   * Get cache statistics (for debugging)
+   */
+  getCacheStats(): { size: number; entries: Array<{ key: string; age: number; replyCount: number }> } {
+    const entries = Array.from(this.cache.entries()).map(([key, data]) => ({
+      key,
+      age: Date.now() - data.timestamp,
+      replyCount: data.replies.length
+    }))
+    return {
+      size: this.cache.size,
+      entries
+    }
+  }
+
+  /**
+   * Get cached discussions list data
+   * Returns null if cache is empty, but returns data even if stale (for merging purposes)
+   */
+  getCachedDiscussionsList(): CachedDiscussionsListData | null {
+    if (!this.discussionsListCache) {
+      logger.debug('[DiscussionFeedCache] Discussions list cache miss')
+      return null
+    }
+
+    const age = Date.now() - this.discussionsListCache.timestamp
+    const isStale = age > this.DISCUSSIONS_LIST_CACHE_TTL_MS
+    
+    if (isStale) {
+      logger.debug('[DiscussionFeedCache] Discussions list cache hit (stale), age:', age, 'ms')
+    } else {
+      logger.debug('[DiscussionFeedCache] Discussions list cache hit (fresh), age:', age, 'ms')
+    }
+    
+    // Return cached data even if stale (caller will merge and update)
+    return this.discussionsListCache
+  }
+
+  /**
+   * Check if cached discussions list data exists and is fresh (not stale)
+   */
+  hasFreshDiscussionsListCache(): boolean {
+    if (!this.discussionsListCache) {
+      return false
+    }
+
+    const age = Date.now() - this.discussionsListCache.timestamp
+    return age <= this.DISCUSSIONS_LIST_CACHE_TTL_MS
+  }
+
+  /**
+   * Store discussions list data in cache
+   * Merges new threads with existing cached threads to prevent count from going down
+   * When merge=true, ALWAYS preserves all existing threads and adds new ones
+   */
+  setCachedDiscussionsList(eventMap: Map<string, any>, dynamicTopics: { mainTopics: any[]; subtopics: any[]; allTopics: any[] }, merge = true): void {
+    let mergedEventMap: Map<string, any>
+    const existingCacheSize = this.discussionsListCache?.eventMap.size || 0
+    const newDataSize = eventMap.size
+    
+    if (merge && this.discussionsListCache) {
+      // Merge with existing cached threads - keep all threads we've ever seen
+      // Start with ALL existing cached threads - this is critical to prevent thread loss
+      mergedEventMap = new Map(this.discussionsListCache.eventMap)
+      
+      // Add or update threads from the new fetch
+      // For existing threads, prefer the new data (which has fresher counts)
+      // For new threads, add them
+      eventMap.forEach((entry, threadId) => {
+        // Always update with new data if it exists (new data has fresher counts from latest fetch)
+        // This ensures we get updated comment/vote counts for all threads
+        mergedEventMap.set(threadId, entry)
+      })
+      
+      const finalSize = mergedEventMap.size
+      logger.debug('[DiscussionFeedCache] Merged discussions list: existing:', existingCacheSize, 'new:', newDataSize, 'total:', finalSize, '(expected at least:', Math.max(existingCacheSize, newDataSize), ')')
+      
+      // Safety check: we should never have fewer threads than we started with (unless new data has fewer)
+      // But we should always have at least as many as the larger of the two sets
+      if (finalSize < Math.max(existingCacheSize, newDataSize)) {
+        logger.warn('[DiscussionFeedCache] WARNING: Merge resulted in fewer threads! Existing:', existingCacheSize, 'New:', newDataSize, 'Final:', finalSize)
+      }
+    } else {
+      // No existing cache or merge=false, use new data directly
+      mergedEventMap = new Map(eventMap)
+      logger.debug('[DiscussionFeedCache] Cached new discussions list (no merge):', eventMap.size, 'threads')
+    }
+    
+    // Store merged event map
+    this.discussionsListCache = {
+      eventMap: mergedEventMap,
+      dynamicTopics: {
+        mainTopics: [...dynamicTopics.mainTopics],
+        subtopics: [...dynamicTopics.subtopics],
+        allTopics: [...dynamicTopics.allTopics]
+      },
+      timestamp: Date.now()
+    }
+    
+    // Final verification
+    if (this.discussionsListCache.eventMap.size !== mergedEventMap.size) {
+      logger.error('[DiscussionFeedCache] ERROR: Cache eventMap size mismatch after storing! Expected:', mergedEventMap.size, 'Got:', this.discussionsListCache.eventMap.size)
+    }
+  }
+
+  /**
+   * Clear discussions list cache
+   */
+  clearDiscussionsListCache(): void {
+    this.discussionsListCache = null
+    logger.debug('[DiscussionFeedCache] Cleared discussions list cache')
+  }
+}
+
+const instance = DiscussionFeedCacheService.getInstance()
+export default instance
+