package generator

import (
	"bytes"
	"fmt"
	"html/template"
	"path/filepath"
	"time"

	"gitcitadel-online/internal/asciidoc"
	"gitcitadel-online/internal/nostr"
)

// HTMLGenerator generates HTML pages from wiki events
type HTMLGenerator struct {
	templates    *template.Template
	asciidocProc *asciidoc.Processor
	linkBaseURL  string
	siteName     string
	siteURL      string
	defaultImage string
}

// PageData represents data for a wiki page
type PageData struct {
	Title           string
	Description     string
	Keywords        string
	CanonicalURL    string
	OGImage         string
	OGType          string
	StructuredData  template.JS
	SiteName        string
	CurrentYear     int
	WikiPages       []WikiPageInfo
	BlogItems       []BlogItemInfo
	FeedItems       []FeedItemInfo
	Content         template.HTML
	Summary         string
	TableOfContents template.HTML
}

// WikiPageInfo represents info about a wiki page for navigations
type WikiPageInfo struct {
	DTag  string
	Title string
}

// BlogItemInfo represents info about a blog item
type BlogItemInfo struct {
	DTag    string
	Title   string
	Summary string
	Content template.HTML
}

// FeedItemInfo represents info about a feed item
type FeedItemInfo struct {
	Author  string
	Content string
	Time    string
	TimeISO string
	Link    string
}

// NewHTMLGenerator creates a new HTML generator
func NewHTMLGenerator(templateDir string, linkBaseURL, siteName, siteURL, defaultImage string) (*HTMLGenerator, error) {
	tmpl := template.New("base").Funcs(template.FuncMap{
		"year": func() int { return time.Now().Year() },
	})

	// Load all templates
	templateFiles := []string{
		"base.html",
		"landing.html",
		"page.html",
		"blog.html",
		"feed_sidebar.html",
		"404.html",
		"500.html",
	}

	for _, file := range templateFiles {
		path := filepath.Join(templateDir, file)
		_, err := tmpl.ParseFiles(path)
		if err != nil {
			return nil, err
		}
	}

	return &HTMLGenerator{
		templates:    tmpl,
		asciidocProc: asciidoc.NewProcessor(linkBaseURL),
		linkBaseURL:  linkBaseURL,
		siteName:     siteName,
		siteURL:      siteURL,
		defaultImage: defaultImage,
	}, nil
}

// ProcessAsciiDoc processes AsciiDoc content to HTML
func (g *HTMLGenerator) ProcessAsciiDoc(content string) (string, error) {
	return g.asciidocProc.Process(content)
}

// GenerateLandingPage generates the static landing page
func (g *HTMLGenerator) GenerateLandingPage(wikiPages []WikiPageInfo, feedItems []FeedItemInfo) (string, error) {
	data := PageData{
		Title:        "Home",
		Description:  "Welcome to " + g.siteName,
		CanonicalURL: g.siteURL + "/",
		OGImage:      g.siteURL + g.defaultImage,
		OGType:       "website",
		SiteName:     g.siteName,
		CurrentYear:  time.Now().Year(),
		WikiPages:    wikiPages,
		FeedItems:    feedItems,
	}

	return g.renderTemplate("landing.html", data)
}

// GenerateWikiPage generates a wiki article page
func (g *HTMLGenerator) GenerateWikiPage(wiki *nostr.WikiEvent, wikiPages []WikiPageInfo, feedItems []FeedItemInfo) (string, error) {
	// Process AsciiDoc content
	htmlContent, err := g.asciidocProc.Process(wiki.Content)
	if err != nil {
		return "", err
	}

	description := wiki.Summary
	if description == "" {
		description = wiki.Title
	}

	canonicalURL := g.siteURL + "/wiki/" + wiki.DTag

	data := PageData{
		Title:        wiki.Title,
		Description:  description,
		CanonicalURL: canonicalURL,
		OGImage:      g.siteURL + g.defaultImage,
		OGType:       "article",
		SiteName:     g.siteName,
		CurrentYear:  time.Now().Year(),
		WikiPages:    wikiPages,
		FeedItems:    feedItems,
		Content:      template.HTML(htmlContent),
		Summary:      wiki.Summary,
	}

	// Add structured data for article
	data.StructuredData = template.JS(g.generateArticleStructuredData(wiki, canonicalURL))

	return g.renderTemplate("page.html", data)
}

// GenerateBlogPage generates the blog index page
func (g *HTMLGenerator) GenerateBlogPage(blogIndex *nostr.IndexEvent, blogItems []BlogItemInfo, feedItems []FeedItemInfo) (string, error) {
	description := blogIndex.Summary
	if description == "" {
		description = "Blog articles from " + g.siteName
	}

	canonicalURL := g.siteURL + "/blog"

	data := PageData{
		Title:        "Blog",
		Description:  description,
		CanonicalURL: canonicalURL,
		OGImage:      g.siteURL + g.defaultImage,
		OGType:       "website",
		SiteName:     g.siteName,
		CurrentYear:  time.Now().Year(),
		BlogItems:    blogItems,
		FeedItems:    feedItems,
	}

	return g.renderTemplate("blog.html", data)
}

// GenerateContactPage generates the contact form page
func (g *HTMLGenerator) GenerateContactPage(success bool, errorMsg string, eventID string, formData map[string]string) (string, error) {
	// Prepare form data with defaults
	subject := ""
	content := ""
	labels := ""
	if formData != nil {
		subject = formData["subject"]
		content = formData["content"]
		labels = formData["labels"]
	}

	// Create form data struct for template
	type ContactFormData struct {
		Subject string
		Content string
		Labels  string
	}

	type ContactPageData struct {
		PageData
		Success  bool
		Error    string
		EventID  string
		FormData ContactFormData
	}

	data := ContactPageData{
		PageData: PageData{
			Title:        "Contact",
			Description:  "Contact " + g.siteName,
			CanonicalURL: g.siteURL + "/contact",
			OGImage:      g.siteURL + g.defaultImage,
			OGType:       "website",
			SiteName:     g.siteName,
			CurrentYear:  time.Now().Year(),
			WikiPages:    []WikiPageInfo{}, // Will be populated if needed
			FeedItems:    []FeedItemInfo{}, // Will be populated if needed
		},
		Success: success,
		Error:   errorMsg,
		EventID: eventID,
		FormData: ContactFormData{
			Subject: subject,
			Content: content,
			Labels:  labels,
		},
	}

	// Render contact template with base template
	// The base template uses {{block "content" .}} which will be filled by contact.html
	// We need to pass the full ContactPageData so the template can access all fields
	baseTmpl := g.templates.Lookup("base.html")
	if baseTmpl == nil {
		return "", fmt.Errorf("template base.html not found")
	}

	// Create a map that includes both PageData fields and contact-specific fields
	templateData := map[string]interface{}{
		"Title":        data.Title,
		"Description":  data.Description,
		"CanonicalURL": data.CanonicalURL,
		"OGImage":      data.OGImage,
		"OGType":       data.OGType,
		"SiteName":     data.SiteName,
		"CurrentYear":  data.CurrentYear,
		"WikiPages":    data.WikiPages,
		"BlogItems":    data.BlogItems,
		"FeedItems":    data.FeedItems,
		"Success":      data.Success,
		"Error":        data.Error,
		"EventID":      data.EventID,
		"FormData":     data.FormData,
	}

	// Execute the base template, which will use the contact.html "content" block
	var buf bytes.Buffer
	if err := baseTmpl.ExecuteTemplate(&buf, "base.html", templateData); err != nil {
		return "", fmt.Errorf("failed to execute base template: %w", err)
	}

	return buf.String(), nil
}

// GenerateErrorPage generates an error page (404 or 500)
func (g *HTMLGenerator) GenerateErrorPage(statusCode int, siteName string) (string, error) {
	var title, message string
	switch statusCode {
	case 404:
		title = "404 - Page Not Found"
		message = "The page you're looking for doesn't exist."
	case 500:
		title = "500 - Server Error"
		message = "Something went wrong on our end. Please try again later."
	default:
		title = "Error"
		message = "An error occurred."
	}

	data := map[string]interface{}{
		"SiteName": siteName,
		"Title":    title,
		"Message":  message,
	}

	tmpl := g.templates.Lookup(fmt.Sprintf("%d.html", statusCode))
	if tmpl == nil {
		return "", fmt.Errorf("template for status %d not found", statusCode)
	}

	var buf bytes.Buffer
	if err := tmpl.Execute(&buf, data); err != nil {
		return "", err
	}

	return buf.String(), nil
}

// renderTemplate renders a template with the base template
func (g *HTMLGenerator) renderTemplate(templateName string, data PageData) (string, error) {
	// The templateName (e.g., "landing.html") defines blocks that are used by base.html
	// We need to execute base.html, which will use the blocks from templateName
	baseTmpl := g.templates.Lookup("base.html")
	if baseTmpl == nil {
		return "", fmt.Errorf("template base.html not found")
	}

	var buf bytes.Buffer
	if err := baseTmpl.ExecuteTemplate(&buf, "base.html", data); err != nil {
		return "", fmt.Errorf("failed to execute base template: %w", err)
	}

	return buf.String(), nil
}

// generateArticleStructuredData generates JSON-LD structured data for an article
func (g *HTMLGenerator) generateArticleStructuredData(wiki *nostr.WikiEvent, url string) string {
	// This is a simplified version - in production, use proper JSON encoding
	return `{
		"@context": "https://schema.org",
		"@type": "Article",
		"headline": "` + wiki.Title + `",
		"description": "` + wiki.Summary + `",
		"url": "` + url + `",
		"publisher": {
			"@type": "Organization",
			"name": "` + g.siteName + `"
		}
	}`
}