package nostr

import (
	"context"
	"fmt"

	"gitcitadel-online/internal/logger"

	"github.com/nbd-wtf/go-nostr"
)

// logFilter logs the exact filter being used for debugging
func logFilter(filter nostr.Filter, context string) {
	logger.WithFields(map[string]interface{}{
		"context": context,
		"kinds":   filter.Kinds,
		"authors": filter.Authors,
		"ids":     filter.IDs,
		"tags":    filter.Tags,
		"limit":   filter.Limit,
	}).Debug("Nostr filter")
}

// WikiService handles wiki-specific operations
type WikiService struct {
	client             *Client
	articleKinds       []int  // Allowed article kinds (from config)
	wikiKind           int    // Primary wiki kind constant (first from wiki_kinds config)
	blogKind           int    // Primary blog kind constant (first from blog_kinds config)
	longformKind       int    // Longform article kind (from config)
	additionalFallback string // Additional fallback relay URL (from config)
	indexKind          int    // Index event kind (from config)
}

// NewWikiService creates a new wiki service
func NewWikiService(client *Client, articleKinds []int, wikiKind int, additionalFallback string, indexKind int, blogKind int, longformKind int) *WikiService {
	return &WikiService{
		client:             client,
		articleKinds:       articleKinds,
		wikiKind:           wikiKind,
		blogKind:           blogKind,
		longformKind:       longformKind,
		additionalFallback: additionalFallback,
		indexKind:          indexKind,
	}
}

// FetchWikiIndex fetches a wiki index by naddr
func (ws *WikiService) FetchWikiIndex(ctx context.Context, naddrStr string) (*IndexEvent, error) {
	// Parse naddr
	naddr, err := ParseNaddr(naddrStr)
	if err != nil {
		return nil, fmt.Errorf("failed to parse naddr: %w", err)
	}

	// Create filter for the index event
	filter := naddr.ToFilter()
	logFilter(filter, fmt.Sprintf("wiki index (kind %d)", ws.indexKind))

	// Fetch the event from The Forest only (primary relay)
	primaryRelay := ws.client.GetPrimaryRelay()
	if primaryRelay == "" {
		return nil, fmt.Errorf("primary relay not configured")
	}
	event, err := ws.client.FetchEventFromRelays(ctx, filter, []string{primaryRelay})
	if err != nil {
		return nil, fmt.Errorf("failed to fetch index event: %w", err)
	}

	// Parse the index event
	index, err := ParseIndexEvent(event, ws.indexKind)
	if err != nil {
		return nil, fmt.Errorf("failed to parse index event: %w", err)
	}

	return index, nil
}

// FetchWikiEvents fetches all wiki events referenced in an index
// Uses ProcessEventsWithCache for the initial fetch, then filters by index items
func (ws *WikiService) FetchWikiEvents(ctx context.Context, index *IndexEvent) ([]*WikiEvent, error) {
	// Build a map of expected items (kind:pubkey:dtag) for fast lookup
	expectedItems := make(map[string]IndexItem)
	for _, item := range index.Items {
		if item.Kind == ws.wikiKind {
			key := fmt.Sprintf("%d:%s:%s", item.Kind, item.Pubkey, item.DTag)
			expectedItems[key] = item
		}
	}

	if len(expectedItems) == 0 {
		return []*WikiEvent{}, nil
	}

	// Use ProcessEventsWithCache to fetch events of this kind
	// Use a high display limit (1000) to ensure we get all events referenced in the index
	// This means we'll fetch 2000 events, which should be enough for most cases
	displayLimit := 1000
	primaryRelay := ws.client.GetPrimaryRelay()
	if primaryRelay == "" {
		return nil, fmt.Errorf("primary relay not configured")
	}

	logger.WithFields(map[string]interface{}{
		"kind":           ws.wikiKind,
		"items":          len(expectedItems),
		"index_event_id": index.Event.ID,
	}).Debug("Fetching wiki events using ProcessEventsWithCache with index")

	// Use standard process with index event ID: fetch index, query only referenced events, merge cache, deduplicate, filter deletions, sort, limit, fetch profiles
	result, err := ws.client.ProcessEventsWithCache(ctx, ws.wikiKind, displayLimit, make(map[string]*nostr.Event), primaryRelay, index.Event.ID, ws.indexKind)
	if err != nil {
		logger.WithField("error", err).Warn("Failed to fetch wiki events using ProcessEventsWithCache")
		return nil, err
	}

	allEvents := result.Events

	logger.WithFields(map[string]interface{}{
		"fetched":  len(allEvents),
		"expected": len(expectedItems),
	}).Debug("Fetched wiki events using ProcessEventsWithCache with index")

	// Build event map by kind:pubkey:dtag for matching
	eventMap := make(map[string]*nostr.Event)
	for _, event := range allEvents {
		// Extract d-tag from event
		var dTag string
		for _, tag := range event.Tags {
			if len(tag) > 0 && tag[0] == "d" && len(tag) > 1 {
				dTag = tag[1]
				break
			}
		}

		if dTag == "" {
			continue // Skip events without d-tag
		}

		key := fmt.Sprintf("%d:%s:%s", event.Kind, event.PubKey, dTag)
		// Keep the newest version if we have multiple
		existing, exists := eventMap[key]
		if !exists || event.CreatedAt > existing.CreatedAt {
			eventMap[key] = event
		}
	}

	// Convert matched events to wiki events, preserving order from index.Items
	var wikiEvents []*WikiEvent
	for _, item := range index.Items {
		if item.Kind != ws.wikiKind {
			continue
		}
		key := fmt.Sprintf("%d:%s:%s", item.Kind, item.Pubkey, item.DTag)
		event, exists := eventMap[key]
		if !exists {
			continue
		}
		wiki, err := ParseWikiEvent(event, ws.wikiKind)
		if err != nil {
			logger.WithFields(map[string]interface{}{
				"key": key,
			}).Warnf("Error parsing wiki event: %v", err)
			continue
		}
		wikiEvents = append(wikiEvents, wiki)
	}

	logger.WithFields(map[string]interface{}{
		"matched":  len(wikiEvents),
		"expected": len(expectedItems),
	}).Debug("Matched wiki events")

	if len(wikiEvents) == 0 && len(index.Items) > 0 {
		logger.WithField("items", len(index.Items)).Warn("No wiki events matched from fetched events")
	}

	return wikiEvents, nil
}

// GetBlogKind returns the blog kind configured in this service
func (ws *WikiService) GetBlogKind() int {
	return ws.blogKind
}

// GetLongformKind returns the longform kind configured in this service
func (ws *WikiService) GetLongformKind() int {
	return ws.longformKind
}

// FetchLongformArticles fetches the newest longform articles (kind 30023) from a specific relay
// Uses the standard ProcessEventsWithCache process
func (ws *WikiService) FetchLongformArticles(ctx context.Context, relayURL string, longformKind int, limit int) ([]*nostr.Event, error) {
	// Use standard process: fetch 2x limit, merge cache, deduplicate, filter deletions, sort, limit, fetch profiles
	result, err := ws.client.ProcessEventsWithCache(ctx, longformKind, limit, make(map[string]*nostr.Event), relayURL, "", 0)
	if err != nil {
		return nil, fmt.Errorf("failed to process longform articles: %w", err)
	}

	// Note: Profiles are available in result.Profiles but not returned here
	// Callers should fetch profiles separately if needed, or we could return both
	return result.Events, nil
}

// FetchIndexEvents fetches all events of a specific kind referenced in an index
// Only supports article kinds configured in the service
// Uses ProcessEventsWithCache for the initial fetch, then filters by index items
func (ws *WikiService) FetchIndexEvents(ctx context.Context, index *IndexEvent, targetKind int) ([]*nostr.Event, error) {
	// Check if the target kind is in the allowed article kinds
	allowed := false
	for _, kind := range ws.articleKinds {
		if kind == targetKind {
			allowed = true
			break
		}
	}
	if !allowed {
		return nil, fmt.Errorf("unsupported event kind: %d (only %v are supported)", targetKind, ws.articleKinds)
	}

	// Build a map of expected items (kind:pubkey:dtag) for fast lookup
	expectedItems := make(map[string]IndexItem)
	for _, item := range index.Items {
		if item.Kind == targetKind {
			key := fmt.Sprintf("%d:%s:%s", item.Kind, item.Pubkey, item.DTag)
			expectedItems[key] = item
		}
	}

	if len(expectedItems) == 0 {
		return []*nostr.Event{}, nil
	}

	// Use ProcessEventsWithCache to fetch events of this kind
	// Use a high display limit (1000) to ensure we get all events referenced in the index
	// This means we'll fetch 2000 events, which should be enough for most cases
	displayLimit := 1000
	primaryRelay := ws.client.GetPrimaryRelay()
	if primaryRelay == "" {
		return nil, fmt.Errorf("primary relay not configured")
	}

	logger.WithFields(map[string]interface{}{
		"kind":           targetKind,
		"items":          len(expectedItems),
		"index_event_id": index.Event.ID,
	}).Debug("Fetching events using ProcessEventsWithCache with index")

	// Use standard process with index event ID: fetch index, query only referenced events, merge cache, deduplicate, filter deletions, sort, limit, fetch profiles
	result, err := ws.client.ProcessEventsWithCache(ctx, targetKind, displayLimit, make(map[string]*nostr.Event), primaryRelay, index.Event.ID, ws.indexKind)
	if err != nil {
		logger.WithField("error", err).Warn("Failed to fetch events using ProcessEventsWithCache")
		return nil, err
	}

	allEvents := result.Events

	logger.WithFields(map[string]interface{}{
		"fetched":  len(allEvents),
		"expected": len(expectedItems),
	}).Debug("Fetched events using ProcessEventsWithCache with index")

	// Build event map by kind:pubkey:dtag for matching
	eventMap := make(map[string]*nostr.Event)
	for _, event := range allEvents {
		// Extract d-tag from event
		var dTag string
		for _, tag := range event.Tags {
			if len(tag) > 0 && tag[0] == "d" && len(tag) > 1 {
				dTag = tag[1]
				break
			}
		}

		if dTag == "" {
			continue // Skip events without d-tag
		}

		key := fmt.Sprintf("%d:%s:%s", event.Kind, event.PubKey, dTag)
		// Keep the newest version if we have multiple
		existing, exists := eventMap[key]
		if !exists || event.CreatedAt > existing.CreatedAt {
			eventMap[key] = event
		}
	}

	// Convert to result slice, preserving order from index.Items
	events := make([]*nostr.Event, 0, len(eventMap))
	for _, item := range index.Items {
		if item.Kind != targetKind {
			continue
		}
		key := fmt.Sprintf("%d:%s:%s", item.Kind, item.Pubkey, item.DTag)
		event, exists := eventMap[key]
		if !exists {
			continue
		}
		events = append(events, event)
	}

	logger.WithFields(map[string]interface{}{
		"matched":  len(events),
		"expected": len(expectedItems),
		"kind":     targetKind,
	}).Debug("Matched index events")

	if len(events) == 0 && len(index.Items) > 0 {
		logger.WithFields(map[string]interface{}{
			"kind":  targetKind,
			"items": len(index.Items),
		}).Warn("No events matched from fetched events")
	}

	return events, nil
}

// FetchWikiEventByDTag fetches a single wiki event by d tag
func (ws *WikiService) FetchWikiEventByDTag(ctx context.Context, pubkey, dTag string) (*WikiEvent, error) {
	filter := nostr.Filter{
		Kinds:   []int{ws.wikiKind},
		Authors: []string{pubkey},
		Tags: map[string][]string{
			"d": {dTag},
		},
		Limit: 1,
	}
	logFilter(filter, fmt.Sprintf("wiki by d-tag %s", dTag))

	// Fetch from The Forest only (primary relay)
	primaryRelay := ws.client.GetPrimaryRelay()
	if primaryRelay == "" {
		return nil, fmt.Errorf("primary relay not configured")
	}
	event, err := ws.client.FetchEventFromRelays(ctx, filter, []string{primaryRelay})
	if err != nil {
		return nil, fmt.Errorf("failed to fetch wiki event: %w", err)
	}

	return ParseWikiEvent(event, ws.wikiKind)
}