package actions

import (
	"context"
	"fmt"
	"strings"
	"time"

	"git.pengzhan.dev/haopengzhan/rsspipe/internal/actions/ai"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/actions/readability"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/actions/status"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/actions/variants"
	aiClientPkg "git.pengzhan.dev/haopengzhan/rsspipe/internal/ai"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/db"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/models"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/worker"
	"go.uber.org/zap"
)

// RegisterDefaultHandlers registers legacy action handlers with worker.Pool
func RegisterDefaultHandlers(pool *worker.Pool, database *db.DB, log *zap.Logger) {
	// 1. Readability Full-Text Scraper
	scraper := readability.NewScraper(15 * time.Second)
	pool.RegisterHandler("readability_scrape", scraper.Handler())

	// 2. Status Handlers (mark_read, mark_starred)
	pool.RegisterHandler("mark_read", status.NewMarkReadHandler())
	pool.RegisterHandler("mark_starred", status.NewMarkStarredHandler())

	// 3. Variant Handlers (set_variant with tag merging)
	pool.RegisterHandler("set_variant", variants.NewSetVariantHandler(database))

	// 4. AI Subsystem Handlers
	aiClient := aiClientPkg.NewClient(45 * time.Second)
	enrichHandler := ai.NewEnrichmentHandler(database, aiClient, log)
	pool.RegisterHandler("ai_enrich", enrichHandler)
	pool.RegisterHandler("ai_summary", enrichHandler) // Backward compatibility alias

	pool.RegisterHandler("ai_agent_action", ai.NewTriageHandler(database, aiClient, pool, log))
}

// RegisterJobEngineHandlers registers async task handlers with the persistent JobEngine
func RegisterJobEngineHandlers(engine *worker.JobEngine, database *db.DB, log *zap.Logger) {
	scraper := readability.NewScraper(20 * time.Second)
	aiClient := aiClientPkg.NewClient(60 * time.Second)

	// 1. Readability Scrape Handler
	engine.RegisterHandler("readability_scrape", func(ctx context.Context, job models.Job) (*models.PatchEntryRequest, map[string]interface{}, error) {
		entryID, _ := job.Payload["entry_id"].(string)
		if entryID == "" {
			return nil, nil, fmt.Errorf("missing entry_id in job payload")
		}

		entry, err := database.GetEntry(entryID)
		if err != nil {
			return nil, nil, fmt.Errorf("entry not found: %w", err)
		}

		res, err := scraper.Handler()(ctx, *entry, job.Payload)
		if err != nil {
			return nil, nil, err
		}

		if res == nil || res.ResultVariant == nil {
			return nil, nil, nil
		}

		patch := &models.PatchEntryRequest{
			Variants: map[string]*models.EntryVariant{
				"readability_full_text": res.ResultVariant,
			},
		}

		return patch, map[string]interface{}{
			"variant_key": "readability_full_text",
			"length":      len(res.ResultVariant.TextValue),
		}, nil
	})

	// 2. AI Summary & AI Enrich Handler
	aiHandler := func(ctx context.Context, job models.Job) (*models.PatchEntryRequest, map[string]interface{}, error) {
		entryID, _ := job.Payload["entry_id"].(string)
		if entryID == "" {
			return nil, nil, fmt.Errorf("missing entry_id in job payload")
		}

		entry, err := database.GetEntry(entryID)
		if err != nil {
			return nil, nil, fmt.Errorf("entry not found: %w", err)
		}

		cfg, prompts := ai.LoadConfig(database)
		if !cfg.Enabled {
			return nil, nil, fmt.Errorf("AI features are disabled. Please enable AI in Settings > AI & Integrations")
		}
		if cfg.Provider != "ollama" && strings.TrimSpace(cfg.APIKey) == "" {
			return nil, nil, fmt.Errorf("AI API key is missing. Please configure an API key in Settings > AI & Integrations")
		}

		prompt, _ := job.Payload["prompt"].(string)
		if prompt == "" {
			prompt, _ = job.Payload["custom_prompt"].(string)
		}
		if prompt == "" {
			for _, p := range prompts {
				if p.IsDefault {
					prompt = p.Prompt
					break
				}
			}
			if prompt == "" && len(prompts) > 0 {
				prompt = prompts[0].Prompt
			}
		}
		if prompt == "" {
			prompt = "You are an expert technical editor. Summarize the following article in exactly 3 concise bullet points, followed by a bold 'Key Takeaway:' sentence.\n\nTitle: {{title}}\nFeed: {{feed_title}}\nContent:\n{{content}}"
		}

		vKey, _ := job.Payload["variant_key"].(string)
		if vKey == "" {
			vKey = "ai_summary"
		}
		cType, _ := job.Payload["content_type"].(string)
		if cType == "" {
			cType = "text"
		}

		resultText, err := aiClient.GenerateEnrichment(ctx, cfg, prompt, *entry)
		if err != nil {
			return nil, nil, fmt.Errorf("ai generation failed: %w", err)
		}

		variant := models.EntryVariant{
			EntryID:     entry.ID,
			VariantKey:  vKey,
			ContentType: cType,
			TextValue:   resultText,
			Metadata: map[string]interface{}{
				"model":       cfg.Model,
				"provider":    cfg.Provider,
				"prompt_used": prompt,
			},
			CreatedAt: time.Now().UTC(),
			UpdatedAt: time.Now().UTC(),
		}

		patch := &models.PatchEntryRequest{
			Variants: map[string]*models.EntryVariant{
				vKey: &variant,
			},
		}

		return patch, map[string]interface{}{
			"variant_key": vKey,
			"model":       cfg.Model,
			"word_count":  len(strings.Fields(resultText)),
		}, nil
	}

	engine.RegisterHandler("ai_summary", aiHandler)
	engine.RegisterHandler("ai_enrich", aiHandler)

	// 3. Add Tags Handler
	engine.RegisterHandler("add_tags", func(ctx context.Context, job models.Job) (*models.PatchEntryRequest, map[string]interface{}, error) {
		entryID, _ := job.Payload["entry_id"].(string)
		if entryID == "" {
			return nil, nil, fmt.Errorf("missing entry_id in job payload")
		}

		var tagsToAdd []string
		if rawTags, ok := job.Payload["tags"].([]interface{}); ok {
			for _, t := range rawTags {
				tagsToAdd = append(tagsToAdd, fmt.Sprintf("%v", t))
			}
		} else if rawTagsStr, ok := job.Payload["tags"].(string); ok {
			for _, t := range strings.Split(rawTagsStr, ",") {
				if tr := strings.TrimSpace(t); tr != "" {
					tagsToAdd = append(tagsToAdd, tr)
				}
			}
		}

		entry, err := database.GetEntry(entryID)
		if err != nil {
			return nil, nil, fmt.Errorf("entry not found: %w", err)
		}

		existingTags := make(map[string]bool)
		if entry.Metadata != nil {
			if curr, ok := entry.Metadata["tags"].([]interface{}); ok {
				for _, t := range curr {
					existingTags[fmt.Sprintf("%v", t)] = true
				}
			}
		}

		for _, t := range tagsToAdd {
			existingTags[t] = true
		}

		var merged []string
		for t := range existingTags {
			merged = append(merged, t)
		}

		patch := &models.PatchEntryRequest{
			Metadata: map[string]interface{}{
				"tags": merged,
			},
		}

		return patch, map[string]interface{}{"tags": merged}, nil
	})

	// 4. Mark Read Handler
	engine.RegisterHandler("mark_read", func(ctx context.Context, job models.Job) (*models.PatchEntryRequest, map[string]interface{}, error) {
		read := true
		return &models.PatchEntryRequest{IsRead: &read}, map[string]interface{}{"is_read": true}, nil
	})

	// 5. Mark Starred Handler
	engine.RegisterHandler("mark_starred", func(ctx context.Context, job models.Job) (*models.PatchEntryRequest, map[string]interface{}, error) {
		starred := true
		return &models.PatchEntryRequest{IsStarred: &starred}, map[string]interface{}{"is_starred": true}, nil
	})
}