package pipeline

import (
	"context"
	"log"
	"strings"
	"time"

	"github.com/redis/go-redis/v9"
	"gorm.io/gorm"

	"spider/internal/extractor"
	"spider/internal/llm"
	"spider/internal/model"
	"spider/internal/telegram"
)

// ScrapePhase Phase 4: TG 消息采集
type ScrapePhase struct {
	db        *gorm.DB
	tgManager *telegram.AccountManager
	llmClient *llm.Client
	settings  Settings
	redis     *redis.Client
	reporter  ProgressReporter
}

// NewScrapePhase creates a new ScrapePhase.
func NewScrapePhase(db *gorm.DB, tgManager *telegram.AccountManager, llmClient *llm.Client, settings Settings, rdb *redis.Client) *ScrapePhase {
	return &ScrapePhase{
		db:        db,
		tgManager: tgManager,
		llmClient: llmClient,
		settings:  settings,
		redis:     rdb,
	}
}

func (p *ScrapePhase) Name() string { return "scrape" }

func (p *ScrapePhase) Run(ctx context.Context, task *model.Task, opts *Options) error {
	log.Printf("[scrape] starting, task_id=%d", task.ID)

	if p.tgManager == nil {
		log.Printf("[scrape] tgManager is nil, skipping")
		return nil
	}

	msgLimit := p.settings.GetInt(ctx, "tg_scraper.message_limit_per_channel", 500)
	delayMsg := p.settings.GetFloat(ctx, "tg_scraper.delay_per_message", 1.0)
	delayChannel := p.settings.GetFloat(ctx, "tg_scraper.delay_per_channel", 5.0)

	if opts.TestRun != nil && opts.TestRun.MessageLimit > 0 {
		msgLimit = opts.TestRun.MessageLimit
	}

	// 取 pending 频道
	var channels []model.Channel
	q := p.db.Where("status = ?", "pending")
	if opts.TestRun != nil && opts.TestRun.ItemLimit > 0 {
		q = q.Limit(opts.TestRun.ItemLimit)
	}
	q.Find(&channels)

	total := len(channels)
	log.Printf("[scrape] found %d pending channels", total)

	for i, ch := range channels {
		if isContextDone(ctx) {
			break
		}

		if p.reporter != nil {
			p.reporter("scrape", i+1, total, "采集频道: @"+ch.Username)
		}

		acc, err := p.tgManager.Acquire(ctx)
		if err != nil {
			log.Printf("[scrape] no available account: %v", err)
			break
		}

		if err := acc.Client.Connect(ctx); err != nil {
			log.Printf("[scrape] connect failed: %v", err)
			p.tgManager.Release(acc, 0)
			p.db.Model(&ch).Update("status", "failed")
			continue
		}

		// LLM 相关性评估
		if p.llmClient != nil {
			score, err := p.llmClient.EvalChannelRelevance(ctx, ch.Title, ch.About, ch.MemberCount)
			if err == nil && score < 0.5 {
				log.Printf("[scrape] skipping @%s, relevance score=%.2f", ch.Username, score)
				p.tgManager.Release(acc, 0)
				p.db.Model(&ch).Update("status", "skipped")
				continue
			}
		}

		// 读置顶消息
		pinnedMsgs, _ := acc.Client.GetPinnedMessages(ctx, ch.Username)
		p.processMessages(ctx, pinnedMsgs, &ch, delayMsg)

		// 读历史消息（断点续传）
		offsetID := ch.LastMessageID
		fetched := 0
		for fetched < msgLimit {
			if isContextDone(ctx) {
				break
			}

			batchSize := 100
			if msgLimit-fetched < batchSize {
				batchSize = msgLimit - fetched
			}

			msgs, err := acc.Client.GetMessages(ctx, ch.Username, offsetID, batchSize)
			if err != nil {
				if fw, ok := err.(*telegram.FloodWaitError); ok {
					log.Printf("[scrape] FloodWait %ds on @%s", fw.Seconds, ch.Username)
					p.tgManager.HandleFloodWait(acc, fw.Seconds)
					acc = nil
				} else {
					log.Printf("[scrape] GetMessages @%s: %v", ch.Username, err)
				}
				break
			}
			if len(msgs) == 0 {
				break
			}

			p.processMessages(ctx, msgs, &ch, delayMsg)

			// 更新断点
			lastID := msgs[len(msgs)-1].ID
			p.db.Model(&ch).Update("last_message_id", lastID)
			offsetID = lastID
			fetched += len(msgs)
		}

		if acc != nil {
			p.tgManager.Release(acc, 0)
		}
		p.db.Model(&ch).Update("status", "scraped")

		select {
		case <-ctx.Done():
			return nil
		case <-time.After(time.Duration(float64(time.Second) * delayChannel)):
		}
	}

	log.Printf("[scrape] done")
	return nil
}

// processMessages 处理一批消息，提取商户写入 merchants_raw
func (p *ScrapePhase) processMessages(ctx context.Context, msgs []telegram.Message, ch *model.Channel, delayMsg float64) {
	for _, msg := range msgs {
		if msg.IsService || msg.Text == "" {
			continue
		}
		if !extractor.ContainsChinese(msg.Text, 0) {
			continue
		}
		if !extractor.HasContact(msg.Text) {
			continue
		}

		// 快速去重（Redis SET NX key）
		if p.redis != nil {
			info := extractor.Extract(msg.Text)
			if info.TgUsername != "" {
				dedupKey := "spider:dedup:merchant:" + info.TgUsername
				set, _ := p.redis.SetNX(ctx, dedupKey, "1", 7*24*time.Hour).Result()
				if !set {
					continue // 已存在，跳过
				}
			}
		}

		// LLM 精准解析
		var merchantInfo *extractor.MerchantInfo
		if p.llmClient != nil {
			merchantInfo, _ = p.llmClient.ParseMerchant(ctx, msg.Text)
		}

		// Fallback 到正则
		if merchantInfo == nil || merchantInfo.TgUsername == "" {
			info := extractor.Extract(msg.Text)
			merchantInfo = &extractor.MerchantInfo{
				TgUsername: info.TgUsername,
				Website:    info.Website,
				Email:      info.Email,
				Phone:      info.Phone,
			}
		}

		if merchantInfo.TgUsername == "" && merchantInfo.Website == "" {
			continue
		}

		raw := &model.MerchantRaw{
			MerchantName:    extractor.CleanMerchantName(merchantInfo.MerchantName),
			TgUsername:      strings.TrimPrefix(merchantInfo.TgUsername, "@"),
			Website:         merchantInfo.Website,
			Email:           merchantInfo.Email,
			Phone:           merchantInfo.Phone,
			Industry:        merchantInfo.Industry,
			SourceType:      "tg_scrape",
			SourceID:        ch.Username,
			OriginalMessage: msg.Text,
			Status:          "raw",
		}
		p.db.Create(raw)

		time.Sleep(time.Duration(float64(time.Second) * delayMsg))
	}
}