package pipeline

import (
	"context"
	"log"
	"strings"

	"gorm.io/gorm"

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

// CrawlPhase Phase 5: 网页爬取
type CrawlPhase struct {
	db            *gorm.DB
	staticCrawler *crawler.StaticCrawler
	dynCrawler    *crawler.DynamicCrawler
	tmeValidator  *crawler.TMeValidator
	llmClient     *llm.Client
	settings      Settings
	reporter      ProgressReporter
}

// NewCrawlPhase creates a new CrawlPhase.
func NewCrawlPhase(db *gorm.DB, llmClient *llm.Client, settings Settings) *CrawlPhase {
	return &CrawlPhase{
		db:            db,
		staticCrawler: crawler.NewStaticCrawler(),
		dynCrawler:    crawler.NewDynamicCrawler(),
		tmeValidator:  crawler.NewTMeValidator(),
		llmClient:     llmClient,
		settings:      settings,
	}
}

func (p *CrawlPhase) Name() string { return "crawl" }

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

	tmeEnabled := true
	if p.settings != nil {
		tmeEnabled = p.settings.GetBool(ctx, "tme_validator.enabled", true)
	}

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

	total := len(navSites)
	merchantCount := 0

	for i, site := range navSites {
		if isContextDone(ctx) {
			break
		}

		if p.reporter != nil {
			p.reporter("crawl", i+1, total, "爬取: "+site.URL)
		}

		// 预过滤
		filterResult := crawler.RuleFilter(site.URL)
		if filterResult == crawler.FilterDiscard {
			p.db.Model(&site).Updates(map[string]interface{}{
				"status":        "filtered",
				"filter_reason": "blacklist",
			})
			continue
		}

		// 不确定的 URL，交 LLM 判断
		if filterResult == crawler.FilterUncertain && p.llmClient != nil {
			isNav, confidence, err := p.llmClient.IsNavSite(ctx, site.URL)
			if err != nil || !isNav || confidence < 0.6 {
				p.db.Model(&site).Updates(map[string]interface{}{
					"status":        "filtered",
					"filter_reason": "llm_reject",
				})
				continue
			}
		}

		// 爬取：先尝试静态，失败则动态
		result := p.staticCrawler.Crawl(ctx, site.URL)
		if result.Error != nil || result.HTML == "" {
			log.Printf("[crawl] static failed for %s, trying dynamic", site.URL)
			result = p.dynCrawler.Crawl(ctx, site.URL)
		}

		if result.Error != nil {
			p.db.Model(&site).Update("status", "failed")
			continue
		}

		// 过滤非中文页面
		snippet := result.HTML
		if len(snippet) > 5000 {
			snippet = snippet[:5000]
		}
		if !extractor.ContainsChinese(snippet, 0) {
			p.db.Model(&site).Updates(map[string]interface{}{
				"status":        "filtered",
				"filter_reason": "non_chinese",
			})
			continue
		}

		// 处理发现的 TG 链接
		for _, tgLink := range result.TgLinks {
			username := crawler.ExtractTGUsername(tgLink)
			if username == "" {
				continue
			}

			// t.me 死号预检
			if tmeEnabled {
				if !p.tmeValidator.IsAlive(ctx, username) {
					log.Printf("[crawl] dead account: %s", username)
					continue
				}
			}

			raw := &model.MerchantRaw{
				TgUsername: username,
				SourceType: "web_crawl",
				SourceID:   site.URL,
				Status:     "raw",
			}
			p.db.Create(raw)
			merchantCount++
		}

		// 处理普通链接（商户官网子页）
		for _, link := range result.Links {
			if isContextDone(ctx) {
				break
			}
			// 排除 TG 链接（已处理）和无效链接
			if strings.Contains(link, "t.me") || strings.Contains(link, "telegram.me") {
				continue
			}
			if crawler.RuleFilter(link) == crawler.FilterDiscard {
				continue
			}

			// 爬商户官网子页提取联系方式
			p.crawlMerchantSite(ctx, link, site.URL)
		}

		p.db.Model(&site).Updates(map[string]interface{}{
			"status":         "scraped",
			"merchant_count": merchantCount,
		})
	}

	log.Printf("[crawl] done: %d merchants found", merchantCount)
	return nil
}

// crawlMerchantSite 爬取商户官网，提取联系方式
func (p *CrawlPhase) crawlMerchantSite(ctx context.Context, siteURL, sourceURL string) {
	subPages := []string{siteURL, siteURL + "/contact", siteURL + "/about", siteURL + "/关于我们"}

	for _, page := range subPages {
		if isContextDone(ctx) {
			break
		}

		result := p.staticCrawler.Crawl(ctx, page)
		if result.Error != nil || result.HTML == "" {
			continue
		}

		info := extractor.Extract(result.HTML)
		if !info.HasContact {
			continue
		}

		raw := &model.MerchantRaw{
			TgUsername: info.TgUsername,
			Website:    siteURL,
			Email:      info.Email,
			Phone:      info.Phone,
			SourceType: "web_crawl",
			SourceID:   sourceURL,
			Status:     "raw",
		}
		if raw.TgUsername != "" || raw.Email != "" || raw.Phone != "" {
			p.db.Create(raw)
		}
		break // 找到联系方式就停止
	}
}