//go:build llm_script

package main

import (
	"context"
	"database/sql"
	"encoding/json"
	"flag"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"regexp"
	"strings"
	"time"

	_ "github.com/lib/pq"
)

type verificationCandidateRow struct {
	ID                   int64
	CandidateDate        string
	EventType            string
	ProviderName         string
	ModelName            string
	ProviderCountry      string
	Title                string
	Summary              string
	CandidateURLs        []string
	Status               string
	VerificationConfidence string
}

type intradayVerificationConfig struct {
	Date        string
	DryRun      bool
	DatabaseURL string
	Timeout     time.Duration
}

type intradayVerificationResult struct {
	CandidateID             int64
	CandidateStatus         string
	VerificationConfidence  string
	VerifierSource          string
	VerifierURL             string
	VerifierStatus          string
	ExtractedFacts          map[string]any
	Notes                   string
}

type intradayVerificationSummary struct {
	CandidateTotal          int `json:"candidate_total"`
	VerifiedTotal           int `json:"verified_total"`
	OfficialConfirmedTotal  int `json:"official_confirmed_total"`
	SecondaryConfirmedTotal int `json:"secondary_confirmed_total"`
	RejectedTotal           int `json:"rejected_total"`
	DryRun                  bool `json:"dry_run"`
}

func main() {
	loadIntradayEnv()
	cfg := intradayVerificationConfig{}
	flag.StringVar(&cfg.Date, "date", intradayDateValue(), "验证日期，格式 YYYY-MM-DD")
	flag.BoolVar(&cfg.DryRun, "dry-run", false, "仅输出摘要，不写数据库")
	flag.Parse()
	cfg.DatabaseURL = intradayDefaultDSN()
	cfg.Timeout = discoveryTimeoutFromEnv()
	if err := runIntradayCandidateVerification(cfg); err != nil {
		fmt.Fprintf(os.Stderr, "verify_intraday_news_candidates: %v\n", err)
		os.Exit(1)
	}
}

func runIntradayCandidateVerification(cfg intradayVerificationConfig) error {
	if strings.TrimSpace(cfg.Date) == "" {
		return fmt.Errorf("date 未设置")
	}
	db, err := sql.Open("postgres", cfg.DatabaseURL)
	if err != nil {
		return fmt.Errorf("open db: %w", err)
	}
	defer db.Close()
	candidates, err := loadIntradayVerificationCandidates(context.Background(), db, cfg.Date)
	if err != nil {
		return err
	}
	results := make([]intradayVerificationResult, 0, len(candidates))
	for _, candidate := range candidates {
		result, err := verifyIntradayCandidate(candidate, cfg.Timeout)
		if err != nil {
			result = intradayVerificationResult{
				CandidateID:            candidate.ID,
				CandidateStatus:        "candidate",
				VerificationConfidence: candidate.VerificationConfidence,
				VerifierStatus:         "error",
				Notes:                  err.Error(),
			}
		}
		results = append(results, result)
	}
	if !cfg.DryRun {
		if err := persistIntradayVerificationResults(context.Background(), db, results); err != nil {
			return err
		}
	}
	return printIntradayVerificationSummary(summarizeIntradayVerification(results, cfg.DryRun))
}

func loadIntradayVerificationCandidates(ctx context.Context, db *sql.DB, date string) ([]verificationCandidateRow, error) {
	rows, err := db.QueryContext(ctx, `
		SELECT id, candidate_date::text, event_type, provider_name, COALESCE(model_name, ''), COALESCE(provider_country, ''),
		       title, COALESCE(summary, ''), COALESCE(candidate_urls::text, '[]'), status, verification_confidence
		FROM intraday_news_candidate
		WHERE candidate_date = $1::date
		  AND status IN ('candidate', 'verifying')
		ORDER BY discovered_at DESC, id DESC`, date)
	if err != nil {
		return nil, fmt.Errorf("query intraday candidates: %w", err)
	}
	defer rows.Close()
	var candidates []verificationCandidateRow
	for rows.Next() {
		var row verificationCandidateRow
		var rawURLs string
		if err := rows.Scan(&row.ID, &row.CandidateDate, &row.EventType, &row.ProviderName, &row.ModelName, &row.ProviderCountry, &row.Title, &row.Summary, &rawURLs, &row.Status, &row.VerificationConfidence); err != nil {
			return nil, fmt.Errorf("scan intraday candidate: %w", err)
		}
		if err := json.Unmarshal([]byte(rawURLs), &row.CandidateURLs); err != nil {
			return nil, fmt.Errorf("unmarshal candidate urls: %w", err)
		}
		candidates = append(candidates, row)
	}
	return candidates, rows.Err()
}

func verifyIntradayCandidate(candidate verificationCandidateRow, timeout time.Duration) (intradayVerificationResult, error) {
	client := &http.Client{Timeout: timeout}
	best := intradayVerificationResult{
		CandidateID:            candidate.ID,
		CandidateStatus:        "candidate",
		VerificationConfidence: candidate.VerificationConfidence,
		VerifierStatus:         "insufficient",
		Notes:                  "未找到足够证据",
		ExtractedFacts:         map[string]any{},
	}
	for _, candidateURL := range candidate.CandidateURLs {
		body, err := fetchVerificationDocument(candidateURL, client)
		if err != nil {
			best = preferVerificationResult(best, intradayVerificationResult{
				CandidateID:            candidate.ID,
				CandidateStatus:        "candidate",
				VerificationConfidence: candidate.VerificationConfidence,
				VerifierURL:            candidateURL,
				VerifierStatus:         "error",
				Notes:                  err.Error(),
				ExtractedFacts:         map[string]any{},
			})
			continue
		}
		result := verifyCandidateDocument(candidate, candidateURL, body)
		if result.CandidateID == 0 {
			result.CandidateID = candidate.ID
		}
		best = preferVerificationResult(best, result)
		if best.CandidateStatus == "verified" && best.VerificationConfidence == "official_confirmed" {
			return best, nil
		}
	}
	return best, nil
}

func fetchVerificationDocument(rawURL string, client *http.Client) (string, error) {
	req, err := http.NewRequest(http.MethodGet, rawURL, nil)
	if err != nil {
		return "", fmt.Errorf("build verification request: %w", err)
	}
	req.Header.Set("User-Agent", "Mozilla/5.0 (compatible; llm-intelligence intraday verifier)")
	resp, err := client.Do(req)
	if err != nil {
		return "", fmt.Errorf("fetch verification document: %w", err)
	}
	defer resp.Body.Close()
	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
		payload, _ := io.ReadAll(resp.Body)
		return "", fmt.Errorf("fetch verification document: unexpected status %d: %s", resp.StatusCode, strings.TrimSpace(string(payload)))
	}
	payload, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("read verification document: %w", err)
	}
	return string(payload), nil
}

func verifyCandidateDocument(candidate verificationCandidateRow, candidateURL, body string) intradayVerificationResult {
	source := classifyVerificationSource(candidate.ProviderName, candidateURL)
	facts := extractVerificationFacts(body)
	modelMatched := bodyMentionsModel(body, candidate.ModelName, candidate.Title)
	result := intradayVerificationResult{
		CandidateID:            candidate.ID,
		CandidateStatus:        "candidate",
		VerificationConfidence: "candidate",
		VerifierSource:         source,
		VerifierURL:            candidateURL,
		VerifierStatus:         "insufficient",
		ExtractedFacts:         facts,
		Notes:                  "证据不足",
	}
	if isOfficialVerificationSource(source) {
		switch normalizeIntradayEventType(candidate.EventType) {
		case "official_release":
			if modelMatched {
				result.CandidateStatus = "verified"
				result.VerificationConfidence = "official_confirmed"
				result.VerifierStatus = "matched"
				result.Notes = "官方页面命中模型发布线索"
			}
		case "promo_campaign":
			if modelMatched && bodyMentionsPromo(body) {
				result.CandidateStatus = "verified"
				result.VerificationConfidence = "official_confirmed"
				result.VerifierStatus = "matched"
				result.Notes = "官方页面命中活动窗口或促销语义"
			}
		case "price_cut", "price_increase":
			if priceResult, ok := deriveVerifiedPriceEvent(candidate.EventType, facts); ok {
				result.CandidateStatus = "verified"
				result.VerificationConfidence = "official_confirmed"
				result.VerifierStatus = "matched"
				result.ExtractedFacts = priceResult
				result.Notes = "官方价格页命中真实价格变化"
			} else if modelMatched {
				result.VerifierStatus = "insufficient"
				result.Notes = "命中模型但缺少可计算的价格变化事实"
			}
		case "leak_or_rumor":
			if modelMatched {
				result.CandidateStatus = "verified"
				result.VerificationConfidence = "secondary_confirmed"
				result.VerifierStatus = "matched"
				result.Notes = "保留为待确认情报，不进入正式事实层"
			}
		}
	} else if modelMatched {
		result.CandidateStatus = "verified"
		result.VerificationConfidence = "secondary_confirmed"
		result.VerifierStatus = "matched"
		result.Notes = "仅二手来源命中，不能进入正式事实层"
	}
	if result.VerifierStatus == "insufficient" && modelMatched && !isOfficialVerificationSource(source) {
		result.VerificationConfidence = "secondary_confirmed"
	}
	return result
}

func isOfficialVerificationSource(source string) bool {
	switch source {
	case "official_page", "official_docs", "official_blog", "pricing_page":
		return true
	default:
		return false
	}
}

func classifyVerificationSource(providerName, rawURL string) string {
	parsed, err := url.Parse(rawURL)
	if err != nil {
		return "secondary_media"
	}
	host := strings.ToLower(parsed.Host)
	path := strings.ToLower(parsed.Path)
	if isOfficialProviderHost(providerName, host) {
		switch {
		case strings.Contains(host, "docs.") || strings.Contains(path, "/docs"):
			return "official_docs"
		case strings.Contains(host, "pricing") || strings.Contains(path, "pricing") || strings.Contains(path, "price"):
			return "pricing_page"
		case strings.Contains(path, "blog") || strings.Contains(path, "news") || strings.Contains(path, "announcement"):
			return "official_blog"
		default:
			return "official_page"
		}
	}
	return "secondary_media"
}

func isOfficialProviderHost(providerName, host string) bool {
	tokens := providerHostTokens(providerName)
	for _, token := range tokens {
		if token != "" && strings.Contains(host, token) {
			return true
		}
	}
	return false
}

func providerHostTokens(providerName string) []string {
	switch strings.ToLower(strings.TrimSpace(providerName)) {
	case "openai":
		return []string{"openai.com"}
	case "anthropic":
		return []string{"anthropic.com"}
	case "google", "google gemini", "gemini":
		return []string{"google.com", "google.dev", "ai.google.dev"}
	case "deepseek":
		return []string{"deepseek.com", "deepseek.ai"}
	case "qwen", "dashscope":
		return []string{"aliyun.com", "dashscope.com"}
	case "xai":
		return []string{"x.ai"}
	case "智谱":
		return []string{"zhipuai.cn"}
	case "百度", "百度文心":
		return []string{"baidu.com", "cloud.baidu.com"}
	case "腾讯", "腾讯混元":
		return []string{"tencent.com", "cloud.tencent.com"}
	case "minimax":
		return []string{"minimax.io", "minimax.chat"}
	default:
		clean := strings.ToLower(strings.TrimSpace(providerName))
		if clean == "" {
			return nil
		}
		return []string{clean}
	}
}

func bodyMentionsModel(body, modelName, title string) bool {
	normBody := normalizeEvidenceText(body)
	for _, candidate := range []string{modelName, title} {
		normCandidate := normalizeEvidenceText(candidate)
		if normCandidate != "" && strings.Contains(normBody, normCandidate) {
			return true
		}
	}
	return false
}

func bodyMentionsPromo(body string) bool {
	lower := strings.ToLower(body)
	for _, marker := range []string{"campaign", "promo", "promotion", "discount", "活动", "优惠", "限时", "窗口"} {
		if strings.Contains(lower, marker) {
			return true
		}
	}
	return false
}

func extractVerificationFacts(body string) map[string]any {
	facts := map[string]any{}
	oldPrice, newPrice, ok := extractPricePair(body)
	if ok {
		facts["old_input_price"] = oldPrice
		facts["new_input_price"] = newPrice
		if oldPrice != 0 {
			facts["price_change_pct"] = ((newPrice - oldPrice) / oldPrice) * 100
		}
	}
	return facts
}

func deriveVerifiedPriceEvent(eventType string, facts map[string]any) (map[string]any, bool) {
	oldValue, oldOK := facts["old_input_price"].(float64)
	newValue, newOK := facts["new_input_price"].(float64)
	changePct, pctOK := facts["price_change_pct"].(float64)
	if !oldOK || !newOK || !pctOK || oldValue <= 0 || newValue <= 0 {
		return nil, false
	}
	normalized := normalizeIntradayEventType(eventType)
	if normalized == "price_cut" && changePct >= 0 {
		return nil, false
	}
	if normalized == "price_increase" && changePct <= 0 {
		return nil, false
	}
	return facts, true
}

func extractPricePair(body string) (float64, float64, bool) {
	oldRe := regexp.MustCompile(`(?i)(old|from)\s*price[^0-9$￥]*[$￥]?([0-9]+(?:\.[0-9]+)?)`)
	newRe := regexp.MustCompile(`(?i)(new|to)\s*price[^0-9$￥]*[$￥]?([0-9]+(?:\.[0-9]+)?)`)
	oldMatch := oldRe.FindStringSubmatch(body)
	newMatch := newRe.FindStringSubmatch(body)
	if len(oldMatch) < 3 || len(newMatch) < 3 {
		return 0, 0, false
	}
	var oldValue, newValue float64
	if _, err := fmt.Sscanf(oldMatch[2], "%f", &oldValue); err != nil {
		return 0, 0, false
	}
	if _, err := fmt.Sscanf(newMatch[2], "%f", &newValue); err != nil {
		return 0, 0, false
	}
	return oldValue, newValue, true
}

func normalizeEvidenceText(value string) string {
	value = strings.ToLower(value)
	re := regexp.MustCompile(`[^a-z0-9\p{Han}]+`)
	value = re.ReplaceAllString(value, "")
	return strings.TrimSpace(value)
}

func preferVerificationResult(current, next intradayVerificationResult) intradayVerificationResult {
	if verificationScore(next) > verificationScore(current) {
		return next
	}
	return current
}

func verificationScore(result intradayVerificationResult) int {
	score := 0
	switch result.CandidateStatus {
	case "verified":
		score += 20
	case "rejected":
		score += 5
	}
	switch result.VerificationConfidence {
	case "official_confirmed":
		score += 10
	case "secondary_confirmed":
		score += 5
	}
	switch result.VerifierStatus {
	case "matched":
		score += 3
	case "contradicted":
		score += 1
	}
	return score
}

func persistIntradayVerificationResults(ctx context.Context, db *sql.DB, results []intradayVerificationResult) error {
	for _, result := range results {
		facts, err := json.Marshal(result.ExtractedFacts)
		if err != nil {
			return fmt.Errorf("marshal extracted facts: %w", err)
		}
		_, err = db.ExecContext(ctx, `
			INSERT INTO intraday_news_verification (
				candidate_id, verifier_source, verifier_url, verifier_status, extracted_facts, notes
			) VALUES ($1, NULLIF($2, ''), NULLIF($3, ''), $4, $5::jsonb, NULLIF($6, ''))`,
			result.CandidateID,
			result.VerifierSource,
			result.VerifierURL,
			result.VerifierStatus,
			string(facts),
			result.Notes,
		)
		if err != nil {
			return fmt.Errorf("insert intraday verification: %w", err)
		}
		_, err = db.ExecContext(ctx, `
			UPDATE intraday_news_candidate
			SET status = $2,
			    verification_confidence = $3,
			    verification_notes = NULLIF($4, ''),
			    updated_at = CURRENT_TIMESTAMP
			WHERE id = $1`,
			result.CandidateID,
			result.CandidateStatus,
			result.VerificationConfidence,
			result.Notes,
		)
		if err != nil {
			return fmt.Errorf("update intraday candidate: %w", err)
		}
	}
	return nil
}

func summarizeIntradayVerification(results []intradayVerificationResult, dryRun bool) intradayVerificationSummary {
	summary := intradayVerificationSummary{CandidateTotal: len(results), DryRun: dryRun}
	for _, result := range results {
		if result.CandidateStatus == "verified" {
			summary.VerifiedTotal++
		}
		switch result.VerificationConfidence {
		case "official_confirmed":
			summary.OfficialConfirmedTotal++
		case "secondary_confirmed":
			summary.SecondaryConfirmedTotal++
		}
		if result.CandidateStatus == "rejected" {
			summary.RejectedTotal++
		}
	}
	return summary
}

func printIntradayVerificationSummary(summary intradayVerificationSummary) error {
	payload, err := json.Marshal(summary)
	if err != nil {
		return err
	}
	fmt.Println(string(payload))
	return nil
}