package handler

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"github.com/yourname/cyrene-ai/gateway/internal/config"
	"github.com/yourname/cyrene-ai/gateway/internal/middleware"
	"github.com/yourname/cyrene-ai/gateway/internal/store"
	"github.com/yourname/cyrene-ai/gateway/internal/ws"
)

// BriefingHandler 每日简报处理器
type BriefingHandler struct {
	cfg            *config.Config
	hub            *ws.Hub
	briefingStore  *store.BriefingStore
	reminderStore  *store.ReminderStore
	httpClient     *http.Client
}

// NewBriefingHandler 创建简报处理器
func NewBriefingHandler(cfg *config.Config, hub *ws.Hub, bs *store.BriefingStore, rs *store.ReminderStore) *BriefingHandler {
	return &BriefingHandler{
		cfg:           cfg,
		hub:           hub,
		briefingStore: bs,
		reminderStore: rs,
		httpClient: &http.Client{
			Timeout: 30 * time.Second,
		},
	}
}

// GenerateBriefingRequest 手动生成简报请求体
type GenerateBriefingRequest struct {
	UserID string `json:"user_id" binding:"required"`
}

// GetBriefing 获取指定日期简报
// GET /api/v1/briefings?user_id=xxx&date=2024-01-01
func (h *BriefingHandler) GetBriefing(c *gin.Context) {
	authUserID := middleware.GetUserID(c)
	userID := c.Query("user_id")
	date := c.Query("date")

	if !strings.HasPrefix(authUserID, "admin_") || userID == "" {
		userID = authUserID
	}

	if userID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "缺少user_id参数"})
		return
	}
	if date == "" {
		date = time.Now().Format("2006-01-02")
	}

	briefing, err := h.briefingStore.GetBriefingByDate(userID, date)
	if err != nil {
		log.Printf("[briefing] 查询简报失败: user=%s date=%s err=%v", userID, date, err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询简报失败: " + err.Error()})
		return
	}

	if briefing == nil {
		c.JSON(http.StatusOK, gin.H{
			"briefing": nil,
			"message":  "当日简报尚未生成",
		})
		return
	}

	c.JSON(http.StatusOK, gin.H{"briefing": briefing})
}

// GetLatestBriefings 获取最近简报列表
// GET /api/v1/briefings/latest?user_id=xxx&limit=7
func (h *BriefingHandler) GetLatestBriefings(c *gin.Context) {
	authUserID := middleware.GetUserID(c)
	userID := c.Query("user_id")

	if !strings.HasPrefix(authUserID, "admin_") || userID == "" {
		userID = authUserID
	}

	if userID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "缺少user_id参数"})
		return
	}

	limit := 7
	if l := c.Query("limit"); l != "" {
		if parsed, err := parseInt(l); err == nil && parsed > 0 && parsed <= 30 {
			limit = parsed
		}
	}

	briefings, err := h.briefingStore.GetLatestBriefings(userID, limit)
	if err != nil {
		log.Printf("[briefing] 查询简报列表失败: user=%s err=%v", userID, err)
		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询简报列表失败: " + err.Error()})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"briefings": briefings,
		"total":     len(briefings),
	})
}

// Generate 手动触发生成今日简报
// POST /api/v1/briefings/generate
func (h *BriefingHandler) Generate(c *gin.Context) {
	authUserID := middleware.GetUserID(c)
	var req GenerateBriefingRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "请求参数无效: " + err.Error()})
		return
	}

	// 非管理员只能为自己生成
	if !strings.HasPrefix(authUserID, "admin_") {
		req.UserID = authUserID
	}

	if req.UserID == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "缺少user_id"})
		return
	}

	result, err := h.GenerateDailyBriefing(req.UserID)
	if err != nil {
		log.Printf("[briefing] 生成简报失败: user=%s err=%v", req.UserID, err)
		c.JSON(http.StatusInternalServerError, gin.H{
			"error":   "生成简报失败: " + err.Error(),
			"success": false,
		})
		return
	}

	// 生成后推送通知
	h.pushBriefingNotification(req.UserID, result)

	c.JSON(http.StatusOK, gin.H{
		"success":  true,
		"briefing": result,
		"message":  "简报已生成并推送",
	})
}

// GenerateDailyBriefing 生成每日简报（核心逻辑）
func (h *BriefingHandler) GenerateDailyBriefing(userID string) (*store.Briefing, error) {
	today := time.Now().Format("2006-01-02")

	briefing := &store.Briefing{
		ID:      "brief_" + generateID(),
		UserID:  userID,
		Date:    today,
		Status:  "pending",
		Weather: &store.WeatherData{},
		News:    []store.NewsItem{},
		Reminders: []store.BriefReminder{},
	}

	// 1. 获取天气数据
	log.Printf("[briefing] 获取天气数据...")
	weather, err := h.fetchWeather("Shanghai")
	if err != nil {
		log.Printf("[briefing] 天气获取失败 (降级): %v", err)
		weather = &store.WeatherData{
			Location:  "未知",
			Temp:      0,
			Condition: "获取天气失败",
			Icon:      "❓",
		}
	}
	briefing.Weather = weather
	log.Printf("[briefing] 天气: %s %.1f°C %s", weather.Location, weather.Temp, weather.Condition)

	// 2. 获取今日待办提醒
	log.Printf("[briefing] 获取待办提醒...")
	reminders, err := h.reminderStore.GetRemindersByUser(userID, "pending", 10, 0)
	if err != nil {
		log.Printf("[briefing] 获取提醒失败: %v", err)
	} else {
		now := time.Now()
		endOfDay := time.Date(now.Year(), now.Month(), now.Day(), 23, 59, 59, 0, now.Location())
		for _, r := range reminders {
			if r.RemindAt.Before(endOfDay) || r.RemindAt.Equal(endOfDay) {
				briefing.Reminders = append(briefing.Reminders, store.BriefReminder{
					ID:       r.ID,
					Title:    r.Title,
					RemindAt: r.RemindAt.Format(time.RFC3339),
				})
			}
		}
	}
	log.Printf("[briefing] 今日待办: %d 项", len(briefing.Reminders))

	// 3. 获取新闻摘要（通过 tool-engine web_search）
	log.Printf("[briefing] 获取新闻摘要...")
	news, err := h.fetchNews()
	if err != nil {
		log.Printf("[briefing] 新闻获取失败 (降级): %v", err)
	}
	briefing.News = news
	log.Printf("[briefing] 新闻: %d 条", len(news))

	// 4. 生成 AI 摘要
	log.Printf("[briefing] 生成 AI 摘要...")
	summary, err := h.generateAISummary(briefing)
	if err != nil {
		log.Printf("[briefing] AI 摘要生成失败 (降级): %v", err)
		summary = h.buildFallbackSummary(briefing)
	}
	briefing.Summary = summary

	// 5. 标记为已生成
	now := time.Now()
	briefing.Status = "generated"
	briefing.GeneratedAt = &now

	// 6. 持久化
	if err := h.briefingStore.CreateOrUpdateBriefing(briefing); err != nil {
		return nil, fmt.Errorf("保存简报失败: %w", err)
	}

	log.Printf("[briefing] 简报已生成: user=%s date=%s", userID, today)
	return briefing, nil
}

// fetchWeather 通过 wttr.in API 获取天气数据
func (h *BriefingHandler) fetchWeather(location string) (*store.WeatherData, error) {
	url := fmt.Sprintf("https://wttr.in/%s?format=j1", location)

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, fmt.Errorf("构建天气请求失败: %w", err)
	}
	req.Header.Set("User-Agent", "Cyrene-AI/1.0")

	resp, err := h.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("请求天气API失败: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("天气API返回状态码 %d", resp.StatusCode)
	}

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取天气响应失败: %w", err)
	}

	// 解析 wttr.in JSON 响应
	var wttrResp struct {
		CurrentCondition []struct {
			TempC       string `json:"temp_C"`
			WeatherDesc []struct {
				Value string `json:"value"`
			} `json:"weatherDesc"`
			WeatherIconURL []struct {
				Value string `json:"value"`
			} `json:"weatherIconUrl"`
		} `json:"current_condition"`
		NearestArea []struct {
			AreaName []struct {
				Value string `json:"value"`
			} `json:"areaName"`
		} `json:"nearest_area"`
	}

	if err := json.Unmarshal(body, &wttrResp); err != nil {
		return nil, fmt.Errorf("解析天气数据失败: %w", err)
	}

	wd := &store.WeatherData{
		Location: location,
	}

	if len(wttrResp.NearestArea) > 0 && len(wttrResp.NearestArea[0].AreaName) > 0 {
		wd.Location = wttrResp.NearestArea[0].AreaName[0].Value
	}

	if len(wttrResp.CurrentCondition) > 0 {
		cc := wttrResp.CurrentCondition[0]
		wd.Temp = parseFloat(cc.TempC)

		if len(cc.WeatherDesc) > 0 {
			wd.Condition = cc.WeatherDesc[0].Value
		}

		// 根据天气描述转 emoji
		wd.Icon = weatherEmoji(wd.Condition)
	}

	return wd, nil
}

// fetchNews 通过 tool-engine web_search 搜索今日新闻
func (h *BriefingHandler) fetchNews() ([]store.NewsItem, error) {
	if h.cfg.ToolEngineURL == "" {
		return nil, fmt.Errorf("ToolEngine URL 未配置")
	}

	today := time.Now().Format("2006年01月02日")
	query := fmt.Sprintf("%s 今日要闻 热点新闻", today)

	reqBody, _ := json.Marshal(map[string]interface{}{
		"arguments": map[string]interface{}{
			"query": query,
			"limit": 5,
		},
	})

	url := fmt.Sprintf("%s/api/v1/tools/web_search/execute", h.cfg.ToolEngineURL)
	req, err := http.NewRequest("POST", url, bytes.NewReader(reqBody))
	if err != nil {
		return nil, fmt.Errorf("构建新闻搜索请求失败: %w", err)
	}
	req.Header.Set("Content-Type", "application/json")

	resp, err := h.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("请求新闻搜索失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("读取新闻搜索结果失败: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("新闻搜索返回状态码 %d: %s", resp.StatusCode, string(body))
	}

	// 解析 tool-engine 单个工具执行响应: {id, output, error?}
	var result struct {
		ID     string `json:"id"`
		Output string `json:"output"`
		Error  string `json:"error,omitempty"`
	}

	if err := json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("解析新闻搜索结果失败: %w", err)
	}

	if result.Error != "" {
		log.Printf("[briefing] 新闻搜索失败: %s", result.Error)
		// 返回降级新闻
		return []store.NewsItem{
			{
				Title:   "未能获取今日新闻",
				URL:     "",
				Source:  "系统",
				Summary: "新闻搜索服务暂时不可用，请稍后再试。",
			},
		}, nil
	}

	var news []store.NewsItem

	// 尝试解析搜索结果为结构化数据
	var searchResults []struct {
		Title   string `json:"title"`
		URL     string `json:"url"`
		Snippet string `json:"snippet"`
		Source  string `json:"source"`
	}

	if err := json.Unmarshal([]byte(result.Output), &searchResults); err != nil {
		// 如果不是 JSON 数组，当做纯文本处理
		news = append(news, store.NewsItem{
			Title:   "今日新闻",
			URL:     "",
			Source:  "搜索引擎",
			Summary: truncateStr(result.Output, 200),
		})
	} else {
		for _, sr := range searchResults {
			news = append(news, store.NewsItem{
				Title:   sr.Title,
				URL:     sr.URL,
				Source:  sr.Source,
				Summary: sr.Snippet,
			})
		}
	}

	if len(news) == 0 {
		news = []store.NewsItem{
			{
				Title:   "未能获取今日新闻",
				URL:     "",
				Source:  "系统",
				Summary: "新闻搜索服务暂时不可用，请稍后再试。",
			},
		}
	}

	// 限制最多 5 条
	if len(news) > 5 {
		news = news[:5]
	}

	return news, nil
}

// generateAISummary 通过 AI-Core 生成人性化摘要
func (h *BriefingHandler) generateAISummary(b *store.Briefing) (string, error) {
	if h.cfg.AICoreURL == "" {
		return "", fmt.Errorf("AI-Core URL 未配置")
	}

	// 构建提示词
	prompt := h.buildSummaryPrompt(b)

	reqBody, _ := json.Marshal(map[string]interface{}{
		"messages": []map[string]interface{}{
			{
				"role":    "system",
				"content": "你是昔涟，一个温柔贴心的AI助手。请用温暖、亲切的语气回复，像朋友一样关心用户。回复使用中文。",
			},
			{
				"role":    "user",
				"content": prompt,
			},
		},
		"max_tokens":  500,
		"temperature": 0.7,
	})

	url := fmt.Sprintf("%s/api/v1/chat/completions", h.cfg.AICoreURL)
	req, err := http.NewRequest("POST", url, bytes.NewReader(reqBody))
	if err != nil {
		return "", fmt.Errorf("构建 AI 请求失败: %w", err)
	}
	req.Header.Set("Content-Type", "application/json")

	resp, err := h.httpClient.Do(req)
	if err != nil {
		return "", fmt.Errorf("请求 AI-Core 失败: %w", err)
	}
	defer resp.Body.Close()

	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", fmt.Errorf("读取 AI 响应失败: %w", err)
	}

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("AI-Core 返回状态码 %d: %s", resp.StatusCode, string(body))
	}

	// 解析 OpenAI 兼容响应
	var aiResp struct {
		Choices []struct {
			Message struct {
				Content string `json:"content"`
			} `json:"message"`
		} `json:"choices"`
	}

	if err := json.Unmarshal(body, &aiResp); err != nil {
		return "", fmt.Errorf("解析 AI 响应失败: %w", err)
	}

	if len(aiResp.Choices) == 0 {
		return "", fmt.Errorf("AI 返回空响应")
	}

	return aiResp.Choices[0].Message.Content, nil
}

// buildSummaryPrompt 构建 AI 摘要提示词
func (h *BriefingHandler) buildSummaryPrompt(b *store.Briefing) string {
	var sb strings.Builder
	today := time.Now().Format("2006年01月02日")

	sb.WriteString(fmt.Sprintf("今天是%s。请根据以下信息，用昔涟温柔的语气为用户生成一份简短的每日简报（控制在200字以内）：\n\n", today))

	// 天气
	if b.Weather != nil && b.Weather.Condition != "" {
		sb.WriteString(fmt.Sprintf("☁️ 天气：%s，%.0f°C，%s\n", b.Weather.Location, b.Weather.Temp, b.Weather.Condition))
	}

	// 待办
	if len(b.Reminders) > 0 {
		sb.WriteString("📋 今日待办：\n")
		for _, r := range b.Reminders {
			sb.WriteString(fmt.Sprintf("  - %s\n", r.Title))
		}
	}

	// 新闻
	if len(b.News) > 0 {
		sb.WriteString("📰 今日新闻：\n")
		for _, n := range b.News {
			if n.Summary != "" {
				sb.WriteString(fmt.Sprintf("  - %s: %s\n", n.Title, n.Summary))
			} else {
				sb.WriteString(fmt.Sprintf("  - %s\n", n.Title))
			}
		}
	}

	sb.WriteString("\n请用昔涟的语气回复，包含：1) 温馨问候 2) 天气提醒 3) 待办提醒 4) 新闻简要 5) 结语祝福。简洁自然即可。")

	return sb.String()
}

// buildFallbackSummary 降级摘要（不依赖 AI）
func (h *BriefingHandler) buildFallbackSummary(b *store.Briefing) string {
	today := time.Now().Format("2006年01月02日")
	var sb strings.Builder

	sb.WriteString(fmt.Sprintf("早上好！今天是%s ☀️\n\n", today))

	if b.Weather != nil && b.Weather.Condition != "" {
		sb.WriteString(fmt.Sprintf("今日%s天气：%s，%.0f°C。", b.Weather.Location, b.Weather.Condition, b.Weather.Temp))
		if b.Weather.Temp < 10 {
			sb.WriteString("天气有点凉，记得多穿件衣服哦～")
		} else if b.Weather.Temp > 30 {
			sb.WriteString("天气比较热，注意防暑降温哦～")
		} else {
			sb.WriteString("天气不错，适合出门走走呢～")
		}
		sb.WriteString("\n\n")
	}

	if len(b.Reminders) > 0 {
		sb.WriteString(fmt.Sprintf("你今天有 %d 项待办事项，记得按时完成哦！\n", len(b.Reminders)))
	} else {
		sb.WriteString("今天没有待办事项，可以轻松一下～\n")
	}

	if len(b.News) > 0 && b.News[0].Title != "未能获取今日新闻" {
		sb.WriteString(fmt.Sprintf("\n今日热点：%s。", b.News[0].Title))
	}

	sb.WriteString("\n\n祝你度过美好的一天！🌸")

	return sb.String()
}

// pushBriefingNotification 推送简报通知到用户
func (h *BriefingHandler) pushBriefingNotification(userID string, b *store.Briefing) {
	bodyPreview := truncateStr(b.Summary, 100)

	notif := &ws.NotificationInfo{
		ID:        "briefing_" + b.ID,
		Type:      "info",
		Title:     fmt.Sprintf("📋 今日简报 (%s)", b.Date),
		Body:      bodyPreview,
		Timestamp: time.Now().UTC().Format(time.RFC3339),
		Data: map[string]interface{}{
			"briefing_id": b.ID,
			"date":        b.Date,
			"type":        "daily_briefing",
		},
	}

	msg := ws.ServerMessage{
		Type:         "notification",
		MessageID:    "briefing_" + b.ID,
		Timestamp:    time.Now().UnixMilli(),
		Notification: notif,
	}

	data, err := json.Marshal(msg)
	if err != nil {
		log.Printf("[briefing] 序列化简报通知失败: %v", err)
		return
	}

	h.hub.SendToUser(userID, data)

	// 更新简报状态为已送达
	now := time.Now()
	b.Status = "delivered"
	b.DeliveredAt = &now
	if err := h.briefingStore.CreateOrUpdateBriefing(b); err != nil {
		log.Printf("[briefing] 更新简报送达状态失败: %v", err)
	}

	log.Printf("[briefing] 简报通知已推送: user=%s date=%s", userID, b.Date)
}

// StartBriefingScheduler 启动简报调度器
// briefingTime 格式: "HH:MM"，默认 "08:00"
func StartBriefingScheduler(handler *BriefingHandler, briefingStore *store.BriefingStore, briefingTime string) {
	if briefingTime == "" {
		briefingTime = "08:00"
	}

	go func() {
		// 每 30 秒检查一次是否到达简报时间
		ticker := time.NewTicker(30 * time.Second)
		defer ticker.Stop()

		log.Printf("[BriefingScheduler] 简报调度器已启动 (简报时间: %s)", briefingTime)

		// 记录今天是否已触发
		lastTriggeredDate := ""

		for range ticker.C {
			now := time.Now()
			currentTime := now.Format("15:04")
			currentDate := now.Format("2006-01-02")

			// 检查是否到达简报时间且今天尚未触发
			if currentTime == briefingTime && currentDate != lastTriggeredDate {
				log.Printf("[BriefingScheduler] 触发每日简报生成: %s", currentDate)
				lastTriggeredDate = currentDate

				// 获取所有用户
				users, err := briefingStore.GetAllUsers()
				if err != nil {
					log.Printf("[BriefingScheduler] 获取用户列表失败: %v", err)
					continue
				}

				// 如果没有从 reminders 表获取到用户，也尝试从 briefings 表获取
				if len(users) == 0 {
					users, _ = briefingStore.GetUsersWithBriefings()
				}

				if len(users) == 0 {
					log.Println("[BriefingScheduler] 没有找到用户，跳过简报生成")
					continue
				}

				for _, userID := range users {
					log.Printf("[BriefingScheduler] 为用户 %s 生成简报...", userID)
					result, err := handler.GenerateDailyBriefing(userID)
					if err != nil {
						log.Printf("[BriefingScheduler] 生成简报失败: user=%s err=%v", userID, err)
						continue
					}
					handler.pushBriefingNotification(userID, result)
				}

				log.Printf("[BriefingScheduler] 每日简报已生成完毕，共 %d 个用户", len(users))
			}
		}
	}()
}

// ========== 辅助函数 ==========

// weatherEmoji 根据天气描述返回对应 emoji
func weatherEmoji(condition string) string {
	c := strings.ToLower(condition)
	switch {
	case strings.Contains(c, "sunny") || strings.Contains(c, "clear") || strings.Contains(c, "晴"):
		return "☀️"
	case strings.Contains(c, "partly cloudy") || strings.Contains(c, "多云"):
		return "⛅"
	case strings.Contains(c, "cloudy") || strings.Contains(c, "阴"):
		return "☁️"
	case strings.Contains(c, "rain") || strings.Contains(c, "drizzle") || strings.Contains(c, "雨"):
		return "🌧️"
	case strings.Contains(c, "thunder") || strings.Contains(c, "雷"):
		return "⛈️"
	case strings.Contains(c, "snow") || strings.Contains(c, "雪"):
		return "❄️"
	case strings.Contains(c, "fog") || strings.Contains(c, "mist") || strings.Contains(c, "雾"):
		return "🌫️"
	case strings.Contains(c, "wind") || strings.Contains(c, "风"):
		return "💨"
	default:
		return "🌤️"
	}
}

// parseFloat 安全解析浮点数
func parseFloat(s string) float64 {
	var f float64
	fmt.Sscanf(s, "%f", &f)
	return f
}

// parseInt 安全解析整数
func parseInt(s string) (int, error) {
	var n int
	_, err := fmt.Sscanf(s, "%d", &n)
	return n, err
}

// truncateStr 截断字符串
func truncateStr(s string, maxLen int) string {
	runes := []rune(s)
	if len(runes) <= maxLen {
		return s
	}
	return string(runes[:maxLen]) + "..."
}