package handlers

import (
	"ankao/internal/database"
	"ankao/internal/models"
	"net/http"
	"os"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"
)

// HomeHandler 首页处理器
func HomeHandler(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{
		"message": "欢迎使用AnKao Web服务",
		"version": "1.0.0",
	})
}

// HealthCheckHandler 健康检查处理器
func HealthCheckHandler(c *gin.Context) {
	c.JSON(http.StatusOK, gin.H{
		"status": "healthy",
	})
}

// GetDailyRanking 获取今日排行榜
func GetDailyRanking(c *gin.Context) {
	db := database.GetDB()

	// 获取查询参数
	limitStr := c.DefaultQuery("limit", "10")
	limit, err := strconv.Atoi(limitStr)
	if err != nil || limit <= 0 || limit > 100 {
		limit = 10
	}

	// 查询今日排行榜（按答题数量和正确率排序）
	var rankings []models.UserStats

	query := `
		SELECT
			u.id as user_id,
			u.username,
			u.nickname,
			u.avatar,
			u.user_type,
			COALESCE(COUNT(ar.id), 0) as total_answers,
			COALESCE(SUM(CASE WHEN ar.is_correct = true THEN 1 ELSE 0 END), 0) as correct_count,
			COALESCE(SUM(CASE WHEN ar.is_correct = false THEN 1 ELSE 0 END), 0) as wrong_count,
			CASE
				WHEN COUNT(ar.id) > 0 THEN
					ROUND(CAST(CAST(SUM(CASE WHEN ar.is_correct = true THEN 1 ELSE 0 END) AS FLOAT) / COUNT(ar.id) * 100 AS NUMERIC), 2)
				ELSE 0
			END as accuracy,
			u.created_at,
			MAX(ar.answered_at) as last_answer_at
		FROM users u
		LEFT JOIN user_answer_records ar ON u.id = ar.user_id
			AND ar.deleted_at IS NULL
			AND DATE(ar.answered_at) = CURRENT_DATE
		WHERE u.deleted_at IS NULL
		GROUP BY u.id, u.username, u.nickname, u.avatar, u.user_type, u.created_at
		HAVING COUNT(ar.id) > 0
		ORDER BY total_answers DESC, accuracy DESC, correct_count DESC
		LIMIT ?
	`

	if err := db.Raw(query, limit).Scan(&rankings).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{
			"success": false,
			"message": "获取排行榜数据失败",
			"error":   err.Error(),
		})
		return
	}

	c.JSON(http.StatusOK, gin.H{
		"success": true,
		"data":    rankings,
	})
}

// StaticFileHandler 静态文件处理器，用于服务前端静态资源
// 使用 NoRoute 避免与 API 路由冲突
func StaticFileHandler(root string) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// 获取请求路径
		path := r.URL.Path

		// 构建完整文件路径
		fullPath := filepath.Join(root, path)

		// 检查文件是否存在
		info, err := os.Stat(fullPath)
		if err != nil {
			// 文件不存在，尝试返回 index.html（SPA 应用）
			indexPath := filepath.Join(root, "index.html")
			if _, err := os.Stat(indexPath); err == nil {
				http.ServeFile(w, r, indexPath)
				return
			}
			http.NotFound(w, r)
			return
		}

		// 如果是目录，尝试返回目录下的 index.html
		if info.IsDir() {
			indexPath := filepath.Join(fullPath, "index.html")
			if _, err := os.Stat(indexPath); err == nil {
				http.ServeFile(w, r, indexPath)
				return
			}
			http.NotFound(w, r)
			return
		}

		// 设置正确的 Content-Type
		setContentType(w, fullPath)

		// 返回文件
		http.ServeFile(w, r, fullPath)
	})
}

// setContentType 根据文件扩展名设置正确的 Content-Type
func setContentType(w http.ResponseWriter, filePath string) {
	ext := strings.ToLower(filepath.Ext(filePath))
	contentTypes := map[string]string{
		".html": "text/html; charset=utf-8",
		".css":  "text/css; charset=utf-8",
		".js":   "application/javascript; charset=utf-8",
		".json": "application/json; charset=utf-8",
		".png":  "image/png",
		".jpg":  "image/jpeg",
		".jpeg": "image/jpeg",
		".gif":  "image/gif",
		".svg":  "image/svg+xml",
		".ico":  "image/x-icon",
		".woff": "font/woff",
		".woff2": "font/woff2",
		".ttf":  "font/ttf",
		".eot":  "application/vnd.ms-fontobject",
	}

	if contentType, ok := contentTypes[ext]; ok {
		w.Header().Set("Content-Type", contentType)
	}
}