package handler

import (
	"fmt"
	"net/http"
	"strconv"
	"time"

	"silk-server-go/internal/config"
	"silk-server-go/internal/middleware"
	"silk-server-go/internal/model"

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

// RegisterVideoClipRoutes 注册录像片段管理路由
func RegisterVideoClipRoutes(rg *gin.RouterGroup, db *gorm.DB, cfg *config.Config) {
	readPerm := middleware.RequirePermission(db, "video:read")
	rg.GET("/video/clips", readPerm, listClips(db))
	rg.GET("/video/clips/:clipId/play", readPerm, playClip(db))
	rg.POST("/video/clips/internal", createClipInternal(db, cfg)) // 白名单接口，无需权限
}

// listClips 录像片段列表（query: cameraId/from/to/limit，按 startAt DESC）
func listClips(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		userID := currentUserID(c)
		if userID == nil {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "未提供用户信息"})
			return
		}

		limit := 50
		if l, err := strconv.Atoi(c.Query("limit")); err == nil && l > 0 {
			limit = l
			if limit > 200 {
				limit = 200
			}
		}

		q := applyRoomScope(db.Model(&model.VideoClip{}), c, "room_id").Order("start_at DESC").Limit(limit)
		if cameraId := c.Query("cameraId"); cameraId != "" {
			q = q.Where("camera_id = ?", cameraId)
		}
		if from := c.Query("from"); from != "" {
			q = q.Where("start_at >= ?", from)
		}
		if to := c.Query("to"); to != "" {
			q = q.Where("start_at <= ?", to)
		}

		clips := make([]model.VideoClip, 0)
		q.Find(&clips)

		// 为每个片段设置 playbackUrl
		for i := range clips {
			token, err := IssueVideoToken(*userID, "clip", strconv.FormatUint(uint64(clips[i].ID), 10), videoTokenTTL)
			if err != nil {
				continue
			}
			url := fmt.Sprintf("/api/v1/video/clips/%d/stream?videoToken=%s", clips[i].ID, token)
			clips[i].PlaybackURL = &url
		}

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

// playClip 获取片段播放地址
func playClip(db *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		userID := currentUserID(c)
		if userID == nil {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "未提供用户信息"})
			return
		}

		clipId := c.Param("clipId")
		if !requireObjectAccess(c, db, "video_clip", clipId) {
			return
		}
		var clip model.VideoClip
		if db.Where("id = ?", clipId).First(&clip).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "video clip not found"})
			return
		}

		format := clip.Format
		if format == "" {
			format = "mp4"
		}

		token, err := IssueVideoToken(*userID, "clip", strconv.FormatUint(uint64(clip.ID), 10), videoTokenTTL)
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "生成播放令牌失败"})
			return
		}

		c.JSON(http.StatusOK, gin.H{
			"clipId":    clip.ID,
			"url":       fmt.Sprintf("/api/v1/video/clips/%d/stream?videoToken=%s", clip.ID, token),
			"format":    format,
			"expiresAt": time.Now().Add(videoTokenTTL).UTC().Format(time.RFC3339),
		})
	}
}

// createClipInternal 内部接口创建录像片段记录（校验 x-api-key header）
func createClipInternal(db *gorm.DB, cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		// 校验 x-api-key
		apiKey := c.GetHeader("x-api-key")
		if apiKey != cfg.InternalAPIKey {
			c.JSON(http.StatusUnauthorized, gin.H{"error": "invalid api key"})
			return
		}

		var body struct {
			CameraID    string  `json:"cameraId"`
			Trigger     string  `json:"trigger"`
			Format      string  `json:"format"`
			StartAt     string  `json:"startAt"`
			DurationSec float64 `json:"durationSec"`
			SizeBytes   string  `json:"sizeBytes"`
			S3Bucket    string  `json:"s3Bucket"`
			S3Key       string  `json:"s3Key"`
			Resolution  string  `json:"resolution"`
			Notes       string  `json:"notes"`
		}
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}

		// 去重：同一 s3Key 不重复创建
		var existing model.VideoClip
		if db.Where("s3_key = ?", body.S3Key).First(&existing).Error == nil {
			c.JSON(http.StatusOK, existing)
			return
		}

		// 解析开始时间
		startAt, err := time.Parse(time.RFC3339, body.StartAt)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid startAt, expected RFC3339 format"})
			return
		}

		// 设置默认值
		trigger := body.Trigger
		if trigger == "" {
			trigger = "schedule"
		}
		format := body.Format
		if format == "" {
			format = "mp4"
		}
		notes := body.Notes
		if notes == "" {
			notes = "自动录制归档"
		}

		clip := model.VideoClip{
			CameraID:    body.CameraID,
			Trigger:     trigger,
			Format:      format,
			StartAt:     startAt,
			DurationSec: body.DurationSec,
			S3Bucket:    &body.S3Bucket,
			S3Key:       &body.S3Key,
			Notes:       &notes,
		}
		// 从 camera 查询 room_id
		var camera model.Camera
		if err := db.Where("id = ?", body.CameraID).First(&camera).Error; err == nil {
			clip.RoomID = camera.RoomID
		}
		if body.SizeBytes != "" {
			if n, err := strconv.ParseInt(body.SizeBytes, 10, 64); err == nil {
				clip.SizeBytes = &n
			}
		}
		if body.Resolution != "" {
			clip.Resolution = &body.Resolution
		}

		if err := db.Create(&clip).Error; err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}

		c.JSON(http.StatusCreated, clip)
	}
}