package handler

import (
	"io"
	"log/slog"
	"net/http"
	"strings"

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

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

// RegisterVideoStreamRoutes 注册视频流代理路由；路由可免 Authorization，但必须校验 videoToken。
func RegisterVideoStreamRoutes(rg *gin.RouterGroup, transcode *service.TranscodeService, db *gorm.DB, media *service.MediaService, cfg *config.Config) {
	SetVideoTokenSecret(cfg.JWTSecret)
	rg.GET("/video/clips/:clipId/stream", streamClip(transcode))
	rg.GET("/video/cameras/:id/live/stream", streamLive(db, media, cfg))
	rg.GET("/video/cameras/:id/live/proxy", proxyLive(db, media, cfg))
}

// streamClip 视频流代理 + ffmpeg 转码
func streamClip(transcode *service.TranscodeService) gin.HandlerFunc {
	return func(c *gin.Context) {
		clipId := c.Param("clipId")
		if !requireVideoToken(c, "clip", clipId) {
			return
		}
		c.Header("Content-Type", "video/mp4")

		if err := transcode.StreamClip(clipId, c.Writer); err != nil {
			slog.Error("视频流转码失败", "clipId", clipId, "error", err)
			if !c.Writer.Written() {
				c.JSON(http.StatusBadGateway, gin.H{"error": err.Error()})
			}
		}
	}
}

// streamLive 实时直播流代理（直接转发，不转码）
func streamLive(db *gorm.DB, media *service.MediaService, cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		cameraId := c.Param("id")
		if !requireVideoToken(c, "camera", cameraId) {
			return
		}

		var camera model.Camera
		if db.Where("id = ?", cameraId).First(&camera).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "camera not found"})
			return
		}
		if camera.GbDeviceID == nil || camera.GbChannelID == nil ||
			*camera.GbDeviceID == "" || *camera.GbChannelID == "" {
			c.JSON(http.StatusBadRequest, gin.H{"error": "摄像头未配置 GB28181"})
			return
		}

		// 调用 WVP 启动流（非阻塞，超时也不影响后续代理）
		sourceURL := ""
		result, err := media.StartPlay(*camera.GbDeviceID, *camera.GbChannelID)
		if err != nil {
			slog.Warn("直播流代理：StartPlay 失败，尝试直接代理", "cameraId", cameraId, "error", err)
			// StartPlay 失败时，直接构造 ZLM FLV 地址
			sourceURL = strings.TrimSuffix(cfg.ZLMAPIBase, "/") + "/rtp/" + *camera.GbDeviceID + "_" + *camera.GbChannelID + ".live.flv?originTypeStr=rtp_push&videoCodec=H264"
		} else {
			sourceURL = result.FLV
		}

		if sourceURL == "" {
			c.JSON(http.StatusServiceUnavailable, gin.H{"error": "无法获取视频流地址"})
			return
		}

		// 确保地址是完整的 ZLM 地址（WVP 返回的可能是相对路径 /rtp/...）
		if strings.HasPrefix(sourceURL, "/") {
			sourceURL = strings.TrimSuffix(cfg.ZLMAPIBase, "/") + sourceURL
		}

		slog.Info("直播流代理", "cameraId", cameraId, "sourceURL", sourceURL)

		resp, err := http.Get(sourceURL)
		if err != nil {
			slog.Error("直播流代理：获取源流失败", "cameraId", cameraId, "error", err)
			c.JSON(http.StatusBadGateway, gin.H{"error": "获取视频流失败"})
			return
		}
		defer resp.Body.Close()

		for key, values := range resp.Header {
			for _, value := range values {
				c.Header(key, value)
			}
		}
		c.Status(resp.StatusCode)

		_, err = io.Copy(c.Writer, resp.Body)
		if err != nil {
			slog.Error("直播流代理：转发流失败", "cameraId", cameraId, "error", err)
		}
	}
}

// proxyLive 实时直播流直接代理（不转码，性能更好）
func proxyLive(db *gorm.DB, media *service.MediaService, cfg *config.Config) gin.HandlerFunc {
	return func(c *gin.Context) {
		cameraId := c.Param("id")
		if !requireVideoToken(c, "camera", cameraId) {
			return
		}

		// 1. 查摄像头
		var camera model.Camera
		if db.Where("id = ?", cameraId).First(&camera).Error != nil {
			c.JSON(http.StatusNotFound, gin.H{"error": "camera not found"})
			return
		}
		if camera.GbDeviceID == nil || camera.GbChannelID == nil ||
			*camera.GbDeviceID == "" || *camera.GbChannelID == "" {
			c.JSON(http.StatusBadRequest, gin.H{"error": "摄像头未配置 GB28181"})
			return
		}

		// 2. 确保 WVP 流在线
		result, err := media.StartPlay(*camera.GbDeviceID, *camera.GbChannelID)
		if err != nil {
			slog.Warn("直播流代理：StartPlay 失败", "cameraId", cameraId, "error", err)
			c.JSON(http.StatusServiceUnavailable, gin.H{"error": "摄像头可能离线: " + err.Error()})
			return
		}

		// 3. 获取 FLV 源地址
		sourceURL := result.FLV
		if sourceURL == "" {
			c.JSON(http.StatusServiceUnavailable, gin.H{"error": "无法获取视频流地址"})
			return
		}

		// 4. 确保地址是完整的 ZLM 地址
		if strings.HasPrefix(sourceURL, "/") {
			sourceURL = strings.TrimSuffix(cfg.ZLMAPIBase, "/") + sourceURL
		}

		slog.Info("直播流代理", "cameraId", cameraId, "sourceURL", sourceURL)

		// 5. 直接代理转发
		resp, err := http.Get(sourceURL)
		if err != nil {
			slog.Error("直播流代理：获取源流失败", "cameraId", cameraId, "error", err)
			c.JSON(http.StatusBadGateway, gin.H{"error": "获取视频流失败"})
			return
		}
		defer resp.Body.Close()

		// 复制响应头
		for key, values := range resp.Header {
			for _, value := range values {
				c.Header(key, value)
			}
		}
		c.Status(resp.StatusCode)

		// 复制响应体
		_, err = io.Copy(c.Writer, resp.Body)
		if err != nil {
			slog.Error("直播流代理：转发流失败", "cameraId", cameraId, "error", err)
		}
	}
}