package video

import (
	"context"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"path/filepath"
	"strings"
	"time"

	common "media/controller/common"
	dto "media/model/dto/video"
	service "media/service/video"

	"gitea.com/red-future/common/beans"
	"gitea.com/red-future/common/utils"
	"github.com/gogf/gf/v2/frame/g"
)

type video struct{}

var Concat = new(video)

// Concat 视频拼接（URL模式） POST /video/concat
func (c *video) Concat(ctx context.Context, req *dto.ConcatReq) (res *dto.ConcatRes, err error) {
	ctx = withUser(ctx)
	g.Log().Infof(ctx, "[视频拼接] 收到请求 入参: method=%s, upload=%v, video_urls=%v",
		req.Method, req.Upload, req.VideoURLs)

	if req.Method == "" {
		req.Method = "auto"
	}

	savePaths, err := downloadVideos(ctx, req.VideoURLs)
	if err != nil {
		return nil, err
	}
	defer cleanupConcat(savePaths)

	svcRes, err := service.Concat.Concat(ctx, &service.ConcatReq{
		VideoPaths: savePaths,
		Method:     req.Method,
		Upload:     req.Upload,
	})
	if err != nil {
		return nil, err
	}

	defer os.Remove(svcRes.OutputPath)
	return toDTORes(svcRes), nil
}

// ConcatAsync 视频拼接-异步（URL模式） POST /video/concat/async
func (c *video) ConcatAsync(ctx context.Context, req *dto.ConcatAsyncReq) (res *dto.CreateConcatTaskRes, err error) {
	ctx = withUser(ctx)
	g.Log().Infof(ctx, "[视频拼接-异步] 收到请求 入参: method=%s, upload=%v, callback=%s, video_urls=%v",
		req.Method, req.Upload, req.CallbackURL, req.VideoURLs)

	if req.Method == "" {
		req.Method = "auto"
	}

	taskID, taskErr := service.Concat.CreateAsyncTask(ctx, req.VideoURLs, req.Method, req.Upload, req.CallbackURL)
	if taskErr != nil {
		return nil, taskErr
	}
	return &dto.CreateConcatTaskRes{TaskID: taskID}, nil
}

// ConcatUpload 视频拼接（文件上传模式） POST /video/concat/upload
func (c *video) ConcatUpload(ctx context.Context, req *dto.ConcatUploadReq) (res *dto.ConcatRes, err error) {
	ctx = withUser(ctx)
	g.Log().Infof(ctx, "[视频拼接-上传] 收到请求 入参: method=%s, upload=%v", req.Method, req.Upload)

	savePaths, err := common.SaveUploadedFilesFromCtx(ctx)
	if err != nil || len(savePaths) < 2 {
		return nil, fmt.Errorf("至少需要2个视频，当前%d个", len(savePaths))
	}
	defer service.CleanupConcat(savePaths)

	if req.Method == "" {
		req.Method = "auto"
	}

	svcRes, err := service.Concat.Concat(ctx, &service.ConcatReq{
		VideoPaths: savePaths,
		Method:     req.Method,
		Upload:     req.Upload,
	})
	if err != nil {
		return nil, err
	}

	defer os.Remove(svcRes.OutputPath)
	return toDTORes(svcRes), nil
}

// ConcatUploadAsync 视频拼接-异步（文件上传模式） POST /video/concat/upload/async
func (c *video) ConcatUploadAsync(ctx context.Context, req *dto.ConcatUploadAsyncReq) (res *dto.CreateConcatTaskRes, err error) {
	ctx = withUser(ctx)
	g.Log().Infof(ctx, "[视频拼接-上传-异步] 收到请求 入参: method=%s, upload=%v, callback=%s",
		req.Method, req.Upload, req.CallbackURL)

	savePaths, err := common.SaveUploadedFilesFromCtx(ctx)
	if err != nil || len(savePaths) < 2 {
		return nil, fmt.Errorf("至少需要2个视频，当前%d个", len(savePaths))
	}
	defer service.CleanupConcat(savePaths)

	if req.Method == "" {
		req.Method = "auto"
	}

	taskID, taskErr := service.Concat.CreateAsyncTaskWithFiles(ctx, savePaths, req.Method, req.Upload, req.CallbackURL)
	if taskErr != nil {
		return nil, taskErr
	}
	return &dto.CreateConcatTaskRes{TaskID: taskID}, nil
}

// GetConcatTask 查询异步拼接任务结果 GET /video/concat/task/{taskId}
func (c *video) GetConcatTask(ctx context.Context, req *dto.GetConcatTaskReq) (res *dto.GetConcatTaskRes, err error) {
	ctx = withUser(ctx)
	return service.Concat.GetTaskResult(ctx, req.TaskID)
}

// withUser 优先从请求头/X-User-Info/Token 提取用户信息，没有则用默认 admin
func withUser(ctx context.Context) context.Context {
	if ctx.Value("user") != nil {
		return ctx
	}

	// 调试：打印 Authorization 头
	if req := g.RequestFromCtx(ctx); req != nil {
		g.Log().Debugf(ctx, "[withUser] Authorization头=%q", req.Header.Get("Authorization"))
	}

	user, err := utils.GetUserInfo(ctx)
	if err == nil && user != nil && user.TenantId > 0 {
		g.Log().Infof(ctx, "[用户信息] 从请求头解析到用户: userName=%s, tenantId=%d", user.UserName, user.TenantId)
		ctx = context.WithValue(ctx, "user", user)
		return ctx
	}

	if err != nil {
		g.Log().Debugf(ctx, "[用户信息] 解析失败(%v), 使用默认admin/tenant=1", err)
	}

	ctx = context.WithValue(ctx, "user", &beans.User{UserName: "admin", TenantId: 1})
	return ctx
}

// toDTORes 将 Service 内部响应类型转换为 DTO 响应类型
func toDTORes(svcRes *service.ConcatRes) *dto.ConcatRes {
	return &dto.ConcatRes{
		OutputPath:  svcRes.OutputPath,
		FileSize:    svcRes.FileSize,
		Duration:    svcRes.Duration,
		DurationStr: svcRes.DurationStr,
		MethodUsed:  svcRes.MethodUsed,
		InputFiles:  svcRes.InputFiles,
		FileURL:     svcRes.FileURL,
	}
}

// downloadVideos 下载视频URL列表
func downloadVideos(ctx context.Context, videoURLs []string) ([]string, error) {
	tempDir := getTempDir(ctx)
	os.MkdirAll(tempDir, 0755)

	var savePaths []string
	for _, videoURL := range videoURLs {
		savePath, dlErr := downloadFromURL(ctx, videoURL, tempDir)
		if dlErr != nil {
			continue
		}
		savePaths = append(savePaths, savePath)
	}
	if len(savePaths) < 2 {
		return savePaths, fmt.Errorf("成功下载的视频不足2个")
	}
	return savePaths, nil
}

func downloadFromURL(ctx context.Context, rawURL, tempDir string) (string, error) {
	parsedURL, err := url.Parse(rawURL)
	if err != nil {
		return "", err
	}
	segments := strings.Split(parsedURL.Path, "/")
	fileName := segments[len(segments)-1]
	if fileName == "" {
		fileName = fmt.Sprintf("video_%d.mp4", time.Now().UnixMilli())
	}
	savePath := filepath.Join(tempDir, fmt.Sprintf("%d_%s", time.Now().UnixMilli(), fileName))

	client := &http.Client{Timeout: 10 * time.Minute}
	resp, err := client.Get(rawURL)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return "", fmt.Errorf("HTTP %d", resp.StatusCode)
	}

	out, err := os.Create(savePath)
	if err != nil {
		return "", err
	}
	defer out.Close()

	_, err = io.Copy(out, resp.Body)
	if err != nil {
		os.Remove(savePath)
	}
	return savePath, err
}

func cleanupConcat(paths []string) {
	for _, p := range paths {
		os.Remove(p)
	}
}

func getTempDir(ctx context.Context) string {
	tempDir := g.Cfg().MustGet(ctx, "ffmpeg.temp_dir", "resource/temp").String()
	if tempDir == "" {
		tempDir = "resource/temp"
	}
	if !filepath.IsAbs(tempDir) {
		absDir, _ := filepath.Abs(tempDir)
		tempDir = absDir
	}
	return tempDir
}