添加视频帧提取功能和阿里云OSS存储支持

- 新增从视频素材提取首帧/尾帧的功能，支持画面连续性编辑
- 添加阿里云OSS存储支持，可配置本地或OSS存储方式
- 导入视频素材时自动探测并更新视频时长信息
- 前端添加从素材提取尾帧的UI界面
- 添加FramePrompt模型的数据库迁移

Co-Authored-By: Claude <noreply@anthropic.com>

application/services/asset_service.go

@@ -2,27 +2,48 @@ package services
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
 	models "github.com/drama-generator/backend/domain/models"
 	"github.com/drama-generator/backend/infrastructure/external/ffmpeg"
+	"github.com/drama-generator/backend/infrastructure/storage"
+	"github.com/drama-generator/backend/pkg/config"
 	"github.com/drama-generator/backend/pkg/logger"
 	"gorm.io/gorm"
 )
 
 type AssetService struct {
-	db     *gorm.DB
-	log    *logger.Logger
-	ffmpeg *ffmpeg.FFmpeg
+	db         *gorm.DB
+	log        *logger.Logger
+	ffmpeg     *ffmpeg.FFmpeg
+	cfg        *config.Config
+	ossStorage *storage.OssStorage
 }
 
-func NewAssetService(db *gorm.DB, log *logger.Logger) *AssetService {
-	return &AssetService{
+func NewAssetService(db *gorm.DB, log *logger.Logger, cfg ...*config.Config) *AssetService {
+	service := &AssetService{
 		db:     db,
 		log:    log,
 		ffmpeg: ffmpeg.NewFFmpeg(log),
 	}
+	if len(cfg) > 0 {
+		service.cfg = cfg[0]
+		// 如果配置了 OSS，初始化 OSS 存储
+		if cfg[0].Storage.Type == "oss" && storage.IsOssConfigured(&cfg[0].Storage.Oss) {
+			ossStorage, err := storage.NewOssStorage(&cfg[0].Storage.Oss)
+			if err != nil {
+				log.Warnw("Failed to initialize OSS storage, falling back to local", "error", err)
+			} else {
+				service.ossStorage = ossStorage
+				log.Infow("OSS storage initialized", "bucket", cfg[0].Storage.Oss.BucketName)
+			}
+		}
+	}
+	return service
 }
 
 type CreateAssetRequest struct {
@@ -264,6 +285,23 @@ func (s *AssetService) ImportFromVideoGen(videoGenID uint) (*models.Asset, error
 		storyboardNum = &videoGen.Storyboard.StoryboardNumber
 	}
 
+	// 如果 duration 为空，尝试使用 FFmpeg 探测
+	duration := videoGen.Duration
+	if duration == nil || *duration == 0 {
+		s.log.Infow("Duration is empty, probing video duration", "video_gen_id", videoGenID)
+		probedDuration, err := s.ffmpeg.GetVideoDuration(*videoGen.VideoURL)
+		if err == nil && probedDuration > 0 {
+			durationInt := int(probedDuration + 0.5) // 四舍五入
+			duration = &durationInt
+			s.log.Infow("Probed video duration", "video_gen_id", videoGenID, "duration", durationInt)
+
+			// 同时更新 VideoGeneration 表
+			s.db.Model(&videoGen).Update("duration", durationInt)
+		} else {
+			s.log.Warnw("Failed to probe video duration", "video_gen_id", videoGenID, "error", err)
+		}
+	}
+
 	asset := &models.Asset{
 		Name:          fmt.Sprintf("Video_%d", videoGen.ID),
 		Type:          models.AssetTypeVideo,
@@ -273,7 +311,7 @@ func (s *AssetService) ImportFromVideoGen(videoGenID uint) (*models.Asset, error
 		StoryboardID:  videoGen.StoryboardID,
 		StoryboardNum: storyboardNum,
 		VideoGenID:    &videoGenID,
-		Duration:      videoGen.Duration,
+		Duration:      duration,
 		Width:         videoGen.Width,
 		Height:        videoGen.Height,
 	}
@@ -283,8 +321,125 @@ func (s *AssetService) ImportFromVideoGen(videoGenID uint) (*models.Asset, error
 	}
 
 	if err := s.db.Create(asset).Error; err != nil {
-		return nil, fmt.Errorf("failed to create asset: %w", err)
+		return nil, fmt.Errorf("failed to create asset: %w\n", err)
 	}
 
 	return asset, nil
 }
+
+// ExtractFrameRequest 视频帧提取请求
+type ExtractFrameRequest struct {
+	Position     string `json:"position"`      // "first" 或 "last"
+	StoryboardID uint   `json:"storyboard_id"` // 关联的分镜 ID
+	FrameType    string `json:"frame_type"`    // image_generations 的帧类型，默认 "first"
+}
+
+// ExtractFrameFromAsset 从视频素材中提取帧并保存到 image_generations 表
+func (s *AssetService) ExtractFrameFromAsset(assetID uint, req *ExtractFrameRequest) (*models.ImageGeneration, error) {
+	// 获取素材
+	var asset models.Asset
+	if err := s.db.First(&asset, assetID).Error; err != nil {
+		return nil, fmt.Errorf("asset not found: %w", err)
+	}
+
+	// 验证是否为视频素材
+	if asset.Type != models.AssetTypeVideo {
+		return nil, fmt.Errorf("asset is not a video")
+	}
+
+	// 默认值
+	position := req.Position
+	if position == "" {
+		position = "last"
+	}
+	frameType := req.FrameType
+	if frameType == "" {
+		frameType = "first" // 提取的尾帧用作下一个分镜的首帧
+	}
+
+	// 生成唯一文件名
+	timestamp := time.Now().Format("20060102_150405")
+	fileName := fmt.Sprintf("frame_%s_%d_%s.jpg", position, assetID, timestamp)
+
+	// 创建临时目录
+	tmpDir := "./data/tmp"
+	if err := os.MkdirAll(tmpDir, 0755); err != nil {
+		return nil, fmt.Errorf("failed to create temp directory: %w", err)
+	}
+	outputPath := filepath.Join(tmpDir, fileName)
+
+	// 使用 FFmpeg 提取帧
+	_, err := s.ffmpeg.ExtractFrame(asset.URL, outputPath, position)
+	if err != nil {
+		return nil, fmt.Errorf("failed to extract frame: %w", err)
+	}
+
+	var imageURL string
+
+	// 根据存储类型上传
+	if s.ossStorage != nil {
+		// 上传到 OSS
+		url, err := s.ossStorage.UploadWithFilename(outputPath, "extracted_frames", fileName)
+		if err != nil {
+			s.log.Errorw("Failed to upload to OSS, falling back to local", "error", err)
+		} else {
+			imageURL = url
+			s.log.Infow("Frame uploaded to OSS", "url", url)
+			// 删除临时文件
+			os.Remove(outputPath)
+		}
+	}
+
+	// 如果 OSS 上传失败或未配置，使用本地存储
+	if imageURL == "" {
+		localPath := "./data/storage"
+		baseURL := "/static"
+		if s.cfg != nil && s.cfg.Storage.LocalPath != "" {
+			localPath = s.cfg.Storage.LocalPath
+		}
+		if s.cfg != nil && s.cfg.Storage.BaseURL != "" {
+			baseURL = s.cfg.Storage.BaseURL
+		}
+
+		// 移动文件到最终位置
+		finalDir := filepath.Join(localPath, "extracted_frames")
+		if err := os.MkdirAll(finalDir, 0755); err != nil {
+			return nil, fmt.Errorf("failed to create output directory: %w", err)
+		}
+		finalPath := filepath.Join(finalDir, fileName)
+		if err := os.Rename(outputPath, finalPath); err != nil {
+			return nil, fmt.Errorf("failed to move file: %w", err)
+		}
+
+		imageURL = fmt.Sprintf("%s/extracted_frames/%s", baseURL, fileName)
+	}
+
+	// 获取 DramaID
+	var dramaID uint
+	if asset.DramaID != nil {
+		dramaID = *asset.DramaID
+	}
+
+	// 创建 image_generation 记录
+	imageGen := &models.ImageGeneration{
+		DramaID:      dramaID,
+		StoryboardID: &req.StoryboardID,
+		Prompt:       fmt.Sprintf("Extracted %s frame from video asset #%d", position, assetID),
+		Status:       models.ImageStatusCompleted,
+		ImageURL:     &imageURL,
+		FrameType:    &frameType,
+	}
+
+	if err := s.db.Create(imageGen).Error; err != nil {
+		return nil, fmt.Errorf("failed to create image generation record: %w", err)
+	}
+
+	s.log.Infow("Frame extracted and saved",
+		"asset_id", assetID,
+		"position", position,
+		"image_gen_id", imageGen.ID,
+		"frame_type", frameType,
+		"image_url", imageURL)
+
+	return imageGen, nil
+}