基本功能实现

internal/service/image/image_service.go

@@ -0,0 +1,92 @@
+package image
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"BingDailyImage/internal/config"
+	"BingDailyImage/internal/model"
+	"BingDailyImage/internal/repo"
+	"BingDailyImage/internal/storage"
+	"BingDailyImage/internal/util"
+
+	"go.uber.org/zap"
+)
+
+func CleanupOldImages(ctx context.Context) error {
+	days := config.GetConfig().Retention.Days
+	if days <= 0 {
+		return nil
+	}
+
+	threshold := time.Now().AddDate(0, 0, -days).Format("2006-01-02")
+	util.Logger.Info("Starting cleanup task", zap.Int("retention_days", days), zap.String("threshold", threshold))
+
+	var images []model.Image
+	if err := repo.DB.Where("date < ?", threshold).Preload("Variants").Find(&images).Error; err != nil {
+		return err
+	}
+
+	for _, img := range images {
+		util.Logger.Info("Deleting old image", zap.String("date", img.Date))
+		for _, v := range img.Variants {
+			if err := storage.GlobalStorage.Delete(ctx, v.StorageKey); err != nil {
+				util.Logger.Warn("Failed to delete storage object", zap.String("key", v.StorageKey), zap.Error(err))
+			}
+		}
+		// 删除 DB 记录 (级联删除由代码处理，或者 GORM 会处理已加载的关联吗？)
+		// 简单起见，手动删除关联
+		repo.DB.Where("image_id = ?", img.ID).Delete(&model.ImageVariant{})
+		repo.DB.Delete(&img)
+	}
+
+	util.Logger.Info("Cleanup task completed", zap.Int("deleted_count", len(images)))
+	return nil
+}
+
+func GetTodayImage() (*model.Image, error) {
+	today := time.Now().Format("2006-01-02")
+	var img model.Image
+	err := repo.DB.Where("date = ?", today).Preload("Variants").First(&img).Error
+	if err != nil {
+		// 如果今天没有，尝试获取最近的一张
+		err = repo.DB.Order("date desc").Preload("Variants").First(&img).Error
+	}
+	return &img, err
+}
+
+func GetRandomImage() (*model.Image, error) {
+	var img model.Image
+	// SQLite 使用 RANDOM(), MySQL/Postgres 使用 RANDOM() 或 RAND()
+	// 简单起见，先查总数再 Offset
+	var count int64
+	repo.DB.Model(&model.Image{}).Count(&count)
+	if count == 0 {
+		return nil, fmt.Errorf("no images found")
+	}
+
+	// 这种方法不适合海量数据，但对于 30 天的数据没问题
+	err := repo.DB.Order("RANDOM()").Preload("Variants").First(&img).Error
+	if err != nil {
+		// 适配 MySQL
+		err = repo.DB.Order("RAND()").Preload("Variants").First(&img).Error
+	}
+	return &img, err
+}
+
+func GetImageByDate(date string) (*model.Image, error) {
+	var img model.Image
+	err := repo.DB.Where("date = ?", date).Preload("Variants").First(&img).Error
+	return &img, err
+}
+
+func GetImageList(limit int) ([]model.Image, error) {
+	var images []model.Image
+	db := repo.DB.Order("date desc").Preload("Variants")
+	if limit > 0 {
+		db = db.Limit(limit)
+	}
+	err := db.Find(&images).Error
+	return images, err
+}