package data

import (
	"context"
	"fmt"
	"time"

	"github.com/go-kratos/kratos/v2/log"
)

// FileMetaRepo implements file metadata persistence operations using GORM.
type FileMetaRepo struct {
	data *Data
	log  *log.Helper
}

// NewFileMetaRepo creates a new FileMetaRepo.
func NewFileMetaRepo(data *Data, logger log.Logger) *FileMetaRepo {
	return &FileMetaRepo{
		data: data,
		log:  log.NewHelper(logger),
	}
}

// Create inserts a new file metadata record.
func (r *FileMetaRepo) Create(ctx context.Context, file *FileMetaPO) error {
	return r.data.DB(ctx).Create(file).Error
}

// GetByID retrieves file metadata by ID. Returns nil if not found.
func (r *FileMetaRepo) GetByID(ctx context.Context, id string) (*FileMetaPO, error) {
	var file FileMetaPO
	err := r.data.DB(ctx).Where("id = ?", id).First(&file).Error
	if err != nil {
		if isRecordNotFound(err) {
			return nil, nil
		}
		return nil, fmt.Errorf("failed to get file meta: %w", err)
	}
	return &file, nil
}

// GetByFolder retrieves all files in a folder, ordered by name.
func (r *FileMetaRepo) GetByFolder(ctx context.Context, folderID string) ([]FileMetaPO, error) {
	var files []FileMetaPO
	err := r.data.DB(ctx).
		Where("folder_id = ?", folderID).
		Order("name").
		Find(&files).Error
	if err != nil {
		return nil, fmt.Errorf("failed to get files by folder: %w", err)
	}
	return files, nil
}

// Move updates the folder_id of a file (moves it to another folder).
func (r *FileMetaRepo) Move(ctx context.Context, fileID string, targetFolderID string, ownerID string) error {
	result := r.data.DB(ctx).Model(&FileMetaPO{}).
		Where("id = ? AND owner_id = ?", fileID, ownerID).
		Updates(map[string]interface{}{
			"folder_id":   targetFolderID,
			"updated_at":  gormNow(),
		})
	if result.Error != nil {
		return fmt.Errorf("failed to move file: %w", result.Error)
	}
	if result.RowsAffected == 0 {
		return fmt.Errorf("file not found or not owned by user")
	}
	return nil
}

// Delete removes a file metadata record by ID and ownerID.
func (r *FileMetaRepo) Delete(ctx context.Context, id string, ownerID string) error {
	result := r.data.DB(ctx).
		Where("id = ? AND owner_id = ?", id, ownerID).
		Delete(&FileMetaPO{})
	if result.Error != nil {
		return fmt.Errorf("failed to delete file meta: %w", result.Error)
	}
	if result.RowsAffected == 0 {
		return fmt.Errorf("file not found or not owned by user")
	}
	return nil
}

// gormNow returns the current UTC time for use in GORM updates.
func gormNow() time.Time {
	return time.Now().UTC()
}