import { getPermissionsAsync, requestPermissionsAsync, createAssetAsync, getAlbumAsync, createAlbumAsync, addAssetsToAlbumAsync } from 'expo-media-library';

const ALBUM_NAME = 'Schnappix';

/**
 * Request necessary media library permissions.
 * @returns Promise<boolean> True if permissions are granted.
 */
export async function requestStoragePermission(): Promise<boolean> {
  const { status, canAskAgain } = await getPermissionsAsync();
  if (status === 'granted') {
    return true;
  }
  
  if (canAskAgain) {
    const { status: newStatus } = await requestPermissionsAsync();
    return newStatus === 'granted';
  }
  
  return false;
}

/**
 * Saves a local image file directly to the public DCIM gallery inside the "Schnappix" album.
 * 
 * @param localUri The local file URI of the image (temp cached file).
 * @returns Promise<string> The permanent URI of the saved asset in the gallery.
 */
export async function saveToGallery(localUri: string): Promise<string> {
  const hasPermission = await requestStoragePermission();
  if (!hasPermission) {
    throw new Error('Storage permission not granted. Cannot save photo to gallery.');
  }

  // 1. Create a media asset from the local file
  const asset = await createAssetAsync(localUri);
  
  try {
    // 2. Check if the "Schnappix" album already exists
    const album = await getAlbumAsync(ALBUM_NAME);
    
    if (!album) {
      // 3. If it doesn't exist, create it with our asset
      await createAlbumAsync(ALBUM_NAME, asset, false);
      console.log(`Created new album "${ALBUM_NAME}" and saved photo.`);
    } else {
      // 4. If it exists, add our asset to it
      await addAssetsToAlbumAsync([asset], album, false);
      console.log(`Saved photo to existing album "${ALBUM_NAME}".`);
    }
    
    return asset.uri;
  } catch (e: any) {
    console.error('Error saving asset to album, returning fallback asset URI:', e);
    try {
      return asset.uri;
    } catch {
      return asset.id;
    }
  }
}