/**
 * Shared Blob Storage utilities.
 *
 * Delegates to @bytelyst/storage for provider-agnostic blob operations.
 * Keeps the same exported API surface for backward compatibility.
 *
 * Expected env vars:
 *   STORAGE_PROVIDER — 'azure' (default) | 'memory'
 *   AZURE_BLOB_CONNECTION_STRING — full connection string (preferred, when provider=azure)
 *   — OR —
 *   AZURE_BLOB_ACCOUNT_NAME + AZURE_BLOB_ACCOUNT_KEY
 */

import {
  getStorage,
  _resetStorage,
  type StorageProvider,
  type StorageBucket,
} from '@bytelyst/storage';

/**
 * Known blob containers and their purposes.
 *
 * Note: This is a convenience list (not enforced). Products can add their own
 * containers as needed.
 */
export const BLOB_CONTAINERS = {
  audio: 'audio', // Dictation audio recordings
  transcripts: 'transcripts', // Exported transcript files (PDF, DOCX, TXT)
  attachments: 'attachments', // Tracker item attachments (screenshots, docs)
  avatars: 'avatars', // User profile images
  releases: 'releases', // Desktop app update binaries
  backups: 'backups', // Cosmos DB JSON backups
  feedbackScreenshots: 'feedback-screenshots', // User feedback screenshot attachments
} as const;

export type BlobContainerName = (typeof BLOB_CONTAINERS)[keyof typeof BLOB_CONTAINERS];

/**
 * Get the storage provider singleton.
 */
export async function getStorageProvider(): Promise<StorageProvider> {
  return getStorage();
}

/**
 * Get a bucket (container) by name.
 */
export async function getBucket(containerName: string): Promise<StorageBucket> {
  const storage = await getStorage();
  return storage.getBucket(containerName);
}

/**
 * Generate a signed URL for direct browser upload (or download).
 *
 * @param containerName - Target container
 * @param blobName - Full blob path (e.g., "product/user123/audio/recording.wav")
 * @param permissions - SAS permissions (default: read)
 * @param expiresInMinutes - Token lifetime (default: 60)
 * @returns Full signed URL for the blob
 */
export async function generateSasUrl(
  containerName: string,
  blobName: string,
  permissions: 'r' | 'w' | 'rw' | 'rwc' | 'rwd' = 'r',
  expiresInMinutes = 60
): Promise<string> {
  const bucket = await getBucket(containerName);
  const perm = permissions.includes('w') ? ('write' as const) : ('read' as const);
  return bucket.getSignedUrl(blobName, {
    permissions: perm,
    expiresIn: expiresInMinutes * 60,
  });
}

/**
 * Check if blob storage is configured.
 */
export function isBlobStorageConfigured(): boolean {
  const provider = process.env.STORAGE_PROVIDER || 'azure';
  if (provider === 'memory') return true;
  return !!(
    process.env.AZURE_BLOB_CONNECTION_STRING ||
    (process.env.AZURE_BLOB_ACCOUNT_NAME && process.env.AZURE_BLOB_ACCOUNT_KEY)
  );
}

/**
 * Test helper: reset module singletons/caches.
 */
export function _resetBlobClient(): void {
  _resetStorage();
}