import type { DrizzleDb } from "../db-connection.js";
import { getSqliteFrom } from "../db-connection.js";

/**
 * Backfill MIME types for audio attachments that were stored with
 * "application/octet-stream" because the EXTENSION_MIME_MAP was
 * missing audio format entries.
 *
 * Updates mime_type based on the file extension in original_filename.
 */

const AUDIO_EXT_MIME: Record<string, string> = {
  mp3: "audio/mpeg",
  wav: "audio/wav",
  ogg: "audio/ogg",
  flac: "audio/flac",
  aac: "audio/aac",
  m4a: "audio/x-m4a",
  opus: "audio/opus",
};

export function migrateBackfillAudioAttachmentMimeTypes(
  database: DrizzleDb,
): void {
  const raw = getSqliteFrom(database);

  for (const [ext, mime] of Object.entries(AUDIO_EXT_MIME)) {
    const pattern = `%.${ext}`;
    const result = raw
      .query(
        `UPDATE attachments
         SET mime_type = ?, kind = 'document'
         WHERE lower(original_filename) LIKE ?
           AND mime_type = 'application/octet-stream'`,
      )
      .run(mime, pattern);

    if ((result as { changes?: number }).changes) {
      console.log(
        `Backfilled ${(result as { changes: number }).changes} .${ext} attachments → ${mime}`,
      );
    }
  }
}

/**
 * Reverse: no-op.
 *
 * The forward migration corrected incorrect MIME types (application/octet-stream)
 * to their proper audio/* values. Restoring the wrong MIME types would break
 * audio playback and file handling. The corrected values are the desired state.
 */
export function migrateBackfillAudioAttachmentMimeTypesDown(
  _database: DrizzleDb,
): void {
  // No-op — see comment above.
}