@doot-games/library

The song store. Songs persist in IndexedDB so the app works offline with no server. A record keeps the original audio Blob plus the generated charts. AudioBuffers are not serializable, so the app re-decodes the blob on play.

Record shape

{ id, title, artist, bpm, offset, source, createdAt, duration,
  audio: Blob, charts: { [difficulty]: chart } }

API

createLibrary({ indexedDB?, dbName? }) returns a store.

• list(), get(id), put(record), remove(id), clear() the core operations.
• onChange(fn) subscribe to writes. Returns an unsubscribe function.
• exportFile() returns a Blob for a single portable .ddr backup. importFile(file) restores one.
• chooseFolder(), exportToFolder(), importFromFolder(), haveFolder(), canFolder optional File System Access sync where supported.

The store depends on nothing else in the workspace and can be reused wherever a blob-backed keyed record store is useful.