first commit

docs/ui/react/react-audio-fingerprint/src/hooks/use-audio-fingerprint/use-audio-fingerprint.md

@@ -0,0 +1,71 @@
+# `useAudioFingerprint` — React hook for the fingerprint pipeline
+
+<!-- begin:auto-docs -->
+_(no submodules)_
+<!-- end:auto-docs -->
+
+## Purpose
+
+`useAudioFingerprint(source, options?)` drives a `FingerprintBackend` off a
+React-managed `AudioDocument` and returns the live state, the resulting
+fingerprint when done, a `0..1` progress fraction, and any error encountered.
+The hook centralises the abort-on-unmount and progress wiring so component
+authors do not have to repeat that work across uploaders, visualisers, and
+match displays.
+
+## Features
+
+- `source` can be `undefined`/`null` to mean "do nothing" — useful while
+  waiting for an upload to decode.
+- `state` cycles through `'idle'` → `'fingerprinting'` → `'done'` (or
+  `'error'`); a fresh source resets the cycle.
+- Abort-on-unmount and abort-on-source-change via internal `AbortController`.
+- Backend swap via `options.backend`; defaults to `LocalBackend`.
+- Wraps non-`ReactAudioFingerprintError` rejections in `FINGERPRINT_FAILED`.
+- Suppresses `ABORTED` errors — they settle back to `'idle'`.
+
+## Usage: Basic Example
+
+```tsx
+import { useAudioFingerprint } from "@suaveplan/react-audio-fingerprint/hooks/use-audio-fingerprint";
+
+function FingerprintPreview({ doc }: { doc: AudioDocument }) {
+    const { state, fingerprint, progress } = useAudioFingerprint(doc);
+    if (state === "fingerprinting") return <progress value={progress} />;
+    if (state === "done") return <span>{fingerprint?.length} pairs</span>;
+    return null;
+}
+```
+
+## Usage: Advanced Example
+
+Inject a custom backend (e.g. the optional Python backend) and surface errors:
+
+```tsx
+import { useAudioFingerprint } from "@suaveplan/react-audio-fingerprint/hooks/use-audio-fingerprint";
+
+function Surface({ doc, backend }: { doc: AudioDocument; backend: FingerprintBackend }) {
+    const { state, error, fingerprint } = useAudioFingerprint(doc, { backend });
+    if (state === "error") return <Banner code={error?.code}>{error?.message}</Banner>;
+    if (state === "done") return <Result fp={fingerprint!} />;
+    return <Spinner />;
+}
+```
+
+## API Reference
+
+- `useAudioFingerprint(source, options?): UseAudioFingerprintResult`.
+- `source: AudioDocument | undefined | null`.
+- `options?: { backend?: FingerprintBackend }`.
+- `UseAudioFingerprintResult = { state, fingerprint, progress, error }`.
+- `state: 'idle' | 'fingerprinting' | 'done' | 'error'`.
+
+## Implementation Notes
+
+The hook uses `useMemo` to stabilise the default `LocalBackend` so changing
+unrelated props does not retrigger the effect. The `alive` flag guarding all
+post-await `setState` calls is the canonical React pattern for protecting
+against the lifecycle race between an async fetch completing and a fast
+unmount. Aborts settle to `'idle'` (not `'error'`) so user-driven cancels do
+not produce a banner. Non-Suaveplan errors get wrapped so consumers can always
+discriminate via `error.code` without an `instanceof` chain.