import { createWasmCodec } from "./wasm-base.js";

function webmMagic(bytes: Uint8Array): boolean {
    // EBML header: 0x1A 0x45 0xDF 0xA3
    if (bytes.byteLength < 4) return false;
    return (
        bytes[0] === 0x1a &&
        bytes[1] === 0x45 &&
        bytes[2] === 0xdf &&
        bytes[3] === 0xa3
    );
}

/** Lazy WebM (audio track) codec backed by `@audio/decode-webm`. Decode-only. */
export const WebMCodec = createWasmCodec({
    name: "webm",
    extensions: ["webm"],
    mimeTypes: ["audio/webm"],
    module: "@audio/decode-webm",
    magic: webmMagic,
    supportsEncode: false,
    load: () =>
        // @ts-expect-error optional dependency resolved at runtime
        import("@audio/decode-webm"),
});