/**
 * AudioWorklet processor for VoicePaste.
 *
 * Captures raw Float32 PCM from the microphone, accumulates samples into
 * ~200ms frames, and posts them to the main thread for resampling + WS send.
 *
 * Communication:
 *   Main → Processor: { command: "start" | "stop" }
 *   Processor → Main: { type: "audio", samples: Float32Array, sampleRate: number }
 */

// AudioWorkletGlobalScope globals (not in standard lib)
declare const sampleRate: number;
declare class AudioWorkletProcessor {
	readonly port: MessagePort;
	constructor();
	process(
		inputs: Float32Array[][],
		outputs: Float32Array[][],
		parameters: Record<string, Float32Array>,
	): boolean;
}
declare function registerProcessor(
	name: string,
	ctor: new () => AudioWorkletProcessor,
): void;

class VoicePasteProcessor extends AudioWorkletProcessor {
	private recording = false;
	private buffer: Float32Array[] = [];
	private bufferLen = 0;
	private readonly frameSize: number;

	constructor() {
		super();
		// ~200ms worth of samples at current sample rate
		this.frameSize = Math.floor(sampleRate * 0.2);

		this.port.onmessage = (e: MessageEvent) => {
			if (e.data.command === "start") {
				this.recording = true;
				this.buffer = [];
				this.bufferLen = 0;
			} else if (e.data.command === "stop") {
				if (this.bufferLen > 0) {
					this.flush();
				}
				this.recording = false;
			}
		};
	}

	process(inputs: Float32Array[][]): boolean {
		if (!this.recording) return true;

		const input = inputs[0];
		if (!input || !input[0]) return true;

		const channelData = input[0];
		this.buffer.push(new Float32Array(channelData));
		this.bufferLen += channelData.length;

		if (this.bufferLen >= this.frameSize) {
			this.flush();
		}

		return true;
	}

	private flush(): void {
		const merged = new Float32Array(this.bufferLen);
		let offset = 0;
		for (const chunk of this.buffer) {
			merged.set(chunk, offset);
			offset += chunk.length;
		}

		this.port.postMessage(
			{ type: "audio", samples: merged, sampleRate: sampleRate },
			[merged.buffer],
		);

		this.buffer = [];
		this.bufferLen = 0;
	}
}

registerProcessor("audio-processor", VoicePasteProcessor);