import { useState, useCallback, useRef } from "react";
import {
  ExpoSpeechRecognitionModule,
  useSpeechRecognitionEvent,
} from "expo-speech-recognition";

export type VoiceState = "idle" | "listening" | "processing" | "error";

export function useVoice() {
  const [state, setState] = useState<VoiceState>("idle");
  const [transcript, setTranscript] = useState("");
  const [error, setError] = useState<string | null>(null);

  useSpeechRecognitionEvent("start", () => setState("listening"));

  useSpeechRecognitionEvent("end", () => {
    setState((s) => (s === "listening" ? "processing" : s));
  });

  useSpeechRecognitionEvent("result", (event) => {
    const best = event.results[0]?.transcript ?? "";
    setTranscript(best);
    if (event.isFinal) setState("idle");
  });

  useSpeechRecognitionEvent("error", (event) => {
    setError(event.error ?? "Voice recognition failed");
    setState("error");
  });

  const start = useCallback(async (lang = "fr-FR") => {
    setError(null);
    setTranscript("");
    const { granted } =
      await ExpoSpeechRecognitionModule.requestPermissionsAsync();
    if (!granted) {
      setError("Microphone permission denied");
      setState("error");
      return;
    }
    ExpoSpeechRecognitionModule.start({ lang, interimResults: true });
  }, []);

  const stop = useCallback(() => {
    ExpoSpeechRecognitionModule.stop();
  }, []);

  const reset = useCallback(() => {
    setTranscript("");
    setError(null);
    setState("idle");
  }, []);

  return { state, transcript, error, start, stop, reset };
}