import { useState, useEffect, useRef, useCallback } from 'react';
import { Platform } from 'react-native';

export interface UseSpeechRecognitionReturn {
    isListening: boolean;
    recognizedText: string;
    startListening: (options?: { continuous?: boolean }) => Promise<void>;
    stopListening: () => void;
    isAvailable: boolean;
    hasPermission: boolean;
    requestPermission: () => Promise<boolean>;
}

export function useSpeechRecognition(): UseSpeechRecognitionReturn {
    const [isListening, setIsListening] = useState(false);
    const [recognizedText, setRecognizedText] = useState('');
    const [isAvailable, setIsAvailable] = useState(false);

    const recognitionRef = useRef<any>(null);

    useEffect(() => {
        if (typeof window !== 'undefined') {
            const SpeechRecognition = (window as any).SpeechRecognition || (window as any).webkitSpeechRecognition;
            if (SpeechRecognition) {
                setIsAvailable(true);
                const recognition = new SpeechRecognition();
                recognition.continuous = false; // Default
                recognition.interimResults = true;
                recognition.lang = 'en-US';

                recognition.onstart = () => {
                    setIsListening(true);
                };

                recognition.onend = () => {
                    setIsListening(false);
                };

                recognition.onresult = (event: any) => {
                    const transcript = Array.from(event.results)
                        .map((result: any) => result[0])
                        .map((result: any) => result.transcript)
                        .join('');

                    setRecognizedText(transcript);
                };

                recognition.onerror = (event: any) => {
                    setIsListening(false);
                };

                recognitionRef.current = recognition;
            }
        }
    }, []);

    const requestPermission = async () => {
        // Web API usually requests permission on start(), but we can return true if available
        return isAvailable;
    };

    const startListening = async (options?: { continuous?: boolean }) => {
        if (!recognitionRef.current) return;

        try {
            recognitionRef.current.continuous = options?.continuous ?? false;
            setRecognizedText('');
            recognitionRef.current.start();
        } catch (e) {
            setIsListening(false);
        }
    };

    const stopListening = () => {
        if (recognitionRef.current) {
            recognitionRef.current.stop();
        }
    };

    return {
        isListening,
        recognizedText,
        startListening,
        stopListening,
        isAvailable,
        hasPermission: isAvailable, // Assume permission handled by browser
        requestPermission
    };
}