import React, { useState, useEffect, useCallback } from 'react';
import SunCalc from 'suncalc';
import { SunClockIcon, AlertTriangleIcon } from '../components/icons';

type PermissionStatus = 'idle' | 'prompting' | 'granted' | 'denied';

const SunTrackerView: React.FC = () => {
    const [permission, setPermission] = useState<PermissionStatus>('idle');
    const [sunData, setSunData] = useState<any>(null);
    const [compassHeading, setCompassHeading] = useState<number>(0);
    const [error, setError] = useState<string>('');

    const handleOrientation = (event: DeviceOrientationEvent) => {
        // webkitCompassHeading is for iOS
        const heading = (event as any).webkitCompassHeading || (360 - event.alpha!);
        setCompassHeading(heading);
    };

    const requestPermissions = useCallback(async () => {
        setPermission('prompting');

        // Geolocation
        if (!("geolocation" in navigator)) {
            setError("Geolocation is not supported by your browser.");
            setPermission('denied');
            return;
        }

        navigator.geolocation.getCurrentPosition(
            (position) => {
                const { latitude, longitude } = position.coords;
                const now = new Date();
                const times = SunCalc.getTimes(now, latitude, longitude);
                const pos = SunCalc.getPosition(now, latitude, longitude);
                setSunData({ ...times, ...pos });

                // Device Orientation (Compass)
                if (typeof (DeviceOrientationEvent as any).requestPermission === 'function') {
                    (DeviceOrientationEvent as any).requestPermission()
                        .then((response: string) => {
                            if (response === 'granted') {
                                window.addEventListener('deviceorientation', handleOrientation);
                                setPermission('granted');
                            } else {
                                setError("Compass permission denied.");
                                setPermission('denied');
                            }
                        });
                } else {
                     window.addEventListener('deviceorientation', handleOrientation);
                     setPermission('granted');
                }
            },
            (error) => {
                setError("Geolocation permission denied. Please enable it in your browser settings.");
                setPermission('denied');
            }
        );
    }, []);

    useEffect(() => {
        return () => {
            window.removeEventListener('deviceorientation', handleOrientation);
        };
    }, []);

    const renderCompass = () => (
        <div className="relative w-48 h-48 mx-auto">
            <div className="w-full h-full rounded-full bg-stone-100 border-4 border-stone-200 flex items-center justify-center">
                <div className="absolute top-0 w-px h-full bg-stone-300"></div>
                <div className="absolute left-0 h-px w-full bg-stone-300"></div>
                <span className="absolute top-1 text-lg font-bold text-red-600">N</span>
                <span className="absolute bottom-1 text-lg font-bold text-stone-600">S</span>
                <span className="absolute left-2 text-lg font-bold text-stone-600">W</span>
                <span className="absolute right-2 text-lg font-bold text-stone-600">E</span>
            </div>
            {sunData && (
                <div className="absolute inset-0 flex items-center justify-center transform" style={{ transform: `rotate(${-compassHeading}deg)` }}>
                    <div className="w-8 h-8 bg-yellow-400 rounded-full shadow-lg"
                        style={{ transform: `rotate(${sunData.azimuth * 180 / Math.PI}deg) translateY(-50px) rotate(${-sunData.azimuth * 180 / Math.PI}deg) `}}
                        title={`Sun Position: Azimuth ${ (sunData.azimuth * 180 / Math.PI + 180).toFixed(0) }°`}
                        />
                </div>
            )}
             <div className="absolute inset-0 flex items-center justify-center transform transition-transform duration-500" style={{ transform: `rotate(${compassHeading}deg)` }}>
                <div className="w-0 h-0 border-l-8 border-l-transparent border-r-8 border-r-transparent border-b-16 border-b-red-600 transform -translate-y-12"></div>
            </div>
        </div>
    );
    
    const renderSunPath = () => {
        if (!sunData) return null;
        const now = new Date();
        const totalDaylight = sunData.sunset.getTime() - sunData.sunrise.getTime();
        const fromSunrise = now.getTime() - sunData.sunrise.getTime();
        const percentOfDay = Math.max(0, Math.min(1, fromSunrise / totalDaylight));

        return (
            <div className="relative h-24 w-full">
                <svg viewBox="0 0 200 100" className="w-full h-full">
                    <path d="M 10 90 A 90 90 0 0 1 190 90" stroke="#d6d3d1" strokeWidth="4" fill="none" />
                    {percentOfDay > 0 && percentOfDay < 1 && (
                         <circle 
                            cx={10 + percentOfDay * 180} 
                            cy={90 - Math.sin(percentOfDay * Math.PI) * 80}
                            r="8"
                            fill="#facc15"
                            stroke="#ca8a04"
                            strokeWidth="2"
                        />
                    )}
                </svg>
                <div className="absolute top-full w-full flex justify-between text-xs font-semibold text-stone-600">
                    <span>{sunData.sunrise.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}</span>
                    <span>{sunData.sunset.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}</span>
                </div>
            </div>
        );
    }
    
    return (
        <div className="space-y-8 max-w-2xl mx-auto">
            <header className="text-center">
                <h2 className="text-3xl font-bold tracking-tight text-stone-900 sm:text-4xl flex items-center justify-center gap-3">
                    <SunClockIcon className="w-8 h-8 text-yellow-500" />
                    Sun Tracker
                </h2>
                <p className="mt-4 text-lg leading-8 text-stone-600">
                    Find the optimal light for your trees. Use this tool to see the sun's path and current position.
                </p>
            </header>

            <div className="bg-white p-6 rounded-xl shadow-lg border border-stone-200">
                {permission === 'granted' ? (
                    <div className="space-y-6">
                        {renderCompass()}
                        <div className="text-center">
                            <p className="text-lg font-bold text-stone-800">Heading: {compassHeading.toFixed(0)}°</p>
                            <p className="text-sm text-stone-600">Point the top of your device North</p>
                        </div>
                        {renderSunPath()}
                    </div>
                ) : (
                    <div className="text-center py-8">
                        <p className="mb-4 text-stone-700">This tool requires permission to access your device's location and orientation to function.</p>
                        <button onClick={requestPermissions} disabled={permission === 'prompting'} className="bg-yellow-500 text-white font-bold py-3 px-6 rounded-lg hover:bg-yellow-600 transition-colors disabled:bg-stone-400">
                            {permission === 'prompting' ? 'Waiting for Permission...' : 'Activate Sun Tracker'}
                        </button>
                        {error && (
                            <div className="mt-6 p-4 bg-red-50 text-red-700 rounded-lg flex items-center gap-3">
                                <AlertTriangleIcon className="w-6 h-6 flex-shrink-0" />
                                <p className="text-left">{error}</p>
                            </div>
                        )}
                    </div>
                )}
            </div>
        </div>
    );
};

export default SunTrackerView;