import React, { useState, useEffect } from 'react';

const ScreenShareModal = ({ onClose, onSelectSource }) => {
    const [activeTab, setActiveTab] = useState('applications'); // applications | screens | devices
    const [sources, setSources] = useState([]);
    const [loading, setLoading] = useState(true);
    const [shareAudio, setShareAudio] = useState(true);

    useEffect(() => {
        loadSources();
    }, []);

    const loadSources = async () => {
        setLoading(true);
        try {
            // Get screen/window sources from Electron
            const desktopSources = await window.cryptoAPI.getScreenSources();
            
            // Get video input devices (webcams)
            const devices = await navigator.mediaDevices.enumerateDevices();
            const videoDevices = devices.filter(d => d.kind === 'videoinput');

            // Categorize
            const apps = desktopSources.filter(s => s.id.startsWith('window'));
            const screens = desktopSources.filter(s => s.id.startsWith('screen'));
            
            const formattedDevices = videoDevices.map(d => ({
                id: d.deviceId,
                name: d.label || `Camera ${d.deviceId.substring(0, 4)}...`,
                isDevice: true,
                thumbnail: null // Devices don't have static thumbnails easily referencable without opening stream
            }));

            setSources({
                applications: apps,
                screens: screens,
                devices: formattedDevices
            });
        } catch (err) {
            console.error("Failed to load sources:", err);
        } finally {
            setLoading(false);
        }
    };

    const handleSelect = (source) => {
        // If device, pass constraints differently (webcams don't have loopback audio)
        if (source.isDevice) {
             onSelectSource({ deviceId: source.id, type: 'device', shareAudio: false });
        } else {
             onSelectSource({ sourceId: source.id, type: 'screen', shareAudio });
        }
        onClose();
    };

    const renderGrid = (items) => {
        if (!items || items.length === 0) return <div style={{ color: '#b9bbbe', padding: 20, textAlign: 'center' }}>No sources found.</div>;

        return (
            <div style={{ display: 'grid', gridTemplateColumns: 'repeat(2, 1fr)', gap: '16px', padding: '16px' }}>
                {items.map(item => (
                    <div 
                        key={item.id}
                        onClick={() => handleSelect(item)}
                        style={{
                            cursor: 'pointer',
                            borderRadius: '4px',
                            padding: '8px',
                        }}
                    >
                        <div style={{ position: 'relative', width: '100%', height: '250px', width: '450px', borderRadius: '8px', overflow: 'hidden', marginBottom: '8px' }}>
                             {/* Thumbnail/Placeholder */}
                             {item.thumbnail ? (
                                <img src={item.thumbnail} alt={item.name} style={{ width: '100%', height: '100%', borderRadius: '8px', objectFit: 'cover', display: 'block' }} />
                            ) : (
                                <div style={{ width: '100%', height: '100%', backgroundColor: '#202225', display: 'flex', alignItems: 'center', justifyContent: 'center', color: '#b9bbbe' }}>
                                    📷
                                </div>
                            )}

                             {/* Hover Overlay */}
                             <div 
                                className="share-overlay"
                                style={{
                                    position: 'absolute',
                                    top: 0, 
                                    left: 0,
                                    width: '100%',
                                    height: '100%',
                                    backgroundColor: 'rgba(0,0,0,0.5)',
                                    display: 'flex',
                                    alignItems: 'center',
                                    justifyContent: 'center',
                                    opacity: 0,
                                    transition: 'opacity 0.2s'
                                }}
                                onMouseEnter={(e) => e.currentTarget.style.opacity = 1}
                                onMouseLeave={(e) => e.currentTarget.style.opacity = 0}
                             >
                                 <button style={{
                                     backgroundColor: '#5865F2',
                                     color: 'white',
                                     border: 'none',
                                     padding: '8px 16px',
                                     borderRadius: '4px',
                                     fontWeight: 'bold',
                                     cursor: 'pointer',
                                     fontSize: '14px',
                                     boxShadow: '0 4px 6px rgba(0,0,0,0.3)'
                                 }}>
                                     Share Screen
                                 </button>
                             </div>
                        </div>

                         <div style={{ display: 'flex', alignItems: 'center', marginTop: '4px', maxWidth: '450px' }}>
                            {item.appIcon && (
                                <img src={item.appIcon} alt="" style={{ width: '20px', height: '20px', marginRight: '8px' }} />
                            )}
                            <div style={{ color: '#dcddde', fontSize: '14px', whiteSpace: 'nowrap', overflow: 'hidden', textOverflow: 'ellipsis', fontWeight: '500' }}>
                                {item.name}
                            </div>
                        </div>
                    </div>
                ))}
            </div>
        );
    };

    return (
        <div style={{
            position: 'fixed',
            top: 0,
            left: 0,
            width: '100%',
            height: '100%',
            backgroundColor: 'rgba(0,0,0,0.7)',
            zIndex: 10000,
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center'
        }} onClick={onClose}>
            <style>{`
                .no-scrollbar::-webkit-scrollbar {
                    display: none;
                }
                .no-scrollbar {
                    -ms-overflow-style: none;
                    scrollbar-width: none;
                }
            `}</style>
            <div style={{
                backgroundColor: '#242429',
                borderRadius: '8px',
                width: '965px',
                height: '740px',
                maxWidth: '95vw',
                maxHeight: '95vh',
                display: 'flex',
                flexDirection: 'column',
                boxShadow: '0 8px 16px rgba(0,0,0,0.24)'
            }} onClick={e => e.stopPropagation()}>
                
                {/* Header/Tabs */}
                <div style={{ display: 'flex', borderBottom: '1px solid #2f3136', padding: '16px 16px 0 16px', flexShrink: 0 }}>
                     <div 
                        onClick={() => setActiveTab('applications')}
                        style={{
                            padding: '8px 16px',
                            cursor: 'pointer',
                            borderBottom: activeTab === 'applications' ? '2px solid white' : '2px solid transparent',
                            color: activeTab === 'applications' ? 'white' : '#b9bbbe',
                            fontWeight: '500'
                        }}
                     >
                         Applications
                     </div>
                     <div 
                        onClick={() => setActiveTab('screens')}
                        style={{
                            padding: '8px 16px',
                            cursor: 'pointer',
                            borderBottom: activeTab === 'screens' ? '2px solid white' : '2px solid transparent',
                            color: activeTab === 'screens' ? 'white' : '#b9bbbe',
                            fontWeight: '500'
                        }}
                     >
                         Screens
                     </div>
                     <div 
                        onClick={() => setActiveTab('devices')}
                        style={{
                            padding: '8px 16px',
                            cursor: 'pointer',
                            borderBottom: activeTab === 'devices' ? '2px solid white' : '2px solid transparent',
                            color: activeTab === 'devices' ? 'white' : '#b9bbbe',
                            fontWeight: '500'
                        }}
                     >
                         Devices
                     </div>
                </div>

                {/* Content */}
                <div className="no-scrollbar" style={{ flex: 1, overflowY: 'auto' }}>
                    {loading ? (
                        <div style={{ display: 'flex', alignItems: 'center', justifyContent: 'center', height: '100%', color: '#b9bbbe' }}>
                            Loading sources...
                        </div>
                    ) : (
                        renderGrid(sources[activeTab])
                    )}
                </div>

                {/* Audio sharing footer — hidden for device sources (webcams) */}
                {activeTab !== 'devices' && (
                    <div style={{
                        borderTop: '1px solid #2f3136',
                        padding: '12px 16px',
                        display: 'flex',
                        alignItems: 'center',
                        flexShrink: 0,
                    }}>
                        <label style={{
                            display: 'flex',
                            alignItems: 'center',
                            gap: '8px',
                            cursor: 'pointer',
                            color: '#dcddde',
                            fontSize: '14px',
                            userSelect: 'none',
                        }}>
                            <input
                                type="checkbox"
                                checked={shareAudio}
                                onChange={(e) => setShareAudio(e.target.checked)}
                                style={{ accentColor: '#5865F2', width: '16px', height: '16px', cursor: 'pointer' }}
                            />
                            Also share computer audio
                        </label>
                    </div>
                )}
            </div>
        </div>
    );
};

export default ScreenShareModal;
