'use client';

import React, { useEffect, useRef, useState, useCallback } from 'react';
import { motion, AnimatePresence } from 'framer-motion';
import { X, Send, FileText, Film, Music, Archive, File } from 'lucide-react';

interface FilePreviewModalProps {
    file: File | null;
    onConfirm: (file: File, caption: string) => Promise<void>;
    onCancel: () => void;
}

function formatFileSize(bytes: number): string {
    if (bytes < 1024) return `${bytes} B`;
    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
    return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
}

function getFileIcon(type: string) {
    if (type.startsWith('video/')) return <Film className="w-12 h-12 text-blue-400" />;
    if (type.startsWith('audio/')) return <Music className="w-12 h-12 text-purple-400" />;
    if (type.includes('pdf') || type.includes('document') || type.includes('word'))
        return <FileText className="w-12 h-12 text-red-400" />;
    if (type.includes('zip') || type.includes('compressed') || type.includes('tar'))
        return <Archive className="w-12 h-12 text-yellow-400" />;
    return <File className="w-12 h-12 text-[#8696a0]" />;
}

function getFileLabel(type: string): string {
    if (type.startsWith('image/')) return 'Imagem';
    if (type.startsWith('video/')) return 'Vídeo';
    if (type.startsWith('audio/')) return 'Áudio';
    if (type.includes('pdf')) return 'PDF';
    return 'Arquivo';
}

export default function FilePreviewModal({ file, onConfirm, onCancel }: FilePreviewModalProps) {
    const [caption, setCaption] = useState('');
    const [sending, setSending] = useState(false);
    const [objectUrl, setObjectUrl] = useState<string | null>(null);
    const captionRef = useRef<HTMLInputElement>(null);

    const isImage = file?.type.startsWith('image/');
    const isVideo = file?.type.startsWith('video/');

    // Create / revoke object URL
    useEffect(() => {
        if (!file) { setObjectUrl(null); return; }
        const url = URL.createObjectURL(file);
        setObjectUrl(url);
        setCaption('');
        setSending(false);
        setTimeout(() => captionRef.current?.focus(), 200);
        return () => URL.revokeObjectURL(url);
    }, [file]);

    // ESC cancels
    useEffect(() => {
        const onKey = (e: KeyboardEvent) => { if (e.key === 'Escape') onCancel(); };
        document.addEventListener('keydown', onKey);
        return () => document.removeEventListener('keydown', onKey);
    }, [onCancel]);

    const handleSend = useCallback(async () => {
        if (!file || sending) return;
        setSending(true);
        try {
            await onConfirm(file, caption.trim());
        } finally {
            setSending(false);
        }
    }, [file, caption, sending, onConfirm]);

    const handleKeyDown = (e: React.KeyboardEvent<HTMLInputElement>) => {
        if (e.key === 'Enter' && !e.shiftKey) {
            e.preventDefault();
            handleSend();
        }
    };

    return (
        <AnimatePresence>
            {file && (
                <motion.div
                    key="file-preview-overlay"
                    initial={{ opacity: 0 }}
                    animate={{ opacity: 1 }}
                    exit={{ opacity: 0 }}
                    transition={{ duration: 0.2 }}
                    className="fixed inset-0 z-[9998] flex flex-col bg-[#111b21]"
                >
                    {/* ── Top bar ── */}
                    <div className="flex items-center justify-between px-5 py-3 bg-[#202c33] shrink-0">
                        <button
                            onClick={onCancel}
                            className="p-2 rounded-full hover:bg-white/10 text-[#aebac1] transition-colors"
                        >
                            <X className="w-5 h-5" />
                        </button>
                        <span className="text-[#e9edef] text-sm font-medium">
                            {file ? getFileLabel(file.type) : ''}
                        </span>
                        <div className="w-9" /> {/* spacer */}
                    </div>

                    {/* ── Preview area ── */}
                    <div className="flex-1 flex items-center justify-center p-4 min-h-0 overflow-hidden">
                        {isImage && objectUrl && (
                            <motion.img
                                src={objectUrl}
                                alt="preview"
                                initial={{ scale: 0.92, opacity: 0 }}
                                animate={{ scale: 1, opacity: 1 }}
                                transition={{ duration: 0.25 }}
                                className="max-w-full max-h-full object-contain rounded-xl shadow-2xl"
                            />
                        )}

                        {isVideo && objectUrl && (
                            <motion.video
                                src={objectUrl}
                                controls
                                initial={{ scale: 0.92, opacity: 0 }}
                                animate={{ scale: 1, opacity: 1 }}
                                transition={{ duration: 0.25 }}
                                className="max-w-full max-h-full rounded-xl shadow-2xl"
                            />
                        )}

                        {!isImage && !isVideo && file && (
                            <motion.div
                                initial={{ scale: 0.92, opacity: 0 }}
                                animate={{ scale: 1, opacity: 1 }}
                                transition={{ duration: 0.25 }}
                                className="flex flex-col items-center gap-4 bg-[#202c33] rounded-2xl px-12 py-10 shadow-2xl"
                            >
                                {getFileIcon(file.type)}
                                <div className="text-center">
                                    <p className="text-[#e9edef] text-sm font-medium max-w-[280px] break-all text-center">
                                        {file.name}
                                    </p>
                                    <p className="text-[#8696a0] text-xs mt-1">{formatFileSize(file.size)}</p>
                                </div>
                            </motion.div>
                        )}
                    </div>

                    {/* ── Caption + Send bar ── */}
                    <div className="shrink-0 bg-[#202c33] px-4 py-3 flex items-center gap-3">
                        <input
                            ref={captionRef}
                            type="text"
                            placeholder="Adicionar legenda…"
                            value={caption}
                            onChange={(e) => setCaption(e.target.value)}
                            onKeyDown={handleKeyDown}
                            disabled={sending}
                            className="flex-1 bg-[#2a3942] text-[#e9edef] placeholder:text-[#8696a0] text-sm rounded-full px-4 py-2.5 outline-none border-none focus:ring-0 disabled:opacity-50"
                        />
                        <button
                            onClick={handleSend}
                            disabled={sending}
                            className="w-11 h-11 bg-[#00a884] hover:bg-[#02c89f] disabled:opacity-50 rounded-full flex items-center justify-center transition-colors shadow-md active:scale-95"
                        >
                            {sending ? (
                                <div className="w-4 h-4 border-2 border-white border-t-transparent rounded-full animate-spin" />
                            ) : (
                                <Send className="w-5 h-5 text-white" />
                            )}
                        </button>
                    </div>
                </motion.div>
            )}
        </AnimatePresence>
    );
}