'use client'

import React, { useState, useEffect, useRef } from 'react'
import { motion, AnimatePresence } from 'framer-motion'
import { PaperPlaneRight, MagnifyingGlass, UserCircle, WarningCircle, List, X } from '@phosphor-icons/react'
import ReactMarkdown from 'react-markdown'
import remarkGfm from 'remark-gfm'
import rehypeHighlight from 'rehype-highlight'
import Window from './Window'
import { useKV } from '../hooks/useKV'

interface Message {
    id: string
    text: string
    sender: string
    userId: string
    timestamp: number
}

interface MessagesProps {
    onClose: () => void
    onMinimize?: () => void
    onMaximize?: () => void
    onFocus?: () => void
    zIndex?: number
}

export function Messages({ onClose, onMinimize, onMaximize, onFocus, zIndex }: MessagesProps) {
    const [messages, setMessages] = useState<Message[]>([])
    const [inputText, setInputText] = useState('')
    const [isLoading, setIsLoading] = useState(false)
    const [error, setError] = useState<string | null>(null)
    const messagesEndRef = useRef<HTMLDivElement>(null)
    const [sidebarOpen, setSidebarOpen] = useState(false)

    // Persistent user identity
    const [userId] = useKV<string>('messages-user-id', `user-${Math.random().toString(36).substring(2, 9)}`)
    const [userName, setUserName] = useKV<string>('messages-user-name', 'Guest')
    const [isEditingName, setIsEditingName] = useState(false)
    const [tempName, setTempName] = useState(userName)

    const fetchMessages = async () => {
        try {
            const res = await fetch('/api/messages')
            if (res.ok) {
                const data = await res.json()
                setMessages(data)
            }
        } catch (err) {
            console.error('Failed to fetch messages', err)
        }
    }

    // Poll for new messages
    useEffect(() => {
        fetchMessages()
        const interval = setInterval(fetchMessages, 3000)
        return () => clearInterval(interval)
    }, [])

    // Scroll to bottom on new messages
    useEffect(() => {
        messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' })
    }, [messages])

    const handleSend = async (e?: React.FormEvent) => {
        e?.preventDefault()
        if (!inputText.trim() || isLoading) return

        setIsLoading(true)
        setError(null)

        try {
            const res = await fetch('/api/messages', {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    text: inputText,
                    sender: userName,
                    userId: userId
                })
            })

            const data = await res.json()

            if (!res.ok) {
                setError(data.error || 'Failed to send message')
            } else {
                setMessages(data)
                setInputText('')
            }
        } catch (err) {
            setError('Network error. Please try again.')
        } finally {
            setIsLoading(false)
        }
    }

    const handleNameSave = () => {
        if (tempName.trim()) {
            setUserName(tempName.trim())
            setIsEditingName(false)
        }
    }

    return (
        <Window
            id="messages"
            title="Messages"
            isOpen={true}
            onClose={onClose}
            onMinimize={onMinimize}
            onMaximize={onMaximize}
            onFocus={onFocus}
            zIndex={zIndex}
            width={800}
            height={600}
            x={100}
            y={50}
            className="messages-window !bg-[#1e1e1e]/80 !backdrop-blur-2xl border border-white/10 shadow-2xl !rounded-xl overflow-hidden"
            contentClassName="!bg-transparent"
            headerClassName="!bg-transparent border-b border-white/5"
        >
            <div className="flex h-full text-white overflow-hidden relative">
                {/* Mobile Sidebar Overlay */}
                <AnimatePresence>
                    {sidebarOpen && (
                        <motion.div
                            initial={{ opacity: 0 }}
                            animate={{ opacity: 1 }}
                            exit={{ opacity: 0 }}
                            className="absolute inset-0 bg-black/50 z-20 md:hidden"
                            onClick={() => setSidebarOpen(false)}
                        />
                    )}
                </AnimatePresence>

                {/* Sidebar */}
                <AnimatePresence>
                    {(sidebarOpen || typeof window !== 'undefined' && window.innerWidth >= 768) && (
                        <motion.div
                            initial={{ x: -256 }}
                            animate={{ x: 0 }}
                            exit={{ x: -256 }}
                            transition={{ type: 'spring', damping: 25, stiffness: 300 }}
                            className={`${sidebarOpen ? 'absolute z-30 h-full' : 'hidden'} md:relative md:flex w-56 sm:w-64 border-r border-white/10 bg-black/90 md:bg-black/20 flex-col`}
                        >
                            <div className="p-3 sm:p-4 border-b border-white/5 flex items-center justify-between">
                                <div className="relative flex-1">
                                    <MagnifyingGlass className="absolute left-3 top-1/2 -translate-y-1/2 text-gray-500" size={14} />
                                    <input
                                        type="text"
                                        placeholder="Search"
                                        className="w-full bg-white/10 border-none rounded-md py-1.5 pl-9 pr-3 text-xs text-white placeholder-gray-500 focus:ring-1 focus:ring-blue-500 outline-none"
                                    />
                                </div>
                                <button
                                    onClick={() => setSidebarOpen(false)}
                                    className="ml-2 p-1 hover:bg-white/10 rounded md:hidden"
                                >
                                    <X size={18} />
                                </button>
                            </div>

                            <div className="flex-1 overflow-y-auto p-2 space-y-1">
                                <div className="p-2 sm:p-3 rounded-lg bg-blue-600/20 border border-blue-500/30 cursor-pointer">
                                    <div className="flex justify-between items-start">
                                        <span className="font-semibold text-xs sm:text-sm">Global Chat</span>
                                        <span className="text-[9px] sm:text-[10px] text-gray-400">Now</span>
                                    </div>
                                    <div className="text-[10px] sm:text-xs text-gray-400 mt-1 truncate">
                                        {messages.length > 0 ? messages[messages.length - 1].text.replace(/[#*`_~\[\]]/g, '') : 'No messages yet'}
                                    </div>
                                </div>
                            </div>

                            {/* User Profile */}
                            <div className="p-3 sm:p-4 border-t border-white/10 bg-black/10">
                                {isEditingName ? (
                                    <div className="flex gap-2">
                                        <input
                                            type="text"
                                            value={tempName}
                                            onChange={(e) => setTempName(e.target.value)}
                                            className="flex-1 bg-white/10 rounded px-2 py-1 text-sm outline-none border border-blue-500 min-w-0"
                                            autoFocus
                                            onKeyDown={(e) => e.key === 'Enter' && handleNameSave()}
                                        />
                                        <button onClick={handleNameSave} className="text-xs text-blue-400 font-medium flex-shrink-0">Save</button>
                                    </div>
                                ) : (
                                    <div className="flex items-center gap-2 sm:gap-3 cursor-pointer hover:bg-white/5 p-1.5 sm:p-2 rounded-md transition-colors" onClick={() => {
                                        setTempName(userName)
                                        setIsEditingName(true)
                                    }}>
                                        <UserCircle size={28} className="text-gray-400 sm:w-8 sm:h-8 flex-shrink-0" />
                                        <div className="flex-1 min-w-0">
                                            <div className="text-xs sm:text-sm font-medium truncate">{userName}</div>
                                            <div className="text-[9px] sm:text-[10px] text-gray-500">Click to change name</div>
                                        </div>
                                    </div>
                                )}
                            </div>
                        </motion.div>
                    )}
                </AnimatePresence>

                {/* Chat Area */}
                <div className="flex-1 flex flex-col bg-transparent relative min-w-0">
                    {/* Header */}
                    <div className="h-12 sm:h-14 border-b border-white/5 flex items-center px-3 sm:px-6 bg-[#252525]/30 backdrop-blur-sm justify-between gap-2">
                        <div className="flex items-center gap-2 sm:gap-3 min-w-0">
                            <button
                                onClick={() => setSidebarOpen(true)}
                                className="p-1.5 hover:bg-white/10 rounded md:hidden flex-shrink-0"
                            >
                                <List size={18} />
                            </button>
                            <div className="flex flex-col min-w-0">
                                <span className="text-xs sm:text-sm font-semibold truncate">To: Everyone</span>
                                <span className="text-[9px] sm:text-[10px] text-gray-400">Global Channel</span>
                            </div>
                        </div>
                        <div className="hidden xs:flex items-center gap-1 sm:gap-2 text-orange-400 bg-orange-400/10 px-2 sm:px-3 py-1 rounded-full border border-orange-400/20 flex-shrink-0">
                            <WarningCircle size={12} className="sm:w-3.5 sm:h-3.5" />
                            <span className="text-[8px] sm:text-[10px] font-medium whitespace-nowrap">Public Chat</span>
                        </div>
                    </div>

                    {/* Messages List */}
                    <div className="flex-1 overflow-y-auto p-3 sm:p-6 space-y-1 [&::-webkit-scrollbar-thumb]:bg-white/20 [&::-webkit-scrollbar-track]:bg-transparent [&::-webkit-scrollbar]:w-2">
                        {messages.map((msg, index) => {
                            const isMe = msg.userId === userId
                            const showHeader = index === 0 || messages[index - 1].userId !== msg.userId
                            const showTimestamp = index === 0 || (msg.timestamp - messages[index - 1].timestamp > 300000) // 5 mins

                            return (
                                <React.Fragment key={msg.id}>
                                    {showTimestamp && (
                                        <div className="text-center my-3 sm:my-4">
                                            <span className="text-[9px] sm:text-[10px] text-gray-500 font-medium">
                                                {new Date(msg.timestamp).toLocaleTimeString([], { hour: 'numeric', minute: '2-digit' })}
                                            </span>
                                        </div>
                                    )}
                                    <motion.div
                                        initial={{ opacity: 0, y: 10 }}
                                        animate={{ opacity: 1, y: 0 }}
                                        className={`flex flex-col ${isMe ? 'items-end' : 'items-start'} ${showHeader ? 'mt-2' : 'mt-0.5'}`}
                                    >
                                        {showHeader && !isMe && (
                                            <span className="text-[9px] sm:text-[10px] text-gray-500 ml-2 sm:ml-3 mb-0.5">{msg.sender}</span>
                                        )}
                                        <div
                                            className={`
                        max-w-[85%] sm:max-w-[70%] px-2.5 sm:px-3 py-1.5 text-xs sm:text-[13px] leading-relaxed break-words relative group select-text
                        ${isMe
                                                    ? 'bg-[#0A84FF] text-white rounded-2xl rounded-br-sm message-bubble-sent'
                                                    : 'bg-[#3a3a3a] text-gray-100 rounded-2xl rounded-bl-sm message-bubble-received'}
                      `}
                                        >
                                            <div className="markdown-content">
                                                <ReactMarkdown remarkPlugins={[remarkGfm]} rehypePlugins={[rehypeHighlight]}>
                                                    {msg.text}
                                                </ReactMarkdown>
                                            </div>
                                            {/* Tail for message bubbles */}
                                            {isMe && showHeader && (
                                                <svg className="absolute -bottom-[1px] -right-[6px] w-4 h-4 text-[#0A84FF]" viewBox="0 0 20 20" fill="currentColor">
                                                    <path d="M0 20C5 20 8 15 10 10V20H0Z" />
                                                </svg>
                                            )}
                                            {!isMe && showHeader && (
                                                <svg className="absolute -bottom-[1px] -left-[6px] w-4 h-4 text-[#3a3a3a] transform scale-x-[-1]" viewBox="0 0 20 20" fill="currentColor">
                                                    <path d="M0 20C5 20 8 15 10 10V20H0Z" />
                                                </svg>
                                            )}
                                        </div>
                                        {/* Delivered status for me */}
                                        {isMe && index === messages.length - 1 && (
                                            <span className="text-[9px] sm:text-[10px] text-gray-500 mr-1 mt-0.5 font-medium">Delivered</span>
                                        )}
                                    </motion.div>
                                </React.Fragment>
                            )
                        })}
                        <div ref={messagesEndRef} />
                    </div>

                    {/* Input Area */}
                    <div className="p-2 sm:p-4 bg-[#1e1e1e]/50 border-t border-white/10 backdrop-blur-md">
                        {error && (
                            <motion.div
                                initial={{ opacity: 0, y: 10 }}
                                animate={{ opacity: 1, y: 0 }}
                                exit={{ opacity: 0 }}
                                className="flex items-center gap-2 text-red-400 text-[10px] sm:text-xs mb-2 px-2 justify-center"
                            >
                                <WarningCircle size={12} className="sm:w-3.5 sm:h-3.5" />
                                {error}
                            </motion.div>
                        )}
                        <form onSubmit={handleSend} className="relative flex items-center gap-2 sm:gap-3 max-w-3xl mx-auto w-full">
                            <div className="flex-1 relative">
                                <input
                                    type="text"
                                    value={inputText}
                                    onChange={(e) => setInputText(e.target.value)}
                                    onKeyDown={(e) => {
                                        if (e.key === 'Enter' && !e.shiftKey) {
                                            e.preventDefault()
                                            handleSend(e)
                                        }
                                    }}
                                    onPaste={(e) => {
                                        // Allow paste - default behavior
                                        e.stopPropagation()
                                    }}
                                    placeholder="iMessage"
                                    maxLength={200}
                                    disabled={isLoading}
                                    className="w-full bg-[#2a2a2a] border border-white/10 rounded-full py-1.5 sm:py-2 pl-3 sm:pl-4 pr-9 sm:pr-10 text-xs sm:text-sm text-white placeholder-gray-500 focus:outline-none focus:border-gray-500 transition-colors select-text"
                                />
                                <button
                                    type="submit"
                                    disabled={!inputText.trim() || isLoading}
                                    className={`
                    absolute right-1 top-1/2 -translate-y-1/2 p-1 sm:p-1.5 rounded-full transition-all
                    ${inputText.trim() && !isLoading ? 'bg-[#0A84FF] text-white scale-100' : 'bg-gray-600 text-gray-400 scale-90 opacity-0 pointer-events-none'}
                  `}
                                >
                                    <PaperPlaneRight size={12} className="sm:w-3.5 sm:h-3.5" weight="fill" />
                                </button>
                            </div>
                        </form>
                        <div className="text-[8px] sm:text-[9px] text-gray-600 text-center mt-1 sm:mt-2 font-medium">
                            {inputText.length}/200 • Enter to send
                        </div>
                    </div>
                </div>            </div>
        </Window>
    )
}