import React, { useState, useEffect } from 'react';
import { motion } from 'framer-motion';
import { User, Copy, Check } from 'lucide-react';
import ReactMarkdown from 'react-markdown';
import remarkGfm from 'remark-gfm';
import { Prism as SyntaxHighlighter } from 'react-syntax-highlighter';
import { vscDarkPlus } from 'react-syntax-highlighter/dist/esm/styles/prism';

export interface MessageProps {
    id: string;
    role: 'user' | 'bot';
    content: string;
    isNew?: boolean;
}

const CodeBlock = ({ inline, className, children, ...props }: { inline?: boolean; className?: string; children?: React.ReactNode } & React.HTMLAttributes<HTMLElement>) => {
    const match = /language-(\w+)/.exec(className || '');
    const [copied, setCopied] = useState(false);

    const handleCopy = () => {
        navigator.clipboard.writeText(String(children).replace(/\n$/, ''));
        setCopied(true);
        setTimeout(() => setCopied(false), 2000);
    };

    return !inline && match ? (
        <div className="relative group mt-5 mb-5 shadow-lg rounded-lg overflow-hidden border border-white/5">
            <div className="flex justify-between items-center bg-[#18181b] px-4 py-2 border-b border-white/5">
                <span className="text-xs font-mono-custom text-slate-400 capitalize">{match[1]}</span>
                <button
                    onClick={handleCopy}
                    className="flex items-center gap-1.5 text-xs text-slate-400 hover:text-slate-200 transition-colors"
                >
                    {copied ? <Check size={14} className="text-emerald-400" /> : <Copy size={14} />}
                    <span>{copied ? 'Copied!' : 'Copy code'}</span>
                </button>
            </div>
            <SyntaxHighlighter
                {...props}
                style={vscDarkPlus}
                language={match[1]}
                PreTag="div"
                className="!m-0 !bg-[#0b0b0f] !p-4 font-mono-custom text-sm custom-scrollbar"
            >
                {String(children).replace(/\n$/, '')}
            </SyntaxHighlighter>
        </div>
    ) : (
        <code {...props} className={`${className} bg-primary/10 px-1.5 py-0.5 rounded-md text-[13px] font-mono-custom text-primary`}>
            {children}
        </code>
    );
};

export const ChatMessage: React.FC<{ message: MessageProps }> = ({ message }) => {
    const isUser = message.role === 'user';
    const [displayedContent, setDisplayedContent] = useState(
        !isUser && message.isNew ? '' : message.content
    );

    useEffect(() => {
        if (isUser || !message.isNew) {
            setDisplayedContent(message.content);
            return;
        }

        let index = 0;
        setDisplayedContent('');
        const timer = setInterval(() => {
            if (index < message.content.length) {
                setDisplayedContent(message.content.substring(0, index + 1));
                index++;
            } else {
                clearInterval(timer);
            }
        }, 15);

        return () => clearInterval(timer);
    }, [message.content, isUser, message.isNew]);

    return (
        <motion.div
            initial={{ opacity: 0, y: 15 }}
            animate={{ opacity: 1, y: 0 }}
            exit={{ opacity: 0, scale: 0.95 }}
            transition={{ duration: 0.3, ease: 'easeOut' }}
            className={`flex w-full mb-6 ${isUser ? 'justify-end' : 'justify-start'}`}
        >
            <div className={`flex max-w-[85%] sm:max-w-[75%] gap-4 ${isUser ? 'flex-row-reverse' : 'flex-row items-start'}`}>
                {/* Avatar */}
                <div className={`flex-shrink-0 w-8 h-8 rounded-full flex items-center justify-center mt-1 
                    ${isUser ? 'bg-[#3c4043]' : 'bg-transparent'}
                `}>
                    {isUser ? (
                        <User size={18} className="text-white" />
                    ) : (
                        <div className="w-8 h-8 relative flex items-center justify-center bg-white/5 rounded-full border border-white/10 shadow-[0_0_15px_rgba(139,92,246,0.2)]">
                            <svg width="18" height="18" viewBox="0 0 24 24" fill="none" className="text-primary drop-shadow-[0_0_8px_rgba(139,92,246,0.6)]">
                                <path d="M12 2L14.809 9.19098L22 12L14.809 14.809L12 22L9.19098 14.809L2 12L9.19098 9.19098L12 2Z" fill="currentColor" />
                            </svg>
                        </div>
                    )}
                </div>

                {/* Message Bubble */}
                <div className={`
                    leading-[1.65] text-[16px] break-words overflow-x-auto
                    ${isUser
                        ? 'bg-primary text-white px-5 py-3 rounded-[24px] rounded-br-sm shadow-[0_4px_15px_rgba(139,92,246,0.15)]'
                        : 'text-foreground pt-1.5'
                    }
                `}>
                    {isUser ? (
                        message.content
                    ) : (
                        <div className="markdown-prose z-10 w-full">
                            <ReactMarkdown
                                remarkPlugins={[remarkGfm]}
                                components={{
                                    code: CodeBlock,
                                    p: ({ children }) => <p className="mb-4 last:mb-0 leading-[1.65] text-slate-300">{children}</p>,
                                    ul: ({ children }) => <ul className="list-disc ml-5 mb-4 space-y-1 text-slate-300">{children}</ul>,
                                    ol: ({ children }) => <ol className="list-decimal ml-5 mb-4 space-y-1 text-slate-300">{children}</ol>,
                                    li: ({ children }) => <li className="mb-1 leading-[1.65]">{children}</li>,
                                    a: ({ href, children }) => <a href={href} className="text-primary hover:text-primary-hover underline underline-offset-2 transition-colors" target="_blank" rel="noreferrer">{children}</a>,
                                    h1: ({ children }) => <h1 className="text-2xl font-bold mb-4 mt-6 text-slate-100">{children}</h1>,
                                    h2: ({ children }) => <h2 className="text-xl font-bold mb-3 mt-5 text-slate-100">{children}</h2>,
                                    h3: ({ children }) => <h3 className="text-lg font-bold mb-3 mt-4 text-slate-100">{children}</h3>,
                                    strong: ({ children }) => <strong className="font-semibold text-slate-200">{children}</strong>,
                                    blockquote: ({ children }) => <blockquote className="border-l-4 border-primary/50 pl-4 py-1.5 my-4 bg-white/5 rounded-r-lg text-slate-300 italic">{children}</blockquote>
                                }}
                            >
                                {displayedContent}
                            </ReactMarkdown>
                            {!displayedContent && !isUser && message.isNew && (
                                <div className="flex gap-1.5 mt-2 h-6 items-center">
                                    <span className="w-1.5 h-1.5 bg-primary/80 rounded-full animate-bounce" style={{ animationDelay: '0ms' }} />
                                    <span className="w-1.5 h-1.5 bg-primary/80 rounded-full animate-bounce" style={{ animationDelay: '150ms' }} />
                                    <span className="w-1.5 h-1.5 bg-primary/80 rounded-full animate-bounce" style={{ animationDelay: '300ms' }} />
                                </div>
                            )}
                        </div>
                    )}
                </div>
            </div>
        </motion.div>
    );
};