'use client';


import React, { useState, useEffect, useRef } from 'react';
import { Sparkles, Send, RefreshCw, BookOpen, Bot, ArrowLeft, BrainCircuit, Zap } from 'lucide-react';
import { ChatMessage, UserUsage } from '@/lib/types';
import { useLanguage } from '@/providers/LanguageProvider';

interface AIPanelProps {
  chatHistory: ChatMessage[];
  onSendMessage: (msg: string) => void;
  onInsertText: (text: string) => void;
  selectedText: string;
  isGenerating: boolean;
  usage?: UserUsage;
}

const AIPanel: React.FC<AIPanelProps> = ({ chatHistory, onSendMessage, onInsertText, selectedText, isGenerating, usage }) => {
  const { t } = useLanguage();
  const [input, setInput] = useState("");
  const messagesEndRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    messagesEndRef.current?.scrollIntoView({ behavior: "smooth" });
  }, [chatHistory, isGenerating]);

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (!input.trim() || isGenerating) return;
    onSendMessage(input);
    setInput("");
  };

  const isLimitReached = usage ? usage.aiActionsCurrent >= usage.aiActionsLimit : false;

  return (
    <div className="flex flex-col h-full bg-theme-panel border-l border-theme-border shadow-xl w-80 lg:w-96 transition-colors duration-300">
      {/* Header with Usage Counter */}
      <div className="p-4 bg-indigo-600 text-white flex items-center justify-between shadow-md">
        <div className="flex items-center gap-2">
          <Sparkles size={20} className="animate-pulse" />
          <h3 className="font-bold tracking-tight">{t('ai_panel.title')}</h3>
        </div>
        {usage && (
          <div className="bg-indigo-900/50 px-2 py-1 rounded text-[10px] font-black flex items-center gap-1">
            <Zap size={10} fill="currentColor" /> {usage.aiActionsCurrent} / {usage.aiActionsLimit === 999999 ? '∞' : usage.aiActionsLimit}
          </div>
        )}
      </div>

      {selectedText && (
        <div className="bg-indigo-50 p-3 border-b border-indigo-100 text-xs text-indigo-800">
          <div className="font-bold flex items-center gap-1 mb-1"><BookOpen size={12} /> {t('ai_panel.context')}</div>
          <div className="italic truncate opacity-80">"{selectedText.substring(0, 60)}..."</div>
        </div>
      )}

      <div className="flex-1 overflow-y-auto p-4 space-y-4 bg-theme-bg transition-colors duration-300">
        {chatHistory.length === 0 && (
          <div className="text-center text-theme-muted mt-10">
            <Bot size={48} className="mx-auto mb-2 opacity-50" />
            <p className="text-sm">{t('ai_panel.greeting')}</p>
            {isLimitReached && (
              <div className="mt-4 p-4 bg-red-50 border border-red-100 rounded-xl text-red-600 text-xs font-bold uppercase animate-pulse">
                {t('ai_panel.limit_reached_upgrade')}
              </div>
            )}
          </div>
        )}

        {chatHistory.map((msg) => (
          <div key={msg.id} className={`flex flex-col ${msg.role === 'user' ? 'items-end' : 'items-start'}`}>
            <div className={`max-w-[85%] rounded-2xl p-4 text-sm shadow-sm transition-colors duration-300 ${msg.role === 'user' ? 'bg-indigo-600 text-white rounded-br-none' : 'bg-theme-panel text-theme-text border border-theme-border rounded-bl-none'}`}>
              {msg.role === 'model' && msg.responseType === 'reflection' && (
                <div className="flex items-center gap-1.5 text-[10px] font-black text-amber-600 mb-1.5 uppercase tracking-wide"><BrainCircuit size={12} /> {t('ai_panel.reflection')}</div>
              )}
              <div className="whitespace-pre-wrap leading-relaxed">{msg.text}</div>
            </div>
          </div>
        ))}

        {isGenerating && (
          <div className="flex justify-start">
            <div className="bg-theme-panel p-3 rounded-2xl rounded-bl-none shadow-sm border border-theme-border flex items-center gap-2 text-xs text-theme-muted transition-colors duration-300">
              <RefreshCw size={14} className="animate-spin" /> {t('ai_panel.ai_working')}
            </div>
          </div>
        )}
        <div ref={messagesEndRef} />
      </div>

      <div className="p-4 bg-theme-panel border-t border-theme-border transition-colors duration-300">
        <form onSubmit={handleSubmit} className="relative">
          <input
            type="text"
            value={input}
            onChange={(e) => setInput(e.target.value)}
            placeholder={isLimitReached ? t('ai_panel.limit_reached') : t('ai_panel.your_message')}
            className="w-full pl-4 pr-12 py-3 bg-theme-bg text-theme-text border border-theme-border rounded-2xl text-sm focus:outline-none focus:border-indigo-500 transition-all disabled:opacity-50"
            disabled={isGenerating || isLimitReached}
          />
          <button
            type="submit"
            disabled={!input.trim() || isGenerating || isLimitReached}
            className="absolute right-1.5 top-1.5 p-2 bg-indigo-600 text-white rounded-xl hover:bg-indigo-700 disabled:opacity-50 transition-colors shadow-md"
          >
            <Send size={18} />
          </button>
        </form>
      </div>
    </div>
  );
};

export default AIPanel;