'use client';

import { useState, useRef, useEffect } from 'react';
import { X, Bot, Sparkles, Send, Shield, BookOpen, Heart, Brain, ChevronDown, Eye, EyeOff } from 'lucide-react';
import ThinkingIndicator from './chat/ThinkingIndicator';
import MarkdownMessage from './chat/MarkdownMessage';

interface Message {
  role: 'user' | 'assistant';
  content: string;
  agent?: string;
  trace?: TraceStep[];
  timestamp?: Date;
}

interface TraceStep {
  agent: string;
  action: string;
  result?: string;
}

const agentIcons: Record<string, typeof Shield> = {
  Gatekeeper: Shield,
  Theologian: BookOpen,
  Healer: Heart,
  Orchestrator: Brain,
  System: Sparkles,
};

const agentColors: Record<string, { bg: string; border: string; text: string }> = {
  Gatekeeper: { bg: 'bg-purple-500/20', border: 'border-purple-500/30', text: 'text-purple-400' },
  Theologian: { bg: 'bg-blue-500/20', border: 'border-blue-500/30', text: 'text-blue-400' },
  Healer: { bg: 'bg-rose-500/20', border: 'border-rose-500/30', text: 'text-rose-400' },
  Orchestrator: { bg: 'bg-amber-500/20', border: 'border-amber-500/30', text: 'text-amber-400' },
  System: { bg: 'bg-neutral-500/20', border: 'border-neutral-500/30', text: 'text-neutral-400' },
};

export default function ChatWidget() {
  const [chatOpen, setChatOpen] = useState(false);
  const [messages, setMessages] = useState<Message[]>([
    {
      role: 'assistant',
      content: "Hello, I'm **ORA**, your AI spiritual companion. I'm here to help you explore Scripture, reflect on your faith, and grow in wisdom. How may I serve you today?",
      agent: 'Gatekeeper',
      timestamp: new Date(),
    }
  ]);
  const [input, setInput] = useState('');
  const [isTyping, setIsTyping] = useState(false);
  const [activeAgent, setActiveAgent] = useState<string>('Gatekeeper');
  const [showTrace, setShowTrace] = useState<Record<number, boolean>>({});
  const messagesEndRef = useRef<HTMLDivElement>(null);

  const scrollToBottom = () => {
    messagesEndRef.current?.scrollIntoView({ behavior: 'smooth' });
  };

  useEffect(() => {
    scrollToBottom();
  }, [messages, isTyping]);

  const handleSend = async () => {
    if (!input.trim()) return;

    const userMsg: Message = {
      role: 'user',
      content: input,
      timestamp: new Date(),
    };

    setMessages(prev => [...prev, userMsg]);
    setInput('');
    setIsTyping(true);
    setActiveAgent('Gatekeeper'); // Start with Gatekeeper

    try {
      const response = await fetch('http://localhost:6000/api/chat', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ message: input })
      });
      const data = await response.json();

      if (data.success) {
        // Simulate agent handoff animation
        if (data.response.agent !== 'Gatekeeper') {
          setActiveAgent(data.response.agent);
          await new Promise(resolve => setTimeout(resolve, 500));
        }

        const assistantMsg: Message = {
          role: 'assistant',
          content: data.response.content,
          agent: data.response.agent,
          trace: data.response.trace || [],
          timestamp: new Date(),
        };

        setMessages(prev => [...prev, assistantMsg]);
      }
    } catch (error) {
      console.error('Chat failed:', error);
      setMessages(prev => [...prev, {
        role: 'assistant',
        content: "I apologize, but I'm having trouble connecting to my reasoning core. Please ensure the ORA backend is running on port 6000.",
        agent: 'System',
        timestamp: new Date(),
      }]);
    } finally {
      setIsTyping(false);
    }
  };

  const toggleTrace = (index: number) => {
    setShowTrace(prev => ({ ...prev, [index]: !prev[index] }));
  };

  const AgentIcon = ({ agent }: { agent: string }) => {
    const Icon = agentIcons[agent] || Sparkles;
    const colors = agentColors[agent] || agentColors.System;
    return (
      <div className={`w-7 h-7 rounded-full ${colors.bg} flex items-center justify-center border ${colors.border}`}>
        <Icon className={`w-3.5 h-3.5 ${colors.text}`} />
      </div>
    );
  };

  return (
    <div className="fixed bottom-6 right-6 z-50 hidden md:block">
      <div className="relative">
        {/* Chat Button */}
        <button
          onClick={() => setChatOpen(!chatOpen)}
          className="relative w-14 h-14 bg-gradient-to-br from-purple-600 to-purple-800 hover:from-purple-500 hover:to-purple-700 text-white rounded-full flex items-center justify-center shadow-[0_4px_30px_rgba(168,85,247,0.4)] hover:shadow-[0_4px_40px_rgba(168,85,247,0.6)] hover:scale-105 active:scale-95 transition-all duration-300 z-50"
        >
          {chatOpen ? (
            <X className="w-6 h-6" />
          ) : (
            <div className="relative">
              <Sparkles className="w-6 h-6 animate-pulse-fast" />
            </div>
          )}
          {!chatOpen && (
            <span className="absolute top-0 right-0 w-3.5 h-3.5 bg-emerald-500 border-2 border-[#0a0a0a] rounded-full">
              <span className="absolute inset-0 rounded-full bg-emerald-400 animate-ping" />
            </span>
          )}
        </button>

        {/* Chat Box */}
        <div
          className={`absolute bottom-[calc(100%+16px)] right-0 w-[420px] bg-[#0a0a0a]/98 backdrop-blur-xl border border-purple-500/20 rounded-2xl shadow-2xl shadow-purple-500/10 transition-all duration-300 overflow-hidden flex flex-col ${
            chatOpen
              ? 'visible opacity-100 translate-y-0 scale-100'
              : 'invisible opacity-0 translate-y-4 scale-95'
          }`}
          style={{ maxHeight: 'calc(100vh - 150px)' }}
        >
          {/* Header */}
          <div className="bg-gradient-to-r from-purple-900/60 to-purple-800/40 p-4 border-b border-white/5 flex items-center justify-between">
            <div className="flex items-center gap-3">
              <div className="relative">
                <div className="w-10 h-10 rounded-full bg-gradient-to-br from-purple-500/30 to-purple-700/30 flex items-center justify-center border border-purple-500/40 animate-orb-glow-purple">
                  <Sparkles className="w-5 h-5 text-purple-300" />
                </div>
                <span className="absolute bottom-0 right-0 w-2.5 h-2.5 bg-emerald-500 border-2 border-[#0a0a0a] rounded-full shadow-[0_0_8px_rgba(16,185,129,0.6)]" />
              </div>
              <div>
                <span className="block text-white text-sm font-semibold tracking-wide">ORA</span>
                <span className="block text-[10px] text-emerald-400 font-medium">
                  Sovereign AI Companion
                </span>
              </div>
            </div>
            <button
              onClick={() => setChatOpen(false)}
              className="p-1.5 rounded-full hover:bg-white/10 text-neutral-400 hover:text-white transition-all"
            >
              <X className="w-5 h-5" />
            </button>
          </div>

          {/* Messages */}
          <div className="flex-1 p-4 space-y-4 min-h-[300px] max-h-[450px] overflow-y-auto bg-[radial-gradient(ellipse_at_top_right,_var(--tw-gradient-stops))] from-purple-500/5 via-transparent to-transparent scrollbar-thin scrollbar-thumb-purple-500/20 scrollbar-track-transparent">
            {messages.map((m, i) => (
              <div
                key={i}
                className={`flex gap-3 items-start animate-message-in ${
                  m.role === 'user' ? 'flex-row-reverse' : ''
                }`}
              >
                {/* Avatar */}
                <div className="shrink-0">
                  {m.role === 'user' ? (
                    <div className="w-7 h-7 rounded-full bg-amber-500/20 flex items-center justify-center border border-amber-500/30">
                      <Bot className="w-3.5 h-3.5 text-amber-400" />
                    </div>
                  ) : (
                    <AgentIcon agent={m.agent || 'System'} />
                  )}
                </div>

                {/* Message Content */}
                <div className="flex flex-col gap-1 max-w-[85%]">
                  {/* Agent Badge */}
                  {m.agent && m.role === 'assistant' && (
                    <div className="flex items-center gap-2">
                      <span className={`text-[9px] font-mono uppercase tracking-wider ${agentColors[m.agent]?.text || 'text-neutral-400'}`}>
                        {m.agent}
                      </span>
                      {m.trace && m.trace.length > 0 && (
                        <button
                          onClick={() => toggleTrace(i)}
                          className="flex items-center gap-1 text-[9px] text-neutral-500 hover:text-purple-400 transition-colors"
                        >
                          {showTrace[i] ? <EyeOff className="w-3 h-3" /> : <Eye className="w-3 h-3" />}
                          {showTrace[i] ? 'Hide' : 'Show'} Reasoning
                        </button>
                      )}
                    </div>
                  )}

                  {/* Trace Steps */}
                  {showTrace[i] && m.trace && m.trace.length > 0 && (
                    <div className="animate-trace-expand mb-2 p-3 rounded-xl bg-white/[0.02] border border-white/5">
                      <div className="text-[9px] text-neutral-500 uppercase tracking-wider mb-2">
                        Reasoning Trace
                      </div>
                      <div className="space-y-2">
                        {m.trace.map((step, j) => (
                          <div key={j} className="flex items-start gap-2 text-[10px]">
                            <div className={`w-4 h-4 rounded shrink-0 flex items-center justify-center ${agentColors[step.agent]?.bg || 'bg-neutral-500/20'}`}>
                              <span className={`text-[8px] font-bold ${agentColors[step.agent]?.text || 'text-neutral-400'}`}>
                                {j + 1}
                              </span>
                            </div>
                            <div>
                              <span className={`font-medium ${agentColors[step.agent]?.text || 'text-neutral-400'}`}>
                                {step.agent}:
                              </span>
                              <span className="text-neutral-400 ml-1">{step.action}</span>
                              {step.result && (
                                <div className="text-neutral-500 mt-0.5 italic">{step.result}</div>
                              )}
                            </div>
                          </div>
                        ))}
                      </div>
                    </div>
                  )}

                  {/* Message Bubble */}
                  <div
                    className={`rounded-2xl p-3.5 text-sm leading-relaxed ${
                      m.role === 'user'
                        ? 'bg-gradient-to-br from-amber-500/15 to-amber-600/10 border border-amber-500/20 rounded-tr-sm'
                        : `bg-gradient-to-br from-purple-500/10 to-purple-600/5 border ${agentColors[m.agent || 'System']?.border || 'border-purple-500/20'} rounded-tl-sm`
                    }`}
                  >
                    <MarkdownMessage
                      content={m.content}
                      variant={m.role}
                    />
                  </div>

                  {/* Timestamp */}
                  {m.timestamp && (
                    <span className="text-[9px] text-neutral-600 px-1">
                      {m.timestamp.toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' })}
                    </span>
                  )}
                </div>
              </div>
            ))}

            {/* Thinking Indicator */}
            {isTyping && (
              <ThinkingIndicator activeAgent={activeAgent} stage="thinking" />
            )}

            <div ref={messagesEndRef} />
          </div>

          {/* Quick Actions */}
          <div className="px-4 py-2 border-t border-white/5 bg-black/20">
            <div className="flex gap-2 overflow-x-auto pb-1 scrollbar-none">
              {['Pray with me', 'Explain a verse', 'Daily reflection'].map((action) => (
                <button
                  key={action}
                  onClick={() => setInput(action)}
                  className="shrink-0 px-3 py-1.5 text-[10px] font-medium text-purple-300 bg-purple-500/10 hover:bg-purple-500/20 border border-purple-500/20 rounded-full transition-all hover:scale-105"
                >
                  {action}
                </button>
              ))}
            </div>
          </div>

          {/* Input */}
          <div className="p-3 border-t border-white/5 bg-black/30">
            <div className="flex items-center gap-2 bg-white/5 border border-white/10 rounded-full px-4 py-2.5 focus-within:border-purple-500/40 focus-within:bg-white/[0.07] transition-all">
              <input
                type="text"
                value={input}
                onChange={(e) => setInput(e.target.value)}
                onKeyDown={(e) => e.key === 'Enter' && !e.shiftKey && handleSend()}
                placeholder="Ask ORA anything..."
                className="bg-transparent border-none focus:outline-none text-sm text-white w-full placeholder-neutral-500"
                disabled={isTyping}
              />
              <button
                onClick={handleSend}
                disabled={isTyping || !input.trim()}
                className={`p-2 rounded-full transition-all ${
                  isTyping || !input.trim()
                    ? 'text-neutral-600 cursor-not-allowed'
                    : 'text-purple-400 hover:text-purple-300 hover:bg-purple-500/20'
                }`}
              >
                <Send className="w-4 h-4" />
              </button>
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}