'use client'

import { useState, useRef, useEffect } from 'react'
import { Send, User } from 'lucide-react'
import ReactMarkdown from 'react-markdown'

// Random Bible-related loading messages
const LOADING_MESSAGES = [
  "Searching the Scriptures...",
  "Seeking wisdom from God's Word...",
  "Consulting the Holy Scriptures...",
  "Finding relevant Bible verses...",
  "Exploring God's eternal truth..."
]

export function ChatInterface() {
  const [messages, setMessages] = useState<Array<{ role: string; content: string }>>([])
  const [input, setInput] = useState('')
  const [loading, setLoading] = useState(false)
  const [loadingMessage, setLoadingMessage] = useState('')
  const [isAuthenticated, setIsAuthenticated] = useState(false)
  const messagesEndRef = useRef<HTMLDivElement>(null)

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

  useEffect(scrollToBottom, [messages])

  // Check authentication status on mount
  useEffect(() => {
    const checkAuth = async () => {
      try {
        const token = localStorage.getItem('authToken')
        if (token) {
          const response = await fetch('/api/auth/me', {
            headers: { 'Authorization': `Bearer ${token}` }
          })
          setIsAuthenticated(response.ok)
        }
      } catch (error) {
        setIsAuthenticated(false)
      }
    }
    checkAuth()
  }, [])

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault()
    if (!input.trim() || loading) return

    const userMessage = { role: 'user', content: input }
    setMessages(prev => [...prev, userMessage])
    setInput('')

    // Pick a random loading message
    const randomMessage = LOADING_MESSAGES[Math.floor(Math.random() * LOADING_MESSAGES.length)]
    setLoadingMessage(randomMessage)
    setLoading(true)

    try {
      const token = localStorage.getItem('authToken')
      const headers: any = { 'Content-Type': 'application/json' }
      if (token) {
        headers['Authorization'] = `Bearer ${token}`
      }

      const res = await fetch('/api/chat', {
        method: 'POST',
        headers,
        body: JSON.stringify({
          messages: [...messages, userMessage]
        })
      })

      const data = await res.json()
      setMessages(prev => [...prev, {
        role: 'assistant',
        content: data.response || 'Ne pare rău, nu am putut genera un răspuns.'
      }])
    } catch (error) {
      console.error('Chat error:', error)
      setMessages(prev => [...prev, {
        role: 'assistant',
        content: 'Ne pare rău, a apărut o eroare. Vă rugăm să încercați din nou.'
      }])
    } finally {
      setLoading(false)
    }
  }

  return (
    <div className="bg-white rounded-lg shadow-md h-[600px] flex flex-col">
      <div className="p-4 border-b">
        <h3 className="text-lg font-semibold">Chat Biblic AI</h3>
        <p className="text-sm text-gray-600">Pune întrebări despre Biblie și primește răspunsuri fundamentate</p>
      </div>

      <div className="flex-1 overflow-y-auto p-4 space-y-4">
        {!isAuthenticated ? (
          <div className="flex flex-col items-center justify-center h-full text-center p-6">
            <User className="w-16 h-16 text-gray-400 mb-4" />
            <h3 className="text-lg font-semibold mb-2">Bun venit la AI Chat Biblic!</h3>
            <p className="text-gray-600 mb-4 max-w-md">
              Pentru a accesa chat-ul AI și a salva conversațiile tale, te rugăm să îți creezi un cont sau să te conectezi.
            </p>
            <button
              onClick={() => {
                window.dispatchEvent(new CustomEvent('auth:sign-in-required'))
              }}
              className="px-6 py-3 bg-blue-500 text-white rounded-lg hover:bg-blue-600 transition-colors"
            >
              Creează Cont / Conectează-te
            </button>
          </div>
        ) : (
          <>
            {messages.length === 0 && (
              <div className="text-center text-gray-500 mt-12">
                <p>Bună ziua! Sunt aici să vă ajut cu întrebările despre Biblie.</p>
                <p className="text-sm mt-2">Puteți începe prin a întreba ceva despre un verset sau o temă biblică.</p>
              </div>
            )}

            {messages.map((msg, idx) => (
          <div
            key={idx}
            className={`flex ${msg.role === 'user' ? 'justify-end' : 'justify-start'}`}
          >
            <div
              className={`max-w-[80%] p-3 rounded-lg ${
                msg.role === 'user'
                  ? 'bg-blue-500 text-white'
                  : 'bg-gray-100 text-gray-800'
              }`}
            >
              {msg.role === 'assistant' ? (
                <div className="prose prose-sm max-w-none">
                  <ReactMarkdown>
                    {msg.content}
                  </ReactMarkdown>
                </div>
              ) : (
                <p>{msg.content}</p>
              )}
            </div>
          </div>
        ))}

        {loading && (
          <div className="flex justify-start">
            <div className="bg-gray-100 p-4 rounded-lg">
              <div className="flex items-center space-x-3">
                <div className="flex space-x-2">
                  <div className="w-2 h-2 bg-blue-500 rounded-full animate-bounce" />
                  <div className="w-2 h-2 bg-blue-500 rounded-full animate-bounce delay-100" />
                  <div className="w-2 h-2 bg-blue-500 rounded-full animate-bounce delay-200" />
                </div>
                <span className="text-sm text-gray-600 italic">{loadingMessage}</span>
              </div>
            </div>
          </div>
            )}
            <div ref={messagesEndRef} />
          </>
        )}
      </div>

      {isAuthenticated && (
        <form onSubmit={handleSubmit} className="p-4 border-t">
          <div className="flex space-x-2">
            <input
              type="text"
              value={input}
              onChange={(e) => setInput(e.target.value)}
              placeholder="Întreabă despre Biblie..."
              className="flex-1 px-4 py-2 border border-gray-300 rounded-lg focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-blue-500"
              disabled={loading}
            />
            <button
              type="submit"
              disabled={loading || !input.trim()}
              className="px-4 py-2 bg-blue-500 text-white rounded-lg hover:bg-blue-600 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
            >
              <Send className="w-5 h-5" />
            </button>
          </div>
        </form>
      )}
    </div>
  )
}