import { useState, useCallback } from 'react';
import { api } from '@/services/api';

export interface ChatMessage {
  id: string;
  role: 'user' | 'assistant';
  content: string;
  type?: 'message' | 'scan_started' | 'transactions' | 'stats' | 'scan_history' | 'search_results' | 'error';
  data?: any;
  timestamp: Date;
}

const WELCOME_MESSAGE: ChatMessage = {
  id: 'welcome',
  role: 'assistant',
  content: "Bonjour! Je suis l'assistant ICC. Je peux scanner vos courriels, afficher les transactions, ou consulter les statistiques. Comment puis-je vous aider?",
  type: 'message',
  timestamp: new Date(),
};

export function useChatAssistant() {
  const [messages, setMessages] = useState<ChatMessage[]>([WELCOME_MESSAGE]);
  const [isLoading, setIsLoading] = useState(false);

  const sendMessage = useCallback(async (text: string) => {
    const userMsg: ChatMessage = {
      id: `user_${Date.now()}`,
      role: 'user',
      content: text,
      timestamp: new Date(),
    };

    setMessages((prev) => [...prev, userMsg]);
    setIsLoading(true);

    try {
      const response = await api.post<{
        type: string;
        message: string;
        data?: any;
      }>('/chat/message', { message: text });

      const assistantMsg: ChatMessage = {
        id: `assistant_${Date.now()}`,
        role: 'assistant',
        content: response.message,
        type: response.type as ChatMessage['type'],
        data: response.data,
        timestamp: new Date(),
      };

      setMessages((prev) => [...prev, assistantMsg]);
    } catch (error: any) {
      const errorMsg: ChatMessage = {
        id: `error_${Date.now()}`,
        role: 'assistant',
        content: error.message || 'Une erreur est survenue. Réessayez.',
        type: 'error',
        timestamp: new Date(),
      };
      setMessages((prev) => [...prev, errorMsg]);
    } finally {
      setIsLoading(false);
    }
  }, []);

  const clearHistory = useCallback(() => {
    setMessages([WELCOME_MESSAGE]);
  }, []);

  return { messages, isLoading, sendMessage, clearHistory };
}