'use client';

import { useState, useCallback } from 'react';
import { MessageList } from './MessageList';
import { ChatInput } from './ChatInput';
import { VoiceInput } from './VoiceInput';
import { ActionPreview } from './ActionPreview';
import { ChatHistory } from './ChatHistory';
import {
  sendChatMessage,
  executeAction,
  sendVoiceMessage,
  type ChatMessage,
  type ActionItem,
} from '@/lib/copilot';

export function ChatInterface() {
  const [messages, setMessages] = useState<ChatMessage[]>([]);
  const [sessionId, setSessionId] = useState<string | undefined>(undefined);
  const [pendingActions, setPendingActions] = useState<ActionItem[]>([]);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [showHistory, setShowHistory] = useState(false);

  const handleSend = useCallback(async (text: string) => {
    if (!text.trim() || loading) return;
    setLoading(true);
    setError(null);
    const userMsg: ChatMessage = {
      id: `temp-${Date.now()}`,
      session_id: sessionId || '',
      role: 'user',
      content: text,
      created_at: new Date().toISOString(),
    };
    setMessages((prev) => [...prev, userMsg]);
    try {
      const result = await sendChatMessage(text, sessionId);
      setSessionId(result.session_id);
      const assistantMsg: ChatMessage = {
        id: result.message_id,
        session_id: result.session_id,
        role: 'assistant',
        content: result.response,
        actions: result.actions,
        created_at: new Date().toISOString(),
      };
      setMessages((prev) => [...prev, assistantMsg]);
      if (result.actions && result.actions.length > 0) {
        setPendingActions(result.actions);
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Ein Fehler ist aufgetreten');
    } finally {
      setLoading(false);
    }
  }, [sessionId, loading]);

  const handleVoice = useCallback(async (audioBase64: string, mimeType: string) => {
    if (loading) return;
    setLoading(true);
    setError(null);
    try {
      const result = await sendVoiceMessage(audioBase64, mimeType, sessionId);
      setSessionId(result.session_id);
      const userMsg: ChatMessage = {
        id: `voice-${Date.now()}`,
        session_id: result.session_id,
        role: 'user',
        content: `🎤 ${result.transcription}`,
        created_at: new Date().toISOString(),
      };
      const assistantMsg: ChatMessage = {
        id: result.message_id,
        session_id: result.session_id,
        role: 'assistant',
        content: result.response,
        actions: result.actions,
        created_at: new Date().toISOString(),
      };
      setMessages((prev) => [...prev, userMsg, assistantMsg]);
      if (result.actions && result.actions.length > 0) {
        setPendingActions(result.actions);
      }
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Spracherkennung fehlgeschlagen');
    } finally {
      setLoading(false);
    }
  }, [sessionId, loading]);

  const handleConfirmAction = useCallback(async (action: ActionItem) => {
    setLoading(true);
    setError(null);
    try {
      const result = await executeAction(action.type, action.params, sessionId);
      const resultMsg: ChatMessage = {
        id: `action-${Date.now()}`,
        session_id: sessionId || '',
        role: 'assistant',
        content: `Aktion "${result.action}" ausgefuehrt. ${result.success ? 'Erfolgreich.' : 'Fehlgeschlagen.'}`,
        created_at: new Date().toISOString(),
      };
      setMessages((prev) => [...prev, resultMsg]);
      setPendingActions((prev) => prev.filter((a) => a !== action));
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Aktion fehlgeschlagen');
    } finally {
      setLoading(false);
    }
  }, [sessionId]);

  const handleDismissAction = useCallback((action: ActionItem) => {
    setPendingActions((prev) => prev.filter((a) => a !== action));
  }, []);

  const handleSelectSession = useCallback((selectedSessionId: string) => {
    setSessionId(selectedSessionId);
    setMessages([]);
    setPendingActions([]);
    setShowHistory(false);
  }, []);

  return (
    <div className="flex gap-4 h-[calc(100vh-12rem)]">
      {showHistory && (
        <ChatHistory
          onSelectSession={handleSelectSession}
          onClose={() => setShowHistory(false)}
        />
      )}
      <div className="flex-1 flex flex-col">
        <div className="flex items-center justify-between mb-2">
          <button
            onClick={() => setShowHistory(!showHistory)}
            className="text-sm text-blue-600 hover:underline"
            data-testid="toggle-history"
          >
            {showHistory ? 'Verlauf ausblenden' : 'Verlauf anzeigen'}
          </button>
        </div>
        <MessageList messages={messages} loading={loading} />
        {error && (
          <div className="text-red-600 text-sm p-2" data-testid="chat-error">
            {error}
          </div>
        )}
        {pendingActions.length > 0 && (
          <ActionPreview
            actions={pendingActions}
            onConfirm={handleConfirmAction}
            onDismiss={handleDismissAction}
          />
        )}
        <div className="flex gap-2 items-end pt-2">
          <ChatInput onSend={handleSend} disabled={loading} />
          <VoiceInput onVoice={handleVoice} disabled={loading} />
        </div>
      </div>
    </div>
  );
}