import 'package:riverpod_annotation/riverpod_annotation.dart';
import 'package:trainhub_flutter/injection.dart';
import 'package:trainhub_flutter/domain/repositories/chat_repository.dart';
import 'package:trainhub_flutter/presentation/chat/chat_state.dart';

part 'chat_controller.g.dart';

@riverpod
class ChatController extends _$ChatController {
  late final ChatRepository _repo;

  @override
  Future<ChatState> build() async {
    _repo = getIt<ChatRepository>();
    final sessions = await _repo.getAllSessions();
    return ChatState(sessions: sessions);
  }

  Future<void> createSession() async {
    final session = await _repo.createSession();
    final sessions = await _repo.getAllSessions();
    state = AsyncValue.data(
      ChatState(sessions: sessions, activeSession: session),
    );
  }

  Future<void> loadSession(String id) async {
    final session = await _repo.getSession(id);
    if (session == null) return;
    final messages = await _repo.getMessages(id);
    final current = state.valueOrNull ?? const ChatState();
    state = AsyncValue.data(
      current.copyWith(activeSession: session, messages: messages),
    );
  }

  Future<void> deleteSession(String id) async {
    await _repo.deleteSession(id);
    final sessions = await _repo.getAllSessions();
    final current = state.valueOrNull ?? const ChatState();
    state = AsyncValue.data(
      current.copyWith(
        sessions: sessions,
        activeSession:
            current.activeSession?.id == id ? null : current.activeSession,
        messages: current.activeSession?.id == id ? [] : current.messages,
      ),
    );
  }

  Future<void> sendMessage(String content) async {
    final current = state.valueOrNull;
    if (current == null) return;
    String sessionId;
    if (current.activeSession == null) {
      final session = await _repo.createSession();
      sessionId = session.id;
      final sessions = await _repo.getAllSessions();
      state = AsyncValue.data(
        current.copyWith(sessions: sessions, activeSession: session),
      );
    } else {
      sessionId = current.activeSession!.id;
    }
    await _repo.addMessage(
      sessionId: sessionId,
      role: 'user',
      content: content,
    );
    final messagesAfterUser = await _repo.getMessages(sessionId);
    state = AsyncValue.data(
      state.valueOrNull!.copyWith(messages: messagesAfterUser, isTyping: true),
    );
    await Future<void>.delayed(const Duration(seconds: 1));
    final String response = _getMockResponse(content);
    await _repo.addMessage(
      sessionId: sessionId,
      role: 'assistant',
      content: response,
    );
    final messagesAfterAi = await _repo.getMessages(sessionId);
    if (messagesAfterAi.length <= 2) {
      final title = content.length > 30
          ? '${content.substring(0, 30)}...'
          : content;
      await _repo.updateSessionTitle(sessionId, title);
    }
    final sessions = await _repo.getAllSessions();
    state = AsyncValue.data(
      state.valueOrNull!.copyWith(
        messages: messagesAfterAi,
        isTyping: false,
        sessions: sessions,
      ),
    );
  }

  String _getMockResponse(String input) {
    final String lower = input.toLowerCase();
    if (lower.contains('plan') || lower.contains('program')) {
      return "I can help you design a training plan! What are your goals? Strength, hypertrophy, or endurance?";
    } else if (lower.contains('squat') || lower.contains('bench')) {
      return "Compound movements are great. Remember to maintain proper form. For squats, keep your chest up and knees tracking over toes.";
    } else if (lower.contains('nutrition') || lower.contains('eat')) {
      return "Nutrition is key. Aim for 1.6-2.2g of protein per kg of bodyweight if you're training hard.";
    }
    return "I'm your AI training assistant. How can I help you today?";
  }
}