import 'package:riverpod_annotation/riverpod_annotation.dart';
import 'package:trainhub_flutter/domain/repositories/note_repository.dart';
import 'package:trainhub_flutter/injection.dart';
import 'package:trainhub_flutter/presentation/settings/knowledge_base_state.dart';

part 'knowledge_base_controller.g.dart';

@riverpod
class KnowledgeBaseController extends _$KnowledgeBaseController {
  late NoteRepository _repo;

  @override
  KnowledgeBaseState build() {
    _repo = getIt<NoteRepository>();
    // Load the current chunk count asynchronously after first build.
    _loadCount();
    return const KnowledgeBaseState();
  }

  // -------------------------------------------------------------------------
  // Load chunk count
  // -------------------------------------------------------------------------

  Future<void> _loadCount() async {
    try {
      final count = await _repo.getChunkCount();
      state = state.copyWith(chunkCount: count);
    } catch (_) {
      // Non-fatal — UI stays at 0.
    }
  }

  // -------------------------------------------------------------------------
  // Save note
  // -------------------------------------------------------------------------

  /// Chunks [text], generates embeddings via Nomic, and stores the result.
  Future<void> saveNote(String text) async {
    if (text.trim().isEmpty) return;

    state = state.copyWith(
      isLoading: true,
      successMessage: null,
      errorMessage: null,
    );

    try {
      await _repo.addNote(text.trim());
      final count = await _repo.getChunkCount();
      state = state.copyWith(
        isLoading: false,
        chunkCount: count,
        successMessage: 'Saved! Knowledge base now has $count chunks.',
      );
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        errorMessage: _friendlyError(e),
      );
    }
  }

  // -------------------------------------------------------------------------
  // Clear knowledge base
  // -------------------------------------------------------------------------

  Future<void> clearKnowledgeBase() async {
    state = state.copyWith(
      isLoading: true,
      successMessage: null,
      errorMessage: null,
    );
    try {
      await _repo.clearAll();
      state = state.copyWith(
        isLoading: false,
        chunkCount: 0,
        successMessage: 'Knowledge base cleared.',
      );
    } catch (e) {
      state = state.copyWith(
        isLoading: false,
        errorMessage: _friendlyError(e),
      );
    }
  }

  // -------------------------------------------------------------------------
  // Helper
  // -------------------------------------------------------------------------

  String _friendlyError(Object e) {
    final msg = e.toString();
    if (msg.contains('Connection refused') ||
        msg.contains('SocketException')) {
      return 'Cannot reach the embedding server. '
          'Make sure AI models are downloaded and the app has had time to '
          'start the inference servers.';
    }
    return 'Error: $msg';
  }
}