import 'dart:io';

import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../models/document.dart';
import '../services/vault_service.dart';

final vaultServiceProvider = FutureProvider<VaultService>((ref) async {
  return VaultService.getInstance();
});

final documentListProvider =
    AsyncNotifierProvider<DocumentListNotifier, List<Document>>(
      DocumentListNotifier.new,
    );

/// The home-screen document list is now sourced from a VAULT SCAN (folders
/// under the vault root containing a source file + optional sidecar), NOT the
/// SQLite `documents` table. The sidecar that travels with the file is the
/// source of truth; there is no SQLite cache for this list (the scan is cheap —
/// one directory listing — and always correct).
class DocumentListNotifier extends AsyncNotifier<List<Document>> {
  Future<VaultService> get _vault =>
      ref.read(vaultServiceProvider.future);

  @override
  Future<List<Document>> build() async {
    return _scan();
  }

  Future<List<Document>> _scan() async {
    final vault = await _vault;
    final notebooks = await vault.scanNotebooks();
    return notebooks.map(_toDocument).toList();
  }

  /// Adapt a scanned [VaultNotebook] into the [Document] shape the home-screen
  /// tiles already render. The notebook folder path doubles as a stable id.
  Document _toDocument(VaultNotebook nb) {
    return Document(
      id: nb.folderPath,
      filename: nb.filename,
      docType: nb.docType,
      filePath: nb.sourceFilePath,
      pageCount: 0,
      createdAt: nb.modified,
      updatedAt: nb.modified,
    );
  }

  /// Re-scan the vault and publish the result. Used by pull-to-refresh and
  /// after an import.
  Future<void> loadDocuments() async {
    state = const AsyncLoading();
    state = await AsyncValue.guard(_scan);
  }

  /// Remove a notebook by deleting its folder (source file + sidecar travel
  /// together, so removing the folder removes the whole notebook). [id] is the
  /// notebook folder path produced by [_toDocument].
  Future<void> removeDocument(String id) async {
    final dir = Directory(id);
    if (await dir.exists()) {
      await dir.delete(recursive: true);
    }
    final current = state.value ?? [];
    state = AsyncData(current.where((d) => d.id != id).toList());
  }
}