relatica/lib/services/entry_manager_service.dart

import 'package:flutter/material.dart';
import 'package:logging/logging.dart';
import 'package:result_monad/result_monad.dart';

import '../friendica_client.dart';
import '../globals.dart';
import '../models/TimelineIdentifiers.dart';
import '../models/entry_tree_item.dart';
import '../models/exec_error.dart';
import '../models/timeline_entry.dart';
import 'auth_service.dart';

class EntryManagerService extends ChangeNotifier {
  static final _logger = Logger('$EntryManagerService');
  final Map<String, EntryTreeItem> _posts = {};
  final List<EntryTreeItem> _orphanedComments = [];
  final Map<String, EntryTreeItem> _allComments = {};

  FutureResult<List<EntryTreeItem>, ExecError> updateTimeline(
      TimelineIdentifiers type) async {
    _logger.fine(() => 'Updating timeline');
    final auth = getIt<AuthService>();
    final clientResult = auth.currentClient;
    if (clientResult.isFailure) {
      _logger.severe('Error getting Friendica client: ${clientResult.error}');
      return clientResult.errorCast();
    }

    final client = clientResult.value;
    final itemsResult = await client.getTimeline(type: type);
    final myHandle = client.credentials.username;
    if (itemsResult.isFailure) {
      _logger.severe('Error getting timeline: ${itemsResult.error}');
      return itemsResult.errorCast();
    }

    itemsResult.value.sort((t1, t2) => t1.id.compareTo(t2.id));
    final updatedPosts =
        await processNewItems(itemsResult.value, myHandle, client);
    _orphanedComments.removeWhere((element) => !element.isOrphaned);
    _logger.finest(() =>
        'End of update # posts: ${_posts.length}, #comments: ${_allComments.length}, #orphans: ${_orphanedComments.length}');
    notifyListeners();
    return Result.ok(updatedPosts);
  }

  Future<List<EntryTreeItem>> processNewItems(
    List<TimelineEntry> items,
    String myHandle,
    FriendicaClient? client,
  ) async {
    final updatedPosts = <EntryTreeItem>[];
    for (final t in items) {
      late EntryTreeItem entry;
      final isMine = t.author == myHandle;
      if (t.parentAuthor.isEmpty) {
        entry = _posts.putIfAbsent(
            t.id, () => EntryTreeItem(t, isMine: isMine, isOrphaned: false));
        updatedPosts.add(entry);
      } else {
        final parent = _posts[t.parentId];
        bool newEntry = false;
        entry = _allComments.putIfAbsent(t.id, () {
          newEntry = true;
          return EntryTreeItem(t, isMine: isMine, isOrphaned: parent == null);
        });
        parent?.addChild(entry);
        if (newEntry && entry.isOrphaned) {
          _orphanedComments.add(entry);
        }
      }
    }

    final orphansToProcess = [];
    for (final c in _orphanedComments) {
      final post = _posts[c.entry.parentId];
      if (post != null) {
        c.isOrphaned = false;
        post.addChild(c);
        continue;
      }

      final comment = _allComments[c.entry.parentId];
      if (comment != null) {
        c.isOrphaned = false;
        comment.addChild(c);
        continue;
      }

      if (client != null) {
        orphansToProcess.add(c);
      }
    }

    for (final o in orphansToProcess) {
      await client
          ?.getPostOrComment(o.id, fullContext: true)
          .andThenSuccessAsync((items) async {
        final moreUpdatedPosts = await processNewItems(items, myHandle, null);
        updatedPosts.addAll(moreUpdatedPosts);
      });
    }
    _logger.finest(
        'Completed processing new items ${client == null ? 'sub level' : 'top level'}');
    return updatedPosts;
  }

  FutureResult<EntryTreeItem, ExecError> toggleFavorited(
      String id, bool newStatus,
      {bool notify = false}) async {
    final auth = getIt<AuthService>();
    final clientResult = auth.currentClient;
    if (clientResult.isFailure) {
      _logger.severe('Error getting Friendica client: ${clientResult.error}');
      return clientResult.errorCast();
    }
    final client = clientResult.value;
    final result = await client.changeFavoriteStatus(id, newStatus);
    if (result.isFailure) {
      return result.errorCast();
    }

    final update = result.value;
    late EntryTreeItem rval;
    if (_posts.containsKey(update.id)) {
      rval = _posts[update.id]!.copy(entry: update);
      _posts[update.id] = rval;
      _updateChildrenEntities(rval, update);
    }

    if (_allComments.containsKey(update.id)) {
      rval = _allComments[update.id]!.copy(entry: update);
      _allComments[update.id] = rval;
      _updateChildrenEntities(rval, update);
    }

    if (notify) {
      notifyListeners();
    }
    return Result.ok(rval);
  }

  void _updateChildrenEntities(EntryTreeItem item, TimelineEntry entry) {
    final updates = item.children.where((element) => element.id == entry.id);
    for (final u in updates) {
      final newItem = u.copy(entry: entry);
      item.children.remove(u);
      item.children.add(newItem);
    }

    for (final c in item.children) {
      _updateChildrenEntities(c, entry);
    }
  }
}