import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:tasq/models/programmer_task.model.dart';
import 'package:tasq/providers/programmer_task_comments_provider.dart';
import 'package:tasq/providers/programmer_task_work_logs_provider.dart';
import 'package:tasq/providers/programmer_tasks_provider.dart';
import 'package:tasq/screens/programmer_tasks/programmer_task_actions.dart';
import 'package:tasq/utils/app_time.dart';

// ---------------------------------------------------------------------------
// Minimal fake Supabase client — only the surface ProgrammerTasksController uses.
// ---------------------------------------------------------------------------

class _FakeUser {
  _FakeUser(this.id);
  final String id;
}

class _FakeAuth {
  _FakeAuth(this._id);
  final String _id;
  _FakeUser? get currentUser => _FakeUser(_id);
}

class _FakeClient {
  _FakeClient(this.userId);
  final String userId;
  int _seq = 0;

  final Map<String, List<Map<String, dynamic>>> tables = {
    'programmer_tasks': [],
    'programmer_task_activity_logs': [],
    'programmer_task_work_logs': [],
    'programmer_task_comments': [],
  };

  _FakeAuth get auth => _FakeAuth(userId);

  _FakeQuery from(String table) => _FakeQuery(this, table);

  String nextTimestamp() {
    _seq += 1;
    return DateTime.utc(2026, 1, 1).add(Duration(seconds: _seq)).toIso8601String();
  }
}

class _FakeQuery implements Future<List<Map<String, dynamic>>> {
  _FakeQuery(this.client, this.table);

  final _FakeClient client;
  final String table;

  final List<MapEntry<String, dynamic>> _eqs = [];
  String? _inField;
  List<String>? _inValues;
  String? _orderField;
  bool _orderAsc = true;
  int? _limit;
  Map<String, dynamic>? _insertPayload;
  Map<String, dynamic>? _updatePayload;

  List<Map<String, dynamic>> get _rows {
    var rows = List<Map<String, dynamic>>.from(client.tables[table] ?? []);
    if (_inField != null && _inValues != null) {
      rows = rows
          .where((r) => _inValues!.contains(r[_inField]?.toString()))
          .toList();
    }
    for (final eq in _eqs) {
      rows = rows.where((r) => r[eq.key] == eq.value).toList();
    }
    if (_orderField != null) {
      rows.sort((a, b) {
        final av = '${a[_orderField]}';
        final bv = '${b[_orderField]}';
        return _orderAsc ? av.compareTo(bv) : bv.compareTo(av);
      });
    }
    if (_limit != null && rows.length > _limit!) {
      rows = rows.sublist(0, _limit!);
    }
    return rows;
  }

  Future<List<Map<String, dynamic>>> get _future async {
    if (_insertPayload != null) {
      final row = Map<String, dynamic>.from(_insertPayload!);
      row['id'] ??= '${table}_${client.tables[table]!.length + 1}';
      row['created_at'] ??= client.nextTimestamp();
      if (table == 'programmer_tasks') {
        row['updated_at'] ??= row['created_at'];
      }
      client.tables[table]!.add(row);
      return [row];
    }
    return _rows;
  }

  _FakeQuery select([String? _]) => this;

  _FakeQuery insert(Map<String, dynamic> payload) {
    _insertPayload = Map<String, dynamic>.from(payload);
    return this;
  }

  _FakeQuery update(Map<String, dynamic> payload) {
    _updatePayload = Map<String, dynamic>.from(payload);
    return this;
  }

  _FakeQuery inFilter(String field, List<dynamic> values) {
    _inField = field;
    _inValues = values.map((v) => v.toString()).toList();
    return this;
  }

  _FakeQuery order(String field, {bool ascending = true}) {
    _orderField = field;
    _orderAsc = ascending;
    return this;
  }

  _FakeQuery limit(int n) {
    _limit = n;
    return this;
  }

  _FakeQuery eq(String field, dynamic value) {
    if (_updatePayload != null) {
      final idx =
          client.tables[table]!.indexWhere((r) => r[field] == value);
      if (idx >= 0) {
        client.tables[table]![idx] = {
          ...client.tables[table]![idx],
          ..._updatePayload!,
        };
      }
      _updatePayload = null;
      return this;
    }
    _eqs.add(MapEntry(field, value));
    return this;
  }

  Future<Map<String, dynamic>?> maybeSingle() async {
    final rows = _rows;
    return rows.isEmpty ? null : Map<String, dynamic>.from(rows.first);
  }

  // Future delegation.
  @override
  Stream<List<Map<String, dynamic>>> asStream() => _future.asStream();
  @override
  Future<List<Map<String, dynamic>>> catchError(Function onError,
          {bool Function(Object error)? test}) =>
      _future.catchError(onError, test: test);
  @override
  Future<R> then<R>(FutureOr<R> Function(List<Map<String, dynamic>>) onValue,
          {Function? onError}) =>
      _future.then(onValue, onError: onError);
  @override
  Future<List<Map<String, dynamic>>> timeout(Duration timeLimit,
          {FutureOr<List<Map<String, dynamic>>> Function()? onTimeout}) =>
      _future.timeout(timeLimit, onTimeout: onTimeout);
  @override
  Future<List<Map<String, dynamic>>> whenComplete(FutureOr<void> Function() a) =>
      _future.whenComplete(a);
}

List<Map<String, dynamic>> _logs(_FakeClient c) =>
    c.tables['programmer_task_activity_logs']!;
Map<String, dynamic> _task(_FakeClient c, String id) =>
    c.tables['programmer_tasks']!.firstWhere((t) => t['id'] == id);

void main() {
  setUpAll(AppTime.initialize);

  group('ProgrammerTasksController.createTask', () {
    test('self-logged task: assignee = creator, no "assigned" log', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);

      final id = await c.createTask(
        title: 'Fix login bug',
        category: ProgrammerTaskCategory.bugFix,
      );

      final row = _task(fake, id);
      expect(row['assignee_id'], 'u1');
      expect(row['creator_id'], 'u1');
      expect(row['status'], ProgrammerTaskStatus.queued);
      expect(_logs(fake).where((l) => l['action_type'] == 'created').length, 1);
      expect(_logs(fake).any((l) => l['action_type'] == 'assigned'), isFalse);
    });

    test('assigned to another programmer records an "assigned" log', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);

      final id = await c.createTask(
        title: 'Build report export',
        category: ProgrammerTaskCategory.softwareDevelopment,
        assigneeId: 'u2',
      );

      expect(_task(fake, id)['assignee_id'], 'u2');
      final assigned =
          _logs(fake).where((l) => l['action_type'] == 'assigned').toList();
      expect(assigned.length, 1);
      expect(assigned.first['meta'], {'assignee_id': 'u2'});
    });
  });

  group('findRunningTaskForCurrentUser (pause-on-switch detection)', () {
    test('returns null when the user has no in_progress task', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      fake.tables['programmer_tasks']!.add({
        'id': 't1',
        'assignee_id': 'u1',
        'status': ProgrammerTaskStatus.queued,
        'created_at': fake.nextTimestamp(),
      });
      expect(await c.findRunningTaskForCurrentUser(), isNull);
    });

    test('returns an in_progress task whose latest event is "started"', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      fake.tables['programmer_tasks']!.add({
        'id': 't1',
        'title': 'Running task',
        'category': ProgrammerTaskCategory.others,
        'assignee_id': 'u1',
        'status': ProgrammerTaskStatus.inProgress,
        'created_at': fake.nextTimestamp(),
      });
      _logs(fake).add({
        'task_id': 't1',
        'action_type': 'started',
        'created_at': fake.nextTimestamp(),
      });

      final running = await c.findRunningTaskForCurrentUser();
      expect(running, isNotNull);
      expect(running!.id, 't1');
    });

    test('a paused in_progress task does NOT count as running', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      fake.tables['programmer_tasks']!.add({
        'id': 't1',
        'title': 'Paused task',
        'category': ProgrammerTaskCategory.others,
        'assignee_id': 'u1',
        'status': ProgrammerTaskStatus.inProgress,
        'created_at': fake.nextTimestamp(),
      });
      _logs(fake).add({
        'task_id': 't1',
        'action_type': 'started',
        'created_at': fake.nextTimestamp(),
      });
      _logs(fake).add({
        'task_id': 't1',
        'action_type': 'paused',
        'created_at': fake.nextTimestamp(),
      });

      expect(await c.findRunningTaskForCurrentUser(), isNull);
    });
  });

  group('lifecycle transitions', () {
    test('startTask sets in_progress + started_at + a "started" log', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.meeting,
      );

      await c.startTask(taskId: id);

      final row = _task(fake, id);
      expect(row['status'], ProgrammerTaskStatus.inProgress);
      expect(row['started_at'], isNotNull);
      expect(_logs(fake).any((l) => l['action_type'] == 'started'), isTrue);
    });

    test('pauseTask is idempotent while already paused', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );
      await c.startTask(taskId: id);

      await c.pauseTask(taskId: id);
      await c.pauseTask(taskId: id); // second call is a no-op

      expect(_logs(fake).where((l) => l['action_type'] == 'paused').length, 1);
    });

    test('resumeTask logs a "resumed" event after a pause', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );
      await c.startTask(taskId: id);
      await c.pauseTask(taskId: id);

      await c.resumeTask(taskId: id);

      expect(_logs(fake).where((l) => l['action_type'] == 'resumed').length, 1);
    });

    test('completeTask sets completed status + timestamp + log', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );
      await c.startTask(taskId: id);

      await c.completeTask(taskId: id);

      final row = _task(fake, id);
      expect(row['status'], ProgrammerTaskStatus.completed);
      expect(row['completed_at'], isNotNull);
      expect(_logs(fake).any((l) => l['action_type'] == 'completed'), isTrue);
    });

    test('cancelTask stores the reason and a "cancelled" log', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );

      await c.cancelTask(taskId: id, reason: 'Descoped');

      final row = _task(fake, id);
      expect(row['status'], ProgrammerTaskStatus.cancelled);
      expect(row['cancellation_reason'], 'Descoped');
      expect(_logs(fake).any((l) => l['action_type'] == 'cancelled'), isTrue);
    });

    test('reassign updates assignee and logs a "reassigned" event', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );

      await c.reassign(taskId: id, newAssigneeId: 'u2');

      expect(_task(fake, id)['assignee_id'], 'u2');
      expect(_logs(fake).any((l) => l['action_type'] == 'reassigned'), isTrue);
    });
  });

  group('startProgrammerTaskWithPausePrompt (pause-on-switch UX)', () {
    _FakeClient seededSwitchState() {
      final fake = _FakeClient('u1');
      // Task A is actively running for u1.
      fake.tables['programmer_tasks']!.add({
        'id': 'A',
        'title': 'Task A',
        'category': ProgrammerTaskCategory.others,
        'assignee_id': 'u1',
        'status': ProgrammerTaskStatus.inProgress,
        'started_at': fake.nextTimestamp(),
        'created_at': fake.nextTimestamp(),
      });
      _logs(fake).add({
        'task_id': 'A',
        'action_type': 'started',
        'created_at': fake.nextTimestamp(),
      });
      // Task B is queued and about to be started.
      fake.tables['programmer_tasks']!.add({
        'id': 'B',
        'title': 'Task B',
        'category': ProgrammerTaskCategory.others,
        'assignee_id': 'u1',
        'status': ProgrammerTaskStatus.queued,
        'created_at': fake.nextTimestamp(),
      });
      return fake;
    }

    ProgrammerTask taskB() => ProgrammerTask(
          id: 'B',
          title: 'Task B',
          category: ProgrammerTaskCategory.others,
          status: ProgrammerTaskStatus.queued,
          assigneeId: 'u1',
          creatorId: 'u1',
          createdAt: DateTime.utc(2026, 1, 1),
          updatedAt: DateTime.utc(2026, 1, 1),
        );

    Widget harness(_FakeClient fake) => ProviderScope(
          overrides: [
            programmerTasksControllerProvider.overrideWithValue(
              ProgrammerTasksController(fake as dynamic),
            ),
          ],
          child: MaterialApp(
            home: Scaffold(
              body: Consumer(
                builder: (context, ref, _) => ElevatedButton(
                  onPressed: () =>
                      startProgrammerTaskWithPausePrompt(context, ref, taskB()),
                  child: const Text('Start B'),
                ),
              ),
            ),
          ),
        );

    testWidgets('prompts, then pauses A and starts B on confirm', (tester) async {
      final fake = seededSwitchState();
      await tester.pumpWidget(harness(fake));

      await tester.tap(find.text('Start B'));
      await tester.pumpAndSettle();

      // The prompt names the currently-running task.
      expect(find.text('Pause current task?'), findsOneWidget);

      await tester.tap(find.text('Pause & Start'));
      await tester.pumpAndSettle();

      expect(
        _logs(fake).any((l) => l['task_id'] == 'A' && l['action_type'] == 'paused'),
        isTrue,
      );
      expect(_task(fake, 'B')['status'], ProgrammerTaskStatus.inProgress);
    });

    testWidgets('cancel leaves both tasks untouched', (tester) async {
      final fake = seededSwitchState();
      await tester.pumpWidget(harness(fake));

      await tester.tap(find.text('Start B'));
      await tester.pumpAndSettle();
      await tester.tap(find.text('Cancel'));
      await tester.pumpAndSettle();

      expect(_logs(fake).any((l) => l['action_type'] == 'paused'), isFalse);
      expect(_task(fake, 'B')['status'], ProgrammerTaskStatus.queued);
    });
  });

  group('projects, adjustments & collaboration', () {
    test('createTask carries project_id', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
        projectId: 'proj-1',
      );
      expect(_task(fake, id)['project_id'], 'proj-1');
    });

    test('setProject updates project_id and logs an update', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );
      await c.setProject(taskId: id, projectId: 'proj-9');
      expect(_task(fake, id)['project_id'], 'proj-9');
      expect(
        _logs(fake).any((l) =>
            l['action_type'] == 'updated' &&
            (l['meta']?['fields'] as List?)?.contains('project_id') == true),
        isTrue,
      );
    });

    test('addAdjustment records a signed adjustment log', () async {
      final fake = _FakeClient('u1');
      final c = ProgrammerTasksController(fake as dynamic);
      final id = await c.createTask(
        title: 't',
        category: ProgrammerTaskCategory.others,
      );
      await c.addAdjustment(
        taskId: id,
        seconds: 1800,
        reason: 'helped',
        sourceTaskId: 'other',
      );
      final adj = _logs(fake).firstWhere((l) => l['action_type'] == 'adjustment');
      expect(adj['meta']['seconds'], 1800);
      expect(adj['meta']['reason'], 'helped');
      expect(adj['meta']['source_task_id'], 'other');
    });

    test('addWorkLog stores helper minutes and omits them for the assignee',
        () async {
      final fake = _FakeClient('u1');
      final wl = ProgrammerTaskWorkLogsController(fake as dynamic);
      await wl.addWorkLog(taskId: 't1', description: 'helped', minutes: 30);
      await wl.addWorkLog(taskId: 't1', description: 'progress'); // assignee note

      final rows = fake.tables['programmer_task_work_logs']!;
      expect(rows.length, 2);
      expect(rows[0]['author_id'], 'u1');
      expect(rows[0]['minutes'], 30);
      expect(rows[1].containsKey('minutes'), isFalse); // null minutes omitted
    });

    test('addComment stores body + author with empty attachments', () async {
      final fake = _FakeClient('u1');
      final cc = ProgrammerTaskCommentsController(fake as dynamic);
      await cc.addComment(taskId: 't1', body: 'looks good');

      final rows = fake.tables['programmer_task_comments']!;
      expect(rows.length, 1);
      expect(rows.first['author_id'], 'u1');
      expect(rows.first['body'], 'looks good');
      expect(rows.first['attachments'], isEmpty);
    });
  });
}