import 'package:flutter_test/flutter_test.dart';
import 'package:uto_manager/domain/entities/authorized_rank.dart';
import 'package:uto_manager/domain/entities/doctrinal_branch.dart';
import 'package:uto_manager/domain/entities/echelon.dart';
import 'package:uto_manager/domain/entities/personnel_record.dart';
import 'package:uto_manager/domain/entities/position_slot.dart';
import 'package:uto_manager/domain/entities/unit_node.dart';
import 'package:uto_manager/domain/services/mtoe_validation_engine.dart';
import 'package:uto_manager/domain/services/validation_isolate.dart';
import 'package:uto_manager/domain/value_objects/duty_mos.dart';

void main() {
  // ---------------------------------------------------------------------------
  // Helpers
  // ---------------------------------------------------------------------------

  UnitNode makeUnit(String id, Echelon echelon, {String? parentId}) => UnitNode(
        unitId: id,
        echelon: echelon,
        branch: DoctrinalBranch.infantry,
        parentUnitId: parentId,
        name: 'Unit $id',
        isKeyLeader: false,
      );

  PositionSlot makeSlot(
    String id,
    String unitId, {
    bool isKeyLeader = false,
    String? assignedPersonnelId,
  }) =>
      PositionSlot(
        slotId: id,
        unitId: unitId,
        positionTitle: isKeyLeader ? 'Squad Leader' : 'Rifleman',
        dutyMos: DutyMos.unvalidated(isKeyLeader ? '11B' : '11B'),
        authorizedRank: isKeyLeader ? AuthorizedRank.e6 : AuthorizedRank.e3,
        isKeyLeader: isKeyLeader,
        assignedPersonnelId: assignedPersonnelId,
      );

  // ---------------------------------------------------------------------------
  // IsolateValidationRunner
  // ---------------------------------------------------------------------------

  group('IsolateValidationRunner', () {
    late IsolateValidationRunner runner;

    setUp(() {
      runner = IsolateValidationRunner();
    });

    tearDown(() async {
      await runner.dispose();
    });

    test('isStarted is false before start()', () {
      expect(runner.isStarted, false);
    });

    test('isStarted is true after start()', () async {
      await runner.start();
      expect(runner.isStarted, true);
    });

    test('start() is idempotent — calling twice does not throw', () async {
      await runner.start();
      await runner.start(); // second call should be a no-op
      expect(runner.isStarted, true);
    });

    test('validate() throws StateError if start() not called', () async {
      expect(
        () => runner.validate(units: const [], slots: const [], personnel: const []),
        throwsStateError,
      );
    });

    test('validate() returns empty findings for empty tree', () async {
      await runner.start();
      final response = await runner.validate(
        units: const [],
        slots: const [],
        personnel: const [],
      );
      expect(response.hasError, false);
      expect(response.findings, isEmpty);
    });

    test('validate() detects vacant key leader (V003)', () async {
      await runner.start();
      final unit = makeUnit('u1', Echelon.squad);
      final slot = makeSlot('sl1', 'u1', isKeyLeader: true); // vacant

      final response = await runner.validate(
        units: [unit],
        slots: [slot],
        personnel: const [],
      );

      expect(response.hasError, false);
      expect(response.findings.any((f) => f.findingCode == 'V003'), true);
    });

    test('validate() detects missing medic in platoon (V004)', () async {
      await runner.start();
      final unit = makeUnit('u1', Echelon.platoon);
      final slot = makeSlot('sl1', 'u1'); // no 68W slot

      final response = await runner.validate(
        units: [unit],
        slots: [slot],
        personnel: const [],
      );

      expect(response.hasError, false);
      expect(response.findings.any((f) => f.findingCode == 'V004'), true);
    });

    test('validate() returns clean result for fully-staffed valid unit', () async {
      await runner.start();
      // A squad with a filled key leader slot and no hierarchy violations.
      final unit = makeUnit('u1', Echelon.squad);
      final keyLeaderSlot = PositionSlot(
        slotId: 'sl1',
        unitId: 'u1',
        positionTitle: 'Squad Leader',
        dutyMos: DutyMos.unvalidated('11B'),
        authorizedRank: AuthorizedRank.e6,
        isKeyLeader: true,
        assignedPersonnelId: 's1',
      );
      final soldier = PersonnelRecord(
        soldierId: 's1',
        name: 'SSG Smith',
        primaryMos: DutyMos.unvalidated('11B'),
        payGrade: AuthorizedRank.e6,
        readinessState: ReadinessState.fullyMissionCapable,
      );

      final response = await runner.validate(
        units: [unit],
        slots: [keyLeaderSlot],
        personnel: [soldier],
      );

      expect(response.hasError, false);
      // V003 should not fire (key leader is filled).
      expect(response.findings.any((f) => f.findingCode == 'V003'), false);
    });

    test('validate() detects structural hierarchy violation (V006)', () async {
      await runner.start();
      // Squad directly under Brigade — invalid.
      final brigade = makeUnit('bde', Echelon.brigade);
      final squad = makeUnit('sq1', Echelon.squad, parentId: 'bde');

      final response = await runner.validate(
        units: [brigade, squad],
        slots: const [],
        personnel: const [],
      );

      expect(response.hasError, false);
      expect(response.findings.any((f) => f.findingCode == 'V006'), true);
      expect(
        response.findings.firstWhere((f) => f.findingCode == 'V006').severity,
        FindingSeverity.critical,
      );
    });

    test('validate() results match synchronous engine output', () async {
      await runner.start();
      final units = [
        makeUnit('bde', Echelon.brigade),
        makeUnit('bn', Echelon.battalion, parentId: 'bde'),
        makeUnit('co', Echelon.company, parentId: 'bn'),
        makeUnit('plt', Echelon.platoon, parentId: 'co'),
      ];
      final slots = [
        makeSlot('sl1', 'plt', isKeyLeader: true), // vacant key leader
      ];

      final isolateResponse = await runner.validate(
        units: units,
        slots: slots,
        personnel: const [],
      );

      // Compare with synchronous engine.
      const syncEngine = MtoeValidationEngine();
      final syncFindings = syncEngine.validate(
        units: units,
        slots: slots,
        personnel: const [],
      );

      expect(isolateResponse.findings.length, syncFindings.length);
      for (var i = 0; i < syncFindings.length; i++) {
        expect(isolateResponse.findings[i].findingCode, syncFindings[i].findingCode);
        expect(isolateResponse.findings[i].severity, syncFindings[i].severity);
      }
    });

    test('dispose() sets isStarted to false', () async {
      await runner.start();
      await runner.dispose();
      expect(runner.isStarted, false);
    });

    test('can restart after dispose()', () async {
      await runner.start();
      await runner.dispose();
      await runner.start();
      expect(runner.isStarted, true);

      final response = await runner.validate(
        units: const [],
        slots: const [],
        personnel: const [],
      );
      expect(response.hasError, false);
    });
  });

  // ---------------------------------------------------------------------------
  // ValidationResponse
  // ---------------------------------------------------------------------------

  group('ValidationResponse', () {
    test('hasError is false when error is null', () {
      const response = ValidationResponse(findings: []);
      expect(response.hasError, false);
    });

    test('hasError is true when error is set', () {
      const response = ValidationResponse(findings: [], error: 'Something went wrong');
      expect(response.hasError, true);
    });
  });
}