const assert = require('node:assert/strict');
const test = require('node:test');

const {
  AlertCreationService,
  createAlertRequestHash,
  normalizeAlertInput,
  isAlertDue
} = require('../src/services/alertCreationService');

const ALERT_INPUT = {
  route_id: 7,
  alert_type: 'delay',
  title: 'Задержка автобуса',
  message: 'Автобус задерживается на 15 минут',
  start_time: '2026-07-11T07:00:00.000Z',
  end_time: null,
  is_active: true
};

function createStoredAlert(overrides = {}) {
  return {
    id: 42,
    route_id: 7,
    alert_type: 'delay',
    title: 'Задержка автобуса',
    message: 'Автобус задерживается на 15 минут',
    start_time: new Date('2026-07-11T07:00:00.000Z'),
    end_time: null,
    is_active: true,
    created_at: new Date('2026-07-11T06:55:00.000Z'),
    notification_route_number: '3',
    ...overrides
  };
}

function createLogger() {
  const errors = [];
  return {
    errors,
    error(message, metadata) {
      errors.push({ message, metadata });
    }
  };
}

test('successfully saved active alert dispatches one notification after the insert', async () => {
  const order = [];
  const pool = {
    async query() {
      order.push('saved');
      return { rows: [createStoredAlert()] };
    }
  };
  const notifications = [];
  const notificationService = {
    async sendAlertCreated(alert) {
      order.push('notified');
      notifications.push(alert);
    }
  };
  const service = new AlertCreationService({
    pool,
    notificationService,
    logger: createLogger()
  });

  const result = await service.createAlert(ALERT_INPUT);

  assert.deepEqual(order, ['saved', 'notified']);
  assert.equal(notifications.length, 1);
  assert.equal(notifications[0].route_number, '3');
  assert.equal('notification_route_number' in result.alert, false);
  assert.equal(result.alert.id, 42);
  assert.equal(result.created, true);
});

test('inactive alert is saved without dispatching a notification', async () => {
  let notificationCalls = 0;
  const service = new AlertCreationService({
    pool: {
      async query() {
        return { rows: [createStoredAlert({ is_active: false })] };
      }
    },
    notificationService: {
      async sendAlertCreated() {
        notificationCalls += 1;
      }
    },
    logger: createLogger()
  });

  const result = await service.createAlert({ ...ALERT_INPUT, is_active: false });

  assert.equal(result.alert.is_active, false);
  assert.equal(notificationCalls, 0);
});

test('future alert is saved but does not dispatch before its start time', async () => {
  let notificationCalls = 0;
  const future = new Date(Date.now() + 60 * 60 * 1000).toISOString();
  const service = new AlertCreationService({
    pool: { async query() { return { rows: [createStoredAlert({ start_time: new Date(future) })] }; } },
    notificationService: { async sendAlertCreated() { notificationCalls += 1; } },
    logger: createLogger()
  });

  const result = await service.createAlert({ ...ALERT_INPUT, start_time: future });

  assert.equal(result.created, true);
  assert.equal(notificationCalls, 0);
  assert.equal(isAlertDue(result.alert), false);
});

test('database failure prevents notification dispatch', async () => {
  const databaseError = new Error('database unavailable');
  let notificationCalls = 0;
  const service = new AlertCreationService({
    pool: {
      async query() {
        throw databaseError;
      }
    },
    notificationService: {
      async sendAlertCreated() {
        notificationCalls += 1;
      }
    },
    logger: createLogger()
  });

  await assert.rejects(() => service.createAlert(ALERT_INPUT), databaseError);
  assert.equal(notificationCalls, 0);
});

test('unexpected notification failure is logged without failing the saved alert', async () => {
  const logger = createLogger();
  const firebaseError = Object.assign(new Error('permission denied'), {
    code: 'messaging/authentication-error'
  });
  const service = new AlertCreationService({
    pool: {
      async query() {
        return { rows: [createStoredAlert()] };
      }
    },
    notificationService: {
      async sendAlertCreated() {
        throw firebaseError;
      }
    },
    logger
  });

  const result = await service.createAlert(ALERT_INPUT);

  assert.equal(result.alert.id, 42);
  assert.equal(logger.errors.length, 1);
  assert.deepEqual(logger.errors[0], {
    message: 'Failed to dispatch alert-created notification',
    metadata: {
      alertId: '42',
      reason: 'permission denied',
      firebaseCode: 'messaging/authentication-error'
    }
  });
});

function createIdempotentPool() {
  const requests = new Map();
  const alerts = new Map();
  let nextAlertId = 1;

  const client = {
    async query(sql, params = []) {
      const normalizedSql = String(sql).replace(/\s+/g, ' ').trim();

      if (['BEGIN', 'COMMIT', 'ROLLBACK'].includes(normalizedSql)) {
        return { rows: [] };
      }

      if (normalizedSql.startsWith('INSERT INTO alert_creation_requests')) {
        const [key, requestHash] = params;

        if (requests.has(key)) {
          return { rows: [] };
        }

        requests.set(key, { request_hash: requestHash, alert_id: null });
        return { rows: [{ idempotency_key: key }] };
      }

      if (normalizedSql.startsWith('SELECT request_hash, alert_id')) {
        return { rows: [requests.get(params[0])] };
      }

      if (normalizedSql.startsWith('WITH inserted AS')) {
        const alert = createStoredAlert({
          id: nextAlertId,
          route_id: params[0],
          alert_type: params[1],
          title: params[2],
          message: params[3],
          start_time: new Date(params[4]),
          end_time: params[5] ? new Date(params[5]) : null,
          is_active: params[6]
        });
        nextAlertId += 1;
        alerts.set(alert.id, alert);
        return { rows: [alert] };
      }

      if (normalizedSql.startsWith('UPDATE alert_creation_requests')) {
        const [key, alertId, responseBody] = params;
        requests.get(key).alert_id = alertId;
        requests.get(key).response_body = JSON.parse(responseBody);
        return { rows: [] };
      }

      throw new Error(`Unexpected query in fake pool: ${normalizedSql}`);
    },
    release() {}
  };

  return {
    requests,
    alerts,
    deleteAlert(alertId) {
      alerts.delete(alertId);

      for (const request of requests.values()) {
        if (request.alert_id === alertId) {
          request.alert_id = null;
        }
      }
    },
    async connect() {
      return client;
    }
  };
}

test('same Idempotency-Key and payload replays the alert without duplicate notification', async () => {
  const pool = createIdempotentPool();
  let notificationCalls = 0;
  const service = new AlertCreationService({
    pool,
    notificationService: {
      async sendAlertCreated() {
        notificationCalls += 1;
      }
    },
    logger: createLogger()
  });

  const first = await service.createAlert(ALERT_INPUT, { idempotencyKey: 'alert-request-1' });
  const replay = await service.createAlert(ALERT_INPUT, { idempotencyKey: 'alert-request-1' });

  assert.equal(first.alert.id, replay.alert.id);
  assert.equal(first.created, true);
  assert.equal(replay.created, false);
  assert.equal(notificationCalls, 1);
});

test('idempotency snapshot prevents a duplicate even after the original alert is deleted', async () => {
  const pool = createIdempotentPool();
  let notificationCalls = 0;
  const service = new AlertCreationService({
    pool,
    notificationService: {
      async sendAlertCreated() {
        notificationCalls += 1;
      }
    },
    logger: createLogger()
  });

  const first = await service.createAlert(ALERT_INPUT, { idempotencyKey: 'alert-request-deleted' });
  pool.deleteAlert(first.alert.id);
  const replay = await service.createAlert(ALERT_INPUT, {
    idempotencyKey: 'alert-request-deleted'
  });

  assert.equal(replay.alert.id, first.alert.id);
  assert.equal(replay.created, false);
  assert.equal(notificationCalls, 1);
});

function createConcurrentIdempotentPool() {
  const requests = new Map();
  let alertInserts = 0;

  function createClient() {
    return {
      async query(sql, params = []) {
        const normalizedSql = String(sql).replace(/\s+/g, ' ').trim();

        if (normalizedSql === 'BEGIN' || normalizedSql === 'ROLLBACK') {
          return { rows: [] };
        }

        if (normalizedSql === 'COMMIT') {
          for (const request of requests.values()) {
            if (!request.committed) {
              request.committed = true;
              request.resolveCommitted();
            }
          }
          return { rows: [] };
        }

        if (normalizedSql.startsWith('INSERT INTO alert_creation_requests')) {
          const [key, requestHash] = params;
          const existing = requests.get(key);

          if (existing) {
            await existing.committedPromise;
            return { rows: [] };
          }

          let resolveCommitted;
          const committedPromise = new Promise((resolve) => {
            resolveCommitted = resolve;
          });
          requests.set(key, {
            request_hash: requestHash,
            alert_id: null,
            response_body: null,
            committed: false,
            committedPromise,
            resolveCommitted
          });
          return { rows: [{ idempotency_key: key }] };
        }

        if (normalizedSql.startsWith('WITH inserted AS')) {
          alertInserts += 1;
          return { rows: [createStoredAlert({ id: 91 })] };
        }

        if (normalizedSql.startsWith('UPDATE alert_creation_requests')) {
          const [key, alertId, responseBody] = params;
          const request = requests.get(key);
          request.alert_id = alertId;
          request.response_body = JSON.parse(responseBody);
          return { rows: [] };
        }

        if (normalizedSql.startsWith('SELECT request_hash, alert_id')) {
          return { rows: [requests.get(params[0])] };
        }

        throw new Error(`Unexpected query in concurrent fake pool: ${normalizedSql}`);
      },
      release() {}
    };
  }

  return {
    get alertInserts() {
      return alertInserts;
    },
    async connect() {
      return createClient();
    }
  };
}

test('concurrent requests with one Idempotency-Key create and notify only once', async () => {
  const pool = createConcurrentIdempotentPool();
  let notificationCalls = 0;
  const service = new AlertCreationService({
    pool,
    notificationService: {
      async sendAlertCreated() {
        notificationCalls += 1;
      }
    },
    logger: createLogger()
  });

  const [first, second] = await Promise.all([
    service.createAlert(ALERT_INPUT, { idempotencyKey: 'concurrent-alert-request' }),
    service.createAlert(ALERT_INPUT, { idempotencyKey: 'concurrent-alert-request' })
  ]);

  assert.equal(first.alert.id, second.alert.id);
  assert.equal([first.created, second.created].filter(Boolean).length, 1);
  assert.equal(pool.alertInserts, 1);
  assert.equal(notificationCalls, 1);
});

test('reusing Idempotency-Key with a different payload is rejected', async () => {
  const service = new AlertCreationService({
    pool: createIdempotentPool(),
    notificationService: { async sendAlertCreated() {} },
    logger: createLogger()
  });

  await service.createAlert(ALERT_INPUT, { idempotencyKey: 'alert-request-2' });

  await assert.rejects(
    () => service.createAlert(
      { ...ALERT_INPUT, message: 'Другое сообщение' },
      { idempotencyKey: 'alert-request-2' }
    ),
    (error) => error.status === 409
  );
});

test('alert request hash is stable for the normalized creation payload', () => {
  const normalized = normalizeAlertInput(ALERT_INPUT);

  assert.equal(createAlertRequestHash(normalized), createAlertRequestHash({ ...normalized }));
  assert.notEqual(
    createAlertRequestHash(normalized),
    createAlertRequestHash({ ...normalized, is_active: false })
  );
});

test('route-number request hashes ignore selection order, spacing and duplicates', () => {
  const a = normalizeAlertInput({ ...ALERT_INPUT, route_id: null, route_numbers: ['27', '2', '5а'] });
  const b = normalizeAlertInput({ ...ALERT_INPUT, route_id: null, route_numbers: [' №5А ', '2', '27', '2'] });
  assert.equal(createAlertRequestHash(a), createAlertRequestHash(b));
  assert.notEqual(createAlertRequestHash(a), createAlertRequestHash({ ...b, route_numbers: ['2', '27'] }));
});