import { describe, expect, test } from 'vitest';

import type { PhysicalDatabaseCapacityPolicy } from './capacityPolicy.js';
import { PhysicalPoolIdentityError, parsePhysicalPoolAgentNameTag } from './physicalPoolIdentity.js';

const policy = (agentName: string): PhysicalDatabaseCapacityPolicy => ({
  agentName,
  engine: 'postgres',
  thresholdType: 'minAvailableCapacityPercent',
  thresholdValue: 20
});

describe('parsePhysicalPoolAgentNameTag', () => {
  test('reads the pool a deployment named', () => {
    expect(parsePhysicalPoolAgentNameTag(['customer-opa'])).toBe('customer-opa');
    expect(parsePhysicalPoolAgentNameTag([' customer-opa '])).toBe('customer-opa');
  });

  test('reports no identity for a deployment that named no pool', () => {
    expect(parsePhysicalPoolAgentNameTag(undefined)).toBeUndefined();
    expect(parsePhysicalPoolAgentNameTag([])).toBeUndefined();
  });

  test('rejects a tag that is not one non-empty name', () => {
    expect(() => parsePhysicalPoolAgentNameTag([''])).toThrow(PhysicalPoolIdentityError);
    expect(() => parsePhysicalPoolAgentNameTag(['   '])).toThrow(PhysicalPoolIdentityError);
    expect(() => parsePhysicalPoolAgentNameTag(['customer-opa', 'other-opa'])).toThrow(/must name exactly one/);
  });

  // Replicas of one deployment publish the same registration.
  test('accepts a name repeated across replicas', () => {
    expect(parsePhysicalPoolAgentNameTag(['customer-opa', 'customer-opa'])).toBe('customer-opa');
  });

  describe('agreement with capacity policies', () => {
    test('accepts a policy for the pool the deployment named', () => {
      expect(parsePhysicalPoolAgentNameTag(['customer-opa'], [policy('customer-opa')])).toBe('customer-opa');
    });

    test('rejects a policy for a pool the deployment does not own', () => {
      expect(() => parsePhysicalPoolAgentNameTag(['customer-opa'], [policy('other-opa')])).toThrow(/must name the same pool/);
    });

    // A deployment scales the pool it owns and nothing else. Accepting a
    // foreign policy alongside a matching one would let proactive evaluation
    // key off a pool the wizard would never resolve to.
    test('rejects a foreign policy published alongside the deployments own', () => {
      expect(() => parsePhysicalPoolAgentNameTag(['customer-opa'], [policy('customer-opa'), policy('other-opa')])).toThrow(
        /must name the same pool/
      );
    });

    // Older workers publish identity only inside the policy.
    test('falls back to the policy name when the deployment published no tag', () => {
      expect(parsePhysicalPoolAgentNameTag(undefined, [policy('customer-opa')])).toBe('customer-opa');
    });

    test('refuses to guess when policies alone name two pools', () => {
      expect(() => parsePhysicalPoolAgentNameTag(undefined, [policy('customer-opa'), policy('other-opa')])).toThrow(
        /publish databaseLifecycle:agentName/
      );
    });
  });
});