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

import {
  createRedisClient,
  resolveRedisUrl,
  runRedisHealthCheck,
} from '../src/redis-connection.js';

describe('resolveRedisUrl', () => {
  it('prefers VALKEY_URL when both env vars are present', () => {
    const url = resolveRedisUrl({
      VALKEY_URL: 'redis://valkey.local:6379',
      REDIS_URL: 'redis://redis.local:6379',
    });

    expect(url).toBe('redis://valkey.local:6379');
  });

  it('falls back to REDIS_URL when VALKEY_URL is missing', () => {
    const url = resolveRedisUrl({
      REDIS_URL: 'redis://redis.local:6379',
    });

    expect(url).toBe('redis://redis.local:6379');
  });

  it('throws loudly when no redis environment variable exists', () => {
    expect(() => resolveRedisUrl({})).toThrowError(
      /Missing required Valkey\/Redis connection URL/i,
    );
  });
});

describe('createRedisClient', () => {
  it('uses env URL for client creation with no hardcoded defaults', () => {
    class FakeRedis {
      public readonly url: string;

      public constructor(url: string) {
        this.url = url;
      }
    }

    const client = createRedisClient({
      env: {
        VALKEY_URL: 'redis://queue.local:6379',
      },
      redisConstructor: FakeRedis,
    });

    expect(client.url).toBe('redis://queue.local:6379');
  });
});

describe('runRedisHealthCheck', () => {
  it('returns healthy status when ping succeeds', async () => {
    const health = await runRedisHealthCheck({
      ping: () => Promise.resolve('PONG'),
    });

    expect(health.ok).toBe(true);
    expect(health.response).toBe('PONG');
    expect(health.latencyMs).toBeTypeOf('number');
    expect(health.latencyMs).toBeGreaterThanOrEqual(0);
  });

  it('returns unhealthy status when ping fails', async () => {
    const health = await runRedisHealthCheck({
      ping: () => Promise.reject(new Error('connection refused')),
    });

    expect(health.ok).toBe(false);
    expect(health.error).toMatch(/connection refused/i);
    expect(health.latencyMs).toBeTypeOf('number');
  });
});