import { describe, it, expect } from 'vitest';
import { loadConfig } from './loader.js';
import { writeFileSync, mkdirSync, rmSync } from 'fs';
import { join } from 'path';
import { tmpdir } from 'os';

describe('loadConfig', () => {
  const testDir = join(tmpdir(), 'flynn-test-config');

  it('loads valid config from file', () => {
    mkdirSync(testDir, { recursive: true });
    const configPath = join(testDir, 'config.yaml');
    writeFileSync(configPath, `
telegram:
  bot_token: "test-token"
  allowed_chat_ids: [123456789]
server:
  port: 18800
models:
  default:
    provider: anthropic
    model: claude-sonnet
`);

    const config = loadConfig(configPath);

    expect(config.telegram.bot_token).toBe('test-token');
    expect(config.telegram.allowed_chat_ids).toContain(123456789);
    expect(config.server.port).toBe(18800);
    expect(config.models.default.provider).toBe('anthropic');

    rmSync(testDir, { recursive: true });
  });

  it('expands environment variables', () => {
    mkdirSync(testDir, { recursive: true });
    const configPath = join(testDir, 'config.yaml');
    process.env.TEST_BOT_TOKEN = 'env-token-value';
    writeFileSync(configPath, `
telegram:
  bot_token: \${TEST_BOT_TOKEN}
  allowed_chat_ids: [123]
server:
  port: 18800
models:
  default:
    provider: anthropic
    model: claude-sonnet
`);

    const config = loadConfig(configPath);

    expect(config.telegram.bot_token).toBe('env-token-value');

    delete process.env.TEST_BOT_TOKEN;
    rmSync(testDir, { recursive: true });
  });

  it('throws on invalid config', () => {
    mkdirSync(testDir, { recursive: true });
    const configPath = join(testDir, 'config.yaml');
    writeFileSync(configPath, `
telegram:
  bot_token: ""
`);

    expect(() => loadConfig(configPath)).toThrow();

    rmSync(testDir, { recursive: true });
  });
});