import { describe, test, expect } from 'bun:test';
import { resolveConfig, ensureStateDir, readVersionHash, getGitRoot } from '../src/config';
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';

describe('config', () => {
  describe('getGitRoot', () => {
    test('returns a path when in a git repo', () => {
      const root = getGitRoot();
      expect(root).not.toBeNull();
      expect(fs.existsSync(path.join(root!, '.git'))).toBe(true);
    });
  });

  describe('resolveConfig', () => {
    test('uses git root by default', () => {
      const config = resolveConfig({});
      const gitRoot = getGitRoot();
      expect(gitRoot).not.toBeNull();
      expect(config.projectDir).toBe(gitRoot);
      expect(config.stateDir).toBe(path.join(gitRoot!, '.gstack'));
      expect(config.stateFile).toBe(path.join(gitRoot!, '.gstack', 'browse.json'));
    });

    test('derives paths from BROWSE_STATE_FILE when set', () => {
      const stateFile = '/tmp/test-config/.gstack/browse.json';
      const config = resolveConfig({ BROWSE_STATE_FILE: stateFile });
      expect(config.stateFile).toBe(stateFile);
      expect(config.stateDir).toBe('/tmp/test-config/.gstack');
      expect(config.projectDir).toBe('/tmp/test-config');
    });

    test('log paths are in stateDir', () => {
      const config = resolveConfig({});
      expect(config.consoleLog).toBe(path.join(config.stateDir, 'browse-console.log'));
      expect(config.networkLog).toBe(path.join(config.stateDir, 'browse-network.log'));
      expect(config.dialogLog).toBe(path.join(config.stateDir, 'browse-dialog.log'));
    });
  });

  describe('ensureStateDir', () => {
    test('creates directory if it does not exist', () => {
      const tmpDir = path.join(os.tmpdir(), `browse-config-test-${Date.now()}`);
      const config = resolveConfig({ BROWSE_STATE_FILE: path.join(tmpDir, '.gstack', 'browse.json') });
      expect(fs.existsSync(config.stateDir)).toBe(false);
      ensureStateDir(config);
      expect(fs.existsSync(config.stateDir)).toBe(true);
      // Cleanup
      fs.rmSync(tmpDir, { recursive: true, force: true });
    });

    test('is a no-op if directory already exists', () => {
      const tmpDir = path.join(os.tmpdir(), `browse-config-test-${Date.now()}`);
      const stateDir = path.join(tmpDir, '.gstack');
      fs.mkdirSync(stateDir, { recursive: true });
      const config = resolveConfig({ BROWSE_STATE_FILE: path.join(stateDir, 'browse.json') });
      ensureStateDir(config); // should not throw
      expect(fs.existsSync(config.stateDir)).toBe(true);
      // Cleanup
      fs.rmSync(tmpDir, { recursive: true, force: true });
    });
  });

  describe('readVersionHash', () => {
    test('returns null when .version file does not exist', () => {
      const result = readVersionHash('/nonexistent/path/browse');
      expect(result).toBeNull();
    });

    test('reads version from .version file adjacent to execPath', () => {
      const tmpDir = path.join(os.tmpdir(), `browse-version-test-${Date.now()}`);
      fs.mkdirSync(tmpDir, { recursive: true });
      const versionFile = path.join(tmpDir, '.version');
      fs.writeFileSync(versionFile, 'abc123def\n');
      const result = readVersionHash(path.join(tmpDir, 'browse'));
      expect(result).toBe('abc123def');
      // Cleanup
      fs.rmSync(tmpDir, { recursive: true, force: true });
    });
  });
});

describe('resolveServerScript', () => {
  // Import the function from cli.ts
  const { resolveServerScript } = require('../src/cli');

  test('uses BROWSE_SERVER_SCRIPT env when set', () => {
    const result = resolveServerScript({ BROWSE_SERVER_SCRIPT: '/custom/server.ts' }, '', '');
    expect(result).toBe('/custom/server.ts');
  });

  test('finds server.ts adjacent to cli.ts in dev mode', () => {
    const srcDir = path.resolve(__dirname, '../src');
    const result = resolveServerScript({}, srcDir, '');
    expect(result).toBe(path.join(srcDir, 'server.ts'));
  });

  test('throws when server.ts cannot be found', () => {
    expect(() => resolveServerScript({}, '/nonexistent/$bunfs', '/nonexistent/browse'))
      .toThrow('Cannot find server.ts');
  });
});

describe('version mismatch detection', () => {
  test('detects when versions differ', () => {
    const stateVersion = 'abc123';
    const currentVersion = 'def456';
    expect(stateVersion !== currentVersion).toBe(true);
  });

  test('no mismatch when versions match', () => {
    const stateVersion = 'abc123';
    const currentVersion = 'abc123';
    expect(stateVersion !== currentVersion).toBe(false);
  });

  test('no mismatch when either version is null', () => {
    const currentVersion: string | null = null;
    const stateVersion: string | undefined = 'abc123';
    // Version mismatch only triggers when both are present
    const shouldRestart = currentVersion !== null && stateVersion !== undefined && currentVersion !== stateVersion;
    expect(shouldRestart).toBe(false);
  });
});