// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

library analyzer.test.resource_utils;

import 'dart:async';
import 'dart:core';

import 'package:analyzer/file_system/file_system.dart';
import 'package:analyzer/file_system/memory_file_system.dart';
import 'package:analyzer/src/generated/source.dart';
import 'package:analyzer/src/util/absolute_path.dart';
import 'package:path/path.dart' as path;
import 'package:unittest/unittest.dart';

bool get isWindows => path.Style.platform == path.Style.windows;

/**
 * Assert that the given path is posix and absolute.
 */
void expectAbsolutePosixPath(String posixPath) {
  expect(posixPath, startsWith('/'),
      reason: 'Expected absolute posix path, but found $posixPath');
}

/**
 * Assert that the given path is posix.
 */
void expectPosixPath(String posixPath) {
  expect(posixPath.indexOf('\\'), -1,
      reason: 'Expected posix path, but found $posixPath');
}

/**
 * Translate the given posixPath to a file URI appropriate for the
 * platform on which the tests are executing.
 */
String posixToOSFileUri(String posixPath) {
  expectPosixPath(posixPath);
  return isWindows ? 'file:///C:$posixPath' : 'file://$posixPath';
}

/**
 * Translate the given posixPath to a path appropriate for the
 * platform on which the tests are executing.
 */
String posixToOSPath(String posixPath) {
  expectPosixPath(posixPath);
  if (isWindows) {
    String windowsPath = posixPath.replaceAll('/', '\\');
    if (posixPath.startsWith('/')) {
      return 'C:$windowsPath';
    }
    return windowsPath;
  }
  return posixPath;
}

/**
 * A convenience utility for setting up a test [MemoryResourceProvider].
 * All supplied paths are assumed to be in [path.posix] format
 * and are automatically translated to [path.context].
 *
 * This class intentionally does not implement [ResourceProvider]
 * directly or indirectly so that it cannot be used as a resource provider.
 * We do not want functionality under test to interact with a resource provider
 * that automatically translates paths.
 */
class TestPathTranslator {
  final MemoryResourceProvider _provider;

  TestPathTranslator(this._provider);

  Resource getResource(String posixPath) =>
      _provider.getResource(posixToOSPath(posixPath));

  File newFile(String posixPath, String content) =>
      _provider.newFile(posixToOSPath(posixPath), content);

  File newFileWithBytes(String posixPath, List<int> bytes) =>
      _provider.newFileWithBytes(posixToOSPath(posixPath), bytes);

  Folder newFolder(String posixPath) =>
      _provider.newFolder(posixToOSPath(posixPath));
}

/**
 * A resource provider for testing that asserts that any supplied paths
 * are appropriate for the OS platform on which the tests are running.
 */
class TestResourceProvider implements ResourceProvider {
  final ResourceProvider _provider;

  TestResourceProvider(this._provider) {
    expect(_provider.absolutePathContext.separator, isWindows ? '\\' : '/');
  }

  @override
  AbsolutePathContext get absolutePathContext => _provider.absolutePathContext;

  @override
  path.Context get pathContext => _provider.pathContext;

  @override
  File getFile(String path) => _provider.getFile(_assertPath(path));

  @override
  Folder getFolder(String path) => _provider.getFolder(_assertPath(path));

  @override
  Future<List<int>> getModificationTimes(List<Source> sources) async {
    return sources.map((source) => 0).toList();
  }

  @override
  Resource getResource(String path) => _provider.getResource(_assertPath(path));

  @override
  Folder getStateLocation(String pluginId) =>
      _provider.getStateLocation(pluginId);

  /**
   * Assert that the given path is valid for the OS platform on which the
   * tests are running.
   */
  String _assertPath(String path) {
    if (isWindows) {
      if (path.contains('/')) {
        fail('Expected windows path, but found: $path');
      }
    } else {
      if (path.contains('\\')) {
        fail('Expected posix path, but found: $path');
      }
    }
    return path;
  }
}