// Copyright (c) 2022, 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.

import 'package:build/build.dart';

/// Factory for the build script.
Builder copyBuilder(_) => _CopyBuilder();

class _CopyBuilder extends Builder {
  @override
  Map<String, List<String>> get buildExtensions => {
        "web/{{}}.dart.js": ["compiled/{{}}.dart.js"],
        "web/static_assets/{{}}.png": ["compiled/static_assets/{{}}.png"],
        "web/static_assets/{{}}.html": ["compiled/static_assets/{{}}.html"],
        "web/static_assets/{{}}.css": ["compiled/static_assets/{{}}.css"],
        "web/manifest.json": ["compiled/manifest.json"],
      };

  @override
  void build(BuildStep buildStep) async {
    final inputAsset = buildStep.inputId;
    final allowedOutputs = buildStep.allowedOutputs;

    if (allowedOutputs.length != 1) {
      return;
    }

    final outputAsset = allowedOutputs.first;
    await _copyBinaryFile(buildStep,
        inputAsset: inputAsset, outputAsset: outputAsset);
  }

  Future<void> _copyBinaryFile(
    BuildStep buildStep, {
    required AssetId inputAsset,
    required AssetId outputAsset,
  }) {
    return buildStep.writeAsBytes(
        outputAsset, buildStep.readAsBytes(inputAsset));
  }
}