// Copyright (c) 2021, 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 '../templates.dart';
import 'common.dart' as common;

/// A generator for a server app using `package:shelf`.
class ServerShelfGenerator extends DefaultGenerator {
  ServerShelfGenerator()
      : super(
          'server-shelf',
          'Server app',
          'A server app using package:shelf.',
          categories: const ['dart', 'server'],
        ) {
    addFile('.gitignore', common.gitignore);
    addFile('analysis_options.yaml', common.analysisOptions);
    addFile('CHANGELOG.md', common.changelog);
    addFile('pubspec.yaml', _pubspec);
    addFile('README.md', _readme);
    addFile('Dockerfile', _dockerfile);
    addFile('.dockerignore', _dockerignore);
    addFile('test/server_test.dart', _test);
    setEntrypoint(
      addFile('bin/server.dart', _main),
    );
  }

  @override
  String getInstallInstructions(
    String directory, {
    String? scriptPath,
  }) =>
      super.getInstallInstructions(
        directory,
        scriptPath: 'bin/server',
      );
}

final String _pubspec = '''
name: __projectName__
description: A server app using the shelf package and Docker.
version: 1.0.0
# repository: https://github.com/my_org/my_repo

environment:
  ${common.sdkConstraint}

dependencies:
  shelf: ^1.4.0
  shelf_router: ^1.1.0

dev_dependencies:
  http: ^1.1.0
  lints: ^5.0.0
  test: ^1.24.0
''';

final String _readme = '''
A server app built using [Shelf](https://pub.dev/packages/shelf),
configured to enable running with [Docker](https://www.docker.com/).

This sample code handles HTTP GET requests to `/` and `/echo/<message>`

# Running the sample

## Running with the Dart SDK

You can run the example with the [Dart SDK](https://dart.dev/get-dart)
like this:

```
\$ dart run bin/server.dart
Server listening on port 8080
```

And then from a second terminal:
```
\$ curl http://0.0.0.0:8080
Hello, World!
\$ curl http://0.0.0.0:8080/echo/I_love_Dart
I_love_Dart
```

## Running with Docker

If you have [Docker Desktop](https://www.docker.com/get-started) installed, you
can build and run with the `docker` command:

```
\$ docker build . -t myserver
\$ docker run -it -p 8080:8080 myserver
Server listening on port 8080
```

And then from a second terminal:
```
\$ curl http://0.0.0.0:8080
Hello, World!
\$ curl http://0.0.0.0:8080/echo/I_love_Dart
I_love_Dart
```

You should see the logging printed in the first terminal:
```
2021-05-06T15:47:04.620417  0:00:00.000158 GET     [200] /
2021-05-06T15:47:08.392928  0:00:00.001216 GET     [200] /echo/I_love_Dart
```
''';

final String _main = r'''
import 'dart:io';

import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart';
import 'package:shelf_router/shelf_router.dart';

// Configure routes.
final _router =
    Router()
      ..get('/', _rootHandler)
      ..get('/echo/<message>', _echoHandler);

Response _rootHandler(Request req) {
  return Response.ok('Hello, World!\n');
}

Response _echoHandler(Request request) {
  final message = request.params['message'];
  return Response.ok('$message\n');
}

void main(List<String> args) async {
  // Use any available host or container IP (usually `0.0.0.0`).
  final ip = InternetAddress.anyIPv4;

  // Configure a pipeline that logs requests.
  final handler = Pipeline()
      .addMiddleware(logRequests())
      .addHandler(_router.call);

  // For running in containers, we respect the PORT environment variable.
  final port = int.parse(Platform.environment['PORT'] ?? '8080');
  final server = await serve(handler, ip, port);
  print('Server listening on port ${server.port}');
}
''';

final String _dockerfile = r'''
# Use latest stable channel SDK.
FROM dart:stable AS build

# Resolve app dependencies.
WORKDIR /app
COPY pubspec.* ./
RUN dart pub get

# Copy app source code (except anything in .dockerignore) and AOT compile app.
COPY . .
RUN dart compile exe bin/server.dart -o bin/server

# Build minimal serving image from AOT-compiled `/server`
# and the pre-built AOT-runtime in the `/runtime/` directory of the base image.
FROM scratch
COPY --from=build /runtime/ /
COPY --from=build /app/bin/server /app/bin/

# Start server.
EXPOSE 8080
CMD ["/app/bin/server"]
''';

final String _dockerignore = r'''
.dockerignore
Dockerfile
build/
.dart_tool/
.git/
.github/
.gitignore
.idea/
.packages
''';

final String _test = r'''
import 'dart:io';

import 'package:http/http.dart';
import 'package:test/test.dart';

void main() {
  final port = '8080';
  final host = 'http://0.0.0.0:$port';
  late Process p;

  setUp(() async {
    p = await Process.start(
      'dart',
      ['run', 'bin/server.dart'],
      environment: {'PORT': port},
    );
    // Wait for server to start and print to stdout.
    await p.stdout.first;
  });

  tearDown(() => p.kill());

  test('Root', () async {
    final response = await get(Uri.parse('$host/'));
    expect(response.statusCode, 200);
    expect(response.body, 'Hello, World!\n');
  });

  test('Echo', () async {
    final response = await get(Uri.parse('$host/echo/hello'));
    expect(response.statusCode, 200);
    expect(response.body, 'hello\n');
  });

  test('404', () async {
    final response = await get(Uri.parse('$host/foobar'));
    expect(response.statusCode, 404);
  });
}
''';