// Copyright (c) 2012, 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.

// @dart = 2.7

library compiler_helper;

import 'dart:async';
import 'package:compiler/compiler_api.dart' as api;
import 'package:compiler/src/commandline_options.dart';
import 'package:compiler/src/common/elements.dart';
import 'package:compiler/src/compiler.dart' show Compiler;
import 'package:compiler/src/elements/entities.dart';
import 'package:compiler/src/js_model/js_strategy.dart';
import 'package:compiler/src/js_model/js_world.dart' show JClosedWorld;
import 'package:expect/expect.dart';
import 'package:_fe_analyzer_shared/src/util/link.dart' show Link;
import 'package:compiler/src/util/memory_compiler.dart';

export 'package:compiler/src/diagnostics/messages.dart';
export 'package:compiler/src/diagnostics/source_span.dart';
export 'package:compiler/src/diagnostics/spannable.dart';
export 'package:compiler/src/util/output_collector.dart';
export 'package:compiler/src/util/util.dart';

String _commonTestPath(bool soundNullSafety) {
  // Pretend this is a web/native test to allow use of 'native' keyword
  // and import of private libraries. However, we have to choose the correct
  // folder to enable / disable  implicit cfe opt out of null safety.
  return soundNullSafety ? 'sdk/tests/web/native' : 'sdk/tests/web_2/native';
}

/// Compile [code] and returns either the code for [methodName] or, if
/// [returnAll] is true, the code for the entire program.
///
/// If [check] is provided, it is executed on the code for [entry] before
/// returning.
Future<String> compile(String code,
    {String entry = 'main',
    String methodName,
    bool enableTypeAssertions = false,
    bool minify = false,
    bool disableInlining = true,
    bool disableTypeInference = true,
    bool omitImplicitChecks = true,
    bool enableVariance = false,
    void check(String generatedEntry),
    bool returnAll = false,
    bool soundNullSafety = false}) async {
  OutputCollector outputCollector = returnAll ? new OutputCollector() : null;
  List<String> options = <String>[];
  if (disableTypeInference) {
    options.add(Flags.disableTypeInference);
  }
  if (enableTypeAssertions) {
    options.add(Flags.enableCheckedMode);
  }
  if (omitImplicitChecks) {
    options.add(Flags.omitImplicitChecks);
  }
  if (minify) {
    options.add(Flags.minify);
  }
  if (disableInlining) {
    options.add(Flags.disableInlining);
  }
  if (enableVariance) {
    options.add('${Flags.enableLanguageExperiments}=variance');
  }

  if (soundNullSafety) {
    options.add(Flags.soundNullSafety);
  } else {
    options.add(Flags.noSoundNullSafety);
  }

  String commonTestPath = _commonTestPath(soundNullSafety);
  Uri entryPoint = Uri.parse('memory:$commonTestPath/main.dart');

  Map<String, String> source;
  methodName ??= entry;
  if (entry != 'main') {
    source = {entryPoint.path: "$code\n\nmain() => $entry;"};
  } else {
    source = {entryPoint.path: code};
  }

  CompilationResult result = await runCompiler(
      entryPoint: entryPoint,
      memorySourceFiles: source,
      options: options,
      outputProvider: outputCollector);
  Expect.isTrue(result.isSuccess);
  Compiler compiler = result.compiler;
  JClosedWorld closedWorld = compiler.backendClosedWorldForTesting;
  ElementEnvironment elementEnvironment = closedWorld.elementEnvironment;
  LibraryEntity mainLibrary = elementEnvironment.mainLibrary;
  FunctionEntity element =
      elementEnvironment.lookupLibraryMember(mainLibrary, methodName);
  JsBackendStrategy backendStrategy = compiler.backendStrategy;
  String generated = backendStrategy.getGeneratedCodeForTesting(element);
  if (check != null) {
    check(generated);
  }
  return returnAll
      ? outputCollector.getOutput('', api.OutputType.js)
      : generated;
}

Future<String> compileAll(String code,
    {bool disableInlining = true,
    bool minify = false,
    bool soundNullSafety = false,
    int expectedErrors,
    int expectedWarnings}) async {
  OutputCollector outputCollector = new OutputCollector();
  DiagnosticCollector diagnosticCollector = new DiagnosticCollector();
  List<String> options = <String>[];
  if (disableInlining) {
    options.add(Flags.disableInlining);
  }
  if (minify) {
    options.add(Flags.minify);
  }
  if (soundNullSafety) {
    options.add(Flags.soundNullSafety);
  } else {
    options.add(Flags.noSoundNullSafety);
  }

  String commonTestPath = _commonTestPath(soundNullSafety);
  Uri entryPoint = Uri.parse('memory:$commonTestPath/main.dart');

  CompilationResult result = await runCompiler(
      entryPoint: entryPoint,
      memorySourceFiles: {entryPoint.path: code},
      options: options,
      outputProvider: outputCollector,
      diagnosticHandler: diagnosticCollector);
  Expect.isTrue(
      result.isSuccess,
      'Unexpected compilation error(s): '
      '${diagnosticCollector.errors}');
  return outputCollector.getOutput('', api.OutputType.js);
}

String anyIdentifier = "[a-zA-Z][a-zA-Z0-9]*";

String getIntTypeCheck(String variable) {
  return "\\($variable ?!== ?\\($variable ?\\| ?0\\)|"
      "\\($variable ?>>> ?0 ?!== ?$variable";
}

String getNumberTypeCheck(String variable) {
  return """\\(typeof $variable ?!== ?"number"\\)""";
}

void checkNumberOfMatches(Iterator it, int nb) {
  bool hasNext = it.moveNext();
  for (int i = 0; i < nb; i++) {
    Expect.isTrue(hasNext, "Found less than $nb matches");
    hasNext = it.moveNext();
  }
  Expect.isFalse(hasNext, "Found more than $nb matches");
}

Future compileAndMatch(String code, String entry, RegExp regexp) {
  return compile(code, entry: entry, check: (String generated) {
    Expect.isTrue(regexp.hasMatch(generated),
        '"$generated" does not match /$regexp/ from source:\n$code');
  });
}

Future compileAndDoNotMatch(String code, String entry, RegExp regexp) {
  return compile(code, entry: entry, check: (String generated) {
    Expect.isFalse(regexp.hasMatch(generated),
        '"$generated" has a match in /$regexp/ from source:\n$code');
  });
}

int length(Link link) => link.isEmpty ? 0 : length(link.tail) + 1;

// Does a compile and then a match where every 'x' is replaced by something
// that matches any variable, and every space is optional.
Future compileAndMatchFuzzy(String code, String entry, String regexp) {
  return compileAndMatchFuzzyHelper(code, entry, regexp, shouldMatch: true);
}

Future compileAndDoNotMatchFuzzy(String code, String entry, String regexp) {
  return compileAndMatchFuzzyHelper(code, entry, regexp, shouldMatch: false);
}

Future compileAndMatchFuzzyHelper(String code, String entry, String regexp,
    {bool shouldMatch}) {
  return compile(code, entry: entry, check: (String generated) {
    String originalRegexp = regexp;
    final xRe = new RegExp('\\bx\\b');
    regexp = regexp.replaceAll(xRe, '(?:$anyIdentifier)');
    final spaceRe = new RegExp('\\s+');
    regexp = regexp.replaceAll(spaceRe, '(?:\\s*)');
    if (shouldMatch) {
      Expect.isTrue(
          new RegExp(regexp).hasMatch(generated),
          "Pattern '$originalRegexp' not found in\n$generated\n"
          "from source\n$code");
    } else {
      Expect.isFalse(new RegExp(regexp).hasMatch(generated),
          "Pattern '$originalRegexp' found in\n$generated\nfrom source\n$code");
    }
  });
}

/// Returns a 'check' function that uses comments in [test] to drive checking.
///
/// The comments contains one or more 'present:' or 'absent:' tags, each
/// followed by a quoted string. For example, the returned checker for the
/// following text will ensure that the argument contains the three characters
/// 'foo' and does not contain the two characters '""':
///
///    // present: "foo"
///    // absent:  '""'
checkerForAbsentPresent(String test) {
  var matches = _directivePattern.allMatches(test).toList();
  checker(String generated) {
    if (matches.isEmpty) {
      Expect.fail("No 'absent:' or 'present:' directives in '$test'");
    }
    for (Match match in matches) {
      String directive = match.group(1);
      Pattern pattern = match.groups([2, 3, 4]).where((s) => s != null).single;
      if (match.group(4) != null) pattern = RegExp(pattern);
      if (directive == 'present') {
        Expect.isTrue(generated.contains(pattern),
            "Cannot find '$pattern' in:\n$generated");
      } else {
        assert(directive == 'absent');
        Expect.isFalse(generated.contains(pattern),
            "Must not find '$pattern' in:\n$generated");
      }
    }
  }

  return checker;
}

RegExp _directivePattern = new RegExp(
    //      \1                     \2        \3         \4
    r'''// *(present|absent): *(?:"([^"]*)"|'([^'']*)'|/(.*)/)''',
    multiLine: true);