// 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.

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';

// Pretend this is a web/native test to allow use of 'native' keyword and import
// of private libraries.
const _commonTestPath = 'sdk/tests/web/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,
}) async {
  OutputCollector? outputCollector = returnAll ? 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');
  }

  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!;
  final element =
      elementEnvironment.lookupLibraryMember(mainLibrary, methodName)
          as FunctionEntity;
  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,
  int? expectedErrors,
  int? expectedWarnings,
}) async {
  OutputCollector outputCollector = OutputCollector();
  DiagnosticCollector diagnosticCollector = DiagnosticCollector();
  List<String> options = <String>[];
  if (disableInlining) {
    options.add(Flags.disableInlining);
  }
  if (minify) {
    options.add(Flags.minify);
  }

  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, {
  required bool shouldMatch,
}) {
  return compile(
    code,
    entry: entry,
    check: (String generated) {
      String originalRegexp = regexp;
      final xRe = RegExp('\\bx\\b');
      regexp = regexp.replaceAll(xRe, '(?:$anyIdentifier)');
      final spaceRe = RegExp('\\s+');
      regexp = regexp.replaceAll(spaceRe, '(?:\\s*)');
      if (shouldMatch) {
        Expect.isTrue(
          RegExp(regexp).hasMatch(generated),
          "Pattern '$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 '$test'");
    }
    for (Match match in matches) {
      String? directive = match.group(1);
      Pattern pattern = match.groups([2, 3, 4]).where((s) => s != null).single!;
      if (match.group(4) != null) pattern = RegExp(pattern as String);
      if (directive == 'present') {
        Expect.isTrue(
          generated.contains(pattern),
          "Cannot find '$pattern' in:\n$generated",
        );
      } else {
        assert(directive == 'absent');
        Expect.isFalse(
          generated.contains(pattern),
          "Must not find '$pattern' in:\n$generated",
        );
      }
    }
  }

  return checker;
}

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