// Copyright (c) 2018, 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 "dart:io" show File, IOSink;
import 'dart:typed_data' show Uint8List;

import 'package:_fe_analyzer_shared/src/util/colors.dart' as colors;
import "package:front_end/src/api_prototype/compiler_options.dart"
    show CompilerOptions, CfeDiagnosticMessage;
import 'package:front_end/src/api_prototype/experimental_flags.dart';
import 'package:front_end/src/api_prototype/expression_compilation_tools.dart'
    show createDefinitionsWithTypes, createTypeParametersWithBounds;
import 'package:front_end/src/api_prototype/incremental_kernel_generator.dart'
    show IncrementalCompilerResult;
import "package:front_end/src/api_prototype/memory_file_system.dart"
    show MemoryFileSystem;
import "package:front_end/src/api_prototype/terminal_color_support.dart"
    show printDiagnosticMessage;
import 'package:front_end/src/base/compiler_context.dart' show CompilerContext;
import 'package:front_end/src/base/incremental_compiler.dart'
    show IncrementalCompiler;
import 'package:front_end/src/base/processed_options.dart'
    show ProcessedOptions;
import 'package:front_end/src/compute_platform_binaries_location.dart'
    show computePlatformBinariesLocation;
import 'package:front_end/src/kernel/utils.dart'
    show serializeComponent, serializeProcedure;
import 'package:front_end/src/source/source_loader.dart';
import 'package:front_end/src/testing/compiler_common.dart';
import "package:kernel/ast.dart"
    show
        Class,
        Component,
        Constructor,
        DartType,
        DynamicType,
        Field,
        Library,
        Member,
        Procedure,
        TreeNode,
        TypeParameter,
        VariableDeclaration;
import 'package:kernel/target/targets.dart' show TargetFlags;
import 'package:kernel/text/ast_to_text.dart' show Printer;
import "package:testing/src/log.dart" show splitLines;
import "package:testing/testing.dart"
    show Chain, ChainContext, Result, Step, TestDescription;
import 'package:vm/modular/target/vm.dart' show VmTarget;
import "package:yaml/yaml.dart" show YamlMap, YamlList, loadYamlNode;

import 'testing_utils.dart' show checkEnvironment;
import 'utils/kernel_chain.dart' show runDiff, openWrite;
import 'utils/suite_utils.dart';
import 'testing/environment_keys.dart';

class Context extends ChainContext {
  final CompilerContext compilerContext;
  final List<CfeDiagnosticMessage> errors;

  @override
  final List<Step> steps;

  final bool fuzz;
  final Set<Uri> fuzzedLibraries = {};
  int fuzzCompiles = 0;

  Context(this.compilerContext, this.errors, bool updateExpectations, this.fuzz)
    : steps = <Step>[
        const ReadTest(),
        const CompileExpression(),
        new MatchProcedureExpectations(
          ".expect",
          updateExpectations: updateExpectations,
        ),
        const OutputParametersMatches(),
      ];

  ProcessedOptions get options => compilerContext.options;

  MemoryFileSystem get fileSystem => options.fileSystem as MemoryFileSystem;

  Future<T> runInContext<T>(Future<T> action(CompilerContext c)) {
    return compilerContext.runInContext<T>(action);
  }

  void reset() {
    errors.clear();
  }

  List<CfeDiagnosticMessage> takeErrors() {
    List<CfeDiagnosticMessage> result = new List<CfeDiagnosticMessage>.from(
      errors,
    );
    errors.clear();
    return result;
  }
}

class CompilationResult {
  Library? compiledInLibrary;
  Procedure? compiledProcedure;
  List<CfeDiagnosticMessage> errors;

  CompilationResult(
    this.compiledInLibrary,
    this.compiledProcedure,
    this.errors,
  );

  String printResult(Uri entryPoint, Context context) {
    StringBuffer buffer = new StringBuffer();
    buffer.write("Errors: {\n");
    for (CfeDiagnosticMessage error in errors) {
      for (String message in error.plainTextFormatted) {
        for (String line in splitLines(message)) {
          buffer.write("  ");
          buffer.write(line);
        }
        buffer.write("\n");
        // TODO(jensj): Ignore context for now.
        // Remove once we have positions on type parameters.
        break;
      }
    }
    buffer.write("}\n");
    if (compiledProcedure == null) {
      buffer.write("<no procedure>");
    } else {
      Printer printer = new Printer(buffer, showLibraryForNames: true);
      printer.writeProcedureInLibrary(compiledProcedure!, compiledInLibrary!);
      printer.writeConstantTable(new Component());
    }
    Uri base = entryPoint.resolve(".");
    return "$buffer".replaceAll("$base", "org-dartlang-testcase:///");
  }
}

class TestCase {
  final TestDescription description;

  final Map<String, String> sources;

  final Uri entryPoint;

  final List<String> definitions;

  final List<String> definitionTypes;

  final List<String> typeDefinitions;

  final List<String> typeBounds;

  final List<String> typeDefaults;

  final bool isStaticMethod;

  final Uri library;

  final String? className;

  final String? methodName;

  final int? offset;

  final String? scriptUri;

  String expression;

  List<CompilationResult> results = [];

  TestCase(
    this.description,
    this.sources,
    this.entryPoint,
    this.definitions,
    this.definitionTypes,
    this.typeDefinitions,
    this.typeBounds,
    this.typeDefaults,
    this.isStaticMethod,
    this.library,
    this.className,
    this.methodName,
    this.offset,
    this.scriptUri,
    this.expression,
  );

  @override
  String toString() {
    return "TestCase("
        "$sources, "
        "$entryPoint, "
        "$definitions, "
        "$definitionTypes, "
        "$typeDefinitions,"
        "$typeBounds,"
        "$typeDefaults,"
        "$library, "
        "$className, "
        "static = $isStaticMethod)";
  }
}

class OutputParametersMatches
    extends Step<List<TestCase>, List<TestCase>, Context> {
  const OutputParametersMatches();

  @override
  String get name => "output parameters matches";

  @override
  Future<Result<List<TestCase>>> run(List<TestCase> tests, Context context) {
    for (TestCase test in tests) {
      for (CompilationResult result in test.results) {
        Procedure? compiledProcedure = result.compiledProcedure;
        if (compiledProcedure == null) continue;
        if (compiledProcedure.function.namedParameters.isNotEmpty) {
          return Future.value(
            fail(tests, "Compiled expression contains named parameters."),
          );
        }
        List<VariableDeclaration> positionals =
            compiledProcedure.function.positionalParameters;
        if (positionals.length != test.definitions.length) {
          return Future.value(
            fail(
              tests,
              "Compiled expression contains a wrong number of "
              "positional parameters: Expected ${test.definitions.length} "
              "(${test.definitions.join(", ")}) "
              "but had ${positionals.length} "
              "(${positionals.map((p) => p.name).join(", ")}).",
            ),
          );
        }
        for (int i = 0; i < positionals.length; i++) {
          if (positionals[i].name != test.definitions[i]) {
            return Future.value(
              fail(
                tests,
                "Compiled expression doesn't contain '${test.definitions[i]}' "
                "but '${positionals[i].name}' as positional parameter $i.",
              ),
            );
          }
        }
      }
    }

    return Future.value(pass(tests));
  }
}

class MatchProcedureExpectations
    extends Step<List<TestCase>, List<TestCase>, Context> {
  final String suffix;
  final bool updateExpectations;

  const MatchProcedureExpectations(
    this.suffix, {
    this.updateExpectations = false,
  });

  @override
  String get name => "match expectations";

  @override
  Future<Result<List<TestCase>>> run(
    List<TestCase> tests,
    Context context,
  ) async {
    String actual = "";
    for (TestCase test in tests) {
      String primary = test.results.first.printResult(test.entryPoint, context);
      actual += primary;
      for (int i = 1; i < test.results.length; ++i) {
        String secondary = test.results[i].printResult(
          test.entryPoint,
          context,
        );
        if (primary != secondary) {
          return fail(
            tests,
            "Multiple expectations don't match on $test:"
            "\nFirst expectation:\n$actual\n"
            "\nSecond expectation:\n$secondary\n",
          );
        }
      }
    }
    TestCase test = tests.first;
    Uri testUri = test.description.uri;
    File expectedFile = new File("${testUri.toFilePath()}$suffix");
    if (await expectedFile.exists()) {
      String expected = await expectedFile.readAsString();
      if (expected.replaceAll("\r\n", "\n").trim() != actual.trim()) {
        if (!updateExpectations) {
          String diff = await runDiff(expectedFile.uri, actual);
          return fail(
            tests,
            "$testUri doesn't match ${expectedFile.uri}\n$diff",
          );
        }
      } else {
        return pass(tests);
      }
    }
    if (updateExpectations) {
      await openWrite(expectedFile.uri, (IOSink sink) {
        sink.writeln(actual.trim());
      });
      return pass(tests);
    } else {
      return fail(tests, """
Please create file ${expectedFile.path} with this content:
$actual""");
    }
  }
}

class ReadTest extends Step<TestDescription, List<TestCase>, Context> {
  const ReadTest();

  @override
  String get name => "read test";

  @override
  Future<Result<List<TestCase>>> run(
    TestDescription description,
    Context context,
  ) async {
    context.reset();
    Uri uri = description.uri;
    String contents = await new File.fromUri(uri).readAsString();

    Uri entryPoint = toTestUri('main.dart');
    List<String> definitions = <String>[];
    List<String> definitionTypes = <String>[];
    List<String> typeDefinitions = <String>[];
    List<String> typeBounds = <String>[];
    List<String> typeDefaults = <String>[];
    bool isStaticMethod = false;
    Uri? library;
    String? className;
    String? methodName;
    int? offset;
    String? scriptUri;
    String? expression;

    dynamic maps = loadYamlNode(contents, sourceUrl: uri);
    if (maps is YamlMap) maps = [maps];

    final List<TestCase> tests = [];
    Map<String, String> sources = {};
    for (YamlMap map in maps) {
      for (String key in map.keys) {
        dynamic value = map[key];
        if (key == "sources") {
          if (value is String) {
            sources['main.dart'] = value;
          } else if (value is YamlMap) {
            value.forEach((key, value) {
              sources[key as String] = value as String;
            });
          }
        } else if (key == "entry_point") {
          entryPoint = toTestUri(value as String);
        } else if (key == "position") {
          Uri uri = entryPoint.resolveUri(Uri.parse(value as String));
          library = uri.removeFragment();
          if (uri.fragment != '') {
            className = uri.fragment;
          }
        } else if (key == "method") {
          methodName = value as String;
        } else if (key == "definitions") {
          definitions = (value as YamlList).map((x) => x as String).toList();
        } else if (key == "definition_types") {
          definitionTypes = (value as YamlList)
              .map((x) => x as String)
              .toList();
        } else if (key == "type_definitions") {
          typeDefinitions = (value as YamlList)
              .map((x) => x as String)
              .toList();
        } else if (key == "type_bounds") {
          typeBounds = (value as YamlList).map((x) => x as String).toList();
        } else if (key == "type_defaults") {
          typeDefaults = (value as YamlList).map((x) => x as String).toList();
        } else if (key == "static") {
          isStaticMethod = value;
        } else if (key == "expression") {
          expression = value;
        } else if (key == "offset") {
          offset = value;
        } else if (key == "scriptUri") {
          Uri uri = entryPoint.resolveUri(Uri.parse(value as String));
          scriptUri = uri.toString();
        } else {
          throw new UnsupportedError("Unknown key: ${key}");
        }
      }
      library ??= entryPoint;
      if (expression == null) {
        return new Result.fail(tests, "No expression to compile.");
      }

      TestCase test = new TestCase(
        description,
        sources,
        entryPoint,
        definitions,
        definitionTypes,
        typeDefinitions,
        typeBounds,
        typeDefaults,
        isStaticMethod,
        library,
        className,
        methodName,
        offset,
        scriptUri,
        expression,
      );
      tests.add(test);
    }
    return new Result.pass(tests);
  }
}

class CompileExpression extends Step<List<TestCase>, List<TestCase>, Context> {
  const CompileExpression();

  @override
  String get name => "compile expression";

  // Compile [test.expression], update [test.errors] with results.
  // As a side effect - verify that generated procedure can be serialized.
  Future<void> compileExpression(
    TestCase test,
    IncrementalCompiler compiler,
    IncrementalCompilerResult compilerResult,
    Context context,
  ) async {
    Map<String, DartType>? definitions = createDefinitionsWithTypes(
      compilerResult.classHierarchy.knownLibraries,
      test.definitionTypes,
      test.definitions,
    );

    if (definitions == null) {
      definitions = {};
      for (String name in test.definitions) {
        definitions[name] = new DynamicType();
      }
    }
    List<TypeParameter>? typeParams = createTypeParametersWithBounds(
      compilerResult.classHierarchy.knownLibraries,
      test.typeBounds,
      test.typeDefaults,
      test.typeDefinitions,
    );
    if (typeParams == null) {
      typeParams = [];
      for (String name in test.typeDefinitions) {
        typeParams.add(
          new TypeParameter(name, new DynamicType(), new DynamicType()),
        );
      }
    }

    SourceLoader loader = compiler.kernelTargetForTesting!.loader;
    Library? libraryLookup =
        (loader.lookupCompilationUnit(test.library) ??
                loader.lookupCompilationUnitByFileUri(test.library))
            ?.libraryBuilder
            .library;

    Procedure? compiledProcedure = await compiler.compileExpression(
      test.expression,
      definitions,
      typeParams,
      "debugExpr",
      test.library,
      className: test.className,
      methodName: test.methodName,
      isStatic: test.isStaticMethod,
      scriptUri: test.scriptUri,
      offset: test.offset ?? TreeNode.noOffset,
    );
    List<CfeDiagnosticMessage> errors = context.takeErrors();
    test.results.add(
      new CompilationResult(libraryLookup, compiledProcedure, errors),
    );
    if (compiledProcedure != null) {
      // Confirm we can serialize generated procedure.
      compilerResult.component.computeCanonicalNames();
      List<int> list = serializeProcedure(compiledProcedure);
      assert(list.length > 0);
    }

    if (context.fuzz) {
      await fuzz(compiler, compilerResult, context);
    }
  }

  Future<void> fuzz(
    IncrementalCompiler compiler,
    IncrementalCompilerResult compilerResult,
    Context context,
  ) async {
    for (Library lib in compilerResult.classHierarchy.knownLibraries) {
      if (!context.fuzzedLibraries.add(lib.importUri)) continue;

      for (Member m in lib.members) {
        await fuzzMember(m, compiler, lib.importUri, context);
      }

      for (Class c in lib.classes) {
        for (Member m in c.members) {
          await fuzzMember(m, compiler, lib.importUri, context);
        }
      }
    }
  }

  Future<void> fuzzMember(
    Member m,
    IncrementalCompiler compiler,
    Uri libraryUri,
    Context context,
  ) async {
    String expression = m.name.text;
    if (m is Field || (m is Procedure && m.isGetter)) {
      // fields and getters are fine as-is
    } else if (m is Procedure && !m.isGetter) {
      expression = "$expression()";
    } else if (m is Constructor) {
      if (m.parent is! Class) {
        return;
      }
      Class parent = m.parent as Class;
      if (m.name.text != "") {
        expression = "${parent.name}.${m.name.text}()";
      } else {
        expression = "${parent.name}()";
      }
    } else {
      throw "Didn't know ${m.runtimeType}";
    }

    String? className;
    if (m.parent is Class && m is! Constructor) {
      Class parent = m.parent as Class;
      className = parent.name;
    }

    await fuzzTryCompile(
      compiler,
      "$expression",
      libraryUri,
      className,
      !m.isInstanceMember,
      context,
    );
    if (className != null && !m.isInstanceMember) {
      await fuzzTryCompile(
        compiler,
        "$className.$expression",
        libraryUri,
        null,
        !m.isInstanceMember,
        context,
      );
    }
    await fuzzTryCompile(
      compiler,
      "$expression.toString()",
      libraryUri,
      className,
      !m.isInstanceMember,
      context,
    );
    if (className != null && !m.isInstanceMember) {
      await fuzzTryCompile(
        compiler,
        "$className.$expression.toString()",
        libraryUri,
        null,
        !m.isInstanceMember,
        context,
      );
    }
    await fuzzTryCompile(
      compiler,
      "$expression.toString() == '42'",
      libraryUri,
      className,
      !m.isInstanceMember,
      context,
    );
    if (className != null && !m.isInstanceMember) {
      await fuzzTryCompile(
        compiler,
        "$className.$expression.toString() == '42'",
        libraryUri,
        null,
        !m.isInstanceMember,
        context,
      );
    }
    await fuzzTryCompile(
      compiler,
      "() { var x = $expression.toString(); x == '42'; }()",
      libraryUri,
      className,
      !m.isInstanceMember,
      context,
    );
    if (className != null && !m.isInstanceMember) {
      await fuzzTryCompile(
        compiler,
        "() { var x = $className.$expression.toString(); x == '42'; }()",
        libraryUri,
        null,
        !m.isInstanceMember,
        context,
      );
    }
  }

  Future<void> fuzzTryCompile(
    IncrementalCompiler compiler,
    String expression,
    Uri libraryUri,
    String? className,
    bool isStatic,
    Context context,
  ) async {
    context.fuzzCompiles++;
    print(
      "Fuzz compile #${context.fuzzCompiles} "
      "('$expression' in $libraryUri $className)",
    );
    Procedure? compiledProcedure = await compiler.compileExpression(
      expression,
      {},
      [],
      "debugExpr",
      libraryUri,
      className: className,
      isStatic: isStatic,
    );
    context.takeErrors();
    if (compiledProcedure != null) {
      // Confirm we can serialize generated procedure.
      List<int> list = serializeProcedure(compiledProcedure);
      assert(list.length > 0);
    }
  }

  @override
  Future<Result<List<TestCase>>> run(
    List<TestCase> tests,
    Context context,
  ) async {
    for (TestCase test in tests) {
      test.sources.forEach((String fileName, String source) {
        context.fileSystem
            .entityForUri(toTestUri(fileName))
            .writeAsStringSync(source);
      });

      IncrementalCompiler sourceCompiler = new IncrementalCompiler(
        context.compilerContext,
      );
      IncrementalCompilerResult sourceCompilerResult = await sourceCompiler
          .computeDelta(entryPoints: [test.entryPoint]);
      Component component = sourceCompilerResult.component;
      List<CfeDiagnosticMessage> errors = context.takeErrors();
      if (!errors.isEmpty) {
        return fail(
          tests,
          "Couldn't compile entry-point: "
          "${errors.map((e) => e.plainTextFormatted.first).toList()}",
        );
      }
      Uri dillFileUri = toTestUri("${test.description.shortName}.dill");
      Uint8List dillData = await serializeComponent(component);
      context.fileSystem.entityForUri(dillFileUri).writeAsBytesSync(dillData);
      Set<Uri> beforeFuzzedLibraries = context.fuzzedLibraries.toSet();
      await compileExpression(
        test,
        sourceCompiler,
        sourceCompilerResult,
        context,
      );

      IncrementalCompiler dillCompiler = new IncrementalCompiler(
        context.compilerContext,
        dillFileUri,
      );
      IncrementalCompilerResult dillCompilerResult = await dillCompiler
          .computeDelta(entryPoints: [test.entryPoint]);
      component = dillCompilerResult.component;
      component.computeCanonicalNames();

      errors = context.takeErrors();
      // Since it compiled successfully from source, the bootstrap-from-Dill
      // should also succeed without errors.
      assert(errors.isEmpty);

      context.fuzzedLibraries.clear();
      context.fuzzedLibraries.addAll(beforeFuzzedLibraries);
      await compileExpression(test, dillCompiler, dillCompilerResult, context);
    }
    return new Result.pass(tests);
  }
}

Future<Context> createContext(
  Chain suite,
  Map<String, String> environment,
) async {
  const Set<String> knownEnvironmentKeys = {
    EnvironmentKeys.updateExpectations,
    EnvironmentKeys.fuzz,
  };
  checkEnvironment(environment, knownEnvironmentKeys);

  final Uri base = Uri.parse("org-dartlang-test:///");

  /// Unused because we supply entry points to [computeDelta] directly above.
  final Uri entryPoint = base.resolve("nothing.dart");

  /// The custom URI used to locate the dill file in the MemoryFileSystem.
  final Uri sdkSummary = base.resolve("vm_platform.dill");

  /// The actual location of the dill file.
  final Uri sdkSummaryFile = computePlatformBinariesLocation(
    forceBuildDir: true,
  ).resolve("vm_platform.dill");

  final MemoryFileSystem fs = new MemoryFileSystem(base);

  fs
      .entityForUri(sdkSummary)
      .writeAsBytesSync(await new File.fromUri(sdkSummaryFile).readAsBytes());

  final List<CfeDiagnosticMessage> errors = <CfeDiagnosticMessage>[];

  final CompilerOptions optionBuilder = new CompilerOptions()
    ..target = new VmTarget(new TargetFlags())
    ..verbose = true
    ..omitPlatform = true
    ..fileSystem = fs
    ..sdkSummary = sdkSummary
    ..onDiagnostic = (CfeDiagnosticMessage message) {
      printDiagnosticMessage(message, print);
      errors.add(message);
    }
    ..environmentDefines = const {}
    ..explicitExperimentalFlags = {}
    ..allowedExperimentalFlagsForTesting = const AllowedExperimentalFlags();

  final ProcessedOptions options = new ProcessedOptions(
    options: optionBuilder,
    inputs: [entryPoint],
  );

  final bool updateExpectations =
      environment[EnvironmentKeys.updateExpectations] == "true";

  final bool fuzz = environment[EnvironmentKeys.fuzz] == "true";

  final CompilerContext compilerContext = new CompilerContext(options);

  // Disable colors to ensure that expectation files are the same across
  // platforms and independent of stdin/stderr.
  colors.enableColors = false;

  return new Context(compilerContext, errors, updateExpectations, fuzz);
}

void main([List<String> arguments = const []]) => internalMain(
  createContext,
  arguments: arguments,
  displayName: "expression suite",
  configurationPath: "../testing.json",
);