namespace Harness {
    export const enum CompilerTestType {
        Conformance,
        Regressions,
        Test262
    }

    interface CompilerFileBasedTest extends FileBasedTest {
        readonly content?: string;
    }

    export class CompilerBaselineRunner extends RunnerBase {
        private basePath = "tests/cases";
        private testSuiteName: TestRunnerKind;
        private emit: boolean;

        public options: string | undefined;

        constructor(public testType: CompilerTestType) {
            super();
            this.emit = true;
            if (testType === CompilerTestType.Conformance) {
                this.testSuiteName = "conformance";
            }
            else if (testType === CompilerTestType.Regressions) {
                this.testSuiteName = "compiler";
            }
            else if (testType === CompilerTestType.Test262) {
                this.testSuiteName = "test262";
            }
            else {
                this.testSuiteName = "compiler"; // default to this for historical reasons
            }
            this.basePath += "/" + this.testSuiteName;
        }

        public kind() {
            return this.testSuiteName;
        }

        public enumerateTestFiles() {
            // see also: `enumerateTestFiles` in tests/webTestServer.ts
            return this.enumerateFiles(this.basePath, /\.tsx?$/, { recursive: true }).map(CompilerTest.getConfigurations);
        }

        public initializeTests() {
            describe(this.testSuiteName + " tests", () => {
                describe("Setup compiler for compiler baselines", () => {
                    this.parseOptions();
                });

                // this will set up a series of describe/it blocks to run between the setup and cleanup phases
                const files = this.tests.length > 0 ? this.tests : IO.enumerateTestFiles(this);
                files.forEach(test => {
                    const file = typeof test === "string" ? test : test.file;
                    this.checkTestCodeOutput(vpath.normalizeSeparators(file), typeof test === "string" ? CompilerTest.getConfigurations(test) : test);
                });
            });
        }

        public checkTestCodeOutput(fileName: string, test?: CompilerFileBasedTest) {
            if (test && ts.some(test.configurations)) {
                test.configurations.forEach(configuration => {
                    describe(`${this.testSuiteName} tests for ${fileName}${configuration ? ` (${getFileBasedTestConfigurationDescription(configuration)})` : ``}`, () => {
                        this.runSuite(fileName, test, configuration);
                    });
                });
            }
            else {
                describe(`${this.testSuiteName} tests for ${fileName}`, () => {
                    this.runSuite(fileName, test);
                });
            }
        }

        private runSuite(fileName: string, test?: CompilerFileBasedTest, configuration?: FileBasedTestConfiguration) {
            // Mocha holds onto the closure environment of the describe callback even after the test is done.
            // Everything declared here should be cleared out in the "after" callback.
            let compilerTest!: CompilerTest;
            before(() => {
                let payload;
                if (test && test.content) {
                    const rootDir = test.file.indexOf("conformance") === -1 ? "tests/cases/compiler/" : ts.getDirectoryPath(test.file) + "/";
                    payload = TestCaseParser.makeUnitsFromTest(test.content, test.file, rootDir);
                }
                compilerTest = new CompilerTest(fileName, payload, configuration);
            });
            it(`Correct errors for ${fileName}`, () => { compilerTest.verifyDiagnostics(); });
            it(`Correct module resolution tracing for ${fileName}`, () => { compilerTest.verifyModuleResolution(); });
            it(`Correct sourcemap content for ${fileName}`, () => { compilerTest.verifySourceMapRecord(); });
            it(`Correct JS output for ${fileName}`, () => { if (this.emit) compilerTest.verifyJavaScriptOutput(); });
            it(`Correct Sourcemap output for ${fileName}`, () => { compilerTest.verifySourceMapOutput(); });
            it(`Correct type/symbol baselines for ${fileName}`, () => { compilerTest.verifyTypesAndSymbols(); });
            after(() => { compilerTest = undefined!; });
        }

        private parseOptions() {
            if (this.options && this.options.length > 0) {
                this.emit = false;

                const opts = this.options.split(",");
                for (const opt of opts) {
                    switch (opt) {
                        case "emit":
                            this.emit = true;
                            break;
                        default:
                            throw new Error("unsupported flag");
                    }
                }
            }
        }
    }

    class CompilerTest {
        private static varyBy: readonly string[] = [
            "module",
            "target",
            "jsx",
            "removeComments",
            "importHelpers",
            "importHelpers",
            "downlevelIteration",
            "isolatedModules",
            "strict",
            "noImplicitAny",
            "strictNullChecks",
            "strictFunctionTypes",
            "strictBindCallApply",
            "strictPropertyInitialization",
            "noImplicitThis",
            "alwaysStrict",
            "allowSyntheticDefaultImports",
            "esModuleInterop",
            "emitDecoratorMetadata",
            "skipDefaultLibCheck",
            "preserveConstEnums",
            "skipLibCheck",
        ];
        private fileName: string;
        private justName: string;
        private configuredName: string;
        private lastUnit: TestCaseParser.TestUnitData;
        private harnessSettings: TestCaseParser.CompilerSettings;
        private hasNonDtsFiles: boolean;
        private result: compiler.CompilationResult;
        private options: ts.CompilerOptions;
        private tsConfigFiles: Compiler.TestFile[];
        // equivalent to the files that will be passed on the command line
        private toBeCompiled: Compiler.TestFile[];
        // equivalent to other files on the file system not directly passed to the compiler (ie things that are referenced by other files)
        private otherFiles: Compiler.TestFile[];

        constructor(fileName: string, testCaseContent?: TestCaseParser.TestCaseContent, configurationOverrides?: TestCaseParser.CompilerSettings) {
            this.fileName = fileName;
            this.justName = vpath.basename(fileName);
            this.configuredName = this.justName;
            if (configurationOverrides) {
                let configuredName = "";
                const keys = Object
                    .keys(configurationOverrides)
                    .map(k => k.toLowerCase())
                    .sort();
                for (const key of keys) {
                    if (configuredName) {
                        configuredName += ",";
                    }
                    configuredName += `${key}=${configurationOverrides[key].toLowerCase()}`;
                }
                if (configuredName) {
                    const extname = vpath.extname(this.justName);
                    const basename = vpath.basename(this.justName, extname, /*ignoreCase*/ true);
                    this.configuredName = `${basename}(${configuredName})${extname}`;
                }
            }

            const rootDir = fileName.indexOf("conformance") === -1 ? "tests/cases/compiler/" : ts.getDirectoryPath(fileName) + "/";

            if (testCaseContent === undefined) {
                testCaseContent = TestCaseParser.makeUnitsFromTest(IO.readFile(fileName)!, fileName, rootDir);
            }

            if (configurationOverrides) {
                testCaseContent = { ...testCaseContent, settings: { ...testCaseContent.settings, ...configurationOverrides } };
            }

            const units = testCaseContent.testUnitData;
            this.harnessSettings = testCaseContent.settings;
            let tsConfigOptions: ts.CompilerOptions | undefined;
            this.tsConfigFiles = [];
            if (testCaseContent.tsConfig) {
                assert.equal(testCaseContent.tsConfig.fileNames.length, 0, `list of files in tsconfig is not currently supported`);
                assert.equal(testCaseContent.tsConfig.raw.exclude, undefined, `exclude in tsconfig is not currently supported`);

                tsConfigOptions = ts.cloneCompilerOptions(testCaseContent.tsConfig.options);
                this.tsConfigFiles.push(this.createHarnessTestFile(testCaseContent.tsConfigFileUnitData!, rootDir, ts.combinePaths(rootDir, tsConfigOptions.configFilePath)));
            }
            else {
                const baseUrl = this.harnessSettings.baseUrl;
                if (baseUrl !== undefined && !ts.isRootedDiskPath(baseUrl)) {
                    this.harnessSettings.baseUrl = ts.getNormalizedAbsolutePath(baseUrl, rootDir);
                }
            }

            this.lastUnit = units[units.length - 1];
            this.hasNonDtsFiles = units.some(unit => !ts.fileExtensionIs(unit.name, ts.Extension.Dts));
            // We need to assemble the list of input files for the compiler and other related files on the 'filesystem' (ie in a multi-file test)
            // If the last file in a test uses require or a triple slash reference we'll assume all other files will be brought in via references,
            // otherwise, assume all files are just meant to be in the same compilation session without explicit references to one another.
            this.toBeCompiled = [];
            this.otherFiles = [];

            if (testCaseContent.settings.noImplicitReferences || /require\(/.test(this.lastUnit.content) || /reference\spath/.test(this.lastUnit.content)) {
                this.toBeCompiled.push(this.createHarnessTestFile(this.lastUnit, rootDir));
                units.forEach(unit => {
                    if (unit.name !== this.lastUnit.name) {
                        this.otherFiles.push(this.createHarnessTestFile(unit, rootDir));
                    }
                });
            }
            else {
                this.toBeCompiled = units.map(unit => {
                    return this.createHarnessTestFile(unit, rootDir);
                });
            }

            if (tsConfigOptions && tsConfigOptions.configFilePath !== undefined) {
                tsConfigOptions.configFilePath = ts.combinePaths(rootDir, tsConfigOptions.configFilePath);
                tsConfigOptions.configFile!.fileName = tsConfigOptions.configFilePath;
            }

            this.result = Compiler.compileFiles(
                this.toBeCompiled,
                this.otherFiles,
                this.harnessSettings,
                /*options*/ tsConfigOptions,
                /*currentDirectory*/ this.harnessSettings.currentDirectory,
                testCaseContent.symlinks
            );

            this.options = this.result.options;
        }

        public static getConfigurations(file: string): CompilerFileBasedTest {
            // also see `parseCompilerTestConfigurations` in tests/webTestServer.ts
            const content = IO.readFile(file)!;
            const settings = TestCaseParser.extractCompilerSettings(content);
            const configurations = getFileBasedTestConfigurations(settings, CompilerTest.varyBy);
            return { file, configurations, content };
        }

        public verifyDiagnostics() {
            // check errors
            Compiler.doErrorBaseline(
                this.configuredName,
                this.tsConfigFiles.concat(this.toBeCompiled, this.otherFiles),
                this.result.diagnostics,
                !!this.options.pretty);
        }

        public verifyModuleResolution() {
            if (this.options.traceResolution) {
                Baseline.runBaseline(this.configuredName.replace(/\.tsx?$/, ".trace.json"),
                    JSON.stringify(this.result.traces.map(Utils.sanitizeTraceResolutionLogEntry), undefined, 4));
            }
        }

        public verifySourceMapRecord() {
            if (this.options.sourceMap || this.options.inlineSourceMap || this.options.declarationMap) {
                const record = Utils.removeTestPathPrefixes(this.result.getSourceMapRecord()!);
                const baseline = (this.options.noEmitOnError && this.result.diagnostics.length !== 0) || record === undefined
                    // Because of the noEmitOnError option no files are created. We need to return null because baselining isn't required.
                    ? null // eslint-disable-line no-null/no-null
                    : record;
                Baseline.runBaseline(this.configuredName.replace(/\.tsx?$/, ".sourcemap.txt"), baseline);
            }
        }

        public verifyJavaScriptOutput() {
            if (this.hasNonDtsFiles) {
                Compiler.doJsEmitBaseline(
                    this.configuredName,
                    this.fileName,
                    this.options,
                    this.result,
                    this.tsConfigFiles,
                    this.toBeCompiled,
                    this.otherFiles,
                    this.harnessSettings);
            }
        }

        public verifySourceMapOutput() {
            Compiler.doSourcemapBaseline(
                this.configuredName,
                this.options,
                this.result,
                this.harnessSettings);
        }

        public verifyTypesAndSymbols() {
            if (this.fileName.indexOf("APISample") >= 0) {
                return;
            }

            const noTypesAndSymbols =
                this.harnessSettings.noTypesAndSymbols &&
                this.harnessSettings.noTypesAndSymbols.toLowerCase() === "true";
            if (noTypesAndSymbols) {
                return;
            }

            Compiler.doTypeAndSymbolBaseline(
                this.configuredName,
                this.result.program!,
                this.toBeCompiled.concat(this.otherFiles).filter(file => !!this.result.program!.getSourceFile(file.unitName)),
                /*opts*/ undefined,
                /*multifile*/ undefined,
                /*skipTypeBaselines*/ undefined,
                /*skipSymbolBaselines*/ undefined,
                !!ts.length(this.result.diagnostics)
            );
        }

        private makeUnitName(name: string, root: string) {
            const path = ts.toPath(name, root, ts.identity);
            const pathStart = ts.toPath(IO.getCurrentDirectory(), "", ts.identity);
            return pathStart ? path.replace(pathStart, "/") : path;
        }

        private createHarnessTestFile(lastUnit: TestCaseParser.TestUnitData, rootDir: string, unitName?: string): Compiler.TestFile {
            return { unitName: unitName || this.makeUnitName(lastUnit.name, rootDir), content: lastUnit.content, fileOptions: lastUnit.fileOptions };
        }
    }
}