// 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 multitest;

import "dart:async";
import "dart:io";
import "test_suite.dart";
import "utils.dart";

// Multitests are Dart test scripts containing lines of the form
// " [some dart code] /// [key]: [error type]"
//
// For each key in the file, a new test file is made containing all
// the normal lines of the file, and all of the multitest lines containing
// that key, in the same order as in the source file.  The new test
// is expected to fail if there is a non-empty error type listed, of
// type 'compile-time error', 'runtime error', 'static type warning', or
// 'dynamic type error'.  The type error tests fail only in checked mode.
// There is also a test created from only the untagged lines of the file,
// with key "none", which is expected to pass.  This library extracts these
// tests, writes them into a temporary directory, and passes them to the test
// runner.  These tests may be referred to in the status files with the
// pattern [test name]/[key].
//
// For example: file I_am_a_multitest.dart
//   aaa
//   bbb /// 02: runtime error
//   ccc /// 02: continued
//   ddd /// 07: static type warning
//   eee
//
// should create three tests:
// I_am_a_multitest_none.dart
//   aaa
//   eee
//
// I_am_a_multitest_02.dart
//   aaa
//   bbb /// 02: runtime error
//   ccc /// 02: continued
//   eee
//
// and I_am_a_multitest_07.dart
//   aaa
//   ddd /// 07: static type warning
//   eee
//
// Note that it is possible to indicate more than one acceptable outcome
// in the case of dynamic and static type warnings
//   aaa
//   ddd /// 07: static type warning, dynamic type error
//   eee

void ExtractTestsFromMultitest(Path filePath,
                               Map<String, String> tests,
                               Map<String, Set<String>> outcomes) {
  // Read the entire file into a byte buffer and transform it to a
  // String. This will treat the file as ascii but the only parts
  // we are interested in will be ascii in any case.
  List bytes = new File.fromPath(filePath).readAsBytesSync();
  String contents = decodeUtf8(bytes);
  int first_newline = contents.indexOf('\n');
  final String line_separator =
      (first_newline == 0 || contents[first_newline - 1] != '\r')
      ? '\n'
      : '\r\n';
  List<String> lines = contents.split(line_separator);
  if (lines.last == '') lines.removeLast();
  bytes = null;
  contents = null;
  Set<String> validMultitestOutcomes = new Set<String>.from(
      ['compile-time error', 'runtime error',
       'static type warning', 'dynamic type error']);

  List<String> testTemplate = new List<String>();
  testTemplate.add(
      '// Test created from multitest named ${filePath.toNativePath()}.');
  // Create the set of multitests, which will have a new test added each
  // time we see a multitest line with a new key.
  Map<String, List<String>> testsAsLines = new Map<String, List<String>>();

  int lineCount = 0;
  for (String line in lines) {
    lineCount++;
    var annotation = new _Annotation.from(line);
    if (annotation != null) {
      testsAsLines.putIfAbsent(annotation.key,
          () => new List<String>.from(testTemplate)).add(line);
      outcomes.putIfAbsent(annotation.key,
          () => new Set<String>());
      if (annotation.rest == 'continued') {
        continue;
      } else {
        for (String nextOutcome in annotation.outcomesList) {
          outcomes[annotation.key].add(nextOutcome);
          if (!validMultitestOutcomes.contains(nextOutcome)) {
            Expect.fail(
              "Invalid test directive '$nextOutcome' on line ${lineCount}:\n"
              "${annotation.rest} ");
          }
        }
      }
    } else {
      testTemplate.add(line);
      for (var test in testsAsLines.values) test.add(line);
    }
  }

  // Check that every key (other than the none case) has at least one outcome
  for (var outcomeKey in outcomes.keys) {
    if (outcomeKey != 'none' && outcomes[outcomeKey].isEmpty) {
      Expect.fail("Test ${outcomeKey} has no valid annotated outcomes.\n"
                  "Expected one of: ${validMultitestOutcomes.toString()}");
    }
  }

  // Add the template, with no multitest lines, as a test with key 'none'.
  testsAsLines['none'] = testTemplate;
  outcomes['none'] = new Set<String>();

  // Copy all the tests into the output map tests, as multiline strings.
  for (String key in testsAsLines.keys) {
    tests[key] = testsAsLines[key].join(line_separator).concat(line_separator);
  }
}

// Represents a mutlitest annotation in the special /// comment.
class _Annotation {
  String key;
  String rest;
  List<String> outcomesList;
  _Annotation() {}
  factory _Annotation.from(String line) {
    if (!line.contains('///')) {
      return null;
    }
    var annotation = new _Annotation();
    var parts = line.split('///')[1].split(':')
        .mappedBy((s) => s.trim()).toList();
    annotation.key = parts[0];
    annotation.rest = parts[1];
    annotation.outcomesList = annotation.rest.split(',')
        .mappedBy((s) => s.trim()).toList();
    return annotation;
  }
}

// Find all relative imports and copy them into the dir that contains
// the generated tests.
Set<Path> _findAllRelativeImports(Path topLibrary) {
  Set<Path> toSearch = new Set<Path>.from([topLibrary]);
  Set<Path> foundImports = new HashSet<Path>();
  Path libraryDir = topLibrary.directoryPath;
  // Matches #import( or #source( followed by " or ' followed by anything
  // except dart:, dart-ext: or /, at the beginning of a line.
  RegExp relativeImportRegExp = new RegExp(
      '^#(import|source)[(]["\'](?!(dart:|dart-ext:|/))([^"\']*)["\']');
  while (!toSearch.isEmpty) {
    var thisPass = toSearch;
    toSearch = new HashSet<Path>();
    for (Path filename in thisPass) {
      File f = new File.fromPath(filename);
      for (String line in f.readAsLinesSync()) {
        Match match = relativeImportRegExp.firstMatch(line);
        if (match != null) {
          Path relativePath = new Path(match.group(3));
          if (foundImports.contains(relativePath)) {
            continue;
          }
          if (relativePath.toString().contains('..')) {
            // This is just for safety reasons, we don't want
            // to unintentionally clobber files relative to the destination
            // dir when copying them ove.
            Expect.fail("relative paths containing .. are not allowed.");
          }
          foundImports.add(relativePath);
          toSearch.add(libraryDir.join(relativePath));
        }
      }
    }
  }
  return foundImports;
}

Future doMultitest(Path filePath, String outputDir, Path suiteDir,
                   CreateTest doTest) {
  // Each new test is a single String value in the Map tests.
  Map<String, String> tests = new Map<String, String>();
  Map<String, Set<String>> outcomes = new Map<String, Set<String>>();
  ExtractTestsFromMultitest(filePath, tests, outcomes);

  Path sourceDir = filePath.directoryPath;
  Path targetDir = CreateMultitestDirectory(outputDir, suiteDir);
  Expect.isNotNull(targetDir);

  // Copy all the relative imports of the multitest.
  Set<Path> importsToCopy = _findAllRelativeImports(filePath);
  List<Future> futureCopies = [];
  for (Path importPath in importsToCopy) {
    // Make sure the target directory exists.
    Path importDir = importPath.directoryPath;
    if (!importDir.isEmpty) {
      TestUtils.mkdirRecursive(targetDir, importDir);
    }
    // Copy file.
    futureCopies.add(TestUtils.copyFile(sourceDir.join(importPath),
                                        targetDir.join(importPath)));
  }

  // Wait until all imports are copied before scheduling test cases.
  return Future.wait(futureCopies).then((_) {
    String baseFilename = filePath.filenameWithoutExtension;
    for (String key in tests.keys) {
      final Path multitestFilename =
          targetDir.append('${baseFilename}_$key.dart');
      final File file = new File.fromPath(multitestFilename);

      file.createSync();
      RandomAccessFile openedFile = file.openSync(FileMode.WRITE);
      var bytes = tests[key].charCodes;
      openedFile.writeListSync(bytes, 0, bytes.length);
      openedFile.closeSync();
      Set<String> outcome = outcomes[key];
      bool enableFatalTypeErrors = outcome.contains('static type warning');
      bool hasRuntimeErrors = outcome.contains('runtime error');
      bool hasCompileError = outcome.contains('compile-time error');
      bool isNegativeIfChecked = outcome.contains('dynamic type error');
      doTest(multitestFilename,
             hasCompileError,
             hasRuntimeErrors,
             isNegativeIfChecked: isNegativeIfChecked,
             hasFatalTypeErrors: enableFatalTypeErrors,
             multitestOutcome: outcome);
    }

    return null;
  });
}


Path CreateMultitestDirectory(String outputDir, Path suiteDir) {
  final String generatedTestDirectory = 'generated_tests';
  Directory generatedTestDir = new Directory('$outputDir/generated_tests');
  if (!new Directory(outputDir).existsSync()) {
    new Directory(outputDir).createSync();
  }
  if (!generatedTestDir.existsSync()) {
    generatedTestDir.createSync();
  }
  var split = suiteDir.segments();
  if (split.last == 'src') {
    // TODO(sigmund): remove this once all tests are migrated to use
    // TestSuite.forDirectory.
    split.removeLast();
  }
  String path = '${generatedTestDir.path}/${split.last}';
  Directory dir = new Directory(path);
  if (!dir.existsSync()) {
    dir.createSync();
  }
  return new Path(new File(path).fullPathSync());
}