// Copyright (c) 2015, 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:async';

import 'package:fake_async/fake_async.dart';
import 'package:test/test.dart';
import 'package:test_api/src/backend/group.dart';
import 'package:test_api/src/backend/invoker.dart';
import 'package:test_api/src/backend/live_test.dart';
import 'package:test_api/src/backend/message.dart';
import 'package:test_api/src/backend/metadata.dart';
import 'package:test_api/src/backend/state.dart';
import 'package:test_api/src/backend/suite.dart';
import 'package:test_api/src/utils.dart';

import '../utils.dart';

void main() {
  Suite suite;
  setUp(() {
    lastState = null;
    suite = Suite(Group.root([]), suitePlatform);
  });

  group('Invoker.current', () {
    var invoker = Invoker.current;
    test('returns null outside of a test body', () {
      expect(invoker, isNull);
    });

    test('returns the current invoker in a test body', () async {
      Invoker invoker;
      var liveTest = _localTest(() {
        invoker = Invoker.current;
      }).load(suite);
      liveTest.onError.listen(expectAsync1((_) {}, count: 0));

      await liveTest.run();
      expect(invoker.liveTest, equals(liveTest));
    });

    test('returns the current invoker in a test body after the test completes',
        () async {
      Status status;
      var completer = Completer();
      var liveTest = _localTest(() {
        // Use the event loop to wait longer than a microtask for the test to
        // complete.
        Future(() {
          status = Invoker.current.liveTest.state.status;
          completer.complete(Invoker.current);
        });
      }).load(suite);
      liveTest.onError.listen(expectAsync1((_) {}, count: 0));

      expect(liveTest.run(), completes);
      var invoker = await completer.future;
      expect(invoker.liveTest, equals(liveTest));
      expect(status, equals(Status.complete));
    });
  });

  group('in a successful test,', () {
    test('the state changes from pending to running to complete', () async {
      State stateInTest;
      LiveTest liveTest;
      liveTest = _localTest(() {
        stateInTest = liveTest.state;
      }).load(suite);
      liveTest.onError.listen(expectAsync1((_) {}, count: 0));

      expect(liveTest.state.status, equals(Status.pending));
      expect(liveTest.state.result, equals(Result.success));

      var future = liveTest.run();

      expect(liveTest.state.status, equals(Status.running));
      expect(liveTest.state.result, equals(Result.success));

      await future;

      expect(stateInTest.status, equals(Status.running));
      expect(stateInTest.result, equals(Result.success));

      expect(liveTest.state.status, equals(Status.complete));
      expect(liveTest.state.result, equals(Result.success));
    });

    test('onStateChange fires for each state change', () {
      var liveTest = _localTest(() {}).load(suite);
      liveTest.onError.listen(expectAsync1((_) {}, count: 0));

      var first = true;
      liveTest.onStateChange.listen(expectAsync1((state) {
        if (first) {
          expect(state.status, equals(Status.running));
          first = false;
        } else {
          expect(state.status, equals(Status.complete));
        }
        expect(state.result, equals(Result.success));
      }, count: 2, max: 2));

      return liveTest.run();
    });

    test('onComplete completes once the test body is done', () {
      var testRun = false;
      var liveTest = _localTest(() {
        testRun = true;
      }).load(suite);

      expect(liveTest.onComplete.then((_) {
        expect(testRun, isTrue);
      }), completes);

      return liveTest.run();
    });
  });

  group('in a test with failures,', () {
    test('a synchronous throw is reported and causes the test to fail', () {
      var liveTest = _localTest(() {
        throw TestFailure('oh no');
      }).load(suite);

      expectSingleFailure(liveTest);
      return liveTest.run();
    });

    test('a synchronous reported failure causes the test to fail', () {
      var liveTest = _localTest(() {
        registerException(TestFailure('oh no'));
      }).load(suite);

      expectSingleFailure(liveTest);
      return liveTest.run();
    });

    test('a failure reported asynchronously during the test causes it to fail',
        () {
      var liveTest = _localTest(() {
        Invoker.current.addOutstandingCallback();
        Future(() => registerException(TestFailure('oh no')));
      }).load(suite);

      expectSingleFailure(liveTest);
      return liveTest.run();
    });

    test('a failure thrown asynchronously during the test causes it to fail',
        () {
      var liveTest = _localTest(() {
        Invoker.current.addOutstandingCallback();
        Future(() => throw TestFailure('oh no'));
      }).load(suite);

      expectSingleFailure(liveTest);
      return liveTest.run();
    });

    test('a failure reported asynchronously after the test causes it to error',
        () {
      var liveTest = _localTest(() {
        Future(() => registerException(TestFailure('oh no')));
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.success),
        const State(Status.complete, Result.failure),
        const State(Status.complete, Result.error)
      ]);

      expectErrors(liveTest, [
        (error) {
          expect(
              lastState, equals(const State(Status.complete, Result.failure)));
          expect(error, isTestFailure('oh no'));
        },
        (error) {
          expect(lastState, equals(const State(Status.complete, Result.error)));
          expect(
              error,
              equals(
                  'This test failed after it had already completed. Make sure to '
                  'use [expectAsync]\n'
                  'or the [completes] matcher when testing async code.'));
        }
      ]);

      return liveTest.run();
    });

    test('multiple asynchronous failures are reported', () {
      var liveTest = _localTest(() {
        Invoker.current.addOutstandingCallback();
        Future(() => throw TestFailure('one'));
        Future(() => throw TestFailure('two'));
        Future(() => throw TestFailure('three'));
        Future(() => throw TestFailure('four'));
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.failure)
      ]);

      expectErrors(liveTest, [
        (error) {
          expect(lastState.status, equals(Status.complete));
          expect(error, isTestFailure('one'));
        },
        (error) {
          expect(error, isTestFailure('two'));
        },
        (error) {
          expect(error, isTestFailure('three'));
        },
        (error) {
          expect(error, isTestFailure('four'));
        }
      ]);

      return liveTest.run();
    });

    test("a failure after an error doesn't change the state of the test", () {
      var liveTest = _localTest(() {
        Future(() => throw TestFailure('fail'));
        throw 'error';
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.error)
      ]);

      expectErrors(liveTest, [
        (error) {
          expect(lastState, equals(const State(Status.complete, Result.error)));
          expect(error, equals('error'));
        },
        (error) {
          expect(error, isTestFailure('fail'));
        }
      ]);

      return liveTest.run();
    });
  });

  group('in a test with errors,', () {
    test('a synchronous throw is reported and causes the test to error', () {
      var liveTest = _localTest(() {
        throw 'oh no';
      }).load(suite);

      expectSingleError(liveTest);
      return liveTest.run();
    });

    test('a synchronous reported error causes the test to error', () {
      var liveTest = _localTest(() {
        registerException('oh no');
      }).load(suite);

      expectSingleError(liveTest);
      return liveTest.run();
    });

    test('an error reported asynchronously during the test causes it to error',
        () {
      var liveTest = _localTest(() {
        Invoker.current.addOutstandingCallback();
        Future(() => registerException('oh no'));
      }).load(suite);

      expectSingleError(liveTest);
      return liveTest.run();
    });

    test('an error thrown asynchronously during the test causes it to error',
        () {
      var liveTest = _localTest(() {
        Invoker.current.addOutstandingCallback();
        Future(() => throw 'oh no');
      }).load(suite);

      expectSingleError(liveTest);
      return liveTest.run();
    });

    test('an error reported asynchronously after the test causes it to error',
        () {
      var liveTest = _localTest(() {
        Future(() => registerException('oh no'));
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.success),
        const State(Status.complete, Result.error)
      ]);

      expectErrors(liveTest, [
        (error) {
          expect(lastState, equals(const State(Status.complete, Result.error)));
          expect(error, equals('oh no'));
        },
        (error) {
          expect(
              error,
              equals(
                  'This test failed after it had already completed. Make sure to '
                  'use [expectAsync]\n'
                  'or the [completes] matcher when testing async code.'));
        }
      ]);

      return liveTest.run();
    });

    test('multiple asynchronous errors are reported', () {
      var liveTest = _localTest(() {
        Invoker.current.addOutstandingCallback();
        Future(() => throw 'one');
        Future(() => throw 'two');
        Future(() => throw 'three');
        Future(() => throw 'four');
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.error)
      ]);

      expectErrors(liveTest, [
        (error) {
          expect(lastState.status, equals(Status.complete));
          expect(error, equals('one'));
        },
        (error) {
          expect(error, equals('two'));
        },
        (error) {
          expect(error, equals('three'));
        },
        (error) {
          expect(error, equals('four'));
        }
      ]);

      return liveTest.run();
    });

    test('an error after a failure changes the state of the test', () {
      var liveTest = _localTest(() {
        Future(() => throw 'error');
        throw TestFailure('fail');
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.failure),
        const State(Status.complete, Result.error)
      ]);

      expectErrors(liveTest, [
        (error) {
          expect(
              lastState, equals(const State(Status.complete, Result.failure)));
          expect(error, isTestFailure('fail'));
        },
        (error) {
          expect(lastState, equals(const State(Status.complete, Result.error)));
          expect(error, equals('error'));
        }
      ]);

      return liveTest.run();
    });
  });

  test("a test doesn't complete until there are no outstanding callbacks",
      () async {
    var outstandingCallbackRemoved = false;
    var liveTest = _localTest(() {
      Invoker.current.addOutstandingCallback();

      // Pump the event queue to make sure the test isn't coincidentally
      // completing after the outstanding callback is removed.
      pumpEventQueue().then((_) {
        outstandingCallbackRemoved = true;
        Invoker.current.removeOutstandingCallback();
      });
    }).load(suite);

    liveTest.onError.listen(expectAsync1((_) {}, count: 0));

    await liveTest.run();
    expect(outstandingCallbackRemoved, isTrue);
  });

  test("a test's prints are captured and reported", () {
    expect(() {
      var liveTest = _localTest(() {
        print('Hello,');
        return Future(() => print('world!'));
      }).load(suite);

      expect(
          liveTest.onMessage.take(2).toList().then((messages) {
            expect(messages[0].type, equals(MessageType.print));
            expect(messages[0].text, equals('Hello,'));
            expect(messages[1].type, equals(MessageType.print));
            expect(messages[1].text, equals('world!'));
          }),
          completes);

      return liveTest.run();
    }, prints(isEmpty));
  });

  group('timeout:', () {
    test('a test times out after 30 seconds by default', () {
      FakeAsync().run((async) {
        var liveTest = _localTest(() {
          Invoker.current.addOutstandingCallback();
        }).load(suite);

        expectStates(liveTest, [
          const State(Status.running, Result.success),
          const State(Status.complete, Result.error)
        ]);

        expectErrors(liveTest, [
          (error) {
            expect(lastState.status, equals(Status.complete));
            expect(error, TypeMatcher<TimeoutException>());
          }
        ]);

        liveTest.run();
        async.elapse(Duration(seconds: 30));
      });
    });

    test("a test's custom timeout takes precedence", () {
      FakeAsync().run((async) {
        var liveTest = _localTest(() {
          Invoker.current.addOutstandingCallback();
        }, metadata: Metadata(timeout: Timeout(Duration(seconds: 15))))
            .load(suite);

        expectStates(liveTest, [
          const State(Status.running, Result.success),
          const State(Status.complete, Result.error)
        ]);

        expectErrors(liveTest, [
          (error) {
            expect(lastState.status, equals(Status.complete));
            expect(error, TypeMatcher<TimeoutException>());
          }
        ]);

        liveTest.run();
        async.elapse(Duration(seconds: 15));
      });
    });

    test('a timeout factor is applied on top of the 30s default', () {
      FakeAsync().run((async) {
        var liveTest = _localTest(() {
          Invoker.current.addOutstandingCallback();
        }, metadata: Metadata(timeout: Timeout.factor(0.5)))
            .load(suite);

        expectStates(liveTest, [
          const State(Status.running, Result.success),
          const State(Status.complete, Result.error)
        ]);

        expectErrors(liveTest, [
          (error) {
            expect(lastState.status, equals(Status.complete));
            expect(error, TypeMatcher<TimeoutException>());
          }
        ]);

        liveTest.run();
        async.elapse(Duration(seconds: 15));
      });
    });

    test('a test with Timeout.none never times out', () {
      FakeAsync().run((async) {
        var liveTest = _localTest(() {
          Invoker.current.addOutstandingCallback();
        }, metadata: Metadata(timeout: Timeout.none))
            .load(suite);

        expectStates(liveTest, [const State(Status.running, Result.success)]);

        liveTest.run();
        async.elapse(Duration(hours: 10));
        expect(liveTest.state.status, equals(Status.running));
      });
    });
  });

  group('waitForOutstandingCallbacks:', () {
    test('waits for the wrapped function to complete', () async {
      var functionCompleted = false;
      await Invoker.current.waitForOutstandingCallbacks(() async {
        await pumpEventQueue();
        functionCompleted = true;
      });

      expect(functionCompleted, isTrue);
    });

    test('waits for registered callbacks in the wrapped function to run',
        () async {
      var callbackRun = false;
      await Invoker.current.waitForOutstandingCallbacks(() {
        pumpEventQueue().then(expectAsync1((_) {
          callbackRun = true;
        }));
      });

      expect(callbackRun, isTrue);
    });

    test("doesn't automatically block the enclosing context", () async {
      var innerFunctionCompleted = false;
      await Invoker.current.waitForOutstandingCallbacks(() {
        Invoker.current.waitForOutstandingCallbacks(() async {
          await pumpEventQueue();
          innerFunctionCompleted = true;
        });
      });

      expect(innerFunctionCompleted, isFalse);
    });

    test(
        "forwards errors to the enclosing test but doesn't remove its "
        'outstanding callbacks', () async {
      var liveTest = _localTest(() async {
        Invoker.current.addOutstandingCallback();
        await Invoker.current.waitForOutstandingCallbacks(() {
          throw 'oh no';
        });
      }).load(suite);

      expectStates(liveTest, [
        const State(Status.running, Result.success),
        const State(Status.complete, Result.error)
      ]);

      var isComplete = false;
      unawaited(liveTest.run().then((_) => isComplete = true));
      await pumpEventQueue();
      expect(liveTest.state.status, equals(Status.complete));
      expect(isComplete, isFalse);
    });
  });

  group('chainStackTraces', () {
    test(
        'if disabled, directs users to run with the flag enabled when '
        'failures occur', () {
      expect(() async {
        var liveTest = _localTest(() {
          expect(true, isFalse);
        }, metadata: Metadata(chainStackTraces: false))
            .load(suite);
        liveTest.onError.listen(expectAsync1((_) {}, count: 1));

        await liveTest.run();
      },
          prints('Consider enabling the flag chain-stack-traces to '
              'receive more detailed exceptions.\n'
              "For example, 'pub run test --chain-stack-traces'.\n"));
    });
  });

  group('printOnFailure:', () {
    test("doesn't print anything if the test succeeds", () {
      expect(() async {
        var liveTest = _localTest(() {
          Invoker.current.printOnFailure('only on failure');
        }).load(suite);
        liveTest.onError.listen(expectAsync1((_) {}, count: 0));

        await liveTest.run();
      }, prints(isEmpty));
    });

    test('prints if the test fails', () {
      expect(() async {
        var liveTest = _localTest(() {
          Invoker.current.printOnFailure('only on failure');
          expect(true, isFalse);
        }).load(suite);
        liveTest.onError.listen(expectAsync1((_) {}, count: 1));

        await liveTest.run();
      }, prints('only on failure\n'));
    });
  });
}

LocalTest _localTest(dynamic Function() body, {Metadata metadata}) {
  metadata ??= Metadata();
  return LocalTest('test', metadata, body);
}