// Copyright 2018 Google
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import "FIRTestCase.h"

#import <FirebaseCore/FIRAppInternal.h>
#import <FirebaseCore/FIRComponent.h>
#import <FirebaseCore/FIRComponentContainerInternal.h>

#import "FIRTestComponents.h"

/// Internally exposed methods and properties for testing.
@interface FIRComponentContainer (TestInternal)

@property(nonatomic, strong) NSMutableDictionary<NSString *, FIRComponentCreationBlock> *components;
@property(nonatomic, strong) NSMutableDictionary<NSString *, id> *cachedInstances;

+ (void)registerAsComponentRegistrant:(Class)klass inSet:(NSMutableSet<Class> *)allRegistrants;

- (instancetype)initWithApp:(FIRApp *)app registrants:(NSMutableSet<Class> *)allRegistrants;

@end

@interface FIRComponentContainerTest : FIRTestCase

@end

@implementation FIRComponentContainerTest

#pragma mark - Registration Tests

- (void)testRegisteringConformingClass {
  NSMutableSet<Class> *allRegistrants = [NSMutableSet<Class> set];
  Class testClass = [FIRTestClass class];
  [FIRComponentContainer registerAsComponentRegistrant:testClass inSet:allRegistrants];
  XCTAssertTrue([allRegistrants containsObject:testClass]);
}

- (void)testRegisteringNonConformingClass {
  NSMutableSet<Class> *allRegistrants = [NSMutableSet<Class> set];
  XCTAssertThrows(
      [FIRComponentContainer registerAsComponentRegistrant:[NSString class] inSet:allRegistrants]);
  XCTAssertTrue(allRegistrants.count == 0);
}

- (void)testComponentsPopulatedOnInit {
  FIRComponentContainer *container = [self containerWithRegistrants:@[ [FIRTestClass class] ]];

  // Verify that the block is stored.
  NSString *protocolName = NSStringFromProtocol(@protocol(FIRTestProtocol));
  FIRComponentCreationBlock creationBlock = container.components[protocolName];
  OCMExpect(creationBlock);
}

#pragma mark - Caching Tests

- (void)testInstanceCached {
  FIRComponentContainer *container =
      [self containerWithRegistrants:@[ [FIRTestClassCached class] ]];

  // Fetch an instance for `FIRTestProtocolCached`, then fetch it again to assert it's cached.
  id<FIRTestProtocolCached> instance1 = FIR_COMPONENT(FIRTestProtocolCached, container);
  XCTAssertNotNil(instance1);
  id<FIRTestProtocolCached> instance2 = FIR_COMPONENT(FIRTestProtocolCached, container);
  XCTAssertNotNil(instance2);
  XCTAssertEqual(instance1, instance2);
}

- (void)testInstanceNotCached {
  FIRComponentContainer *container = [self containerWithRegistrants:@[ [FIRTestClass class] ]];

  // Retrieve an instance from the container, then fetch it again and ensure it's not the same
  // instance.
  id<FIRTestProtocol> instance1 = FIR_COMPONENT(FIRTestProtocol, container);
  XCTAssertNotNil(instance1);
  id<FIRTestProtocol> instance2 = FIR_COMPONENT(FIRTestProtocol, container);
  XCTAssertNotNil(instance2);
  XCTAssertNotEqual(instance1, instance2);
}

- (void)testRemoveAllCachedInstances {
  FIRComponentContainer *container = [self containerWithRegistrants:@[
    [FIRTestClass class], [FIRTestClassCached class], [FIRTestClassEagerCached class]
  ]];

  // Retrieve an instance of FIRTestClassCached to ensure it's cached.
  id<FIRTestProtocolCached> cachedInstance1 = FIR_COMPONENT(FIRTestProtocolCached, container);
  id<FIRTestProtocolEagerCached> eagerInstance1 =
      FIR_COMPONENT(FIRTestProtocolEagerCached, container);

  // FIRTestClassEagerCached and FIRTestClassCached instances should be cached at this point.
  XCTAssertTrue(container.cachedInstances.count == 2);

  // Remove the instances and verify cachedInstances is empty, and that new instances returned from
  // the container don't match the old ones.
  [container removeAllCachedInstances];
  XCTAssertTrue(container.cachedInstances.count == 0);

  id<FIRTestProtocolCached> cachedInstance2 = FIR_COMPONENT(FIRTestProtocolCached, container);
  XCTAssertNotEqual(cachedInstance1, cachedInstance2);
  id<FIRTestProtocolEagerCached> eagerInstance2 =
      FIR_COMPONENT(FIRTestProtocolEagerCached, container);
  XCTAssertNotEqual(eagerInstance1, eagerInstance2);
}

#pragma mark - Instantiation Tests

- (void)testEagerInstantiation {
  // Create a container with `FIRTestClassEagerCached` as a registrant, which provides the
  // implementation for `FIRTestProtocolEagerCached` and requires eager instantiation as well as
  // caching so the test can verify it was eagerly instantiated.
  FIRComponentContainer *container =
      [self containerWithRegistrants:@[ [FIRTestClassEagerCached class] ]];
  NSString *protocolName = NSStringFromProtocol(@protocol(FIRTestProtocolEagerCached));
  XCTAssertNotNil(container.cachedInstances[protocolName]);
}

#pragma mark - Input Validation Tests

- (void)testProtocolAlreadyRegistered {
  // Register two classes that provide the same protocol. Only one should be stored, and there
  // should be a log stating that the protocol has already been registered. Right now there's no
  // guarantee which one will be registered first since it's an NSSet under the hood, but that could
  // change in the future.
  // TODO(wilsonryan): Assert that the log gets called warning that it's already been registered.
  FIRComponentContainer *container =
      [self containerWithRegistrants:@[ [FIRTestClass class], [FIRTestClassDuplicate class] ]];
  XCTAssert(container.components.count == 1);
}

#pragma mark - Convenience Methods

/// Create a container that has registered the test class.
- (FIRComponentContainer *)containerWithRegistrants:(NSArray<Class> *)registrants {
  id appMock = OCMClassMock([FIRApp class]);
  NSMutableSet<Class> *allRegistrants = [NSMutableSet<Class> set];

  // Initialize the container with the test classes.
  for (Class c in registrants) {
    [FIRComponentContainer registerAsComponentRegistrant:c inSet:allRegistrants];
  }

  return [[FIRComponentContainer alloc] initWithApp:appMock registrants:allRegistrants];
}

@end