/***********************************************************************************
 *
 * Copyright (c) 2012 Olivier Halligon
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 ***********************************************************************************/


// Compile this only if SDK version (…MAX_ALLOWED) is iOS7+/10.9+ because NSURLSession is a class only known starting these SDKs
// (this code won't compile if we use an eariler SDKs, like when building with Xcode4)
#if (defined(__IPHONE_OS_VERSION_MAX_ALLOWED) && __IPHONE_OS_VERSION_MAX_ALLOWED >= 70000) \
 || (defined(__MAC_OS_X_VERSION_MAX_ALLOWED) && __MAC_OS_X_VERSION_MAX_ALLOWED >= 1090)

#import <XCTest/XCTest.h>
#import <OHHTTPStubs/OHHTTPStubs.h>

@interface NSURLSessionTests : XCTestCase <NSURLSessionDataDelegate> @end

@implementation NSURLSessionTests
{
    NSMutableData* _receivedData;
    XCTestExpectation* _taskDidCompleteExpectation;
}

- (void)setUp
{
    [super setUp];
    [OHHTTPStubs removeAllStubs];
    _receivedData = nil;
}

- (void)_test_NSURLSession:(NSURLSession*)session
               jsonForStub:(id)json
                completion:(void(^)(NSError* errorResponse,id jsonResponse))completion
{
    if ([NSURLSession class])
    {
        static const NSTimeInterval kRequestTime = 0.0;
        static const NSTimeInterval kResponseTime = 0.2;
        
        [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) {
            return YES;
        } withStubResponse:^OHHTTPStubsResponse *(NSURLRequest *request) {
            return [[OHHTTPStubsResponse responseWithJSONObject:json statusCode:200 headers:nil]
                    requestTime:kRequestTime responseTime:kResponseTime];
        }];
        
        XCTestExpectation* expectation = [self expectationWithDescription:@"NSURLSessionDataTask completed"];
        
        __block __strong id dataResponse = nil;
        __block __strong NSError* errorResponse = nil;
        NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"foo://unknownhost:666"]];
        request.HTTPMethod = @"GET";
        [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
        [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
        
        NSURLSessionDataTask *task =  [session dataTaskWithRequest:request
                                                 completionHandler:^(NSData *data, NSURLResponse *response, NSError *error)
        {
            errorResponse = error;
            if (!error)
            {
                NSError *jsonError = nil;
                NSDictionary *jsonObject = [NSJSONSerialization JSONObjectWithData:data options:0 error:&jsonError];
                XCTAssertNil(jsonError, @"Unexpected error deserializing JSON response");
                dataResponse = jsonObject;
            }
            [expectation fulfill];
        }];

        [task resume];
        
        [self waitForExpectationsWithTimeout:kRequestTime+kResponseTime+0.5 handler:nil];
        
        completion(errorResponse, dataResponse);
    }
}

// The shared session use the same mechanism as NSURLConnection
// (based on protocols registered via +[NSURLProtocol registerClass:] and all)
// and no NSURLSessionConfiguration
- (void)test_SharedNSURLSession
{
    if ([NSURLSession class])
    {
        NSURLSession *session = [NSURLSession sharedSession];
        
        NSDictionary* json = @{@"Success": @"Yes"};
        [self _test_NSURLSession:session jsonForStub:json completion:^(NSError *errorResponse, id jsonResponse) {
            XCTAssertNil(errorResponse, @"Unexpected error");
            XCTAssertEqualObjects(jsonResponse, json, @"Unexpected data received");
        }];
    }
    else
    {
        NSLog(@"/!\\ Test skipped because the NSURLSession class is not available on this OS version. Run the tests a target with a more recent OS.\n");
    }
}

- (void)test_NSURLSessionDefaultConfig
{
    if ([NSURLSessionConfiguration class] && [NSURLSession class])
    {
        NSURLSessionConfiguration* config = [NSURLSessionConfiguration defaultSessionConfiguration];
        NSURLSession *session = [NSURLSession sessionWithConfiguration:config];
        
        NSDictionary* json = @{@"Success": @"Yes"};
        [self _test_NSURLSession:session jsonForStub:json completion:^(NSError *errorResponse, id jsonResponse) {
            XCTAssertNil(errorResponse, @"Unexpected error");
            XCTAssertEqualObjects(jsonResponse, json, @"Unexpected data received");
        }];
    }
    else
    {
        NSLog(@"/!\\ Test skipped because the NSURLSession class is not available on this OS version. Run the tests a target with a more recent OS.\n");
    }
}

- (void)test_NSURLSessionEphemeralConfig
{
    if ([NSURLSessionConfiguration class] && [NSURLSession class])
    {
        NSURLSessionConfiguration* config = [NSURLSessionConfiguration ephemeralSessionConfiguration];
        NSURLSession *session = [NSURLSession sessionWithConfiguration:config];
        
        NSDictionary* json = @{@"Success": @"Yes"};
        [self _test_NSURLSession:session jsonForStub:json completion:^(NSError *errorResponse, id jsonResponse) {
            XCTAssertNil(errorResponse, @"Unexpected error");
            XCTAssertEqualObjects(jsonResponse, json, @"Unexpected data received");
        }];
    }
    else
    {
        NSLog(@"/!\\ Test skipped because the NSURLSession class is not available on this OS version. Run the tests a target with a more recent OS.\n");
    }
}

- (void)test_NSURLSessionDefaultConfig_Disabled
{
    if ([NSURLSessionConfiguration class] && [NSURLSession class])
    {
        NSURLSessionConfiguration* config = [NSURLSessionConfiguration ephemeralSessionConfiguration];
        [OHHTTPStubs setEnabled:NO forSessionConfiguration:config]; // Disable stubs for this session
        NSURLSession *session = [NSURLSession sessionWithConfiguration:config];
        
        NSDictionary* json = @{@"Success": @"Yes"};
        [self _test_NSURLSession:session jsonForStub:json completion:^(NSError *errorResponse, id jsonResponse) {
            // Stubs were disable for this session, so we should get an error instead of the stubs data
            XCTAssertNotNil(errorResponse, @"Expected error but none found");
            XCTAssertNil(jsonResponse, @"Data should not have been received as stubs should be disabled");
        }];
    }
    else
    {
        NSLog(@"/!\\ Test skipped because the NSURLSession class is not available on this OS version. Run the tests a target with a more recent OS.\n");
    }
}

- (void)test_NSURLSession_DataTask_DelegateMethods
{
    if ([NSURLSessionConfiguration class] && [NSURLSession class])
    {
        NSData* expectedResponse = [NSStringFromSelector(_cmd) dataUsingEncoding:NSUTF8StringEncoding];
        [OHHTTPStubs stubRequestsPassingTest:^BOOL(NSURLRequest *request) {
            return [request.URL.scheme isEqualToString:@"stub"];
        } withStubResponse:^OHHTTPStubsResponse *(NSURLRequest *request) {
            return [[OHHTTPStubsResponse responseWithData:expectedResponse statusCode:200 headers:nil]
                    responseTime:0.5];
        }];
        
        _taskDidCompleteExpectation = [self expectationWithDescription:@"NSURLSessionDataTask completion delegate method called"];
        
        NSURLSessionConfiguration* config = [NSURLSessionConfiguration defaultSessionConfiguration];
        NSURLSession* session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];
        
        [[session dataTaskWithURL:[NSURL URLWithString:@"stub://foo"]] resume];
        
        [self waitForExpectationsWithTimeout:5 handler:nil];
        
        XCTAssertEqualObjects(_receivedData, expectedResponse, @"Unexpected response");
    }
    else
    {
        NSLog(@"/!\\ Test skipped because the NSURLSession class is not available on this OS version. Run the tests a target with a more recent OS.\n");
    }
}

//---------------------------------------------------------------
#pragma mark - Delegate Methods

- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveResponse:(NSURLResponse *)response completionHandler:(void (^)(NSURLSessionResponseDisposition))completionHandler
{
    _receivedData = [NSMutableData new];
    completionHandler(NSURLSessionResponseAllow);
}
- (void)URLSession:(NSURLSession *)session dataTask:(NSURLSessionDataTask *)dataTask didReceiveData:(NSData *)data
{
    [_receivedData appendData:data];
}
- (void)URLSession:(NSURLSession *)session task:(NSURLSessionTask *)task didCompleteWithError:(NSError *)error
{
    [_taskDidCompleteExpectation fulfill];
}

@end

#else
#warning Unit Tests using NSURLSession were not compiled nor executed, because NSURLSession is only available since iOS7/OSX10.9 SDK. \
-------- Compile using iOS7 or OSX10.9 SDK then launch the tests on the iOS7 simulator or an OSX10.9 target for them to be executed.
#endif