// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2016 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See http://swift.org/LICENSE.txt for license information
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//

#if DEPLOYMENT_RUNTIME_OBJC || os(Linux)
    import Foundation
    import XCTest
#else
    import SwiftFoundation
    import SwiftXCTest
#endif

class TestURLSession : XCTestCase {

    var serverPort: Int = -1

    static var allTests: [(String, (TestURLSession) -> () throws -> Void)] {
        return [
            ("test_dataTaskWithURL", test_dataTaskWithURL),
            ("test_dataTaskWithURLRequest", test_dataTaskWithURLRequest),
            ("test_dataTaskWithURLCompletionHandler", test_dataTaskWithURLCompletionHandler),
            ("test_dataTaskWithURLRequestCompletionHandler", test_dataTaskWithURLRequestCompletionHandler),
            ("test_downloadTaskWithURL", test_downloadTaskWithURL),
            ("test_downloadTaskWithURLRequest", test_downloadTaskWithURLRequest),
            ("test_downloadTaskWithRequestAndHandler", test_downloadTaskWithRequestAndHandler),
            ("test_downloadTaskWithURLAndHandler", test_downloadTaskWithURLAndHandler),
            ("test_finishTaskAndInvalidate", test_finishTasksAndInvalidate)
        ]
    }

    private func runServer(with condition: ServerSemaphore) throws {
        let start = 21961
        for port in start...(start+100) { //we must find at least one port to bind
            do {
                serverPort = port
                let test = try TestURLSessionServer(port: UInt16(port))
                try test.start(started: condition)
                try test.readAndRespond()
                test.stop()
            } catch let e as ServerError {
                if e.operation != "bind" { continue }
                throw e
            }
        }
    }

    func test_dataTaskWithURL() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let urlString = "http://127.0.0.1:\(serverPort)/Nepal"
        let url = URL(string: urlString)!
        let d = DataTask(with: expectation(description: "data task"))                         
        d.run(with: url)
        waitForExpectations(timeout: 12)
        if !d.error {
            XCTAssertEqual(d.capital, "Kathmandu", "test_dataTaskWithURLRequest returned an unexpected result")
        }
    }
    
    func test_dataTaskWithURLCompletionHandler() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return 
            }
        }
        serverReady.wait()
        let urlString = "http://127.0.0.1:\(serverPort)/USA"
        let url = URL(string: urlString)!
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        let session = URLSession(configuration: config, delegate: nil, delegateQueue: nil)
        let expect = expectation(description: "URL test with completion handler")
        var expectedResult = "unknown"
        let task = session.dataTask(with: url) { data, response, error in
            if let e = error {
                XCTAssertEqual(e.code, NSURLErrorTimedOut, "Unexpected error code")
                expect.fulfill()
                return
            }

            let httpResponse = response as! HTTPURLResponse?
            XCTAssertEqual(200, httpResponse!.statusCode, "HTTP response code is not 200") 
            expectedResult = String(data: data!, encoding: String.Encoding.utf8)!
            XCTAssertEqual("Washington, D.C.", expectedResult, "Did not receive expected value")
            expect.fulfill()
        }
        task.resume()
        waitForExpectations(timeout: 12)
    }

    func test_dataTaskWithURLRequest() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let urlString = "http://127.0.0.1:\(serverPort)/Peru"
        let urlRequest = URLRequest(url: URL(string: urlString)!)
        let d = DataTask(with: expectation(description: "data task"))     
        d.run(with: urlRequest)
        waitForExpectations(timeout: 12)
        if !d.error {
            XCTAssertEqual(d.capital, "Lima", "test_dataTaskWithURLRequest returned an unexpected result")
        }
    }

    func test_dataTaskWithURLRequestCompletionHandler() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let urlString = "http://127.0.0.1:\(serverPort)/Italy"
        let urlRequest = URLRequest(url: URL(string: urlString)!)
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        let session = URLSession(configuration: config, delegate: nil, delegateQueue: nil)
        let expect = expectation(description: "URL test with completion handler")
        var expectedResult = "unknown"
        let task = session.dataTask(with: urlRequest) { data, response, error in
            if let e = error {
                XCTAssertEqual(e.code, NSURLErrorTimedOut, "Unexpected error code")
                expect.fulfill()
                return
            }
            let httpResponse = response as! HTTPURLResponse?
            XCTAssertEqual(200, httpResponse!.statusCode, "HTTP response code is not 200")
            expectedResult = String(data: data!, encoding: String.Encoding.utf8)!
            XCTAssertEqual("Rome", expectedResult, "Did not receive expected value")
            expect.fulfill()
        }
        task.resume()
        waitForExpectations(timeout: 12)
    }

    func test_downloadTaskWithURL() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let urlString = "http://127.0.0.1:\(serverPort)/country.txt"
        let url = URL(string: urlString)!   
        let d = DownloadTask(with: expectation(description: "download task with delegate"))
        d.run(with: url)
        waitForExpectations(timeout: 12)
    }

    func test_downloadTaskWithURLRequest() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let urlString = "http://127.0.0.1:\(serverPort)/country.txt"
        let urlRequest = URLRequest(url: URL(string: urlString)!)
        let d = DownloadTask(with: expectation(description: "download task with delegate"))
        d.run(with: urlRequest)
        waitForExpectations(timeout: 12)
    }

    func test_downloadTaskWithRequestAndHandler() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        let session = URLSession(configuration: config, delegate: nil, delegateQueue: nil)
        let expect = expectation(description: "download task with handler")
        let req = URLRequest(url: URL(string: "http://127.0.0.1:\(serverPort)/country.txt")!)
        let task = session.downloadTask(with: req) { (_, _, error) -> Void in
            if let e = error {
                XCTAssertEqual(e.code, NSURLErrorTimedOut, "Unexpected error code")
            }
            expect.fulfill()
        }
        task.resume()
        waitForExpectations(timeout: 12)
    }

    func test_downloadTaskWithURLAndHandler() {
        let serverReady = ServerSemaphore()
        globalDispatchQueue.async {
            do {
                try self.runServer(with: serverReady)
            } catch {
                XCTAssertTrue(true)
                return
            }
        }
        serverReady.wait()
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        let session = URLSession(configuration: config, delegate: nil, delegateQueue: nil)
        let expect = expectation(description: "download task with handler")
        let req = URLRequest(url: URL(string: "http://127.0.0.1:\(serverPort)/country.txt")!)
        let task = session.downloadTask(with: req) { (_, _, error) -> Void in
            if let e = error {
                XCTAssertEqual(e.code, NSURLErrorTimedOut, "Unexpected error code")
            }
            expect.fulfill()
        }
        task.resume()
        waitForExpectations(timeout: 12)
    }
    
    func test_finishTasksAndInvalidate() {
        let invalidateExpectation = expectation(description: "URLSession wasn't invalidated")
        let delegate = SessionDelegate(invalidateExpectation: invalidateExpectation)
        let url = URL(string: "http://127.0.0.1:\(serverPort)/Nepal")!
        let session = URLSession(configuration: URLSessionConfiguration.default,
                                 delegate: delegate, delegateQueue: nil)
        let completionExpectation = expectation(description: "dataTask completion block wasn't called")
        let task = session.dataTask(with: url) { _ in
            completionExpectation.fulfill()
        }
        task.resume()
        session.finishTasksAndInvalidate()
        waitForExpectations(timeout: 12)
    }
}

class SessionDelegate: NSObject, URLSessionDelegate {
    let invalidateExpectation: XCTestExpectation
    init(invalidateExpectation: XCTestExpectation){
        self.invalidateExpectation = invalidateExpectation
    }
    func urlSession(_ session: URLSession, didBecomeInvalidWithError error: Error?) {
        invalidateExpectation.fulfill()
    }
}

class DataTask : NSObject {
    let dataTaskExpectation: XCTestExpectation!
    var capital = "unknown"
    var session: URLSession! = nil
    var task: URLSessionDataTask! = nil
    public var error = false

    init(with expectation: XCTestExpectation) {
       dataTaskExpectation = expectation 
    }

    func run(with request: URLRequest) {
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
        task = session.dataTask(with: request)
        task.resume()
    }
    
    func run(with url: URL) {
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
        task = session.dataTask(with: url)
        task.resume()
    }
}

extension DataTask : URLSessionDataDelegate {
     public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive data: Data) {
         capital = String(data: data, encoding: String.Encoding.utf8)!
         dataTaskExpectation.fulfill()
     }
}

extension DataTask : URLSessionTaskDelegate {
    public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: NSError?) {
         guard let e = error else { return }
         XCTAssertEqual(e.code, NSURLErrorTimedOut, "Unexpected error code")
         dataTaskExpectation.fulfill()
         self.error = true
     }
} 

class DownloadTask : NSObject {
    var totalBytesWritten: Int64 = 0
    let dwdExpectation: XCTestExpectation!
    var session: URLSession! = nil
    var task: URLSessionDownloadTask! = nil

    init(with expectation: XCTestExpectation) {
        dwdExpectation = expectation
    }

    func run(with url: URL) {
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
        task = session.downloadTask(with: url)
        task.resume()
    }

    func run(with urlRequest: URLRequest) {
        let config = URLSessionConfiguration.default
        config.timeoutIntervalForRequest = 8
        session = URLSession(configuration: config, delegate: self, delegateQueue: nil)
        task = session.downloadTask(with: urlRequest)
        task.resume()
    }
}

extension DownloadTask : URLSessionDownloadDelegate {
    
    public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64,
                           totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) -> Void {
        self.totalBytesWritten = totalBytesWritten
    }
    
    public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didFinishDownloadingTo location: URL) {
        do {
            let attr = try FileManager.default.attributesOfItem(atPath: location.path)
            XCTAssertEqual((attr[.size]! as? NSNumber)!.int64Value, totalBytesWritten, "Size of downloaded file not equal to total bytes downloaded")
        } catch {
            XCTFail("Unable to calculate size of the downloaded file")
        }
        dwdExpectation.fulfill()
   }
}

extension DownloadTask : URLSessionTaskDelegate {
   public func urlSession(_ session: URLSession, task: URLSessionTask, didCompleteWithError error: NSError?) {
       guard let e = error else { return }
       XCTAssertEqual(e.code, NSURLErrorTimedOut, "Unexpected error code")
       dwdExpectation.fulfill()
   }
}