//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
// swift-tools-version:4.0
//
// swift-tools-version:4.0
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import XCTest
import NIO
import Network
@testable import NIOTransportServices


class NIOTSSocketOptionTests: XCTestCase {
    private var options: NWProtocolTCP.Options!

    override func setUp() {
        self.options = NWProtocolTCP.Options()
    }

    override func tearDown() {
        self.options = nil
    }

    private func assertProperty<T: Equatable>(called path: KeyPath<NWProtocolTCP.Options, T>,
                                              correspondsTo socketOption: SocketOption,
                                              defaultsTo defaultValue: T,
                                              and defaultSocketOptionValue: SocketOptionValue,
                                              canBeSetTo unusualValue: SocketOptionValue,
                                              whichLeadsTo newInnerValue: T) throws {
        // Confirm the default is right.
        let actualDefaultSocketOptionValue = try self.options.valueFor(socketOption: socketOption)
        XCTAssertEqual(self.options[keyPath: path], defaultValue)
        XCTAssertEqual(actualDefaultSocketOptionValue, defaultSocketOptionValue)

        // Confirm that we can set this to a new value, and that it leads to the right outcome.
        try self.options.applyChannelOption(option: socketOption, value: unusualValue)
        XCTAssertEqual(self.options[keyPath: path], newInnerValue)
        XCTAssertEqual(try self.options.valueFor(socketOption: socketOption), unusualValue)

        // And confirm that we can set it back to the default.
        try self.options.applyChannelOption(option: socketOption, value: actualDefaultSocketOptionValue)
        XCTAssertEqual(self.options[keyPath: path], defaultValue)
        XCTAssertEqual(actualDefaultSocketOptionValue, defaultSocketOptionValue)
    }

    func testReadingAndSettingNoDelay() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.noDelay,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_NODELAY),
                                defaultsTo: false, and: 0,
                                canBeSetTo: 1, whichLeadsTo: true)
    }

    func testReadingAndSettingNoPush() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.noPush,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_NOPUSH),
                                defaultsTo: false, and: 0,
                                canBeSetTo: 1, whichLeadsTo: true)
    }

    func testReadingAndSettingNoOpt() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.noOptions,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_NOOPT),
                                defaultsTo: false, and: 0,
                                canBeSetTo: 1, whichLeadsTo: true)
    }

    func testReadingAndSettingKeepaliveCount() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.keepaliveCount,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_KEEPCNT),
                                defaultsTo: 0, and: 0,
                                canBeSetTo: 5, whichLeadsTo: 5)
    }

    func testReadingAndSettingKeepaliveIdle() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.keepaliveIdle,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_KEEPALIVE),
                                defaultsTo: 0, and: 0,
                                canBeSetTo: 5, whichLeadsTo: 5)
    }

    func testReadingAndSettingKeepaliveInterval() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.keepaliveInterval,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_KEEPINTVL),
                                defaultsTo: 0, and: 0,
                                canBeSetTo: 5, whichLeadsTo: 5)
    }

    func testReadingAndSettingMaxSeg() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.maximumSegmentSize,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_MAXSEG),
                                defaultsTo: 0, and: 0,
                                canBeSetTo: 5, whichLeadsTo: 5)
    }

    func testReadingAndSettingConnectTimeout() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.connectionTimeout,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_CONNECTIONTIMEOUT),
                                defaultsTo: 0, and: 0,
                                canBeSetTo: 5, whichLeadsTo: 5)
    }

    func testReadingAndSettingConnectDropTime() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.connectionDropTime,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_RXT_CONNDROPTIME),
                                defaultsTo: 0, and: 0,
                                canBeSetTo: 5, whichLeadsTo: 5)
    }

    func testReadingAndSettingFinDrop() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.retransmitFinDrop,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_RXT_FINDROP),
                                defaultsTo: false, and: 0,
                                canBeSetTo: 1, whichLeadsTo: true)
    }

    func testReadingAndSettingAckStretching() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.disableAckStretching,
                                correspondsTo: SocketOption(level: IPPROTO_TCP, name: TCP_SENDMOREACKS),
                                defaultsTo: false, and: 0,
                                canBeSetTo: 1, whichLeadsTo: true)
    }

    func testReadingAndSettingKeepalive() throws {
        try self.assertProperty(called: \NWProtocolTCP.Options.enableKeepalive,
                                correspondsTo: SocketOption(level: SOL_SOCKET, name: SO_KEEPALIVE),
                                defaultsTo: false, and: 0,
                                canBeSetTo: 1, whichLeadsTo: true)
    }

    func testWritingNonexistentSocketOption() {
        let option = SocketOption(level: Int32.max, name: Int32.max)

        do {
            try self.options.applyChannelOption(option: option, value: 0)
        } catch let err as NIOTSErrors.UnsupportedSocketOption {
            XCTAssertEqual(err.optionValue.0, Int32.max)
            XCTAssertEqual(err.optionValue.1, Int32.max)
        } catch {
            XCTFail("Unexpected error \(error)")
        }
    }

    func testReadingNonexistentSocketOption() {
        let option = SocketOption(level: Int32.max, name: Int32.max)

        do {
            _ = try self.options.valueFor(socketOption: option)
        } catch let err as NIOTSErrors.UnsupportedSocketOption {
            XCTAssertEqual(err.optionValue.0, Int32.max)
            XCTAssertEqual(err.optionValue.1, Int32.max)
        } catch {
            XCTFail("Unexpected error \(error)")
        }
    }
}