main.swift

//===----------------------------------------------------------------------===//
//
// 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
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
import NIO
import NIOHTTP1

print("Please enter line to send to the server")
let line = readLine(strippingNewline: true)!

private final class HTTPEchoHandler: ChannelInboundHandler {
    public typealias InboundIn = HTTPClientResponsePart
    public typealias OutboundOut = HTTPClientRequestPart

    public func channelRead(context: ChannelHandlerContext, data: NIOAny) {

        let clientResponse = self.unwrapInboundIn(data)
        
        switch clientResponse {
        case .head(let responseHead):
            print("Received status: \(responseHead.status)")
        case .body(var byteBuffer):
            if let string = byteBuffer.readString(length: byteBuffer.readableBytes) {
                print("Received: '\(string)' back from the server.")
            } else {
                print("Received the line back from the server.")
            }
        case .end:
            print("Closing channel.")
            context.close(promise: nil)
        }
    }

    public func errorCaught(context: ChannelHandlerContext, error: Error) {
        print("error: ", error)

        // As we are not really interested getting notified on success or failure we just pass nil as promise to
        // reduce allocations.
        context.close(promise: nil)
    }

    public func channelActive(context: ChannelHandlerContext) {
        print("Client connected to \(context.remoteAddress!)")

        // We are connected. It's time to send the message to the server to initialize the ping-pong sequence.
        
        var buffer = context.channel.allocator.buffer(capacity: line.utf8.count)
        buffer.writeString(line)

        var headers = HTTPHeaders()
        headers.add(name: "Content-Type", value: "text/plain; charset=utf-8")
        headers.add(name: "Content-Length", value: "\(buffer.readableBytes)")

        // This sample only sends an echo request.
        // The sample server has more functionality which can be easily tested by playing with the URI.
        // For example, try "/dynamic/count-to-ten" or "/dynamic/client-ip"
        
        let requestHead = HTTPRequestHead(version: HTTPVersion(major: 1, minor: 1),
                                          method: .GET,
                                          uri: "/dynamic/echo",
                                          headers: headers)

        context.write(self.wrapOutboundOut(.head(requestHead)), promise: nil)
        
        context.write(self.wrapOutboundOut(.body(.byteBuffer(buffer))), promise: nil)
        
        context.writeAndFlush(self.wrapOutboundOut(.end(nil)), promise: nil)
    }
}

let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
let bootstrap = ClientBootstrap(group: group)
    // Enable SO_REUSEADDR.
    .channelOption(ChannelOptions.socket(SocketOptionLevel(SOL_SOCKET), SO_REUSEADDR), value: 1)
    .channelInitializer { channel in
        channel.pipeline.addHTTPClientHandlers(position: .first,
                                               leftOverBytesStrategy: .fireError).flatMap {
            channel.pipeline.addHandler(HTTPEchoHandler())
        }
    }
defer {
    try! group.syncShutdownGracefully()
}

// First argument is the program path
let arguments = CommandLine.arguments
let arg1 = arguments.dropFirst().first
let arg2 = arguments.dropFirst(2).first

let defaultHost = "::1"
let defaultPort: Int = 8888

enum ConnectTo {
    case ip(host: String, port: Int)
    case unixDomainSocket(path: String)
}

let connectTarget: ConnectTo
switch (arg1, arg1.flatMap(Int.init), arg2.flatMap(Int.init)) {
case (.some(let h), _ , .some(let p)):
    /* we got two arguments, let's interpret that as host and port */
    connectTarget = .ip(host: h, port: p)
case (.some(let portString), .none, _):
    /* couldn't parse as number, expecting unix domain socket path */
    connectTarget = .unixDomainSocket(path: portString)
case (_, .some(let p), _):
    /* only one argument --> port */
    connectTarget = .ip(host: defaultHost, port: p)
default:
    connectTarget = .ip(host: defaultHost, port: defaultPort)
}

let channel = try { () -> Channel in
    switch connectTarget {
    case .ip(let host, let port):
        return try bootstrap.connect(host: host, port: port).wait()
    case .unixDomainSocket(let path):
        return try bootstrap.connect(unixDomainSocketPath: path).wait()
    }
}()

// Will be closed after we echo-ed back to the server.
try channel.closeFuture.wait()

print("Client closed")