//===----------------------------------------------------------------------===//
//
// 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

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

private final class EchoHandler: ChannelInboundHandler {
    public typealias InboundIn = ByteBuffer
    public typealias OutboundOut = ByteBuffer
    private var numBytes = 0

    public func channelRead(ctx: ChannelHandlerContext, data: NIOAny) {
        numBytes -= self.unwrapInboundIn(data).readableBytes

        assert(numBytes >= 0)

        if numBytes == 0 {
            print("Received the line back from the server, closing channel")
            ctx.close(promise: nil)
        }
    }

    public func errorCaught(ctx: 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.
        ctx.close(promise: nil)
    }

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

        // We are connected its time to send the message to the server to initialize the ping-pong sequence.
        var buffer = ctx.channel.allocator.buffer(capacity: line.utf8.count)
        buffer.write(string: line)
        self.numBytes = buffer.readableBytes
        ctx.writeAndFlush(self.wrapOutboundOut(buffer), 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.add(handler: EchoHandler())
    }
defer {
    try! group.syncShutdownGracefully()
}

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

let defaultHost = "::1"
let defaultPort: Int = 9999

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")
