#include <stdio.h>
#include <unistd.h>

#include "muduo/base/Logging.h"
#include "muduo/net/EventLoop.h"
#include "muduo/net/TcpServer.h"

using namespace muduo;
using namespace muduo::net;

const char* g_file = NULL;

// FIXME: use FileUtil::readFile()
string readFile(const char* filename)
{
    string content;
    FILE*  fp = ::fopen(filename, "rb");
    if (fp) {
        // inefficient!!!
        const int kBufSize = 1024 * 1024;
        char      iobuf[kBufSize];
        ::setbuffer(fp, iobuf, sizeof iobuf);

        char   buf[kBufSize];
        size_t nread = 0;
        while ((nread = ::fread(buf, 1, sizeof buf, fp)) > 0) {
            content.append(buf, nread);
        }
        ::fclose(fp);
    }
    return content;
}

void onHighWaterMark(const TcpConnectionPtr& conn, size_t len)
{
    LOG_INFO << "HighWaterMark " << len;
}

void onConnection(const TcpConnectionPtr& conn)
{
    LOG_INFO << "FileServer - " << conn->peerAddress().toIpPort() << " -> "
             << conn->localAddress().toIpPort() << " is "
             << (conn->connected() ? "UP" : "DOWN");
    if (conn->connected()) {
        LOG_INFO << "FileServer - Sending file " << g_file << " to "
                 << conn->peerAddress().toIpPort();
        conn->setHighWaterMarkCallback(onHighWaterMark, 64 * 1024);
        string fileContent = readFile(g_file);
        conn->send(fileContent);
        conn->shutdown();
        LOG_INFO << "FileServer - done";
    }
}

int main(int argc, char* argv[])
{
    LOG_INFO << "pid = " << getpid();
    if (argc > 1) {
        g_file = argv[1];

        EventLoop   loop;
        InetAddress listenAddr(2021);
        TcpServer   server(&loop, listenAddr, "FileServer");
        server.setConnectionCallback(onConnection);
        server.start();
        loop.loop();
    } else {
        fprintf(stderr, "Usage: %s file_for_downloading\n", argv[0]);
    }
}