#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <sstream>
#include <netinet/in.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <netdb.h>
#include <assert.h>

using namespace std;

const int BUFSIZE=100240;

int MakeServerSocket(const char *port) {
	const int MAXNAMELEN = 255;
	const int BACKLOG = 3;
	char localhostname[MAXNAMELEN]; // local host name
	int s;
	int len;
	struct sockaddr_in sa;
	struct hostent *hp;
	struct servent *sp;
	int portnum;
	int ret;
	hp = gethostbyname("198.110.204.9");
	sscanf(port, "%d", &portnum);
	if (portnum ==  0) {
		sp=getservbyname(port, "tcp");
		portnum = ntohs(sp->s_port);
	}
	sa.sin_port = htons(portnum);

	bcopy((char *)hp->h_addr, (char *)&sa.sin_addr, hp->h_length);
	sa.sin_family = hp->h_addrtype;

	s = socket(hp->h_addrtype, SOCK_STREAM, 0);

	ret = bind(s, (struct sockaddr *)&sa, sizeof(sa));
	if (ret < 0)
		perror("Bad");
	listen(s, BACKLOG);
	cout << "Waiting for connection on port " << port << endl;
	return s;
}

string getContentType(string filename){
	string fileExt = "";
	size_t pos = filename.find(".");
	if(pos != string::npos) fileExt = filename.substr(pos+1);
	return fileExt;
}

string setContentType(string ct){
	string contentType = "";
	if(ct == "txt"){
		contentType = "text/plain";
	} else if(ct == "jpg"){
		contentType = "image/jpeg";
	} else if(ct == "html"){
		contentType = "text/html";
	}

	return contentType;
}

main(int argc, char *argv[]) {

	int s, len, ret;
	char buf[BUFSIZE];
	s = MakeServerSocket(argv[1]);

	while (1) {
		struct sockaddr_in sa;
		int sa_len = sizeof(sa);
		int fd = accept(s, (struct sockaddr *)&sa, (unsigned int *)&sa_len);
		assert(fd != -1);

		int len = read(fd, buf, BUFSIZE);
		cout << "------------Read says:" << len << "--------\n";
		buf[len] = 0;
		cout << buf << endl;

		string str = buf;
		string get, filename, version;
		string res = str + "\r\n";
		istringstream is (res);
    	is >> get;
    	is >> filename;
    	is >> version;

		string vrsn = version.substr(5);
		string ct = getContentType(filename.substr(1));
		string fileExt = setContentType(ct);
		int in = open(filename.substr(1).c_str(), O_RDONLY);

		if (in == -1){
			string msg = "HTTP/1.0 404\r\nContent-Type: text/plain\r\n\r\n\r\nThe file was not found";
			write(fd, msg.c_str(), strlen(msg.c_str()));
			perror("Could not open input file");
			exit(1);
		}

		int fileLength = read(in, buf, BUFSIZE);
		buf[fileLength] = 0;
		char *fileContents = buf;

		while (fileLength > 0) {

			string msg =  "HTTP/1.0 200 OK\r\nContent-Type:" + fileExt + "\r\n\r\n\r\nHere is response data";
			int bytes_written;

			if(vrsn == "1.1" || vrsn == "1.0"){
				write(fd, msg.c_str(), strlen(msg.c_str()));
				bytes_written = write(fd, fileContents, fileLength);
			} else {
				bytes_written = write(fd, fileContents, fileLength);
			}

        	fileLength -= bytes_written;
        	fileContents += bytes_written;

		}

		close(fd);
	}
}