//HTTPD Server


#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <errno.h> 
#include <string.h>
#include <malloc.h>
#include <pthread.h>
#include <iostream.h>
#include <string>
#include <fstream.h>

#define SERVERPORT 8000
#define SERVERNAME "karlsworld"
#define MAX_PENDING 20
#define MAXTHREADS 20
#define MAX_LINE 256
#define BUFFERSIZE 20000
#define HEADERSIZE 500
#define MESSAGESIZE 1000
#define SERVERROOT	"docroot"
#define TEMPDIR 	"/home/karl/tmp"
#define DELAY 500

void *server_thread(void *arg);
const char *getFNFError(char *location);
const char *getFNRError(char *location);
string int2string(int x);

int new_s;

int main(int argc, char * argv[]) {
	struct sockaddr_in sin;
	char buf[MAX_LINE];
	//int new_s;
	int s, len;
	//thread_index = 0;

	cout << "\nRunning Karl's Web Server on Port " << int2string(SERVERPORT) << "\n\n";

	bzero((char *)&sin, sizeof(sin));
	sin.sin_family = AF_INET;
	sin.sin_addr.s_addr = INADDR_ANY;
	sin.sin_port = htons(SERVERPORT);

	if ((s = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
		perror("httpd: socket error");
		exit(1);
	}
	if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
		perror("httpd: socket error");
		exit(1);
	}

	listen(s, MAX_PENDING);
	//printf("\nWaiting for a connection\n");

	for (;;) {
		
		//if (thread_index>=MAXTHREADS) thread_index=0;
		if ((new_s = accept(s, (struct sockaddr *)&sin, &len)) < 0) {
			perror("httpd: server accept error");
			exit(1);
		}
		
		pthread_t thread_handle;
		pthread_create(&thread_handle, NULL, server_thread, NULL);
		
		close(thread_handle);
		//for (int x=0;x<DELAY;x++){
		//}
		//thread_index++;
		//server_thread(NULL);
	}
}

string int2string(int x) {
	if (x==0) return "0";
	else {
		string ret="";
		for (int y=x;y>0;y/=10) {
			ret = (char)((y%10)+'0') + ret;
			//cout << ret << "\n";
		}
		return ret;
	}
}


void *server_thread(void *arg) {
	//int *t = (int *)arg;
	int tSocket = new_s;
	int len=0;
	bool removefile = 0;

	char *crequest=(char *)(malloc(sizeof(char)*BUFFERSIZE));
	//cout << "Entered server thread.\n";
	ifstream infile;

	len = read(tSocket,crequest,BUFFERSIZE);
	//cout << "Recieved request " << crequest << "\n";
	if (len <=0) return;
	string request = crequest;

	delete(crequest);

	//cout << "No error yet\n";
	int docstart=request.find("GET");
	if (docstart==string::npos) return;
	docstart += 4;
	int docend=request.find(" HTTP",docstart);
	if (docend==string::npos) {
		docend=request.length()-2;
	}
	string location = request.substr(docstart,docend-docstart);
	string query = "";
	
	int qsloc = location.find("?");
	if (qsloc!=string::npos) {
		
		//cout << "Here's the Error!\n";
		query = location.substr(qsloc+1,location.length()-qsloc-1);
		location = location.substr(0,qsloc);
		//cout << "Stripped Query String " << query << "\n";
	}
		

	int floc=location.rfind("/");
	if (floc==string::npos) return;
	int dloc=location.find(".",floc);

	//add index.html if necessary
	if (dloc==string::npos) {
		string tlocation = SERVERROOT;
		string addme = "/index.html";
		if (location.at(location.length()-1)=='/') {
			addme = "index.html";
		}
		tlocation += location + addme;
		infile.open(tlocation.c_str(),ios::in);
		if (infile) {
			location+=addme;
			floc=location.rfind("/");
			dloc=location.find(".",floc);
		}
		infile.close();
	}


	//directory listing
	if (dloc==string::npos) {
		cout << "Sending directory " << location << "\n";
		string dircommand="ls -l ";
		dircommand += SERVERROOT;
		dircommand += location+"> "+location.substr(floc+1,location.length()-1)+".tmp";
		system(dircommand.c_str());
		location = location.substr(floc+1,location.length()-1)+".tmp";
		infile.open(location.c_str(), ios::in);
		removefile=1;
		send(tSocket,"HTTP/1.0 200 OK\r\n", strlen("HTTP/1.0 200 OK\r\n"),0);
		send(tSocket,"Content-type: text/plain\r\n\r\n", strlen("Content-type: text/plain\r\n\r\n"), 0);
	}
	//HTML file
	else if	(location.find("cgi",dloc)!=string::npos) {
		cout << "Running CGI file " << location << "\n";
		
		string servenv = "SERVER_PORT=";
		servenv+=int2string(SERVERPORT);
		query = "QUERY_STRING="+query;
		string content_length = "CONTENT_LENGTH=" + int2string(query.length());
		string servname = "SERVER_NAME=";
		servname+=SERVERNAME;
		putenv("REQUEST_METHOD=GET");
		putenv(servenv.c_str());
		putenv(query.c_str());
		putenv(content_length.c_str());
		putenv(servname.c_str());
		string dircommand="cd ";
		dircommand += SERVERROOT;
		dircommand += location.substr(0,floc);
		dircommand += "; ./"+location.substr(floc+1,location.length()-1)+"> "+location.substr(floc+1,location.length()-1)+".tmp";
		system(dircommand.c_str());
		location = SERVERROOT+location+".tmp";
		infile.open(location.c_str(), ios::in);
		removefile=1;
	}
	else {
	location = SERVERROOT + location;

	cout << "Looking for file: " << location << "\n";
	infile.open(location.c_str(), ios::in);

	if (!infile) {
		send(tSocket,"HTTP/1.0 404 error\r\n", strlen("HTTP/1.0 404 error\r\n"),0);
		send(tSocket,"Content-type: text/html\r\n\r\n", strlen("Content-type: text/html\r\n\r\n"), 0);
		send(tSocket,getFNFError(location.c_str()),strlen(getFNFError(location.c_str())),0);
		close(tSocket);
		return;
	}
	
	//HTML file
	else if (location.find("htm",dloc)!=string::npos) {
	send(tSocket,"HTTP/1.0 200 OK\r\n", strlen("HTTP/1.0 200 OK\r\n"),0);
	send(tSocket,"Content-type: text/html\r\n\r\n", strlen("Content-type: text/html\r\n\r\n"), 0);
	}
	//TXT file
	else if (location.find("txt",dloc)!=string::npos) {
	send(tSocket,"HTTP/1.0 200 OK\r\n", strlen("HTTP/1.0 200 OK\r\n"),0);
	send(tSocket,"Content-type: text/plain\r\n\r\n", strlen("Content-type: text/plain\r\n\r\n"), 0);
	}
	//CSS file
	else if (location.find("css",dloc)!=string::npos) {
	send(tSocket,"HTTP/1.0 200 OK\r\n", strlen("HTTP/1.0 200 OK\r\n"),0);
	send(tSocket,"Content-type: text/plain\r\n\r\n", strlen("Content-type: text/css\r\n\r\n"), 0);
	}
	//GIF file
	else if (location.find("gif",dloc)!=string::npos) {
	send(tSocket,"HTTP/1.0 200 OK\r\n", strlen("HTTP/1.0 200 OK\r\n"),0);
	send(tSocket,"Content-type: image/gif\r\n\r\n", strlen("Content-type: image/gif\r\n\r\n"), 0);
	}
	//JPG file
	else if (location.find("jpg",dloc)!=string::npos) {
	send(tSocket,"HTTP/1.0 200 OK\r\n", strlen("HTTP/1.0 200 OK\r\n"),0);
	send(tSocket,"Content-type: image/jpeg\r\n\r\n", strlen("Content-type: image/jpeg\r\n\r\n"), 0);
	}
	else {
		send(tSocket,"HTTP/1.0 404 error\r\n", strlen("HTTP/1.0 404 error\r\n"),0);
		send(tSocket,"Content-type: text/html\r\n\r\n", strlen("Content-type: text/html\r\n\r\n"), 0);
		send(tSocket,getFNRError(location.c_str()),strlen(getFNRError(location.c_str())),0);
		infile.close();
		close(tSocket);
		return;
	}
	}



	//send(tSocket,"What Up!\r\n",strlen("What Up!\r\n"),0);

	while (!infile.eof()) {		
		unsigned char *finput=(unsigned char *)malloc(BUFFERSIZE*sizeof(char));
		//cout << "Reading File\n";
		//infile.get(finput, BUFFERSIZE, '\0');
		infile.read(finput, BUFFERSIZE);
		//cout << "Read: " << finput << "\n";
		send(tSocket,(char *)finput,infile.gcount(),0);//strlen(finput),0);
		delete(finput);
	}
	infile.close();
	close(tSocket);
	if (removefile) {
		string dircommand="rm "+location;
		system(dircommand.c_str());
	}
}

const char *getFNFError(char *location) {
	string docstuff= location;
	docstuff = "<HTML><HEAD><TITLE>Error! File Not Found</TITLE></HEAD>
			\n<BODY><H1>404 Error!</H1><H2>File Not Found</H2>\n
			Error: The requested file (" + docstuff;
	docstuff += ") was not found.\n</BODY></HTML>";
	return docstuff.c_str();
}

const char *getFNRError(char *location) {
	string docstuff = location;
	docstuff = "<HTML><HEAD><TITLE>Error! File Not Recognized</TITLE></HEAD>\n
			<BODY><H1>404 Error!</H1><H2>File Not Recognized</H2>\n
			Error: the requested file (" + docstuff;
	docstuff += ") was not recognized.\n</BODY></HTML>";
	return docstuff.c_str();
}