/* Website in C - mind@metalshell.com
 *
 * This code was meant to show the flexibility
 * and speed of coding a site in C. [ Nobody Likes PHP! =) ]
 *
 * This example will show how to create a fully developed
 * website in C, using mysql (optional).
 *
 * I did a speed test; Printing 2,000 lines containing 100 'A's
 * per line using php and C; the results were: C (0.120s) PHP (0.605s)
 *
 * Note: I used a version of my own printing example to make
 *	 the HTML output look alot nicer.. eprint() is optional.
 *
 * libmysqlclient.a: path may be different.
 * To compile: gcc example.c -o example.cgi -lz /usr/lib/mysql/libmysqlclient.a
 *
 * to view VIA web browser: turn ExecCGI on in httpd.conf
 * and move example.cgi to your html folder.
 */

#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
/* header path may be different */
#include "/usr/include/mysql/mysql.h"

/* To setup your mysql db so the example will work please
 * open mysql; and paste the following:
 *
 * create database Cexample;
 *
 * use Cexample;
 * create TABLE person (
 *   id mediumint(9) NOT NULL auto_increment,
 *   name char(40) NOT NULL,
 *   birth char(40) NOT NULL,
 *   addy char(40) NOT NULL,
 *   phone char(40) NOT NULL,
 *   PRIMARY KEY  (id)
 * );
 *
 * insert into person VALUES( NULL, 'John Doe', '01-20-66',
 * 'N. Burboun ST.', '800-123-4567' );
 *
 * insert into person VALUES( NULL, 'Jane Doe', '12-09-72',
 * 'S. Burboun ST.', '800-987-6543');
 *
 */

/* edit USER, and PASS */
#define		MySQL_HOST	"localhost"
#define		MySQL_USER	"ChangeME"
#define		MySQL_PASS	"ChangeME"
#define		MySQL_DATA	"Cexample"

MYSQL_RES       *res;
MYSQL_ROW       row;

int	TabMe = 0;
void eprint(int b, char *fmt, ...);
void ShowError(char *x, char *e);
void StartHtml();
void GetBirth(int x);
void GetAddress(int x);
void GetPhone(int x);
void GetShowAll(int x);
int StartQuery();

/* This structure is for our apache string parser
 * when it parses for example id=1&0 our parser will
 * execute GetBirth(0);
 */
struct
{
	int	id;
	void	(*func)(int);
}
DefExt[]=
{
	{ 1,	GetBirth   },
	{ 2,	GetAddress },
	{ 3,	GetPhone   },
	{ 4,	GetShowAll },
	{ 0,	NULL },
};

int main()
{
	MYSQL		mysql;
	char		query[100];

	/* Initial start of our site's source */
	printf("Content-Type: text/html\n\n");

	/* Check to see if any arguments were passed through
	 * our program. If not show front page. */
	if ((StartQuery()) == -1)
	{
		StartHtml();

		if (!(mysql_connect(&mysql, MySQL_HOST, MySQL_USER, MySQL_PASS)))
			ShowError(NULL, "MySQL SERVER down");

		if (mysql_select_db(&mysql, MySQL_DATA))
			ShowError(NULL, "MySQL database error");

		snprintf(query, sizeof(query), "select * from person order by name");
		if (mysql_query(&mysql,query))
			ShowError(NULL, "MySQL server error");

		res = mysql_store_result(&mysql);
		while ((row = mysql_fetch_row(res)))
		{
			eprint( 0, "<font>%s - </font>\n", row[1]);
			eprint( 0, "<a href=\"?id=1&%s\">Birth Day</a>\n", row[0]);
			eprint( 0, "<font> - </font>\n");
			eprint( 0, "<a href=\"?id=2&%s\">Address</a>\n", row[0]);
			eprint( 0, "<font> - </font>\n");
			eprint( 0, "<a href=\"?id=3&%s\">Phone</a>\n", row[0]);
			eprint( 0, "<font> - </font>\n");
			eprint( 0, "<a href=\"?id=4&%s\">Show All</a><br>\n", row[0]);
		}

		mysql_close(&mysql);
		mysql_free_result(res);

		eprint(-1, "</html>\n");
		return 1;
	}

	eprint(-1, "</html>\n");
	return 1;
}

int StartQuery()
{
	int	i, g, b;
	char	*x, *y, *z, *e;

	(char *)y = malloc(100);
	(char *)z = malloc(100);
	(char *)e = malloc(100);

	/* Apache will set QUERY_STRING=id=x&x */
	x = getenv("QUERY_STRING");

	/* If it doesn't exsist return a negative value
	 * to initialize our front page */
	if (x == NULL || x[0] == 0) { return -1; }

	/* Always perform checks on everything you write
	 * to prevent program flaws and or overflows */
	if (strlen(x) >= 100)
	{
		ShowError(x, "Your request was too big");
		return 0;
	}

	for (i = 0, b = 0, g = 0; i < strlen(x); i++)
	{
		if (g == 1)
		{
			if (i > 8)
			{
				ShowError(x, "Id too long");
				return 0;
			}

			if (x[i] == '&')
			{
				if (x[i+1] == 0)
				{
					ShowError(x, "Missing field");
					return 0;
				}
				g++;
				b = 0;

				continue;
			} else {
				z[b] = x[i];
				b++;

				continue;
			}
		}

		if (g == 2)
		{
			e[b] = x[i];
			b++;

			continue;
		}

		if (x[i] == '=')
		{
			g++; b = 0;
			if (!(strncmp(y, "id", 2)))
			{
				continue;
			} else {
				ShowError(x, "Invalid extention");
				return 0;
			}
		}

		y[b] = x[i];
		b++;
	}

	if (strncmp(y, "id", 2) || z[0] == 0 || e[0] == 0)
	{
		ShowError(x, "Invalid extention");
		return 0;
	}

	b = atoi(z); g = atoi(e);
	for (i = 0; DefExt[i].id; i++)
	{
		if (DefExt[i].id == b)
		{
			StartHtml();

			DefExt[i].func(g);
			return 1;
		}
	}

	ShowError(x, "Invalid ID");
	return 1;
}

/* The mysql concept was derived from detour's mysql select
 * example found at: http://www.metalshell.com/view/source/18/
 */
void GetMysql(char *query)
{
	MYSQL           mysql;

	if (strlen(query) < 10)
		ShowError(NULL, "MySQL query string too low");

	if (!(mysql_connect(&mysql, MySQL_HOST, MySQL_USER, MySQL_PASS)))
	{
		fprintf(stderr,"mysql_connect() Failed: %s\n",mysql_error(&mysql));
		ShowError(NULL, "MySQL SERVER down");
	}

	if (mysql_select_db(&mysql, MySQL_DATA))
		ShowError(NULL, "MySQL database error");

	if (mysql_query(&mysql,query))
		ShowError(NULL, "MySQL server error");

	res = mysql_store_result(&mysql);
	row = mysql_fetch_row(res);

	mysql_close(&mysql);
	mysql_free_result(res);
}

void GetBirth(int x)
{
	char	query[100];

	snprintf(query, sizeof(query), "select * from person where id = %i", x);
	GetMysql(query);

	eprint( 0, "<font> %s's Birth date is: %s</font>\n", row[1], row[2]);
}

void GetAddress(int x)
{
	char	query[100];

	snprintf(query, sizeof(query), "select * from person where id = %i", x);
	GetMysql(query);

	eprint( 0, "<font> %s's Address is: %s</font>\n", row[1], row[3]);
}

void GetPhone(int x)
{
	char	query[100];

	snprintf(query, sizeof(query), "select * from person where id = %i", x);
	GetMysql(query);

	eprint( 0, "<font> %s's Phone Number is: %s</font>\n", row[1], row[4]);
}

void GetShowAll(int x)
{
	char	query[100];

	snprintf(query, sizeof(query), "select * from person where id = %i", x);
	GetMysql(query);

	eprint( 0, "<font> <b><u>%s</b></u> </font><br>\n", row[1]);
	eprint( 0, "<font> Birth day: %s</font><br>\n", row[2]);
	eprint( 0, "<font> Address  : %s</font><br>\n", row[3]);
	eprint( 0, "<font> Phone Num: %s</font><br>\n", row[4]);
}

void StartHtml()
{
	eprint( 0, "<html>\n");
	eprint( 1, "<head>\n");
	eprint( 1, "<title> Website in C - Example </title>\n");
	eprint(-1, "</head>\n\n");
}

/* Error printing */
void ShowError(char *x, char *e)
{
	if (e == NULL) strcpy(e, "Unknown Error!");

        /* Some prints resized to fit MS source code area */
	eprint( 0, "<html>\n");
	eprint( 1, "<head>\n");
	eprint( 1, "<title>An Error Occured!</title>\n");
	eprint(-1, "</head>\n\n");
	eprint( 0, "<br><br><br><br><br><br><br>\n");
	if (x != NULL)
        {
		eprint( 0, "<div align=center><font size=4>An error occured: \"%s\" ", e);
                printf("While trying to process your request of \"%s\"</font></div>\n", x);
	}else {
		eprint( 0, "<div align=center><font size=4>An error occured: \"%s\" ", e);
                printf("While trying to process your request.</font></div>\n");
        }
	eprint( 0, "<div align=center><font size=4>If this error keeps occuring please ");
        printf("email the site admin</font></div>\n");
	eprint(-1, "</html>\n");
	exit(-1);
}

/* eprint - mind@metalshell.com [http://www.metalshell.com]
 *
 * Example:
 *   eprint( 0, "test1\n");  No Change (just print)
 *   eprint( 1, "test2\n");  Add a tab
 *   eprint( 1, "test3\n");  Add a tab
 *   eprint(-1, "test4\n");  Remove a tab
 *   eprint(-1, "test5\n");  Remove a tab
 *   eprint( 0, "test6\n");  No Change (just print)
 *
 *   ;test1
 *   ;<tab>test2
 *   ;<tab><tab>test3
 *   ;<tab>test4
 *   ;test5
 *   ;test6
 */
void eprint(int b, char *fmt, ...)
{
	va_list		list;
	char            *p, *r;
	int             e, x;

	if (b == -1) TabMe--;
	if (b ==  1) TabMe++;

	for (x = 0; x < TabMe; x++) putc('\t', stdout);

	va_start( list, fmt );
	for ( p = fmt ; *p ; ++p )
	{
		if ( *p != '%' )
		{
			putc( *p, stdout );
		} else {
			switch ( *++p )
			{
				case 's':
				{
					r = va_arg( list, char * );

					printf("%s", r);
					continue;
				}

				case 'i':
				{
					e = va_arg( list, int );

					printf("%i", e);
					continue;
				}

				default:
				{
					if (!x)
						putc( *p, stdout );
					else
						x = 0;
				}
			}
		}
	}
	va_end(list);
	fflush(stdout);
}