#include "cgi.h"
#include "stdinc.h"

void content_type(char *type)
{
	printf("Content-type: %s\r\n\r\n", type);
}

void *param_add(param_t *list, char *name, char *value)
{
	param_t *cursor = list;
	if (name == NULL || value == NULL)
		return list;

	if (cursor == NULL) {
		cursor = calloc(1, sizeof(param_t));
		cursor->name = strdup(name);
		cursor->value = strdup(value);
		html_escape(cursor->value);
		cursor->next = NULL;
	} 

	for (cursor = list; cursor->next; cursor = cursor->next);

	if (cursor->next == NULL) {
		cursor->next = calloc(1, sizeof(param_t));	
		cursor = cursor->next;
		cursor->name = strdup(name);
		cursor->value = strdup(value);
		html_escape(cursor->value);
		cursor->next = NULL;
	} else
		bork("Should not be here!");

	return list;
}

char *html_escape(char *string)
{
	char *p = string;
	int i;
	char *hex[] = {"A", "B", "C", "D", "E", "F"};

	char *again = p;
	for (i = 10; i < 255; i++) {
		p = again;
		char esc[6] = { 0 };
		char res[6] = { 0 };
		sprintf(esc, "%%%x", i);
		
		sprintf(res, "%c", i);
		char *pos = NULL;
		while ((pos = strstr(p, esc)) != NULL) {
			if (pos) {
				memmove(pos, pos + 1 + strlen(res), strlen(pos));
				*pos = (char) res[0];
			}
	
		}
		
		p = again;

		int x;
		for (x = 1; x < 9; x++) {
			int y;
			for (y = 0; y < 6; y++) {
				sprintf(esc, "%%%d%s", x, hex[y]);
				sprintf(res, "%d%s", x, hex[y]);
				while ((pos = strstr(p, esc)) != NULL) {
					memmove(pos, pos + strlen(res), strlen(pos));
					*pos = (char) strtol(res, (char **) NULL, 16);
				}
			}
		}	
	
		while ((pos = strstr(p, "+")) != NULL) 
			*pos = ' ';
		
	}

	return string;	
}

char *param(char *name)
{
	param_t *cursor = _params->next;

	while (cursor) {
		if (!(strcmp(cursor->name, name))) 
			return strdup(cursor->value);

		cursor = cursor->next;
	}

	return NULL;
}

void param_free(param_t *list)
{
	while (list) {
		param_t *next = list->next;
		free(list->name);
		free(list->value);
		free(list);
		list = next;
	}
}



void *get_params(void)
{
	_params = calloc(1, sizeof(param_t));
	int post = 0;

	char *method = getenv("REQUEST_METHOD");
	if (method == NULL)
		return NULL;
	else if (!strcmp(method, "POST") || !strcmp(method, "GET")) {
		if (!strcmp(method, "POST"))
			post = 1;
		char *buf;
		char *p;

		if (post) {
			char *length = getenv("CONTENT_LENGTH");
			int bytes = atoi(length);
			if (bytes == 0)
				bork("CONTENT_LENGTH is zero");
			buf = calloc(1, bytes);
			size_t len = read(fileno(stdin), buf, bytes);
			buf[len] = '\0';
		} else 
			buf = strdup(getenv("QUERY_STRING"));

		if (strlen(buf) == 0)
			return NULL;

		p = buf;

		while (1) {
			char *start = p;
			p = strchr(start, '=');
			*p = '\0';
			char *name = strdup(start);
			p++;
			char *end = strchr(p, '&');
			if (end != NULL)
				*end = '\0';
			char *value = strdup(p);
			_params = param_add(_params, name, value);
			if (end == NULL)
				break;
			else 	
				p = end + 1;
		}
		
	}

	return _params;
}