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

#include <sys/time.h>
#include <sys/types.h>
#include <sys/ioctl.h>

#include "event.h"
#include "http.h"
#include "list.h"
#include "logging.h"
#include "sockaddr.h"
#include "tcpsocket.h"

static LIST_HEAD(http_cb_list);

static void destroy_http_con(struct http_con *con)
{
	close(event_get_fd(con->event));
	event_remove_fd(con->event);

	if (con->req_data != NULL)
		free(con->req_data);

	if (con->req_headers != NULL)
		free(con->req_headers);

	if (con->req_args != NULL)
		free(con->req_args);

	free(con);
}

int http_send_header(struct http_con *con, char *code, char *type)
{
	char buf[256];
	int len = snprintf(buf, sizeof(buf), "HTTP/1.0 %s\r\nContent-Type: %s\r\nConnection: close\r\n\r\n", code, type);
	write(con->fd, buf, len);
	return 0;
}

int http_send_error(struct http_con *con, char *code, char *msg)
{
	http_send_header(con, code, "text/plain");
	write(con->fd, msg, strlen(msg));
	return 0;
}

static int parse_headers(struct http_con *con)
{
	char *data = con->req_data;
	while ((data = strstr(data, "\r\n")) && data < con->req_data + con->req_size) {
		con->req_header_cnt++;
		data += 2;
	}

	con->req_headers = malloc(con->req_header_cnt * sizeof(char *));
	if (con->req_headers == NULL)
		return -1;

	int i = 0;
	data = con->req_data;

	do {
		con->req_headers[i++] = data;

		data = strstr(data, "\r\n");
		if (data == NULL)
			break;

		*data++ = '\0';
		*data++ = '\0';

	} while (data < con->req_data + con->req_size);
	return 0;
}

static int parse_args(struct http_con *con)
{
	/* seperate GET (in req->data) */
	char *req = strchr(con->req_data, ' ');
	*req++ = '\0';

	/* HTTP/1.1 will go to header[0] */
	char *tmp = strchr(req, ' ');
	*tmp++ = '\0';
	con->req_headers[0] = tmp;

	/* count args */
	tmp = req;
	while (*tmp != '\0' && tmp < con->req_data + con->req_size) {
		if (*tmp == '?' || *tmp == '&')
			con->req_arg_cnt++;

		tmp++;
	}
	con->req_arg_cnt++;

	/* alloc args */
	con->req_args = malloc(con->req_arg_cnt * sizeof(char *));
	if (con->req_args == NULL)
		return -1;

	int i = 0;
	tmp = req;

	con->req_args[i++] = tmp;
	while (*tmp != '\0' && tmp < con->req_data + con->req_size) {
		if (*tmp == '?' || *tmp == '&') {
			*tmp++ = '\0';
			con->req_args[i++] = tmp;
		}
		tmp++;
	}
	return 0;
}

static int http_content_handler(int fd, void *privdata)
{
	struct http_con *con = (struct http_con *)privdata;

	if (ioctl(fd, FIONREAD, &con->req_size) == -1) {
		log_print(LOG_WARN, "http_content_handler(): ioctl(FIONREAD)");
		destroy_http_con(con);
		return -1;
	}

	con->req_data = malloc(con->req_size);
	if (con->req_data == NULL) {
		log_print(LOG_WARN, "http_content_handler(): out of memory");
		destroy_http_con(con);
		return -1;
	}

	con->req_size = read(fd, con->req_data, con->req_size);
	if (con->req_size <= 0) {
		log_print(LOG_WARN, "http_content_handler(): read()");
		destroy_http_con(con);
		return -1;
	}

	if (strncmp(con->req_data, "GET ", 4) != 0) {
		http_send_error(con, "400 Invalid Request", "Not a GET request\r\n");
		destroy_http_con(con);
		return -1;
	}

	if (parse_headers(con) < 0) {
		http_send_error(con, "400 Invalid Request", "Error parsing headers\r\n");
		destroy_http_con(con);
		return -1;
	}

	if (parse_args(con) < 0) {
		http_send_error(con, "400 Invalid Request", "Error parsing arguments\r\n");
		destroy_http_con(con);
		return -1;
	}

	struct http_callback *entry;
	list_for_each_entry(entry, &http_cb_list, list) {

		if ((entry->wildcard == 1 && strncmp(entry->name, con->req_args[0], strlen(entry->name)) == 0) ||
		    (entry->wildcard == 0 && strcmp(entry->name, con->req_args[0]) == 0)) {

			entry->callback(con, entry->privdata);
			destroy_http_con(con);
			return 0;
		}
	}

	http_send_error(con, "404 Not Found", "File not found\r\n");
	destroy_http_con(con);
	return 0;
}

int http_listen_handler(int fd, void *privdata)
{
	struct http_con *con = malloc(sizeof(struct http_con));
	if (con == NULL) {
		log_print(LOG_WARN, "http_listen_handler(): out of memory");
		return 0;
	}

	memset(con, 0, sizeof(struct http_con));

	unsigned int i = sizeof(con->addr);
	con->fd = accept(fd, (struct sockaddr *)&con->addr, &i);
	if (con->fd < 0) {
		free(con);
		return 0;
	}

	con->event = event_add_readfd(NULL, con->fd, http_content_handler, con);
	return 0;
}

struct http_callback * http_add_cb(const char *name,
					int wildcard,
					int (* callback)(struct http_con *con, void *privdata),
					void *privdata)
{
	struct http_callback *hcb = malloc(sizeof(struct http_callback));
	if (hcb == NULL) {
		log_print(LOG_WARN, "http_create_cb(): out of memory");
		return NULL;
	}

	hcb->name = strdup(name);
	hcb->wildcard = wildcard;
	hcb->callback = callback;
	hcb->privdata = privdata;

	list_add_tail(&hcb->list, &http_cb_list);
	return hcb;
}

int http_remove_cb(struct http_callback *hcb)
{
	list_del(&hcb->list);
	free(hcb->name);
	free(hcb);
	return 0;
}

int http_file_cb(struct http_con *con, void *privdata)
{
	log_print(LOG_DEBUG, "req: %s", con->req_args[0]);
	http_send_header(con, "500 NOT OK", "text/plain");
	return 0;
}