#include "core.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <sys/ioctl.h>
#include <netinet/in.h>
#include <ifaddrs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/tcp.h>
#include <fcntl.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/sendfile.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <errno.h>

static int tip_client_method_not_found(struct tip_client *cli)
{
	/* To meet RFC 7231, this function MUST generate an Allow header field
	 * containing the correct methods. For example: "Allow: POST\r\n"
	 */
	char buf[] = "HTTP/1.1 405 Method Not Allowed\r\n"
		     "Content-Length: 0\r\n\r\n";

	send(tip_client_socket(cli), buf, strlen(buf), 0);

	return -1;
}

static int tip_client_file_not_found(struct tip_client *cli)
{
	char buf[] = "HTTP/1.1 404 Not Found\r\n"
		     "Content-Length: 0\r\n\r\n";

	send(tip_client_socket(cli), buf, strlen(buf), 0);

	return -1;
}

/* TODO: sanitize uri, don't escape directory serving files. */
static bool sanitize(const char *uri)
{
	return true;
}

#define BLOCK 1024000

int tip_client_state_process_payload(struct tip_client *cli)
{
	const char *trailer, *x_redirect;
	enum tip_http_method method;
	bool allow_redirect = true;
	char _uri[32], *uri = _uri;
	char path[PATH_MAX + 1];
	char redirect[5];
	struct stat st;
	int err;

/*	syslog(LOG_DEBUG, "%s:rhu %.32s ...\n",
	       inet_ntoa(cli->addr.sin_addr),
	       ntohs(cli->addr.sin_port), cli->buf); */

	if (!strncmp(cli->buf, "GET", strlen("GET"))) {
		method = TIP_METHOD_GET;
		if (sscanf(cli->buf, "GET %31s HTTP/1.1", uri) != 1)
			return tip_client_method_not_found(cli);
	} else {
		return tip_client_method_not_found(cli);
	}

	x_redirect = strstr(cli->buf, "X-Accept-Redirect: ");
	if (x_redirect &&
	    sscanf(x_redirect, "X-Accept-Redirect: %4s", redirect) == 1 &&
	    !strncmp(redirect, "off", strlen("off")))
		allow_redirect = false;

	trailer = strstr(cli->buf, "\r\n\r\n");

	if (!sanitize(uri))
		return tip_client_method_not_found(cli);

	snprintf(path, PATH_MAX, "%s/%s", root, uri);

	err = stat(path, &st);
	if (err < 0)
		return tip_client_file_not_found(cli);

	/* skip initial / */
	uri++;

	cli->uri = strdup(uri);
	cli->path = strdup(path);
	cli->size = st.st_size;
	cli->allow_redirect = allow_redirect;

	num_clients++;
	if (cli->size > FILE_SIZE_THRESHOLD && num_clients > max_clients) {
		if (!tip_client_redirect(cli)) {
			tip_client_pending(cli);
			return 1;
		}
	}

	cli->state = TIP_CLIENT_PROCESSING_REQUEST_2;

	return 0;
}

int tip_client_state_process_payload_reply(struct tip_client *cli)
{
	char buf[1024];
	int fd;

	if (cli->redirect) {
		snprintf(buf, sizeof(buf),
			 "HTTP/1.1 301 Moves Permanently\r\nLocation: http://%s:%hu/%s\r\n\r\n",
			 inet_ntoa(cli->redirect_addr.sin_addr),
			 htons(cli->redirect_addr.sin_port), cli->uri);
		send(tip_client_socket(cli), buf, strlen(buf), 0);

		return 1;
	}

	fd = open(cli->path, O_RDONLY);
	if (fd < 0)
		return tip_client_file_not_found(cli);

	snprintf(buf, sizeof(buf),
		 "HTTP/1.1 200 OK\r\nContent-Length: %lu\r\n\r\n",
		 cli->size);

	send(tip_client_socket(cli), buf, strlen(buf), 0);

	cli->fd = fd;
	cli->state = TIP_CLIENT_PROCESSING_REQUEST_3;

	return 0;
}

int tip_client_state_process_payload_bulk(struct tip_client *cli)
{
	sendfile(tip_client_socket(cli), cli->fd, &cli->offset, BLOCK);

	if (cli->offset >= cli->size)
		return 1;

	return 0;
}