/*
 * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
 *
 * Licensed under the GPL v2. For licencing details see COPYING.
 */

/** \file http_send.c paraslash's http sender */

#include <sys/types.h>
#include <dirent.h>

#include "para.h"
#include "error.h"
#include "string.h"
#include "server.cmdline.h"
#include "afh.h"
#include "afs.h"
#include "server.h"
#include "http.h"
#include "vss.h"
#include "list.h"
#include "send.h"
#include "close_on_fork.h"
#include "net.h"
#include "fd.h"
#include "chunk_queue.h"
#include "acl.h"

/** Message sent to clients that do not send a valid get request. */
#define HTTP_ERR_MSG "HTTP/1.0 400 Bad Request\n"

/** The possible states of a client from the server's POV. */
enum http_client_status {
	/** We accepted the connection on the tcp socket. */
	HTTP_CONNECTED,
	/** Successfully received the get request. */
	HTTP_GOT_GET_REQUEST,
	/** Connection is ready for sending audio data. */
	HTTP_STREAMING,
	/** We didn't receive a valid get request. */
	HTTP_INVALID_GET_REQUEST
};

/** For each connected client, a structure of this type is maintained. */
struct private_http_sender_data {
	/** The current state of this client. */
	enum http_client_status status;
};

static struct sender_status http_sender_status, *hss = &http_sender_status;

static int http_send_msg(struct sender_client *sc, const char *msg)
{
	int ret = send_buffer(sc->fd, msg);

	if (ret < 0)
		shutdown_client(sc, hss);
	return ret;
}

static void http_send_ok_msg(struct sender_client *sc)
{
	PARA_INFO_LOG("sending http ok message to fd %d\n", sc->fd);
	http_send_msg(sc, HTTP_OK_MSG);
}

static int http_send_err_msg(struct sender_client *sc)
{
	PARA_NOTICE_LOG("sending bad request message to fd %d\n", sc->fd);
	return http_send_msg(sc, HTTP_ERR_MSG);
}

static void http_shutdown_clients(void)
{
	shutdown_clients(hss);
}

static void http_send(long unsigned current_chunk,
	__a_unused long unsigned chunks_sent, const char *buf, size_t len,
	const char *header_buf, size_t header_len)
{
	struct sender_client *sc, *tmp;

	list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
		struct private_http_sender_data *phsd = sc->private_data;
		if (phsd->status != HTTP_STREAMING)
			continue;
		send_chunk(sc, hss, 0, current_chunk, buf, len, header_buf,
			header_len);
	}
}

static void http_post_select(fd_set *rfds, __a_unused fd_set *wfds)
{
	struct sender_client *sc, *tmp;
	struct private_http_sender_data *phsd;

	if (hss->listen_fd < 0)
		return;
	list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
		phsd = sc->private_data;
		switch (phsd->status) {
		case HTTP_STREAMING: /* nothing to do */
			break;
		case HTTP_CONNECTED: /* need to recv get request */
			if (FD_ISSET(sc->fd, rfds)) {
				if (recv_pattern(sc->fd, HTTP_GET_MSG, MAXLINE)
						< 0) {
					phsd->status = HTTP_INVALID_GET_REQUEST;
				} else {
					phsd->status = HTTP_GOT_GET_REQUEST;
					PARA_INFO_LOG("received get request\n");
				}
			}
			break;
		case HTTP_GOT_GET_REQUEST: /* need to send ok msg */
			phsd->status = HTTP_STREAMING;
			http_send_ok_msg(sc);
			break;
		case HTTP_INVALID_GET_REQUEST: /* need to send err msg */
			if (http_send_err_msg(sc) >= 0)
				shutdown_client(sc, hss);
			break;
		}
	}
	if (!FD_ISSET(hss->listen_fd, rfds))
		return;
	sc = accept_sender_client(hss);
	if (!sc)
		return;
	phsd = para_malloc(sizeof(*phsd));
	sc->private_data = phsd;
	phsd->status = HTTP_CONNECTED;
}

static void http_pre_select(int *max_fileno, fd_set *rfds, fd_set *wfds)
{
	struct sender_client *sc, *tmp;

	if (hss->listen_fd < 0)
		return;
	para_fd_set(hss->listen_fd, rfds, max_fileno);
	list_for_each_entry_safe(sc, tmp, &hss->client_list, node) {
		struct private_http_sender_data *phsd = sc->private_data;
		if (phsd->status == HTTP_CONNECTED) /* need to recv get request */
			para_fd_set(sc->fd, rfds, max_fileno);
		if (phsd->status == HTTP_GOT_GET_REQUEST ||
				phsd->status == HTTP_INVALID_GET_REQUEST)
			para_fd_set(sc->fd, wfds, max_fileno);
	}
}

static int http_com_on(__a_unused struct sender_command_data *scd)
{
	return generic_com_on(hss, IPPROTO_TCP);
}

static int http_com_off(__a_unused struct sender_command_data *scd)
{
	generic_com_off(hss);
	return 1;
}

static int http_com_deny(struct sender_command_data *scd)
{
	generic_com_deny(scd, hss);
	return 1;
}

static int http_com_allow(struct sender_command_data *scd)
{
	generic_com_allow(scd, hss);
	return 1;
}

static char *http_info(void)
{
	return get_sender_info(hss, "http");
}

/**
 * The init function of the http sender.
 *
 * \param s Pointer to the http sender struct.
 *
 * It initializes all function pointers of \a s, the client list and the access
 * control list. If the autostart option was given, the tcp port is opened.
 */
void http_send_init(struct sender *s)
{
	int ret;
	s->info = http_info;
	s->send = http_send;
	s->pre_select = http_pre_select;
	s->post_select = http_post_select;
	s->shutdown_clients = http_shutdown_clients;
	s->help = generic_sender_help;
	s->client_cmds[SENDER_ON] = http_com_on;
	s->client_cmds[SENDER_OFF] = http_com_off;
	s->client_cmds[SENDER_DENY] = http_com_deny;
	s->client_cmds[SENDER_ALLOW] = http_com_allow;
	s->client_cmds[SENDER_ADD] = NULL;
	s->client_cmds[SENDER_DELETE] = NULL;

	init_sender_status(hss, conf.http_access_arg, conf.http_access_given,
		conf.http_port_arg, conf.http_max_clients_arg,
		conf.http_default_deny_given);
	if (conf.http_no_autostart_given)
		return;
	ret = generic_com_on(hss, IPPROTO_TCP);
	if (ret < 0)
		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
}