#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdarg.h>
#include <ctype.h>

#include "event.h"
#include "ircsession.h"
#include "linebuffer.h"
#include "logging.h"
#include "sockaddr.h"
#include "tcpsocket.h"

struct irc_session * irc_create_session(void)
{
	struct irc_session *session = malloc(sizeof(struct irc_session));
	if (session == NULL)
		return NULL;

	memset(session, 0, sizeof(struct irc_session));

	session->state = IRC_NONE;
	session->inbuf = create_linebuffer(4096);
	session->outbuf = create_linebuffer(4096);

	return session;
}

void irc_destroy_session(struct irc_session *session)
{
	linebuffer_free(session->outbuf);
	linebuffer_free(session->inbuf);
	free(session);
}

static int irc_write_cb(int fd, void *privdata)
{
	struct irc_session *session = (struct irc_session *)privdata;
	linebuffer_writefd(session->outbuf, fd);

	/* remove write fd again */
	event_add_writefd(session->handler, 0, NULL, NULL);
	return 0;
}

int irc_send(struct irc_session *session, const char *fmt, ...)
{
	va_list az;
	va_start(az, fmt);
	linebuffer_vprintf(session->outbuf, fmt, az);
	va_end (az);

	linebuffer_put(session->outbuf, "\r\n", 2);

	/* schedule a write */
	event_add_writefd(session->handler, 0, irc_write_cb, session);
	return 0;
}

static int irc_read_cb(int fd, void *privdata)
{
	struct irc_session *session = (struct irc_session *)privdata;

	int len = linebuffer_readfd(session->inbuf, fd);
	if (len <= 0) {
		session->state = IRC_DISCONNECTED;
		log_print(LOG_DEBUG, "irc_read_cb(): disconnected from %s", get_sockaddr_buf(&session->srv_addr));
		return -1;
	}

	char *line;
	while ((line = linebuffer_getline(session->inbuf, &len)) != NULL) {
		char *p = line;
		char *prefix = NULL;

		log_print(LOG_DEBUG, "irc_read_cb(): from %s (%d): %s", get_sockaddr_buf(&session->srv_addr), len, line);

		if (line[0] == ':' ) {
			while ( *p && *p != ' ')
				p++;

			*p++ = '\0';

			prefix = line +1;
		}

		int code = 0;
		char *command = NULL;
		if (isdigit(p[0]) && isdigit(p[1]) && isdigit(p[2])) {
			p[3] = '\0';
			code = atoi(p);
			p += 4;

		} else {
			command = p;
			while ( *p && *p != ' ')
				p++;

			*p++ = '\0';
		}

		if (strncmp(line, "PING", 4) == 0) {
			irc_send(session, "PONG %s", line +6);
			linebuffer_freeline(session->inbuf);
			continue;
		}

		if (code != 0) {
			if ((code == 376 || code == 422) && session->state == IRC_CONNECTED) {
				session->state = IRC_MOTD_RECEIVED;

				linebuffer_freeline(session->inbuf);
				if (session->channel_key)
					return irc_send(session, "JOIN %s :%s", session->channel, session->channel_key);
				else
					return irc_send(session, "JOIN %s", session->channel);
			}

		} else {
			if (!strcmp(command, "JOIN"))
				session->state = IRC_JOINED;
		}

		linebuffer_freeline(session->inbuf);
	}
	return 0;
}

static int irc_connect_cb(int fd, void *privdata)
{
	struct irc_session *session = (struct irc_session *)privdata;

	if (tcp_connect_error(fd)) {
		session->state = IRC_CONNECTION_FAILED;
		log_print(LOG_DEBUG, "irc_connect_cb(): failed to connect to %s", get_sockaddr_buf(&session->srv_addr));
		return -1;
	}

	session->state = IRC_CONNECTED;
	event_add_readfd(session->handler, 0, irc_read_cb, session);
	event_add_writefd(session->handler, 0, NULL, NULL);

	log_print(LOG_DEBUG, "irc_connect_cb(): connected to %s", get_sockaddr_buf(&session->srv_addr));

	if (session->server_pass != NULL)
		irc_send(session, "PASS %s", session->server_pass);

	irc_send(session, "NICK %s", session->nickname);
	irc_send(session, "USER %s unknown unknown :%s",
		session->username ? session->username : "nobody",
		session->realname ? session->realname : "noname");

	return 0;
}

int irc_connect(struct irc_session *session)
{
	/* TODO: check state before connecting */

	session->sock = tcp_connect_nonblock(&session->srv_addr);
	if (session->sock < 0)
		return -1;

	session->state = IRC_CONNECTING;
	session->handler = event_add_writefd(NULL, session->sock, irc_connect_cb, session);

	log_print(LOG_DEBUG, "irc_connect(): connecting to %s", get_sockaddr_buf(&session->srv_addr));
	return 0;
}