/* HelpServ functions.
 *
 * IRC Services is copyright (c) 1996-2007 Andrew Church.
 *     E-mail: <achurch@achurch.org>
 * Parts written by Andrew Kempe and others.
 * This program is free but copyrighted software; see the file COPYING for
 * details.
 */

#include "services.h"
#include "modules.h"
#include "conffile.h"
#include "language.h"
#include <sys/stat.h>

/*************************************************************************/

static Module *module;

static char *s_HelpServ;
static char *desc_HelpServ;
static char *HelpDir;

/*************************************************************************/
/*************************** HelpServ routine ****************************/
/*************************************************************************/

/* Main HelpServ routine. */

static void helpserv(const char *source, char *topic)
{
    FILE *f;
    struct stat st;
    char buf[PATH_MAX+1], *ptr;
    const char *s;
    char *old_topic;	/* an unclobbered (by strtok) copy */
    User *u;

    if (strnicmp(topic, "\1PING ", 6) == 0) {
	s = strtok(topic, " ");
	if (!(s = strtok(NULL, "")))
	    s = "\1";
	notice(s_HelpServ, source, "\1PING %s", s);
	return;
    }

    old_topic = sstrdup(topic);
    u = get_user(source);

    /* As we copy path parts, (1) lowercase everything and (2) make sure
     * we don't let any special characters through -- this includes '.'
     * (which could get parent dir) or '/' (which couldn't _really_ do
     * anything nasty if we keep '.' out, but better to be on the safe
     * side).  Special characters turn into '_'.
     */
    strscpy(buf, HelpDir, sizeof(buf));
    ptr = buf + strlen(buf);
    for (s = strtok(topic, " "); s && ptr-buf < sizeof(buf)-1;
						s = strtok(NULL, " ")) {
	*ptr++ = '/';
	while (*s && ptr-buf < sizeof(buf)-1) {
	    if (*s == '.' || *s == '/')
		*ptr++ = '_';
	    else
		*ptr++ = tolower(*s);
	    s++;
	}
	*ptr = 0;
    }

    /* If we end up at a directory, go for an "index" file/dir if
     * possible.
     */
    while (ptr-buf < sizeof(buf)-6
		&& stat(buf, &st) == 0 && S_ISDIR(st.st_mode)) {
	strcpy(ptr, "/index");
	ptr += strlen(ptr);
    }

    /* Send the file, if it exists.
     */
    if (!(f = fopen(buf, "r"))) {
	if (debug)
	    module_log_perror("debug: Cannot open help file %s", buf);
	if (u) {
	    notice_lang(s_HelpServ, u, NO_HELP_AVAILABLE, old_topic);
	} else {
	    notice(s_HelpServ, source,
			"Sorry, no help available for \2%s\2.", old_topic);
	}
    } else {
	while (fgets(buf, sizeof(buf), f)) {
	    s = strtok(buf, "\n");
	    /* Use this odd construction to prevent any %'s in the text from
	     * doing weird stuff to the output.  Also replace blank lines by
	     * spaces (see send.c/notice_list() for an explanation of why).
	     */
	    notice(s_HelpServ, source, "%s", s ? s : " ");
	}
	fclose(f);
    }
    free(old_topic);
}

/*************************************************************************/
/**************************** Event callbacks ****************************/
/*************************************************************************/

/* Handler for introducing nicks. */

static int do_introduce(const char *nick)
{
    if (!nick || irc_stricmp(nick, s_HelpServ) == 0) {
	send_nick(s_HelpServ, ServiceUser, ServiceHost, ServerName,
		  desc_HelpServ, pseudoclient_modes);
	if (nick)
	    return 1;
    }
    return 0;
}

/*************************************************************************/

/* Handler for PRIVMSGs. */

static int do_privmsg(const char *source, const char *target, char *buf)
{
    if (irc_stricmp(target, s_HelpServ) == 0) {
	helpserv(source, buf);
	return 1;
    }
    return 0;
}

/*************************************************************************/

/* Handler for WHOIS's. */

static int do_whois(const char *source, char *who, char *extra)
{
    if (irc_stricmp(who, s_HelpServ) == 0) {
	send_cmd(ServerName, "311 %s %s %s %s * :%s", source, who,
		 ServiceUser, ServiceHost, desc_HelpServ);
	send_cmd(ServerName, "312 %s %s %s :%s", source, who,
		 ServerName, ServerDesc);
	send_cmd(ServerName, "318 %s %s End of /WHOIS response.", source, who);
	return 1;
    } else {
	return 0;
    }
}

/*************************************************************************/
/***************************** Module stuff ******************************/
/*************************************************************************/

const int32 module_version = MODULE_VERSION_CODE;

ConfigDirective module_config[] = {
    { "HelpDir",          { { CD_STRING, CF_DIRREQ, &HelpDir } } },
    { "HelpServName",     { { CD_STRING, CF_DIRREQ, &s_HelpServ },
                            { CD_STRING, 0, &desc_HelpServ } } },
    { NULL }
};

/*************************************************************************/

static int do_reconfigure(int after_configure)
{
    static char old_s_HelpServ[NICKMAX];
    static char *old_desc_HelpServ = NULL;

    if (!after_configure) {
	/* Before reconfiguration: save old values. */
	free(old_desc_HelpServ);
	strscpy(old_s_HelpServ, s_HelpServ, NICKMAX);
	old_desc_HelpServ = strdup(desc_HelpServ);
    } else {
	/* After reconfiguration: handle value changes. */
	if (strcmp(old_s_HelpServ, s_HelpServ) != 0)
	    send_nickchange(old_s_HelpServ, s_HelpServ);
	if (!old_desc_HelpServ || strcmp(old_desc_HelpServ,desc_HelpServ) != 0)
	    send_namechange(s_HelpServ, desc_HelpServ);
	free(old_desc_HelpServ);
	old_desc_HelpServ = NULL;
    }  /* if (!after_configure) */
    return 0;
}

/*************************************************************************/

int init_module(Module *module_)
{
    module = module_;

    if (!add_callback(NULL, "reconfigure", do_reconfigure)
     || !add_callback(NULL, "introduce_user", do_introduce)
     || !add_callback(NULL, "m_privmsg", do_privmsg)
     || !add_callback(NULL, "m_whois", do_whois)
    ) {
	exit_module(0);
	return 0;
    }

    if (linked)
	do_introduce(NULL);

    return 1;
}

/*************************************************************************/

int exit_module(int shutdown_unused)
{
#ifdef CLEAN_COMPILE
    shutdown_unused = shutdown_unused;
#endif

    if (linked)
	send_cmd(s_HelpServ, "QUIT :");

    remove_callback(NULL, "m_whois", do_whois);
    remove_callback(NULL, "m_privmsg", do_privmsg);
    remove_callback(NULL, "introduce_user", do_introduce);
    remove_callback(NULL, "reconfigure", do_reconfigure);

    return 1;
}

/*************************************************************************/