/*
 *  This file is part of uIRC. (https://git.redxen.eu/caskd/uIRC)
 *  Copyright (c) 2019, 2020 Alex-David Denes
 *
 *  uIRC is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  uIRC is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with uIRC.  If not, see <https://www.gnu.org/licenses/>.
*/
#include "uirc.h"

const char* const uirc_ircmd[] = {
    [ADMIN] = "ADMIN",
    [AWAY] = "AWAY",
    [CONNECT] = "CONNECT",
    [DIE] = "DIE",
    [ERROR] = "ERROR",
    [INFO] = "INFO",
    [INVITE] = "INVITE",
    [ISON] = "ISON",
    [JOIN] = "JOIN",
    [KICK] = "KICK",
    [KILL] = "KILL",
    [LINKS] = "LINKS",
    [LIST] = "LIST",
    [LUSERS] = "LUSERS",
    [MODE] = "MODE",
    [MOTD] = "MOTD",
    [NAMES] = "NAMES",
    [NICK] = "NICK",
    [NOTICE] = "NOTICE",
    [OPER] = "OPER",
    [PART] = "PART",
    [PASS] = "PASS",
    [PING] = "PING",
    [PONG] = "PONG",
    [PRIVMSG] = "PRIVMSG",
    [QUIT] = "QUIT",
    [REHASH] = "REHASH",
    [RESTART] = "RESTART",
    [SERVER] = "SERVER",
    [SERVICE] = "SERVICE",
    [SERVLIST] = "SERVLIST",
    [SQUERY] = "SQUERY",
    [SQUIT] = "SQUIT",
    [STATS] = "STATS",
    [SUMMON] = "SUMMON",
    [TIME] = "TIME",
    [TOPIC] = "TOPIC",
    [TRACE] = "TRACE",
    [USERHOST] = "USERHOST",
    [USERS] = "USERS",
    [USER] = "USER",
    [VERSION] = "VERSION",
    [WALLOPS] = "WALLOPS",
    [WHOIS] = "WHOIS",
    [WHOWAS] = "WHOWAS",
    [WHO] = "WHO",
#ifdef UIRC_IRCV3
    [ACCOUNT] = "ACCOUNT",
    [ACC] = "ACC",
    [ACK] = "ACK",
    [AUTHENTICATE] = "AUTHENTICATE",
    [BATCH] = "BATCH",
    [CAP] = "CAP",
    [CHGHOST] = "CHGHOST",
    [FAIL] = "FAIL",
    [MONITOR] = "MONITOR",
    [NOTE] = "NOTE",
    [RENAME] = "RENAME",
    [RESUME] = "RESUME",
    [SETNAME] = "SETNAME",
    [WARN] = "WARN",
    [WEBIRC] = "WEBIRC"
#endif
};

#ifdef UIRC_IRCV3
struct tagmapping {
	const char* const name;
	IRC_Tag* assg;
};
#endif
signed int Ircmd_stoi(char* str)
{
	if (str == NULL)
		return ERR_UIRC_NULL_ARGS;
	for (unsigned short i = UIRC_FCMD; i <= UIRC_LCMD; i++) {
		if (uirc_ircmd[i] != NULL && strcmp(uirc_ircmd[i], str) == 0)
			return i;
	}
	return ERR_UIRC_UNKNOWN_TOKEN;
}
signed int Tok_mesg(char* str, IRC_Message* out)
{
	if (str == NULL || out == NULL)
		return ERR_UIRC_NULL_ARGS;
	int ret;
	char *progr = str, *command;
#ifdef UIRC_IRCV3
	if (*progr == '@') {
		char* tags;
		if ((tags = strtok_r(progr, " ", &progr)) != NULL) {
			if ((ret = Tok_tags(tags, &out->tags)) < 0)
				return ret;
		} else
			return ERR_UIRC_INVALID_FORMAT;
	}
#endif
	if (*progr == ':') {
		char* prefix;
		if ((prefix = strtok_r(progr, " ", &progr)) != NULL) {
			if ((ret = Tok_user(prefix, &out->name, false)) < 0)
				return ret;
		} else
			return ERR_UIRC_INVALID_FORMAT;
	}

	if ((command = strtok_r(NULL, " ", &progr)) != NULL) {
		if (!(out->cmd = (isalpha(*command)) ? Ircmd_stoi(command) : atoi(command)))
			return ERR_UIRC_UNKNOWN_TOKEN;
	} else {
		return ERR_UIRC_INVALID_FORMAT;
	}

	int i;
	for (i = 0; *progr != ':' && i < 14 && *progr; i++) {
		if ((out->args[i] = strtok_r(NULL, " ", &progr)) == NULL)
			return ERR_UIRC_INVALID_FORMAT;
	}
	out->args[i] = NULL;
	if (*progr)
		out->trailing = (*progr == ':') ? progr + 1 : progr;
	return 1;
}
signed int Assm_mesg(char* buf, IRC_Message* in)
{
	if (buf == NULL || in == NULL)
		return ERR_UIRC_BUFFER_ERR;
	char* pos = buf;
	int cnt, ret;

#ifdef UIRC_IRCV3
	if ((ret = Assm_tags(pos, &in->tags)) < 0)
		return ret;
	else
		pos += ret;
#endif
	if (in->name.nick != NULL || in->name.host != NULL) {
		*(pos++) = ':';
		if ((ret = Assm_user(pos, &in->name, false)) <= 0)
			return ret;
		else
			pos += ret;
		*(pos++) = ' ';
	}
	if ((uirc_ircmd[in->cmd] != NULL) && ((cnt = sprintf(pos, "%s", uirc_ircmd[in->cmd])) > 0))
		pos += cnt;
	else
		return ERR_UIRC_GENERIC;
	for (unsigned int i = 0; i < 14 && in->args[i] != NULL; i++) {
		if ((cnt = sprintf(pos, " %s", in->args[i])) > 0)
			pos += cnt;
		else
			return ERR_UIRC_BUFFER_ERR;
	}
	if (in->trailing != NULL) {
		if ((cnt = sprintf(pos, " :%s", in->trailing)) > 0)
			pos += cnt;
		else
			return ERR_UIRC_GENERIC;
	}
	if ((cnt = sprintf(pos, "\r\n")) == 2)
		pos += cnt;
	else
		return ERR_UIRC_BUFFER_ERR;
	return pos - buf;
}
signed int Val_mesg(IRC_Message* mesg)
{
	if (mesg == NULL)
		return ERR_UIRC_NULL_ARGS;
	for (unsigned int i = 0; i < 14 && mesg->args[i] != NULL; i++) {
		if (Val_type_nocrlf(mesg->args[i]) != 1)
			return ERR_UIRC_VAL_FAILED;
		if (Val_type_nospcl(mesg->args[i]) != 1)
			return ERR_UIRC_VAL_FAILED;
	}
	if (mesg->trailing != NULL) {
		if (Val_type_nocrlf(mesg->trailing) != 1)
			return ERR_UIRC_VAL_FAILED;
	}
	return 1;
}
signed int Val_type_nocrlf(char* str)
{
	if (str == NULL)
		return ERR_UIRC_NULL_ARGS;
	for (; *str; str++) {
		if (*str == '\r' || *str == '\n')
			return 0;
	}
	return 1;
}
signed int Val_type_nospcl(char* str)
{
	if (str == NULL)
		return ERR_UIRC_NULL_ARGS;
	for (; *str; str++) {
		if (*str == ' ' || *str == ':')
			return 0;
	}
	return 1;
}
signed int Val_type_noblcm(char* str)
{
	if (str == NULL)
		return ERR_UIRC_NULL_ARGS;
	for (; *str; str++) {
		if (*str == '\a' || *str == ',')
			return 0;
	}
	return 1;
}
signed int Val_channame(char* chan)
{
	if (chan == NULL)
		return ERR_UIRC_NULL_ARGS;
	if (*chan != '#' || *chan != '+' || *chan != '!' || *chan != '&')
		return 0;
	char* clps = ++chan;
	if ((clps = strchr(chan, ':')) != NULL) {
		*clps = '\0';
		if (Val_type_nospcl(chan) != 1 || Val_type_nocrlf(chan) != 1 || Val_type_noblcm(chan) != 1) {
			*clps = ':';
			return 0;
		}
		*clps = ':';
		chan = ++clps;
	}
	if (Val_type_nospcl(chan) != 1 || Val_type_nocrlf(chan) != 1 || Val_type_noblcm(chan) != 1)
		return 0;
	return 1;
}
#ifdef UIRC_IRCV3
signed int Assm_tags(char* buf, IRC_Tags* in)
{
	if (buf == NULL || in == NULL)
		return ERR_UIRC_NULL_ARGS;
	char* pos = buf;
	int cnt;
	struct tagmapping tagmps[] = {
	    {.name = "time", .assg = &in->time},
	    {.name = "account", .assg = &in->account},
	    {.name = "batch", .assg = &in->batch},
	    {.name = "label", .assg = &in->label},
	    {.name = "msgid", .assg = &in->msgid},
	    {.name = "multiline-concat", .assg = &in->multiline_concat},
	    {.name = "typing", .assg = &in->typing},
	    {.name = "react", .assg = &in->react},
	    {.name = "reply", .assg = &in->reply}};
	for (unsigned int i = 0; i < sizeof(tagmps) / sizeof(struct tagmapping); i++) {
		if ((*tagmps[i].assg).value != NULL) {
			if (pos == buf) {
				if (sprintf(pos++, "@") != 1)
					return ERR_UIRC_BUFFER_ERR;
			} else {
				if (sprintf(pos++, ";") != 1)
					return ERR_UIRC_BUFFER_ERR;
			}
			if ((*tagmps[i].assg).clientbound) {
				if (sprintf(pos++, "+") != 1)
					return ERR_UIRC_BUFFER_ERR;
			}
			cnt = (*(*tagmps[i].assg).value) ? sprintf(pos, "%s=%s", tagmps[i].name, (*tagmps[i].assg).value) : sprintf(pos, "%s", tagmps[i].name);
			if (cnt > 0)
				pos += cnt;
			else
				return ERR_UIRC_BUFFER_ERR;
		}
	}
	return pos - buf;
}
signed int Tok_tags(char* str, IRC_Tags* out)
{
	if (str == NULL || out == NULL)
		return ERR_UIRC_NULL_ARGS;
	char *cval, *cpos = str, *ctag = NULL;
	bool clientbound;
	const struct tagmapping tagmps[] = {
	    {.name = "time", .assg = &out->time},
	    {.name = "account", .assg = &out->account},
	    {.name = "batch", .assg = &out->batch},
	    {.name = "label", .assg = &out->label},
	    {.name = "msgid", .assg = &out->msgid},
	    {.name = "multiline-concat", .assg = &out->multiline_concat},
	    {.name = "typing", .assg = &out->typing},
	    {.name = "react", .assg = &out->react},
	    {.name = "reply", .assg = &out->reply}};
	if (*cpos == '@')
		cpos++;
	while ((ctag = strtok_r(NULL, "; ", &cpos)) != NULL) {
		clientbound = false;
		if (*ctag == '+') {
			ctag++;
			clientbound = true;
		}
		if ((cval = strchr(ctag, '=')) != NULL)
			*(cval++) = '\0';
		for (unsigned int i = 0; i < sizeof(tagmps) / sizeof(struct tagmapping); i++) {
			if (!strcmp(ctag, tagmps[i].name)) {
				/* If the tag is present we point it to the value if given, or to the delimiter ('\0')
				 * This is done for a few reasons. First, we have a non-null address so we show that
				 * the tag is present and second, we have no value that way
				 */
				(*tagmps[i].assg).value = (cval != NULL) ? cval : ctag + strlen(ctag);
				(*tagmps[i].assg).clientbound = clientbound;
			}
		}
	}
	return 1;
}
#endif
signed int Assm_user(char* buf, IRC_User* in, bool useorig)
{
	if (buf == NULL || in == NULL)
		return ERR_UIRC_NULL_ARGS;
	int cnt;
	char* pos = buf;
	if (in->nick == NULL && in->host != NULL) {
		if ((cnt = sprintf(pos, "%s", in->host)) > 0)
			pos += cnt;
		else
			return ERR_UIRC_BUFFER_ERR;
	} else if (in->nick != NULL) {
		if ((cnt = sprintf(pos, "%s", in->nick)) > 0)
			pos += cnt;
		else
			return ERR_UIRC_BUFFER_ERR;
		if (in->user != NULL) {
			if ((cnt = sprintf(pos, "!%s", in->user)) > 0)
				pos += cnt;
			else
				return ERR_UIRC_BUFFER_ERR;
		}
		if (useorig && in->orig != NULL) {
			if ((cnt = sprintf(pos, "%%%s", in->orig)) > 0)
				pos += cnt;
			else
				return ERR_UIRC_BUFFER_ERR;
		}
		if (in->host != NULL) {
			if ((cnt = sprintf(pos, "@%s", in->host)) > 0)
				pos += cnt;
			else
				return ERR_UIRC_BUFFER_ERR;
		}
	} else
		return ERR_UIRC_NULL_ARGS;
	return pos - buf;
}
signed int Tok_user(char* str, IRC_User* out, bool useorig)
{
	char* pos = (*str == ':') ? str + 1 : str;
	if ((out->host = strchr(pos, '@')) != NULL)
		*(out->host++) = '\0';
	if (useorig && (out->orig = strchr(pos, '%')) != NULL)
		*(out->orig++) = '\0';
	if ((out->user = strchr(pos, '!')) != NULL) /* RFC2812 says this cannot be here without the host but RFC1459 says it can, we accept both options */
		*((char*)out->user++) = '\0';
	if (!*(out->nick = pos)) /* NOTE: This may be the server instead of a nick according to RFC2812, it is left to the library out to decide how to interpret this based on the context. */
		return ERR_UIRC_INVALID_FORMAT;
	return 1;
}