/*
 *  ircd-ratbox: A slightly useful ircd.
 *  channel.h: The ircd channel header.
 *
 *  Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center
 *  Copyright (C) 1996-2002 Hybrid Development Team
 *  Copyright (C) 2002-2004 ircd-ratbox development team
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 */

#ifndef INCLUDED_channel_h
#define INCLUDED_channel_h

#define MODEBUFLEN      200

/* Maximum mode changes allowed per client, per server is different */
#define MAXMODEPARAMS   4
#define MAXMODEPARAMSSERV 10

#include <setup.h>
#include "hook.h"

struct Client;

/* mode structure for channels */
struct Mode
{
	unsigned int mode;
	int limit;
	char key[KEYLEN];
	unsigned int join_num;
	unsigned int join_time;
	char forward[LOC_CHANNELLEN + 1];
};

/* channel structure */
struct Channel
{
	rb_dlink_node node;
	struct Mode mode;
	char *mode_lock;
	char *topic;
	char *topic_info;
	time_t topic_time;
	time_t last_knock;	/* don't allow knock to flood */

	rb_dlink_list members;	/* channel members */
	rb_dlink_list locmembers;	/* local channel members */

	rb_dlink_list invites;
	rb_dlink_list banlist;
	rb_dlink_list exceptlist;
	rb_dlink_list invexlist;
	rb_dlink_list quietlist;

	time_t first_received_message_time;	/* channel flood control */
	int received_number_of_privmsgs;
	int flood_noticed;

	unsigned int join_count;  /* joins within delta */
	unsigned int join_delta;  /* last ts of join */

	time_t bants;
	time_t channelts;
	char *chname;

	struct Client *last_checked_client;
	time_t last_checked_ts;
	unsigned int last_checked_type;
	int last_checked_result;
};

struct membership
{
	rb_dlink_node channode;
	rb_dlink_node locchannode;
	rb_dlink_node usernode;

	struct Channel *chptr;
	struct Client *client_p;
	unsigned int flags;

	time_t bants;
};

#define BANLEN 195
struct Ban
{
	char *banstr;
	char *who;
	time_t when;
	char *forward;
	rb_dlink_node node;
};

struct mode_letter
{
	int mode;
	char letter;
};

struct ChModeChange
{
	char letter;
	const char *arg;
	const char *id;
	int dir;
	int mems;
};

typedef void ChannelModeFunc(struct Client *source_p, struct Channel *chptr,
		int alevel, const char *arg, int *errors, int dir, char c, long mode_type);

enum chm_flags
{
	CHM_CAN_QUERY  = 1 << 0,
	CHM_OPS_QUERY  = 1 << 1,
	CHM_ARG_SET    = 1 << 2,
	CHM_ARG_DEL    = 1 << 3,
	CHM_ARGS       = CHM_ARG_SET | CHM_ARG_DEL,
	CHM_QUERYABLE  = CHM_ARGS | CHM_CAN_QUERY,
};

struct ChannelMode
{
	ChannelModeFunc *set_func;
	long mode_type;
	enum chm_flags flags;
};

typedef int (*ExtbanFunc)(const char *data, struct Client *client_p,
		struct Channel *chptr, long mode_type);

/* can_send results */
#define CAN_SEND_NO	0
#define CAN_SEND_NONOP  1
#define CAN_SEND_OPV	2

/* channel status flags */
#define CHFL_PEON		0x0000	/* normal member of channel */
#define CHFL_VOICE      	0x0001	/* the power to speak */
#define CHFL_HALFOP		0x0002	/* Half operator */
#define CHFL_CHANOP	     	0x0004	/* Channel operator */

#define CHFL_BANNED		0x0008  /* cached as banned */
#define CHFL_QUIETED		0x0010  /* cached as being +q victim */
#define ONLY_SERVERS		0x0020
#define ONLY_OPERS		0x0040
#define ALL_MEMBERS		CHFL_PEON
#define ONLY_CHANOPS		CHFL_CHANOP
#define ONLY_HALFOPS		CHFL_HALFOP
#define ONLY_CHANOPSHALFOPS	(CHFL_CHANOP|CHFL_HALFOP)
#define ONLY_CHANOPSVOICED	(CHFL_CHANOP|CHFL_VOICE)
#define ONLY_CHANOPSHALFOPSVOICED	(CHFL_CHANOP|CHFL_HALFOP|CHFL_VOICE)

#define is_chanop(x)	((x) && (x)->flags & CHFL_CHANOP)
#define is_halfop(x)	((x) && (x)->flags & CHFL_HALFOP)
#define is_voiced(x)	((x) && (x)->flags & CHFL_VOICE)
#define is_chanop_voiced(x) ((x) && (x)->flags & (CHFL_CHANOP|CHFL_VOICE))
#define is_any_op(x)    ((x) && (x)->flags & (CHFL_CHANOP|CHFL_HALFOP))
#define can_send_banned(x) ((x) && (x)->flags & (CHFL_BANNED|CHFL_QUIETED))

/* channel modes ONLY */
#define MODE_PRIVATE    0x0001
#define MODE_SECRET     0x0002
#define MODE_MODERATED  0x0004
#define MODE_TOPICLIMIT 0x0008
#define MODE_INVITEONLY 0x0010
#define MODE_NOPRIVMSGS 0x0020
#define MODE_REGONLY	0x0040
#define MODE_EXLIMIT	0x0100  /* exempt from list limits, +b/+e/+I/+q */
#define MODE_PERMANENT  0x0200  /* permanant channel, +P */
#define MODE_OPMODERATE 0x0400  /* send rejected messages to ops */
#define MODE_FREEINVITE 0x0800  /* allow free use of /invite */
#define MODE_FREETARGET 0x1000  /* can be forwarded to without authorization */
#define MODE_DISFORWARD 0x2000  /* disable channel forwarding */
#define MODE_HIDEBANS	0x1000000 /* disallow non-chanops from seeing ban/quiet lists */

#define CHFL_BAN        0x10000000	/* ban channel flag */
#define CHFL_EXCEPTION  0x20000000	/* exception to ban channel flag */
#define CHFL_INVEX      0x40000000
#define CHFL_QUIET      0x80000000

/* mode flags for direction indication */
#define MODE_QUERY     0
#define MODE_ADD       1
#define MODE_DEL       -1
#define MODE_OP_QUERY  2

#define SecretChannel(x)        ((x) && ((x)->mode.mode & MODE_SECRET))
#define HiddenChannel(x)        ((x) && ((x)->mode.mode & MODE_PRIVATE))
#define PubChannel(x)           ((!x) || ((x)->mode.mode &\
                                 (MODE_PRIVATE | MODE_SECRET)) == 0)

/* channel visible */
#define ShowChannel(v,c)        (PubChannel(c) || IsMember((v),(c)))

#define IsMember(who, chan) ((who && who->user && \
                find_channel_membership(chan, who)) ? 1 : 0)

#define IsChannelName(name) ((name) && (IsChanPrefix(*(name))))

/* extban function results */
#define EXTBAN_INVALID -1  /* invalid mask, false even if negated */
#define EXTBAN_NOMATCH  0  /* valid mask, no match */
#define EXTBAN_MATCH    1  /* matches */

int iter_comm_channels_step(rb_dlink_node *pos1, rb_dlink_node *pos2,
		struct membership **ms1, struct membership **ms2,
		struct Channel **chptr);


/* Iterate two sorted linked lists of channels, with heads headN, in lockstep.
   At each iteration, chptr will be a channel in at least one of the lists,
   and each msN will be non-null iff the channel is in its corresponding list.

   head1 and head2 must be linked list heads.
   pos1, pos2, ms1, ms2 must be names of modifiable variables, and should not
   be modified during iteration. It is safe to break or continue at any point
   without any special cleanup.

   rb_dlink_node_t *pos1, *pos2, *head1, *head2;
   struct membership *ms1, *ms2;
   struct Channel *chptr;
*/
#define ITER_COMM_CHANNELS(pos1, pos2, head1, head2, ms1, ms2, chptr) \
		for ((pos1) = (head1), (pos2) = (head2); \
			iter_comm_channels_step((pos1), (pos2), &(ms1), &(ms2), &(chptr)); \
			(ms1) && ((pos1) = (pos1)->next), (ms2) && ((pos2) = (pos2)->next))


extern rb_dlink_list global_channel_list;
void init_channels(void);

struct Channel *allocate_channel(const char *chname);
void free_channel(struct Channel *chptr);
struct Ban *allocate_ban(const char *, const char *, const char *);
void free_ban(struct Ban *bptr);


extern void destroy_channel(struct Channel *);

extern int can_send(struct Channel *chptr, struct Client *who,
		    struct membership *);
extern bool flood_attack_channel(enum message_type msgtype, struct Client *source_p,
				struct Channel *chptr, char *chname);
struct matchset;
extern int is_banned(struct Channel *chptr, struct Client *who,
                     struct membership *msptr, const struct matchset *ms,
                     const char **);
extern int is_quieted(struct Channel *chptr, struct Client *who,
		     struct membership *msptr, const struct matchset *ms);
extern int can_join(struct Client *source_p, struct Channel *chptr,
		    const char *key, const char **forward);

extern struct membership *find_channel_membership(struct Channel *, struct Client *);
extern const char *find_channel_status(struct membership *msptr, int combine);
extern void add_user_to_channel(struct Channel *, struct Client *, int flags);
extern void remove_user_from_channel(struct membership *);
extern void remove_user_from_channels(struct Client *);
extern void invalidate_bancache_user(struct Client *);

extern void free_channel_list(rb_dlink_list *);

extern bool check_channel_name(const char *name);

extern void channel_member_names(struct Channel *chptr, struct Client *,
				 int show_eon);

extern void del_invite(struct Channel *chptr, struct Client *who);

const char *channel_modes(struct Channel *chptr, struct Client *who);

extern struct Channel *find_bannickchange_channel(struct Client *client_p);

extern void check_spambot_warning(struct Client *source_p, const char *name);

extern void check_splitmode(void *);

void set_channel_topic(struct Channel *chptr, const char *topic,
		       const char *topic_info, time_t topicts);

extern void init_chcap_usage_counts(void);
extern void set_chcap_usage_counts(struct Client *serv_p);
extern void unset_chcap_usage_counts(struct Client *serv_p);
extern void send_cap_mode_changes(struct Client *client_p, struct Client *source_p,
				  struct Channel *chptr, struct ChModeChange foo[], int);

void resv_chan_forcepart(const char *name, const char *reason, int temp_time);

extern void set_channel_mode(struct Client *client_p, struct Client *source_p,
            	struct Channel *chptr, struct membership *msptr, int parc, const char *parv[]);
extern void set_channel_mlock(struct Client *client_p, struct Client *source_p,
            	struct Channel *chptr, const char *newmlock, bool propagate);

extern struct ChannelMode chmode_table[256];

extern struct Ban * add_id(struct Client *source_p, struct Channel *chptr, const char *banid,
	const char *forward, rb_dlink_list * list, long mode_type);

extern struct Ban * del_id(struct Channel *chptr, const char *banid, rb_dlink_list * list,
	long mode_type);

extern ExtbanFunc extban_table[256];

extern int match_extban(const char *banstr, struct Client *client_p, struct Channel *chptr, long mode_type);
extern int valid_extban(const char *banstr, struct Client *client_p, struct Channel *chptr, long mode_type);
const char * get_extban_string(void);

extern int get_channel_access(struct Client *source_p, struct Channel *chptr, struct membership *msptr, int dir, const char *modestr);

extern void send_channel_join(struct Channel *chptr, struct Client *client_p);
extern void send_batched_channel_join(struct Channel *chptr, struct Client *client_p, const char *batch);

#endif /* INCLUDED_channel_h */
