/*
 * Copyright (c) 2000-2004 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef _EVENT_H_
#define _EVENT_H_

#ifdef __cplusplus
extern "C" {
#endif

#include <stdarg.h>

#ifdef WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
typedef unsigned char u_char;
typedef unsigned short u_short;
#endif

#define EVLIST_TIMEOUT	0x01
#define EVLIST_INSERTED	0x02
#define EVLIST_SIGNAL	0x04
#define EVLIST_ACTIVE	0x08
#define EVLIST_INTERNAL	0x10
#define EVLIST_INIT	0x80

/* EVLIST_X_ Private space: 0x1000-0xf000 */
#define EVLIST_ALL	(0xf000 | 0x9f)

#define EV_TIMEOUT	0x01
#define EV_READ		0x02
#define EV_WRITE	0x04
#define EV_SIGNAL	0x08
#define EV_PERSIST	0x10	/* Persistant event */

/* Fix so that ppl dont have to run with <sys/queue.h> */
#ifndef TAILQ_ENTRY
#define _EVENT_DEFINED_TQENTRY
#define TAILQ_ENTRY(type)						\
struct {								\
	struct type *tqe_next;	/* next element */			\
	struct type **tqe_prev;	/* address of previous next element */	\
}
#endif /* !TAILQ_ENTRY */
#ifndef RB_ENTRY
#define _EVENT_DEFINED_RBENTRY
#define RB_ENTRY(type)							\
struct {								\
	struct type *rbe_left;		/* left element */		\
	struct type *rbe_right;		/* right element */		\
	struct type *rbe_parent;	/* parent element */		\
	int rbe_color;			/* node color */		\
}
#endif /* !RB_ENTRY */

struct event_base;
struct event {
	TAILQ_ENTRY (event) ev_next;
	TAILQ_ENTRY (event) ev_active_next;
	TAILQ_ENTRY (event) ev_signal_next;
	RB_ENTRY (event) ev_timeout_node;

	struct event_base *ev_base;
	int ev_fd;
	short ev_events;
	short ev_ncalls;
	short *ev_pncalls;	/* Allows deletes in callback */

	struct timeval ev_timeout;

	int ev_pri;		/* smaller numbers are higher priority */

	void (*ev_callback)(int, short, void *arg);
	void *ev_arg;

	int ev_res;		/* result passed to event callback */
	int ev_flags;
};

#define EVENT_SIGNAL(ev)	(int)(ev)->ev_fd
#define EVENT_FD(ev)		(int)(ev)->ev_fd

/*
 * Key-Value pairs.  Can be used for HTTP headers but also for
 * query argument parsing.
 */
struct evkeyval {
	TAILQ_ENTRY(evkeyval) next;

	char *key;
	char *value;
};

#ifdef _EVENT_DEFINED_TQENTRY
#undef TAILQ_ENTRY
struct event_list;
struct evkeyvalq;
#undef _EVENT_DEFINED_TQENTRY
#else
TAILQ_HEAD (event_list, event);
TAILQ_HEAD (evkeyvalq, evkeyval);
#endif /* _EVENT_DEFINED_TQENTRY */
#ifdef _EVENT_DEFINED_RBENTRY
#undef RB_ENTRY
#undef _EVENT_DEFINED_RBENTRY
#endif /* _EVENT_DEFINED_RBENTRY */

struct eventop {
	char *name;
	void *(*init)(void);
	int (*add)(void *, struct event *);
	int (*del)(void *, struct event *);
	int (*recalc)(struct event_base *, void *, int);
	int (*dispatch)(struct event_base *, void *, struct timeval *);
	void (*dealloc)(void *);
};

#define TIMEOUT_DEFAULT	{5, 0}

void *event_init(void);
int event_dispatch(void);
int event_base_dispatch(struct event_base *);
void event_base_free(struct event_base *);

#define _EVENT_LOG_DEBUG 0
#define _EVENT_LOG_MSG   1
#define _EVENT_LOG_WARN  2
#define _EVENT_LOG_ERR   3
typedef void (*event_log_cb)(int severity, const char *msg);
void event_set_log_callback(event_log_cb cb);

/* Associate a different event base with an event */
int event_base_set(struct event_base *, struct event *);

#define EVLOOP_ONCE	0x01
#define EVLOOP_NONBLOCK	0x02
int event_loop(int);
int event_base_loop(struct event_base *, int);
int event_loopexit(struct timeval *);	/* Causes the loop to exit */
int event_base_loopexit(struct event_base *, struct timeval *);

#define evtimer_add(ev, tv)		event_add(ev, tv)
#define evtimer_set(ev, cb, arg)	event_set(ev, -1, 0, cb, arg)
#define evtimer_del(ev)			event_del(ev)
#define evtimer_pending(ev, tv)		event_pending(ev, EV_TIMEOUT, tv)
#define evtimer_initialized(ev)		((ev)->ev_flags & EVLIST_INIT)

#define timeout_add(ev, tv)		event_add(ev, tv)
#define timeout_set(ev, cb, arg)	event_set(ev, -1, 0, cb, arg)
#define timeout_del(ev)			event_del(ev)
#define timeout_pending(ev, tv)		event_pending(ev, EV_TIMEOUT, tv)
#define timeout_initialized(ev)		((ev)->ev_flags & EVLIST_INIT)

#define signal_add(ev, tv)		event_add(ev, tv)
#define signal_set(ev, x, cb, arg)	\
	event_set(ev, x, EV_SIGNAL|EV_PERSIST, cb, arg)
#define signal_del(ev)			event_del(ev)
#define signal_pending(ev, tv)		event_pending(ev, EV_SIGNAL, tv)
#define signal_initialized(ev)		((ev)->ev_flags & EVLIST_INIT)

void event_set(struct event *, int, short, void (*)(int, short, void *), void *);
int event_once(int, short, void (*)(int, short, void *), void *, struct timeval *);

int event_add(struct event *, struct timeval *);
int event_del(struct event *);
void event_active(struct event *, int, short);

int event_pending(struct event *, short, struct timeval *);

#ifdef WIN32
#define event_initialized(ev)		((ev)->ev_flags & EVLIST_INIT && (ev)->ev_fd != (int)INVALID_HANDLE_VALUE)
#else
#define event_initialized(ev)		((ev)->ev_flags & EVLIST_INIT)
#endif

/* Some simple debugging functions */
const char *event_get_version(void);
const char *event_get_method(void);

/* These functions deal with event priorities */

int	event_priority_init(int);
int	event_base_priority_init(struct event_base *, int);
int	event_priority_set(struct event *, int);

/* These functions deal with buffering input and output */

struct evbuffer {
	u_char *buffer;
	u_char *orig_buffer;

	size_t misalign;
	size_t totallen;
	size_t off;

	void (*cb)(struct evbuffer *, size_t, size_t, void *);
	void *cbarg;
};

/* Just for error reporting - use other constants otherwise */
#define EVBUFFER_READ		0x01
#define EVBUFFER_WRITE		0x02
#define EVBUFFER_EOF		0x10
#define EVBUFFER_ERROR		0x20
#define EVBUFFER_TIMEOUT	0x40

struct bufferevent;
typedef void (*evbuffercb)(struct bufferevent *, void *);
typedef void (*everrorcb)(struct bufferevent *, short what, void *);

struct event_watermark {
	size_t low;
	size_t high;
};

struct bufferevent {
	struct event ev_read;
	struct event ev_write;

	struct evbuffer *input;
	struct evbuffer *output;

	struct event_watermark wm_read;
	struct event_watermark wm_write;

	evbuffercb readcb;
	evbuffercb writecb;
	everrorcb errorcb;
	void *cbarg;

	int timeout_read;	/* in seconds */
	int timeout_write;	/* in seconds */

	short enabled;	/* events that are currently enabled */
};

struct bufferevent *bufferevent_new(int fd,
    evbuffercb readcb, evbuffercb writecb, everrorcb errorcb, void *cbarg);
int bufferevent_base_set(struct event_base *base, struct bufferevent *bufev);
int bufferevent_priority_set(struct bufferevent *bufev, int pri);
void bufferevent_free(struct bufferevent *bufev);
int bufferevent_write(struct bufferevent *bufev, void *data, size_t size);
int bufferevent_write_buffer(struct bufferevent *bufev, struct evbuffer *buf);
size_t bufferevent_read(struct bufferevent *bufev, void *data, size_t size);
int bufferevent_enable(struct bufferevent *bufev, short event);
int bufferevent_disable(struct bufferevent *bufev, short event);
void bufferevent_settimeout(struct bufferevent *bufev,
    int timeout_read, int timeout_write);

#define EVBUFFER_LENGTH(x)	(x)->off
#define EVBUFFER_DATA(x)	(x)->buffer
#define EVBUFFER_INPUT(x)	(x)->input
#define EVBUFFER_OUTPUT(x)	(x)->output

struct evbuffer *evbuffer_new(void);
void evbuffer_free(struct evbuffer *);
int evbuffer_expand(struct evbuffer *, size_t);
int evbuffer_add(struct evbuffer *, const void *, size_t);
int evbuffer_remove(struct evbuffer *, void *, size_t);
char *evbuffer_readline(struct evbuffer *);
int evbuffer_add_buffer(struct evbuffer *, struct evbuffer *);
int evbuffer_add_printf(struct evbuffer *, const char *fmt, ...);
int evbuffer_add_vprintf(struct evbuffer *, const char *fmt, va_list ap);
void evbuffer_drain(struct evbuffer *, size_t);
int evbuffer_write(struct evbuffer *, int);
int evbuffer_read(struct evbuffer *, int, int);
u_char *evbuffer_find(struct evbuffer *, const u_char *, size_t);
void evbuffer_setcb(struct evbuffer *, void (*)(struct evbuffer *, size_t, size_t, void *), void *);

/* 
 * Marshaling tagged data - We assume that all tags are inserted in their
 * numeric order - so that unknown tags will always be higher than the
 * known ones - and we can just ignore the end of an event buffer.
 */

void evtag_init(void);

void evtag_marshal(struct evbuffer *evbuf, u_int8_t tag, const void *data,
    u_int32_t len);

void encode_int(struct evbuffer *evbuf, u_int32_t number);

void evtag_marshal_int(struct evbuffer *evbuf, u_int8_t tag,
    u_int32_t integer);

void evtag_marshal_string(struct evbuffer *buf, u_int8_t tag,
    const char *string);

void evtag_marshal_timeval(struct evbuffer *evbuf, u_int8_t tag,
    struct timeval *tv);

void evtag_test(void);

int evtag_unmarshal(struct evbuffer *src, u_int8_t *ptag,
    struct evbuffer *dst);
int evtag_peek(struct evbuffer *evbuf, u_int8_t *ptag);
int evtag_peek_length(struct evbuffer *evbuf, u_int32_t *plength);
int evtag_payload_length(struct evbuffer *evbuf, u_int32_t *plength);
int evtag_consume(struct evbuffer *evbuf);

int evtag_unmarshal_int(struct evbuffer *evbuf, u_int8_t need_tag,
    u_int32_t *pinteger);

int evtag_unmarshal_fixed(struct evbuffer *src, u_int8_t need_tag, void *data,
    size_t len);

int evtag_unmarshal_string(struct evbuffer *evbuf, u_int8_t need_tag,
    char **pstring);

int evtag_unmarshal_timeval(struct evbuffer *evbuf, u_int8_t need_tag,
    struct timeval *ptv);

#ifdef __cplusplus
}
#endif

#endif /* _EVENT_H_ */