/*****************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * $Id: hiperfifo.c,v 1.7 2008/05/22 21:20:09 danf Exp $
 *
 * Example application source code using the multi socket interface to
 * download many files at once.
 *
 * Written by Jeff Pohlmeyer

Requires libevent and a (POSIX?) system that has mkfifo().

This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
sample programs.

When running, the program creates the named pipe "hiper.fifo"

Whenever there is input into the fifo, the program reads the input as a list
of URL's and creates some new easy handles to fetch each URL via the
curl_multi "hiper" API.


Thus, you can try a single URL:
  % echo http://www.yahoo.com > hiper.fifo

Or a whole bunch of them:
  % cat my-url-list > hiper.fifo

The fifo buffer is handled almost instantly, so you can even add more URL's
while the previous requests are still being downloaded.

Note:
  For the sake of simplicity, URL length is limited to 1023 char's !

This is purely a demo app, all retrieved data is simply discarded by the write
callback.

*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include <sys/poll.h>
#include <curl/curl.h>
//#include <event.h>
#include <ev.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <errno.h>

#define DPRINT(x...) printf(x)

#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */


/* Global information, common to all connections */
typedef struct _GlobalInfo
{
	struct ev_loop *loop;
//  struct event fifo_event;
	struct ev_io fifo_event;

//	struct event timer_event;
	struct ev_timer timer_event;
	CURLM *multi;
	int prev_running;
	int still_running;
	FILE* input;
} GlobalInfo;


/* Information associated with a specific easy handle */
typedef struct _ConnInfo
{
	CURL *easy;
	char *url;
	GlobalInfo *global;
	char error[CURL_ERROR_SIZE];
} ConnInfo;


/* Information associated with a specific socket */
typedef struct _SockInfo
{
	curl_socket_t sockfd;
	CURL *easy;
	int action;
	long timeout;
//	struct event ev;
	struct ev_io ev;
	int evset;
	GlobalInfo *global;
} SockInfo;

static void timer_cb(EV_P_ struct ev_timer *w, int revents);

/* Update the event timer after curl_multi library calls */
static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
{
	DPRINT("%s %li\n", __PRETTY_FUNCTION__,  timeout_ms);
//	struct timeval timeout;
//	(void)multi; /* unused */

//	timeout.tv_sec = timeout_ms/1000;
//	timeout.tv_usec = (timeout_ms%1000)*1000;
//	fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms);
//	evtimer_add(&g->timer_event, &timeout);
	ev_timer_stop(g->loop, &g->timer_event);
	if (timeout_ms > 0)
	{
		double  t = timeout_ms / 1000;
    	ev_timer_init(&g->timer_event, timer_cb, t, 0.);
		ev_timer_start(g->loop, &g->timer_event);
	}else
		timer_cb(g->loop, &g->timer_event, 0);
	return 0;
}

/* Die if we get a bad CURLMcode somewhere */
static void mcode_or_die(const char *where, CURLMcode code)
{
	if ( CURLM_OK != code )
	{
		const char *s;
		switch ( code )
		{
		case     CURLM_CALL_MULTI_PERFORM: s="CURLM_CALL_MULTI_PERFORM"; break;
		case     CURLM_OK:                 s="CURLM_OK";                 break;
		case     CURLM_BAD_HANDLE:         s="CURLM_BAD_HANDLE";         break;
		case     CURLM_BAD_EASY_HANDLE:    s="CURLM_BAD_EASY_HANDLE";    break;
		case     CURLM_OUT_OF_MEMORY:      s="CURLM_OUT_OF_MEMORY";      break;
		case     CURLM_INTERNAL_ERROR:     s="CURLM_INTERNAL_ERROR";     break;
		case     CURLM_UNKNOWN_OPTION:     s="CURLM_UNKNOWN_OPTION";     break;
		case     CURLM_LAST:               s="CURLM_LAST";               break;
		default: s="CURLM_unknown";
			break;
		case     CURLM_BAD_SOCKET:         s="CURLM_BAD_SOCKET";
			fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
			/* ignore this error */
			return;
		}
		fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
		exit(code);
	}
}



/* Check for completed transfers, and remove their easy handles */
static void check_run_count(GlobalInfo *g)
{
	DPRINT("%s prev %i still %i\n", __PRETTY_FUNCTION__, g->prev_running, g->still_running);
	if ( g->prev_running > g->still_running )
	{
		char *eff_url=NULL;
		CURLMsg *msg;
		int msgs_left;
		ConnInfo *conn=NULL;
		CURL*easy;
		CURLcode res;

		fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
		/*
		  I am still uncertain whether it is safe to remove an easy handle
		  from inside the curl_multi_info_read loop, so here I will search
		  for completed transfers in the inner "while" loop, and then remove
		  them in the outer "do-while" loop...
	   */
		do
		{
			easy=NULL;
			while ( (msg = curl_multi_info_read(g->multi, &msgs_left)) )
			{
				if ( msg->msg == CURLMSG_DONE )
				{
					easy=msg->easy_handle;
					res=msg->data.result;
//					break;
				}

				if ( easy )
				{
					curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
					curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
					fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
					curl_multi_remove_handle(g->multi, easy);
					free(conn->url);
					curl_easy_cleanup(easy);
					free(conn);
				}
			}
		} while ( easy );
	}
	g->prev_running = g->still_running;
}



/* Called by libevent when we get action on a multi socket */
//static void event_cb(int fd, short kind, void *userp)
static void event_cb(EV_P_ struct ev_io *w, int revents)
{
	DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
//	GlobalInfo *g = (GlobalInfo*) userp;
	GlobalInfo *g = (GlobalInfo*) w->data;
	CURLMcode rc;
//	(void)kind;	/* unused */

	int action = (revents&EV_READ?CURL_POLL_IN:0)|(revents&EV_WRITE?CURL_POLL_OUT:0);
	do
	{
//		rc = curl_multi_socket(g->multi, fd, &g->still_running);
		rc = curl_multi_socket_action(g->multi, w->fd, action, &g->still_running);
	} while ( rc == CURLM_CALL_MULTI_PERFORM );
	mcode_or_die("event_cb: curl_multi_socket", rc);
	check_run_count(g);
	if ( g->still_running <= 0 )
	{
		fprintf(MSG_OUT, "last transfer done, kill timeout\n");
//		if ( evtimer_pending(&g->timer_event, NULL) )
//		{
//			evtimer_del(&g->timer_event);
//		}
		ev_timer_stop(g->loop, &g->timer_event);
	}
}



/* Called by libevent when our timeout expires */
//static void timer_cb(int fd, short kind, void *userp)
static void timer_cb(EV_P_ struct ev_timer *w, int revents)
{
	DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);

	GlobalInfo *g = (GlobalInfo *)w->data;
	CURLMcode rc;
//	(void)fd;
//	(void)kind;

	do
	{
//		rc = curl_multi_socket(g->multi, CURL_SOCKET_TIMEOUT, &g->still_running);
		rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0, &g->still_running);
//		rc = curl_multi_socket_all(g->multi, &g->still_running);
	} while ( rc == CURLM_CALL_MULTI_PERFORM );
	mcode_or_die("timer_cb: curl_multi_socket", rc);
	check_run_count(g);
}



/* Clean up the SockInfo structure */
//static void remsock(SockInfo *f)
static void remsock(SockInfo *f, GlobalInfo *g)
{
	printf("%s  \n", __PRETTY_FUNCTION__);
	if ( f )
	{
		if ( f->evset )
//			event_del(&f->ev);
			ev_io_stop(g->loop, &f->ev);
		free(f);
	}
}



/* Assign information to a SockInfo structure */
static void setsock(SockInfo*f, curl_socket_t s, CURL*e, int act, GlobalInfo*g)
{
	printf("%s  \n", __PRETTY_FUNCTION__);

//	int kind = (act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0)|EV_PERSIST;
	int kind = (act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0);

	f->sockfd = s;
	f->action = act;
	f->easy = e;
	if ( f->evset )
//		event_del(&f->ev);
		ev_io_stop(g->loop, &f->ev);
//	event_set(&f->ev, f->sockfd, kind, event_cb, g);
	ev_io_init(&f->ev, event_cb, f->sockfd, kind);
	f->ev.data = g;
	f->evset=1;
//	event_add(&f->ev, NULL);
	ev_io_start(g->loop, &f->ev);
}



/* Initialize a new SockInfo structure */
static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
{
	SockInfo *fdp = calloc(sizeof(SockInfo), 1);

	fdp->global = g;
	setsock(fdp, s, easy, action, g);
	curl_multi_assign(g->multi, s, fdp);
}

/* CURLMOPT_SOCKETFUNCTION */
static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
{
	DPRINT("%s e %p s %i what %i cbp %p sockp %p\n", __PRETTY_FUNCTION__, e, s, what, cbp, sockp);

	GlobalInfo *g = (GlobalInfo*) cbp;
	SockInfo *fdp = (SockInfo*) sockp;
	const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};

	fprintf(MSG_OUT,
			"socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
	if ( what == CURL_POLL_REMOVE )
	{
		fprintf(MSG_OUT, "\n");
		remsock(fdp, g);
	} else
	{
		if ( !fdp )
		{
			fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
			addsock(s, e, what, g);
		} else
		{
			fprintf(MSG_OUT,
					"Changing action from %s to %s\n",
					whatstr[fdp->action], whatstr[what]);
			setsock(fdp, s, e, what, g);
		}
	}
	return 0;
}



/* CURLOPT_WRITEFUNCTION */
static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
{
	size_t realsize = size * nmemb;
	ConnInfo *conn = (ConnInfo*) data;
	(void)ptr;
	(void)conn;
	return realsize;
}


/* CURLOPT_PROGRESSFUNCTION */
static int prog_cb (void *p, double dltotal, double dlnow, double ult,
					double uln)
{
	ConnInfo *conn = (ConnInfo *)p;
	(void)ult;
	(void)uln;

	fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
	return 0;
}


/* Create a new easy handle, and add it to the global curl_multi */
static void new_conn(char *url, GlobalInfo *g )
{
	ConnInfo *conn;
	CURLMcode rc;

	conn = calloc(1, sizeof(ConnInfo));
	memset(conn, 0, sizeof(ConnInfo));
	conn->error[0]='\0';

	conn->easy = curl_easy_init();
	if ( !conn->easy )
	{
		fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
		exit(2);
	}
	conn->global = g;
	conn->url = strdup(url);
	curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
	curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
	curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, &conn);
	curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
	curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
	curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
	curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
	curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
	curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
	curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
	curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);

	fprintf(MSG_OUT,
			"Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
	rc =curl_multi_add_handle(g->multi, conn->easy);
//	g->prev_running++;
	mcode_or_die("new_conn: curl_multi_add_handle", rc);
/*	do
	{
		rc = curl_multi_socket_all(g->multi, &g->still_running);
	} while ( CURLM_CALL_MULTI_PERFORM == rc );
*/
	mcode_or_die("new_conn: curl_multi_socket_all", rc);
	check_run_count(g);
}

/* This gets called whenever data is received from the fifo */
//static void fifo_cb(int fd, short event, void *arg)
static void fifo_cb(EV_P_ struct ev_io *w, int revents)
{
	char s[1024];
	long int rv=0;
	int n=0;
//	GlobalInfo *g = (GlobalInfo *)arg;
	GlobalInfo *g = (GlobalInfo *)w->data;
//	(void)fd; /* unused */
//	(void)event; /* unused */

	do
	{
		s[0]='\0';
		rv=fscanf(g->input, "%1023s%n", s, &n);
		s[n]='\0';
		if ( n && s[0] )
		{
//			new_conn(s,arg);  /* if we read a URL, go get it! */
			new_conn(s,g);  /* if we read a URL, go get it! */
		} else break;
	} while ( rv != EOF );
}

/* Create a named pipe and tell libevent to monitor it */
static int init_fifo (GlobalInfo *g)
{
	struct stat st;
	static const char *fifo = "hiper.fifo";
	int sockfd;

	fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
	if ( lstat (fifo, &st) == 0 )
	{
		if ( (st.st_mode & S_IFMT) == S_IFREG )
		{
			errno = EEXIST;
			perror("lstat");
			exit (1);
		}
	}
	unlink(fifo);
	if ( mkfifo (fifo, 0600) == -1 )
	{
		perror("mkfifo");
		exit (1);
	}
	sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
	if ( sockfd == -1 )
	{
		perror("open");
		exit (1);
	}
	g->input = fdopen(sockfd, "r");

	fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
//	event_set(&g->fifo_event, sockfd, EV_READ | EV_PERSIST, fifo_cb, g);
	ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
//	event_add(&g->fifo_event, NULL);
	ev_io_start(g->loop, &g->fifo_event);
	return(0);
}

int main(int argc, char **argv)
{
	GlobalInfo g;
	CURLMcode rc;
	(void)argc;
	(void)argv;

	memset(&g, 0, sizeof(GlobalInfo));
	g.loop = ev_default_loop(0);

//	event_init();
	init_fifo(&g);
	g.multi = curl_multi_init();
//	evtimer_set(&g.timer_event, timer_cb, &g);
	ev_timer_init(&g.timer_event, timer_cb, 0., 0.);
	g.timer_event.data = &g;
	g.fifo_event.data = &g;
	curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
	curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
	curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
	curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
	do
	{
		rc = curl_multi_socket_all(g.multi, &g.still_running);
	} while ( CURLM_CALL_MULTI_PERFORM == rc );
//	event_dispatch();
	ev_loop(g.loop, 0);
	curl_multi_cleanup(g.multi);
	return 0;
}