/*
 * app_intercept.c -- A Module To Intercept a Ringing Call
 * 
 * Copyright (c) 2004-2007 Anthony Minessale II <anthmct@yahoo.com>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <stdio.h> 
#include <asterisk/file.h>
#include <asterisk/logger.h>
#include <asterisk/channel.h>
#include <asterisk/pbx.h>
#include <asterisk/utils.h>
#include <asterisk/options.h>
#include <asterisk/musiconhold.h>
#include <asterisk/module.h>
#include <asterisk/features.h>
#include <asterisk/cli.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <pthread.h>

static char *tdesc = "Intercept an unaswered Call.";
static char *app = "Intercept";
static char *synopsis = "Intercept([<Channel Name>|<varmatch>|auto])\n"
"\n"
"Intercept an unanswered channel:\n"
" A) who's name begins with <Channel Name>\n"
"    e.g. Intercept(SIP/1000)\n"
" B) Containing the variable INTERCEPT_TAG matching <varmatch>\n"
"    e.g. Intercept(GROUP1) will match calls that Set(INTERCEPT_TAG=GROUP1)\n"
" C) The first encountered unanswered channel if 'auto' was specified.\n"
"    e.g. Intercept(auto)\n";

STANDARD_LOCAL_USER;
LOCAL_USER_DECL;


static struct ast_channel *ast_find_chan(struct ast_channel *me, char *match) {
	struct ast_channel *chan;
	chan = ast_channel_walk_locked(NULL);
	char *var;
	int state;

	while (chan) {

		if ((var = pbx_builtin_getvar_helper(chan,"INTERCEPT_TAG")) && !strcasecmp(var, match)) {
			return chan;
		} else if ( (chan->_state == AST_STATE_RING && chan != me ) && 
					(!strncasecmp(chan->name, match, strlen(match)) || (!strcasecmp(match, "auto")))) {
			return chan;
		} else if ( (chan->_state == AST_STATE_RINGING && chan != me ) && 
					(!strncasecmp(chan->name, match, strlen(match)) || (!strcasecmp(match, "auto")))) {
			return chan;
		}
		

		ast_mutex_unlock(&chan->lock);
		chan = ast_channel_walk_locked(chan);
	}
	return NULL;
}

static int intercept_exec(struct ast_channel *chan, void *data)
{
	int res=0;
	struct localuser *u;
	struct ast_channel *newchan;
	struct ast_channel *target_chan;
    struct ast_frame *f;
	struct ast_bridge_config config;
	char *chan_match;

	if (!data || ast_strlen_zero((char *) data)) {
        ast_log(LOG_WARNING, "Intercept requires an argument.\n");
        return -1;
    }


	chan_match = ast_strdupa((char *) data);
	if ((target_chan = ast_find_chan(chan, chan_match))) {
		ast_mutex_unlock(&target_chan->lock);

	} else {
		ast_log(LOG_WARNING, "No Channels To intercept.\n");
		return -1;
	}
	
	LOCAL_USER_ADD(u);
	newchan = ast_channel_alloc(0);
	snprintf(newchan->name, sizeof (newchan->name), "Intercept/%s",target_chan->name);
	
	newchan->readformat = target_chan->readformat;
	newchan->writeformat = target_chan->writeformat;
	newchan->_state = AST_STATE_UP;
	ast_clear_flag(newchan, AST_FLAGS_ALL);
	newchan->_softhangup = 0;
	ast_channel_masquerade(newchan, target_chan);

	if ((f = ast_read(newchan))) {
		ast_frfree(f);
		memset(&config,0,sizeof(struct ast_bridge_config));

		if (option_verbose  > 2) 
			ast_verbose(VERBOSE_PREFIX_3
						"%s Drops Back to Pass, Picked Off by %s! ... The 10 ... the 5 ... Touchdown!!!\n", 
						newchan->name, chan->name);		
		
		if(!(res = ast_channel_make_compatible(chan, newchan))) {
			chan->appl = "Bridged Call";
			res = ast_bridge_call(chan,newchan,&config);
		} else {
			ast_verbose("DoH! cant make chans compat.\n");
		}
	}
	ast_hangup(newchan);

	LOCAL_USER_REMOVE(u);
	return res ? 0 : -1;
}


int unload_module(void)
{
	STANDARD_HANGUP_LOCALUSERS;
	return ast_unregister_application(app);
}

int load_module(void)
{
	return ast_register_application(app, intercept_exec, tdesc, synopsis);
}

char *description(void)
{
	return tdesc;
}

int usecount(void)
{
	int res;
	STANDARD_USECOUNT(res);
	return res;
}

char *key()
{
	return ASTERISK_GPL_KEY;
}