/*
 * app_changrab.c
 * Copyright (c) 2004-2007 Anthony Minessale II <anthmct@yahoo.com>
 *
 * Thanks to Clod Patry <cpatry@gmail.com> for his help.
 *
 * 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/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>

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 1.48 $")

static char *app = "ChanGrab";
static char *tdesc = "Take over an existing channel and bridge to it.";
static char *synopsis = "ChanGrab(<Channel Name>|[flags])\n"
	"\nTake over the specified channel (ending any call it is currently\n"
	"involved in.) and bridge that channel to the caller.\n\n"
	"Flags:\n\n"
	"   -- 'b' Indicates that you want to grab the channel that the\n"
	"          specified channel is Bridged to.\n\n"
	"   -- 'r' Only incercept the channel if the channel has not\n" "          been answered yet\n";

/* Prototypes */
int load_module(void);
int unload_module(void);
char *description(void);


static struct ast_channel *my_ast_get_channel_by_name_locked(char *channame)
{
	struct ast_channel *chan;
	chan = ast_channel_walk_locked(NULL);
	while (chan) {
		if (!strncasecmp(chan->name, channame, strlen(channame)))
			return chan;
		ast_mutex_unlock(&chan->lock);
		chan = ast_channel_walk_locked(chan);
	}
	return NULL;
}

static int changrab_exec(struct ast_channel *chan, void *data)
{
	int res = 0;
	struct ast_channel *newchan;
	struct ast_channel *oldchan;
	struct ast_frame *f;
	struct ast_bridge_config config;
	char *info = NULL;
	char *flags = NULL;

	if (!data || ast_strlen_zero(data)) {
		ast_log(LOG_WARNING, "changrab requires an argument (chan)\n");
		return -1;
	}

	if ((info = ast_strdupa((char *) data))) {
		if ((flags = strchr(info, '|'))) {

			*flags = '\0';
			flags++;
		}
	}

	if ((oldchan = my_ast_get_channel_by_name_locked(info))) {
		ast_mutex_unlock(&oldchan->lock);
	} else {
		ast_log(LOG_WARNING, "No Such Channel: %s\n", (char *) data);
		return -1;
	}

	if (flags && oldchan->_bridge && strchr(flags, 'b')) {
		oldchan = oldchan->_bridge;
	}

	if (flags && strchr(flags, 'r') && oldchan->_state == AST_STATE_UP) {
		return -1;
	}

	newchan = ast_channel_alloc(0, AST_STATE_DOWN, 0, 0, "ChanGrab/%s", oldchan->name);
	newchan->readformat = oldchan->readformat;
	newchan->writeformat = oldchan->writeformat;
	ast_channel_masquerade(newchan, oldchan);
	if ((f = ast_read(newchan))) {
		ast_frfree(f);
		memset(&config, 0, sizeof(struct ast_bridge_config));
		ast_set_flag(&(config.features_callee), AST_FEATURE_REDIRECT);
		ast_set_flag(&(config.features_caller), AST_FEATURE_REDIRECT);

		if (newchan->_state != AST_STATE_UP) {
			ast_answer(newchan);
		}

		chan->appl = "Bridged Call";
		res = ast_bridge_call(chan, newchan, &config);
		ast_hangup(newchan);
	}

	return res ? 0 : -1;
}


struct ast_bridge_thread_obj {
	struct ast_bridge_config bconfig;
	struct ast_channel *chan;
	struct ast_channel *peer;
};

static void *ast_bridge_call_thread(void *data)
{
	struct ast_bridge_thread_obj *tobj = data;
	tobj->chan->appl = "Redirected Call";
	tobj->chan->data = tobj->peer->name;
	tobj->peer->appl = "Redirected Call";
	tobj->peer->data = tobj->chan->name;
	if (tobj->chan->cdr) {
		ast_cdr_reset(tobj->chan->cdr, 0);
		ast_cdr_setdestchan(tobj->chan->cdr, tobj->peer->name);
	}
	if (tobj->peer->cdr) {
		ast_cdr_reset(tobj->peer->cdr, 0);
		ast_cdr_setdestchan(tobj->peer->cdr, tobj->chan->name);
	}


	ast_bridge_call(tobj->peer, tobj->chan, &tobj->bconfig);
	ast_hangup(tobj->chan);
	ast_hangup(tobj->peer);
	tobj->chan = tobj->peer = NULL;
	free(tobj);
	tobj = NULL;
	return NULL;
}

static void ast_bridge_call_thread_launch(struct ast_channel *chan, struct ast_channel *peer)
{
	pthread_t thread;
	pthread_attr_t attr;
	int result;
	struct ast_bridge_thread_obj *tobj;

	if ((tobj = malloc(sizeof(struct ast_bridge_thread_obj)))) {
		memset(tobj, 0, sizeof(struct ast_bridge_thread_obj));
		tobj->chan = chan;
		tobj->peer = peer;


		result = pthread_attr_init(&attr);
		pthread_attr_setschedpolicy(&attr, SCHED_RR);
		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
		result = ast_pthread_create(&thread, &attr, ast_bridge_call_thread, tobj);
		result = pthread_attr_destroy(&attr);
	}
}


#define CGUSAGE "Usage: changrab [-[bB]] <channel> <exten>@<context> [pri]\n"
static int changrab_cli(int fd, int argc, char *argv[])
{
	char *chan_name_1, *chan_name_2 = NULL, *context, *exten, *flags = NULL;
	char *pria = NULL;
	struct ast_channel *xferchan_1, *xferchan_2;
	int pri = 0, x = 1;

	if (argc < 3) {
		ast_cli(fd, CGUSAGE);
		return -1;
	}
	chan_name_1 = argv[x++];
	if (chan_name_1[0] == '-') {
		flags = ast_strdupa(chan_name_1);
		if (flags && (strchr(flags, 'h'))) {
			chan_name_1 = argv[x++];
			if ((xferchan_1 = my_ast_get_channel_by_name_locked(chan_name_1))) {
				ast_mutex_unlock(&xferchan_1->lock);
				ast_hangup(xferchan_1);
				ast_verbose("OK, good luck!\n");
				return 0;
			} else
				return -1;
		} else if (flags && (strchr(flags, 'm') || strchr(flags, 'M'))) {
			chan_name_1 = argv[x++];
			if ((xferchan_1 = my_ast_get_channel_by_name_locked(chan_name_1))) {
				ast_mutex_unlock(&xferchan_1->lock);
				strchr(flags, 'm') ? ast_moh_start(xferchan_1, NULL, NULL) : ast_moh_stop(xferchan_1);
			} else
				return 1;
			return 0;
		}
		if (argc < 4) {
			ast_cli(fd, CGUSAGE);
			return -1;
		}
		chan_name_1 = argv[x++];
	}

	exten = ast_strdupa(argv[x++]);
	if ((context = strchr(exten, '@'))) {
		*context = 0;
		context++;
		if (!(context && exten)) {
			ast_cli(fd, CGUSAGE);
			return -1;
		}
		if ((pria = strchr(context, ':'))) {
			*pria = '\0';
			pria++;
			pri = atoi(pria);
		} else {
			pri = argv[x] ? atoi(argv[x++]) : 1;
		}
		if (!pri)
			pri = 1;
	} else if (strchr(exten, '/')) {
		chan_name_2 = exten;
	}


	xferchan_1 = my_ast_get_channel_by_name_locked(chan_name_1);

	if (!xferchan_1) {
		ast_log(LOG_WARNING, "No Such Channel: %s\n", chan_name_1);
		return -1;
	}

	ast_mutex_unlock(&xferchan_1->lock);
	if (flags && strchr(flags, 'b')) {
		if (ast_bridged_channel(xferchan_1)) {
			xferchan_1 = ast_bridged_channel(xferchan_1);
		}
	}

	if (chan_name_2) {
		struct ast_frame *f;
		struct ast_channel *newchan_1, *newchan_2;


		if (!(newchan_1 = ast_channel_alloc(0, AST_STATE_DOWN, 0, 0, "ChanGrab/%s", xferchan_1->name))) {
			ast_log(LOG_WARNING, "Memory Error!\n");
			ast_hangup(newchan_1);
			return -1;
		} else {
			newchan_1->readformat = xferchan_1->readformat;
			newchan_1->writeformat = xferchan_1->writeformat;
			ast_channel_masquerade(newchan_1, xferchan_1);
			if ((f = ast_read(newchan_1))) {
				ast_frfree(f);
			} else {
				ast_hangup(newchan_1);
				return -1;
			}
		}

		if (!(xferchan_2 = my_ast_get_channel_by_name_locked(chan_name_2))) {
			ast_log(LOG_WARNING, "No Such Channel: %s\n", chan_name_2);
			ast_hangup(newchan_1);
			return -1;
		}

		ast_mutex_unlock(&xferchan_2->lock);

		if (flags && strchr(flags, 'B')) {
			if (ast_bridged_channel(xferchan_2)) {
				xferchan_2 = ast_bridged_channel(xferchan_2);
			}
		}

		if (!(newchan_2 = ast_channel_alloc(0, AST_STATE_DOWN, 0, 0, "ChanGrab/%s", xferchan_2->name))) {
			ast_log(LOG_WARNING, "Memory Error!\n");
			ast_hangup(newchan_1);
			return -1;
		} else {
			newchan_2->readformat = xferchan_2->readformat;
			newchan_2->writeformat = xferchan_2->writeformat;
			ast_channel_masquerade(newchan_2, xferchan_2);

			if ((f = ast_read(newchan_2))) {
				ast_frfree(f);
			} else {
				ast_hangup(newchan_1);
				ast_hangup(newchan_2);
				return -1;
			}
		}

		ast_bridge_call_thread_launch(newchan_1, newchan_2);

	} else {
		ast_verbose("Transferring_to context %s, extension %s, priority %d\n", context, exten, pri);
		ast_async_goto(xferchan_1, context, exten, pri);

		if (xferchan_1)
			ast_mutex_unlock(&xferchan_1->lock);
	}
	return 0;
}

struct fast_originate_helper {
	char tech[256];
	char data[256];
	int timeout;
	char app[256];
	char appdata[256];
	char cid_name[256];
	char cid_num[256];
	char context[256];
	char exten[256];
	char idtext[256];
	int priority;
	struct ast_variable *vars;
};



#define USAGE "Usage: originate <channel> <exten>@<context> [pri] [callerid] [timeout]\n"

static void *originate(void *arg)
{
	struct fast_originate_helper *in = arg;
	int reason = 0;
	struct ast_channel *chan = NULL;

	ast_pbx_outgoing_exten(in->tech, AST_FORMAT_SLINEAR, in->data, in->timeout, in->context, in->exten, in->priority,
						   &reason, 1, !ast_strlen_zero(in->cid_num) ? in->cid_num : NULL,
						   !ast_strlen_zero(in->cid_name) ? in->cid_name : NULL, NULL, NULL, &chan);

	/* Locked by ast_pbx_outgoing_exten or ast_pbx_outgoing_app */
	if (chan) {
		ast_mutex_unlock(&chan->lock);
	}
	free(in);
	return NULL;
}


static int originate_cli(int fd, int argc, char *argv[])
{
	char *chan_name_1, *context, *exten, *tech, *data, *callerid;
	int pri = 0, to = 60000;
	struct fast_originate_helper *in;
	pthread_t thread;
	pthread_attr_t attr;
	int result;
	char *num = NULL;

	if (argc < 3) {
		ast_cli(fd, USAGE);
		return -1;
	}
	chan_name_1 = argv[1];

	exten = ast_strdupa(argv[2]);
	if ((context = strchr(exten, '@'))) {
		*context = 0;
		context++;
	}
	if (!(context && exten)) {
		ast_cli(fd, CGUSAGE);
		return -1;
	}


	pri = argv[3] ? atoi(argv[3]) : 1;
	if (!pri)
		pri = 1;

	tech = ast_strdupa(chan_name_1);
	if ((data = strchr(tech, '/'))) {
		*data = '\0';
		data++;
	}
	if (!(tech && data)) {
		ast_cli(fd, USAGE);
		return -1;
	}
	in = malloc(sizeof(struct fast_originate_helper));
	if (!in) {
		ast_cli(fd, "No Memory!\n");
		return -1;
	}
	memset(in, 0, sizeof(struct fast_originate_helper));

	callerid = (argc > 4) ? argv[4] : NULL;
	to = (argc > 5) ? atoi(argv[5]) : 60000;

	strncpy(in->tech, tech, sizeof(in->tech));
	strncpy(in->data, data, sizeof(in->data));
	in->timeout = to;
	if (callerid) {
		if ((num = strchr(callerid, ':'))) {
			*num = '\0';
			num++;
			strncpy(in->cid_num, num, sizeof(in->cid_num));
		}
		strncpy(in->cid_name, callerid, sizeof(in->cid_name));
	}
	strncpy(in->context, context, sizeof(in->context));
	strncpy(in->exten, exten, sizeof(in->exten));
	in->priority = pri;

	ast_cli(fd, "Originating Call %s/%s %s %s %d\n", in->tech, in->data, in->context, in->exten, in->priority);


	result = pthread_attr_init(&attr);
	pthread_attr_setschedpolicy(&attr, SCHED_RR);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	result = ast_pthread_create(&thread, &attr, originate, in);
	result = pthread_attr_destroy(&attr);
	return 0;
}



static char *complete_exten_at_context(const char *line, const char *word, int pos, int state)
{
	char *ret = NULL;
	int which = 0;

#ifdef BROKEN_READLINE
	/*
	 * Fix arguments, *word is a new allocated structure, REMEMBER to
	 * free *word when you want to return from this function ...
	 */
	if (fix_complete_args(line, &word, &pos)) {
		ast_log(LOG_ERROR, "Out of free memory\n");
		return NULL;
	}
#endif

	/*
	 * exten@context completion ...
	 */
	if (pos == 2) {
		struct ast_context *c;
		struct ast_exten *e;
		char *context = NULL, *exten = NULL, *delim = NULL;

		/* now, parse values from word = exten@context */
		if ((delim = strchr(word, (int) '@'))) {
			/* check for duplicity ... */
			if (delim != strrchr(word, (int) '@')) {
#ifdef BROKEN_READLINE
				free(word);
#endif
				return NULL;
			}

			*delim = '\0';
			exten = strdup(word);
			context = strdup(delim + 1);
			*delim = '@';
		} else {
			exten = strdup(word);
		}
#ifdef BROKEN_READLINE
		free(word);
#endif

		if (ast_lock_contexts()) {
			ast_log(LOG_ERROR, "Failed to lock context list\n");
			free(context);
			free(exten);
			return NULL;
		}

		/* find our context ... */
		c = ast_walk_contexts(NULL);
		while (c) {
			/* our context? */
			if ((!context || !strlen(context)) ||	/* if no input, all contexts ... */
				(context && !strncmp(ast_get_context_name(c), context, strlen(context)))) {	/* if input, compare ... */
				/* try to complete extensions ... */
				e = ast_walk_context_extensions(c, NULL);
				while (e) {

					if (!strncasecmp(ast_get_context_name(c), "macro-", 6)
						|| !strncasecmp(ast_get_extension_name(e), "_", 1)) {
						e = ast_walk_context_extensions(c, e);
						continue;
					}

					/* our extension? */
					if ((!exten || !strlen(exten)) ||	/* if not input, all extensions ... */
						(exten && !strncmp(ast_get_extension_name(e), exten, strlen(exten)))) {	/* if input, compare ... */

						if (++which > state) {
							/* If there is an extension then return
							 * exten@context.
							 */


							if (exten) {
								ret = malloc(strlen(ast_get_extension_name(e)) + strlen(ast_get_context_name(c)) + 2);
								if (ret)
									sprintf(ret, "%s@%s", ast_get_extension_name(e), ast_get_context_name(c));

							}
							free(exten);
							free(context);

							ast_unlock_contexts();

							return ret;
						}
					}
					e = ast_walk_context_extensions(c, e);
				}
			}
			c = ast_walk_contexts(c);
		}

		ast_unlock_contexts();

		free(exten);
		free(context);

		return NULL;
	}

	/*
	 * Complete priority ...
	 */
	if (pos == 3) {
		char *delim, *exten, *context, *dupline, *duplinet, *ec;
		struct ast_context *c;

		dupline = strdup(line);
		if (!dupline) {
#ifdef BROKEN_READLINE
			free(word);
#endif
			return NULL;
		}
		duplinet = dupline;

		strsep(&duplinet, " ");	/* skip 'remove' */
		strsep(&duplinet, " ");	/* skip 'extension */

		if (!(ec = strsep(&duplinet, " "))) {
			free(dupline);
#ifdef BROKEN_READLINE
			free(word);
#endif
			return NULL;
		}

		/* wrong exten@context format? */
		if (!(delim = strchr(ec, (int) '@')) || (strchr(ec, (int) '@') != strrchr(ec, (int) '@'))) {
#ifdef BROKEN_READLINE
			free(word);
#endif
			free(dupline);
			return NULL;
		}

		/* check if there is exten and context too ... */
		*delim = '\0';
		if ((!strlen(ec)) || (!strlen(delim + 1))) {
#ifdef BROKEN_READLINE
			free(word);
#endif
			free(dupline);
			return NULL;
		}

		exten = strdup(ec);
		context = strdup(delim + 1);
		free(dupline);

		if (ast_lock_contexts()) {
			ast_log(LOG_ERROR, "Failed to lock context list\n");
#ifdef BROKEN_READLINE
			free(word);
#endif
			free(exten);
			free(context);
			return NULL;
		}

		/* walk contexts */
		c = ast_walk_contexts(NULL);
		while (c) {
			if (!strcmp(ast_get_context_name(c), context)) {
				struct ast_exten *e;

				/* walk extensions */
				free(context);
				e = ast_walk_context_extensions(c, NULL);
				while (e) {
					if (!strcmp(ast_get_extension_name(e), exten)) {
						struct ast_exten *priority;
						char buffer[10];

						free(exten);
						priority = ast_walk_extension_priorities(e, NULL);
						/* serve priorities */
						do {
							snprintf(buffer, 10, "%u", ast_get_extension_priority(priority));
							if (!strncmp(word, buffer, strlen(word))) {
								if (++which > state) {
#ifdef BROKEN_READLINE
									free(word);
#endif
									ast_unlock_contexts();
									return strdup(buffer);
								}
							}
							priority = ast_walk_extension_priorities(e, priority);
						} while (priority);

#ifdef BROKEN_READLINE
						free(word);
#endif
						ast_unlock_contexts();
						return NULL;
					}
					e = ast_walk_context_extensions(c, e);
				}
#ifdef BROKEN_READLINE
				free(word);
#endif
				free(exten);
				ast_unlock_contexts();
				return NULL;
			}
			c = ast_walk_contexts(c);
		}

#ifdef BROKEN_READLINE
		free(word);
#endif
		free(exten);
		free(context);

		ast_unlock_contexts();
		return NULL;
	}
#ifdef BROKEN_READLINE
	free(word);
#endif
	return NULL;
}


static char *complete_ch_helper(const char *line, const char *word, int pos, int state)
{
	struct ast_channel *c;
	int which = 0;
	char *ret;

	c = ast_channel_walk_locked(NULL);
	while (c) {
		if (!strncasecmp(word, c->name, strlen(word))) {
			if (++which > state)
				break;
		}
		ast_mutex_unlock(&c->lock);
		c = ast_channel_walk_locked(c);
	}
	if (c) {
		ret = strdup(c->name);
		ast_mutex_unlock(&c->lock);
	} else
		ret = NULL;
	return ret;
}

static char *complete_cg(const char *line, const char *word, int pos, int state)
{

	if (pos == 1) {
		return complete_ch_helper(line, word, pos, state);
	} else if (pos >= 2) {
		return complete_exten_at_context(line, word, pos, state);
	}
	return NULL;

}

static char *complete_org(const char *line, const char *word, int pos, int state)
{

	if (pos >= 2) {
		return complete_exten_at_context(line, word, pos, state);
	}
	return NULL;

}

static struct ast_cli_entry cli_changrab = { {"changrab", NULL}, changrab_cli, "ChanGrab", "ChanGrab", complete_cg };
static struct ast_cli_entry cli_originate = { {"cgoriginate", NULL}, originate_cli, "Originate", "Originate", complete_org };

int unload_module(void)
{
	ast_cli_unregister(&cli_changrab);
	ast_cli_unregister(&cli_originate);
	return ast_unregister_application(app);
}

int load_module(void)
{
	ast_cli_register(&cli_changrab);
	ast_cli_register(&cli_originate);
	return ast_register_application(app, changrab_exec, tdesc, synopsis);
}

char *description(void)
{
	return tdesc;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Take over an existing channel and bridge to it.");