/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2014, Digium, Inc.
 *
 * Richard Mudgett <rmudgett@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief Stasis bridge subclass.
 *
 * \author Richard Mudgett <rmudgett@digium.com>
 *
 * See Also:
 * \arg \ref AstCREDITS
 */


#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/bridge.h"
#include "asterisk/bridge_after.h"
#include "asterisk/bridge_internal.h"
#include "asterisk/bridge_features.h"
#include "asterisk/stasis_app.h"
#include "asterisk/stasis_channels.h"
#include "stasis_bridge.h"
#include "control.h"
#include "command.h"
#include "app.h"
#include "asterisk/stasis_app.h"
#include "asterisk/pbx.h"

/* ------------------------------------------------------------------- */

static struct ast_bridge_methods bridge_stasis_v_table;

static void bridge_stasis_run_cb(struct ast_channel *chan, void *data)
{
	RAII_VAR(char *, app_name, NULL, ast_free);
	struct ast_app *app_stasis;

	/* Take ownership of the swap_app memory from the datastore */
	app_name = app_get_replace_channel_app(chan);
	if (!app_name) {
		ast_log(LOG_ERROR, "Failed to get app name for %s (%p)\n", ast_channel_name(chan), chan);
		return;
	}

	/* find Stasis() */
	app_stasis = pbx_findapp("Stasis");
	if (!app_stasis) {
		ast_log(LOG_WARNING, "Could not find application (Stasis)\n");
		return;
	}

	if (ast_check_hangup_locked(chan)) {
		/* channel hungup, don't run Stasis() */
		return;
	}

	/* run Stasis() */
	pbx_exec(chan, app_stasis, app_name);
}

static int add_channel_to_bridge(
	struct stasis_app_control *control,
	struct ast_channel *chan, void *obj)
{
	struct ast_bridge *bridge = obj;
	int res;

	res = control_add_channel_to_bridge(control,
		chan, bridge);
	return res;
}

static void bridge_stasis_queue_join_action(struct ast_bridge *self,
	struct ast_bridge_channel *bridge_channel)
{
	ast_channel_lock(bridge_channel->chan);
	command_prestart_queue_command(bridge_channel->chan, add_channel_to_bridge,
		ao2_bump(self), __ao2_cleanup);
	ast_channel_unlock(bridge_channel->chan);
}

/*!
 * \internal
 * \brief Push this channel into the Stasis bridge.
 * \since 12.5.0
 *
 * \param self Bridge to operate upon.
 * \param bridge_channel Bridge channel to push.
 * \param swap Bridge channel to swap places with if not NULL.
 *
 * \note On entry, self is already locked.
 *
 * \retval 0 on success.
 * \retval -1 on failure.  The channel did not get pushed.
 */
static int bridge_stasis_push(struct ast_bridge *self, struct ast_bridge_channel *bridge_channel, struct ast_bridge_channel *swap)
{
	struct stasis_app_control *control = stasis_app_control_find_by_channel(bridge_channel->chan);

	if (!control && !stasis_app_channel_is_internal(bridge_channel->chan)) {
		/* channel not in Stasis(), get it there */
		/* Attach after-bridge callback and pass ownership of swap_app to it */
		if (ast_bridge_set_after_callback(bridge_channel->chan,
			bridge_stasis_run_cb, NULL, NULL)) {
			ast_log(LOG_ERROR, "Failed to set after bridge callback\n");
			return -1;
		}

		bridge_stasis_queue_join_action(self, bridge_channel);

		/* Return -1 so the push fails and the after-bridge callback gets called */
		return -1;
	}

	ao2_cleanup(control);
	if (self->allowed_capabilities & STASIS_BRIDGE_MIXING_CAPABILITIES) {
		ast_bridge_channel_update_linkedids(bridge_channel, swap);
		if (ast_test_flag(&self->feature_flags, AST_BRIDGE_FLAG_SMART)) {
			ast_bridge_channel_update_accountcodes(bridge_channel, swap);
		}
	}

	return ast_bridge_base_v_table.push(self, bridge_channel, swap);
}

static int bridge_stasis_moving(struct ast_bridge_channel *bridge_channel, void *hook_pvt,
		struct ast_bridge *src, struct ast_bridge *dst)
{
	if (src->v_table == &bridge_stasis_v_table &&
			dst->v_table != &bridge_stasis_v_table) {
		RAII_VAR(struct ast_json *, blob, NULL, ast_json_unref);
		RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
		struct ast_channel *chan;

		chan = bridge_channel->chan;
		ast_assert(chan != NULL);

		control = stasis_app_control_find_by_channel(chan);
		if (!control) {
			return -1;
		}

		blob = ast_json_pack("{s: s}", "app", app_name(control_app(control)));

		stasis_app_channel_set_stasis_end_published(chan);

		ast_channel_publish_blob(chan, ast_stasis_end_message_type(), blob);
	}

	return -1;
}

/*!
 * \internal
 * \brief Pull this channel from the Stasis bridge.
 * \since 12.5.0
 *
 * \param self Bridge to operate upon.
 * \param bridge_channel Bridge channel to pull.
 *
 * \note On entry, self is already locked.
 *
 * \return Nothing
 */
static void bridge_stasis_pull(struct ast_bridge *self, struct ast_bridge_channel *bridge_channel)
{
	if ((self->allowed_capabilities & STASIS_BRIDGE_MIXING_CAPABILITIES)
		&& ast_test_flag(&self->feature_flags, AST_BRIDGE_FLAG_SMART)) {
		ast_bridge_channel_update_accountcodes(NULL, bridge_channel);
	}

	ast_bridge_move_hook(bridge_channel->features, bridge_stasis_moving, NULL, NULL, 0);

	ast_bridge_base_v_table.pull(self, bridge_channel);
}

struct ast_bridge *bridge_stasis_new(uint32_t capabilities, unsigned int flags, const char *name, const char *id)
{
	void *bridge;

	bridge = bridge_alloc(sizeof(struct ast_bridge), &bridge_stasis_v_table);
	bridge = bridge_base_init(bridge, capabilities, flags, "Stasis", name, id);
	bridge = bridge_register(bridge);

	return bridge;
}

void bridge_stasis_init(void)
{
	/* Setup the Stasis bridge subclass v_table. */
	bridge_stasis_v_table = ast_bridge_base_v_table;
	bridge_stasis_v_table.name = "stasis";
	bridge_stasis_v_table.push = bridge_stasis_push;
	bridge_stasis_v_table.pull = bridge_stasis_pull;
}