This patch implements the REST API's for POST /channels/{channelId}/play

and GET /playback/{playbackId}.

This allows an external application to initiate playback of a sound on a
channel while the channel is in the Stasis application.

/play commands are issued asynchronously, and return immediately with
the URL of the associated /playback resource. Playback commands queue up,
playing in succession. The /playback resource shows the state of a
playback operation as enqueued, playing or complete. (Although the
operation will only be in the 'complete' state for a very short time,
since it is almost immediately freed up).

(closes issue ASTERISK-21283)
(closes issue ASTERISK-21586)
Review: https://reviewboard.asterisk.org/r/2531/



git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@389587 65c4cc65-6c06-0410-ace0-fbb531ad65f3

12 files changed, 575 insertions, 75 deletions

diff --git a/res/res_stasis_http.c b/res/res_stasis_http.c
index 75a13284e..63e2601e8 100644
--- a/res/res_stasis_http.c
+++ b/res/res_stasis_http.c
@@ -330,6 +330,15 @@ void stasis_http_response_alloc_failed(struct stasis_http_response *response)
 	response->response_text = "Internal Server Error";
 }
 
+void stasis_http_response_created(struct stasis_http_response *response,
+	const char *url)
+{
+	response->message = ast_json_null();
+	response->response_code = 201;
+	response->response_text = "Created";
+	ast_str_append(&response->headers, 0, "Location: %s\r\n", url);
+}
+
 static void add_allow_header(struct stasis_rest_handlers *handler,
 			     struct stasis_http_response *response)
 {
diff --git a/res/res_stasis_http_channels.c b/res/res_stasis_http_channels.c
index aa4481903..89c0cf09c 100644
--- a/res/res_stasis_http_channels.c
+++ b/res/res_stasis_http_channels.c
@@ -327,6 +327,9 @@ static void stasis_http_play_on_channel_cb(
 		if (strcmp(i->name, "media") == 0) {
 			args.media = (i->value);
 		} else
+		if (strcmp(i->name, "lang") == 0) {
+			args.lang = (i->value);
+		} else
 		{}
 	}
 	for (i = path_vars; i; i = i->next) {
diff --git a/res/res_stasis_json_events.c b/res/res_stasis_json_events.c
index 10d36be42..e96d84e4f 100644
--- a/res/res_stasis_json_events.c
+++ b/res/res_stasis_json_events.c
@@ -116,30 +116,18 @@ struct ast_json *stasis_json_event_bridge_created_create(
 	return ast_json_ref(message);
 }
 
-struct ast_json *stasis_json_event_channel_destroyed_create(
-	struct ast_channel_snapshot *channel_snapshot,
+struct ast_json *stasis_json_event_playback_finished_create(
 	struct ast_json *blob
 	)
 {
 	RAII_VAR(struct ast_json *, message, NULL, ast_json_unref);
 	RAII_VAR(struct ast_json *, event, NULL, ast_json_unref);
 	struct ast_json *validator;
-	int ret;
 
-	ast_assert(channel_snapshot != NULL);
 	ast_assert(blob != NULL);
-	ast_assert(ast_json_object_get(blob, "channel") == NULL);
 	ast_assert(ast_json_object_get(blob, "type") == NULL);
 
-	validator = ast_json_object_get(blob, "cause");
-	if (validator) {
-		/* do validation? XXX */
-	} else {
-		/* fail message generation if the required parameter doesn't exist */
-		return NULL;
-	}
-
-	validator = ast_json_object_get(blob, "cause_txt");
+	validator = ast_json_object_get(blob, "playback");
 	if (validator) {
 		/* do validation? XXX */
 	} else {
@@ -152,13 +140,7 @@ struct ast_json *stasis_json_event_channel_destroyed_create(
 		return NULL;
 	}
 
-	ret = ast_json_object_set(event,
-		"channel", ast_channel_snapshot_to_json(channel_snapshot));
-	if (ret) {
-		return NULL;
-	}
-
-	message = ast_json_pack("{s: o}", "channel_destroyed", ast_json_ref(event));
+	message = ast_json_pack("{s: o}", "playback_finished", ast_json_ref(event));
 	if (!message) {
 		return NULL;
 	}
@@ -245,29 +227,23 @@ struct ast_json *stasis_json_event_channel_caller_id_create(
 	return ast_json_ref(message);
 }
 
-struct ast_json *stasis_json_event_channel_hangup_request_create(
-	struct ast_channel_snapshot *channel_snapshot,
+struct ast_json *stasis_json_event_playback_started_create(
 	struct ast_json *blob
 	)
 {
 	RAII_VAR(struct ast_json *, message, NULL, ast_json_unref);
 	RAII_VAR(struct ast_json *, event, NULL, ast_json_unref);
 	struct ast_json *validator;
-	int ret;
 
-	ast_assert(channel_snapshot != NULL);
 	ast_assert(blob != NULL);
-	ast_assert(ast_json_object_get(blob, "channel") == NULL);
 	ast_assert(ast_json_object_get(blob, "type") == NULL);
 
-	validator = ast_json_object_get(blob, "soft");
-	if (validator) {
-		/* do validation? XXX */
-	}
-
-	validator = ast_json_object_get(blob, "cause");
+	validator = ast_json_object_get(blob, "playback");
 	if (validator) {
 		/* do validation? XXX */
+	} else {
+		/* fail message generation if the required parameter doesn't exist */
+		return NULL;
 	}
 
 	event = ast_json_deep_copy(blob);
@@ -275,13 +251,7 @@ struct ast_json *stasis_json_event_channel_hangup_request_create(
 		return NULL;
 	}
 
-	ret = ast_json_object_set(event,
-		"channel", ast_channel_snapshot_to_json(channel_snapshot));
-	if (ret) {
-		return NULL;
-	}
-
-	message = ast_json_pack("{s: o}", "channel_hangup_request", ast_json_ref(event));
+	message = ast_json_pack("{s: o}", "playback_started", ast_json_ref(event));
 	if (!message) {
 		return NULL;
 	}
@@ -350,6 +320,56 @@ struct ast_json *stasis_json_event_application_replaced_create(
 	return ast_json_ref(message);
 }
 
+struct ast_json *stasis_json_event_channel_destroyed_create(
+	struct ast_channel_snapshot *channel_snapshot,
+	struct ast_json *blob
+	)
+{
+	RAII_VAR(struct ast_json *, message, NULL, ast_json_unref);
+	RAII_VAR(struct ast_json *, event, NULL, ast_json_unref);
+	struct ast_json *validator;
+	int ret;
+
+	ast_assert(channel_snapshot != NULL);
+	ast_assert(blob != NULL);
+	ast_assert(ast_json_object_get(blob, "channel") == NULL);
+	ast_assert(ast_json_object_get(blob, "type") == NULL);
+
+	validator = ast_json_object_get(blob, "cause");
+	if (validator) {
+		/* do validation? XXX */
+	} else {
+		/* fail message generation if the required parameter doesn't exist */
+		return NULL;
+	}
+
+	validator = ast_json_object_get(blob, "cause_txt");
+	if (validator) {
+		/* do validation? XXX */
+	} else {
+		/* fail message generation if the required parameter doesn't exist */
+		return NULL;
+	}
+
+	event = ast_json_deep_copy(blob);
+	if (!event) {
+		return NULL;
+	}
+
+	ret = ast_json_object_set(event,
+		"channel", ast_channel_snapshot_to_json(channel_snapshot));
+	if (ret) {
+		return NULL;
+	}
+
+	message = ast_json_pack("{s: o}", "channel_destroyed", ast_json_ref(event));
+	if (!message) {
+		return NULL;
+	}
+
+	return ast_json_ref(message);
+}
+
 struct ast_json *stasis_json_event_channel_varset_create(
 	struct ast_channel_snapshot *channel_snapshot,
 	struct ast_json *blob
@@ -587,6 +607,50 @@ struct ast_json *stasis_json_event_channel_state_change_create(
 	return ast_json_ref(message);
 }
 
+struct ast_json *stasis_json_event_channel_hangup_request_create(
+	struct ast_channel_snapshot *channel_snapshot,
+	struct ast_json *blob
+	)
+{
+	RAII_VAR(struct ast_json *, message, NULL, ast_json_unref);
+	RAII_VAR(struct ast_json *, event, NULL, ast_json_unref);
+	struct ast_json *validator;
+	int ret;
+
+	ast_assert(channel_snapshot != NULL);
+	ast_assert(blob != NULL);
+	ast_assert(ast_json_object_get(blob, "channel") == NULL);
+	ast_assert(ast_json_object_get(blob, "type") == NULL);
+
+	validator = ast_json_object_get(blob, "soft");
+	if (validator) {
+		/* do validation? XXX */
+	}
+
+	validator = ast_json_object_get(blob, "cause");
+	if (validator) {
+		/* do validation? XXX */
+	}
+
+	event = ast_json_deep_copy(blob);
+	if (!event) {
+		return NULL;
+	}
+
+	ret = ast_json_object_set(event,
+		"channel", ast_channel_snapshot_to_json(channel_snapshot));
+	if (ret) {
+		return NULL;
+	}
+
+	message = ast_json_pack("{s: o}", "channel_hangup_request", ast_json_ref(event));
+	if (!message) {
+		return NULL;
+	}
+
+	return ast_json_ref(message);
+}
+
 struct ast_json *stasis_json_event_channel_entered_bridge_create(
 	struct ast_bridge_snapshot *bridge_snapshot,
 	struct ast_channel_snapshot *channel_snapshot
diff --git a/res/res_stasis_json_events.exports.in b/res/res_stasis_json_events.exports.in
index e3f59ca76..8be4c849b 100644
--- a/res/res_stasis_json_events.exports.in
+++ b/res/res_stasis_json_events.exports.in
@@ -2,18 +2,20 @@
 	global:
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_userevent_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_bridge_created_create;
-		LINKER_SYMBOL_PREFIXstasis_json_event_channel_destroyed_create;
+		LINKER_SYMBOL_PREFIXstasis_json_event_playback_finished_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_snapshot_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_caller_id_create;
-		LINKER_SYMBOL_PREFIXstasis_json_event_channel_hangup_request_create;
+		LINKER_SYMBOL_PREFIXstasis_json_event_playback_started_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_bridge_destroyed_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_application_replaced_create;
+		LINKER_SYMBOL_PREFIXstasis_json_event_channel_destroyed_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_varset_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_left_bridge_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_created_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_stasis_start_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_dialplan_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_state_change_create;
+		LINKER_SYMBOL_PREFIXstasis_json_event_channel_hangup_request_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_entered_bridge_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_channel_dtmf_received_create;
 		LINKER_SYMBOL_PREFIXstasis_json_event_stasis_end_create;
diff --git a/res/res_stasis_playback.c b/res/res_stasis_playback.c
new file mode 100644
index 000000000..5f54a14b4
--- /dev/null
+++ b/res/res_stasis_playback.c
@@ -0,0 +1,320 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * David M. Lee, II <dlee@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 res_stasis playback support.
+ *
+ * \author David M. Lee, II <dlee@digium.com>
+ */
+
+/*** MODULEINFO
+	<depend type="module">res_stasis</depend>
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/app.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/file.h"
+#include "asterisk/logger.h"
+#include "asterisk/module.h"
+#include "asterisk/stasis_app_impl.h"
+#include "asterisk/stasis_app_playback.h"
+#include "asterisk/stasis_channels.h"
+#include "asterisk/stringfields.h"
+#include "asterisk/uuid.h"
+
+/*! Number of hash buckets for playback container. Keep it prime! */
+#define PLAYBACK_BUCKETS 127
+
+/*! Number of milliseconds of media to skip */
+#define PLAYBACK_SKIPMS 250
+
+#define SOUND_URI_SCHEME "sound:"
+#define RECORDING_URI_SCHEME "recording:"
+
+STASIS_MESSAGE_TYPE_DEFN(stasis_app_playback_snapshot_type);
+
+/*! Container of all current playbacks */
+static struct ao2_container *playbacks;
+
+/*! Playback control object for res_stasis */
+struct stasis_app_playback {
+	AST_DECLARE_STRING_FIELDS(
+		AST_STRING_FIELD(id);	/*!< Playback unique id */
+		AST_STRING_FIELD(media);	/*!< Playback media uri */
+		AST_STRING_FIELD(language);	/*!< Preferred language */
+		);
+	/*! Current playback state */
+	enum stasis_app_playback_state state;
+	/*! Control object for the channel we're playing back to */
+	struct stasis_app_control *control;
+};
+
+static int playback_hash(const void *obj, int flags)
+{
+	const struct stasis_app_playback *playback = obj;
+	const char *id = flags & OBJ_KEY ? obj : playback->id;
+	return ast_str_hash(id);
+}
+
+static int playback_cmp(void *obj, void *arg, int flags)
+{
+	struct stasis_app_playback *lhs = obj;
+	struct stasis_app_playback *rhs = arg;
+	const char *rhs_id = flags & OBJ_KEY ? arg : rhs->id;
+
+	if (strcmp(lhs->id, rhs_id) == 0) {
+		return CMP_MATCH | CMP_STOP;
+	} else {
+		return 0;
+	}
+}
+
+static const char *state_to_string(enum stasis_app_playback_state state)
+{
+	switch (state) {
+	case STASIS_PLAYBACK_STATE_QUEUED:
+		return "queued";
+	case STASIS_PLAYBACK_STATE_PLAYING:
+		return "playing";
+	case STASIS_PLAYBACK_STATE_COMPLETE:
+		return "done";
+	}
+
+	return "?";
+}
+
+static struct ast_json *playback_to_json(struct stasis_app_playback *playback)
+{
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+
+	if (playback == NULL) {
+		return NULL;
+	}
+
+	json = ast_json_pack("{s: s, s: s, s: s, s: s}",
+		"id", playback->id,
+		"media_uri", playback->media,
+		"language", playback->language,
+		"state", state_to_string(playback->state));
+
+	return ast_json_ref(json);
+}
+
+static void playback_publish(struct stasis_app_playback *playback)
+{
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+	RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_message *, message, NULL, ao2_cleanup);
+
+	ast_assert(playback != NULL);
+
+	json = playback_to_json(playback);
+	if (json == NULL) {
+		return;
+	}
+
+	message = ast_channel_blob_create_from_cache(
+		stasis_app_control_get_channel_id(playback->control),
+		stasis_app_playback_snapshot_type(), json);
+	if (message == NULL) {
+		return;
+	}
+
+	stasis_app_control_publish(playback->control, message);
+}
+
+static void playback_set_state(struct stasis_app_playback *playback,
+	enum stasis_app_playback_state state)
+{
+	SCOPED_AO2LOCK(lock, playback);
+
+	playback->state = state;
+	playback_publish(playback);
+}
+
+static void playback_cleanup(struct stasis_app_playback *playback)
+{
+	playback_set_state(playback, STASIS_PLAYBACK_STATE_COMPLETE);
+
+	ao2_unlink_flags(playbacks, playback,
+		OBJ_POINTER | OBJ_UNLINK | OBJ_NODATA);
+}
+
+static void *__app_control_play_uri(struct stasis_app_control *control,
+	struct ast_channel *chan, void *data)
+{
+	RAII_VAR(struct stasis_app_playback *, playback, NULL,
+		playback_cleanup);
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+	const char *file;
+	int res;
+	/* Even though these local variables look fairly pointless, the avoid
+	 * having a bunch of NULL's passed directly into
+	 * ast_control_streamfile() */
+	const char *fwd = NULL;
+	const char *rev = NULL;
+	const char *stop = NULL;
+	const char *pause = NULL;
+	const char *restart = NULL;
+	int skipms = PLAYBACK_SKIPMS;
+	long offsetms = 0;
+
+	playback = data;
+	ast_assert(playback != NULL);
+
+	playback_set_state(playback, STASIS_PLAYBACK_STATE_PLAYING);
+
+	if (ast_channel_state(chan) != AST_STATE_UP) {
+		ast_answer(chan);
+	}
+
+	if (ast_begins_with(playback->media, SOUND_URI_SCHEME)) {
+		/* Play sound */
+		file = playback->media + strlen(SOUND_URI_SCHEME);
+	} else if (ast_begins_with(playback->media, RECORDING_URI_SCHEME)) {
+		/* Play recording */
+		file = playback->media + strlen(RECORDING_URI_SCHEME);
+	} else {
+		/* Play URL */
+		ast_log(LOG_ERROR, "Unimplemented\n");
+		return NULL;
+	}
+
+	res = ast_control_streamfile(chan, file, fwd, rev, stop, pause,
+		restart, skipms, &offsetms);
+
+	if (res != 0) {
+		ast_log(LOG_WARNING, "%s: Playback failed for %s",
+			ast_channel_uniqueid(chan), playback->media);
+	}
+
+	return NULL;
+}
+
+static void playback_dtor(void *obj)
+{
+	struct stasis_app_playback *playback = obj;
+
+	ast_string_field_free_memory(playback);
+}
+
+struct stasis_app_playback *stasis_app_control_play_uri(
+	struct stasis_app_control *control, const char *uri,
+	const char *language)
+{
+	RAII_VAR(struct stasis_app_playback *, playback, NULL, ao2_cleanup);
+	char id[AST_UUID_STR_LEN];
+
+	ast_debug(3, "%s: Sending play(%s) command\n",
+		stasis_app_control_get_channel_id(control), uri);
+
+	playback = ao2_alloc(sizeof(*playback), playback_dtor);
+	if (!playback || ast_string_field_init(playback, 128) ){
+		return NULL;
+	}
+
+	ast_uuid_generate_str(id, sizeof(id));
+	ast_string_field_set(playback, id, id);
+	ast_string_field_set(playback, media, uri);
+	ast_string_field_set(playback, language, language);
+	playback->control = control;
+	ao2_link(playbacks, playback);
+
+	playback_set_state(playback, STASIS_PLAYBACK_STATE_QUEUED);
+
+	ao2_ref(playback, +1);
+	stasis_app_send_command_async(
+		control, __app_control_play_uri, playback);
+
+
+	ao2_ref(playback, +1);
+	return playback;
+}
+
+enum stasis_app_playback_state stasis_app_playback_get_state(
+	struct stasis_app_playback *control)
+{
+	SCOPED_AO2LOCK(lock, control);
+	return control->state;
+}
+
+const char *stasis_app_playback_get_id(
+	struct stasis_app_playback *control)
+{
+	/* id is immutable; no lock needed */
+	return control->id;
+}
+
+struct ast_json *stasis_app_playback_find_by_id(const char *id)
+{
+	RAII_VAR(struct stasis_app_playback *, playback, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
+
+	playback = ao2_find(playbacks, id, OBJ_KEY);
+	if (playback == NULL) {
+		return NULL;
+	}
+
+	json = playback_to_json(playback);
+	return ast_json_ref(json);
+}
+
+int stasis_app_playback_control(struct stasis_app_playback *playback,
+	enum stasis_app_playback_media_control control)
+{
+	SCOPED_AO2LOCK(lock, playback);
+	ast_assert(0); /* TODO */
+	return -1;
+}
+
+static int load_module(void)
+{
+	int r;
+
+	r = STASIS_MESSAGE_TYPE_INIT(stasis_app_playback_snapshot_type);
+	if (r != 0) {
+		return AST_MODULE_LOAD_FAILURE;
+	}
+
+	playbacks = ao2_container_alloc(PLAYBACK_BUCKETS, playback_hash,
+		playback_cmp);
+	if (!playbacks) {
+		return AST_MODULE_LOAD_FAILURE;
+	}
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+static int unload_module(void)
+{
+	ao2_cleanup(playbacks);
+	playbacks = NULL;
+	STASIS_MESSAGE_TYPE_CLEANUP(stasis_app_playback_snapshot_type);
+	return 0;
+}
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS,
+	"Stasis application playback support",
+	.load = load_module,
+	.unload = unload_module,
+	.nonoptreq = "res_stasis");
diff --git a/res/res_stasis_playback.exports.in b/res/res_stasis_playback.exports.in
new file mode 100644
index 000000000..0ad493c49
--- /dev/null
+++ b/res/res_stasis_playback.exports.in
@@ -0,0 +1,6 @@
+{
+	global:
+		LINKER_SYMBOL_PREFIXstasis_app_*;
+	local:
+		*;
+};
diff --git a/res/stasis/control.c b/res/stasis/control.c
index e32781b5f..1cc818616 100644
--- a/res/stasis/control.c
+++ b/res/stasis/control.c
@@ -56,7 +56,8 @@ struct stasis_app_control *control_create(struct ast_channel *channel)
 		return NULL;
 	}
 
-	control->command_queue = ao2_container_alloc_list(0, 0, NULL, NULL);
+	control->command_queue = ao2_container_alloc_list(
+		AO2_ALLOC_OPT_LOCK_MUTEX, 0, NULL, NULL);
 
 	control->channel = channel;
 
@@ -75,10 +76,8 @@ static struct stasis_app_command *exec_command(
 		return NULL;
 	}
 
-	ao2_lock(control);
-	ao2_ref(command, +1);
+	/* command_queue is a thread safe list; no lock needed */
 	ao2_link(control->command_queue, command);
-	ao2_unlock(control);
 
 	ao2_ref(command, +1);
 	return command;
@@ -182,8 +181,6 @@ int control_dispatch_all(struct stasis_app_control *control,
 	struct ao2_iterator i;
 	void *obj;
 
-	SCOPED_AO2LOCK(lock, control);
-
 	ast_assert(control->channel == chan);
 
 	i = ao2_iterator_init(control->command_queue, AO2_ITERATOR_UNLINK);
diff --git a/res/stasis_http/resource_channels.c b/res/stasis_http/resource_channels.c
index 3cc97c511..4e404dc1d 100644
--- a/res/stasis_http/resource_channels.c
+++ b/res/stasis_http/resource_channels.c
@@ -24,6 +24,7 @@
  */
 
 /*** MODULEINFO
+	<depend type="module">res_stasis_app_playback</depend>
 	<support_level>core</support_level>
  ***/
 
@@ -31,10 +32,14 @@
 
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
+#include "asterisk/file.h"
 #include "asterisk/stasis_app.h"
+#include "asterisk/stasis_app_playback.h"
 #include "asterisk/stasis_channels.h"
 #include "resource_channels.h"
 
+#include <limits.h>
+
 /*!
  * \brief Finds the control object for a channel, filling the response with an
  * error, if appropriate.
@@ -131,9 +136,53 @@ void stasis_http_unhold_channel(struct ast_variable *headers, struct ast_unhold_
 {
 	ast_log(LOG_ERROR, "TODO: stasis_http_unhold_channel\n");
 }
-void stasis_http_play_on_channel(struct ast_variable *headers, struct ast_play_on_channel_args *args, struct stasis_http_response *response)
+
+void stasis_http_play_on_channel(struct ast_variable *headers,
+	struct ast_play_on_channel_args *args,
+	struct stasis_http_response *response)
 {
-	ast_log(LOG_ERROR, "TODO: stasis_http_play_on_channel\n");
+	RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
+	RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL, ao2_cleanup);
+	RAII_VAR(struct stasis_app_playback *, playback, NULL, ao2_cleanup);
+	RAII_VAR(char *, playback_url, NULL, ast_free);
+	const char *language;
+
+	ast_assert(response != NULL);
+
+	control = find_control(response, args->channel_id);
+	if (control == NULL) {
+		/* Response filled in by find_control */
+		return;
+	}
+
+	snapshot = stasis_app_control_get_snapshot(control);
+	if (!snapshot) {
+		stasis_http_response_error(
+			response, 404, "Not Found",
+			"Channel not found");
+		return;
+	}
+
+	language = S_OR(args->lang, snapshot->language);
+
+	playback = stasis_app_control_play_uri(control, args->media, language);
+	if (!playback) {
+		stasis_http_response_error(
+			response, 500, "Internal Server Error",
+			"Failed to answer channel");
+		return;
+	}
+
+	ast_asprintf(&playback_url, "/playback/%s",
+		stasis_app_playback_get_id(playback));
+	if (!playback_url) {
+		stasis_http_response_error(
+			response, 500, "Internal Server Error",
+			"Out of memory");
+		return;
+	}
+
+	stasis_http_response_created(response, playback_url);
 }
 void stasis_http_record_channel(struct ast_variable *headers, struct ast_record_channel_args *args, struct stasis_http_response *response)
 {
@@ -143,8 +192,8 @@ void stasis_http_get_channel(struct ast_variable *headers,
 			     struct ast_get_channel_args *args,
 			     struct stasis_http_response *response)
 {
-	RAII_VAR(struct stasis_caching_topic *, caching_topic, NULL, ao2_cleanup);
 	RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
+	struct stasis_caching_topic *caching_topic;
 	struct ast_channel_snapshot *snapshot;
 
 	caching_topic = ast_channel_topic_all_cached();
@@ -154,7 +203,6 @@ void stasis_http_get_channel(struct ast_variable *headers,
 			"Message bus not initialized");
 		return;
 	}
-	ao2_ref(caching_topic, +1);
 
 	msg = stasis_cache_get(caching_topic, ast_channel_snapshot_type(),
 			       args->channel_id);
diff --git a/res/stasis_http/resource_channels.h b/res/stasis_http/resource_channels.h
index 2c78589b7..8a35072f0 100644
--- a/res/stasis_http/resource_channels.h
+++ b/res/stasis_http/resource_channels.h
@@ -200,6 +200,8 @@ struct ast_play_on_channel_args {
 	const char *channel_id;
 	/*! \brief Media's URI to play. */
 	const char *media;
+	/*! \brief For sounds, selects language for sound */
+	const char *lang;
 };
 /*!
  * \brief Start playback of media.
diff --git a/res/stasis_http/resource_playback.c b/res/stasis_http/resource_playback.c
index 99f2e09eb..f016a0095 100644
--- a/res/stasis_http/resource_playback.c
+++ b/res/stasis_http/resource_playback.c
@@ -27,11 +27,22 @@
 
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 
+#include "asterisk/stasis_app_playback.h"
 #include "resource_playback.h"
 
-void stasis_http_get_playback(struct ast_variable *headers, struct ast_get_playback_args *args, struct stasis_http_response *response)
+void stasis_http_get_playback(struct ast_variable *headers,
+	struct ast_get_playback_args *args,
+	struct stasis_http_response *response)
 {
-	ast_log(LOG_ERROR, "TODO: stasis_http_get_playback\n");
+	RAII_VAR(struct ast_json *, playback, NULL, ast_json_unref);
+	playback = stasis_app_playback_find_by_id(args->playback_id);
+	if (playback == NULL) {
+		stasis_http_response_error(response, 404, "Not Found",
+			"Playback not found");
+		return;
+	}
+
+	stasis_http_response_ok(response, ast_json_ref(playback));
 }
 void stasis_http_stop_playback(struct ast_variable *headers, struct ast_stop_playback_args *args, struct stasis_http_response *response)
 {
diff --git a/res/stasis_json/resource_channels.h b/res/stasis_json/resource_channels.h
index 45e1031fc..c561d306a 100644
--- a/res/stasis_json/resource_channels.h
+++ b/res/stasis_json/resource_channels.h
@@ -40,7 +40,17 @@
 /*
  * JSON models
  *
+ * CallerID
+ * - name: string (required)
+ * - number: string (required)
+ * Dialed
  * Originated
+ * Playback
+ * - language: string
+ * - media_uri: string (required)
+ * - id: string (required)
+ * - target_uri: string (required)
+ * - state: string (required)
  * DialplanCEP
  * - priority: long (required)
  * - exten: string (required)
@@ -61,10 +71,6 @@
  * - hangupsource: string (required)
  * - dialplan: DialplanCEP (required)
  * - data: string (required)
- * CallerID
- * - name: string (required)
- * - number: string (required)
- * Dialed
  */
 
 #endif /* _ASTERISK_RESOURCE_CHANNELS_H */
diff --git a/res/stasis_json/resource_events.h b/res/stasis_json/resource_events.h
index 63abe0f85..d63181788 100644
--- a/res/stasis_json/resource_events.h
+++ b/res/stasis_json/resource_events.h
@@ -68,18 +68,15 @@ struct ast_json *stasis_json_event_bridge_created_create(
 	);
 
 /*!
- * \brief Notification that a channel has been destroyed.
+ * \brief Event showing the completion of a media playback operation.
  *
- * \param channel The channel to be used to generate this event
  * \param blob JSON blob containing the following parameters:
- * - cause: integer - Integer representation of the cause of the hangup (required)
- * - cause_txt: string - Text representation of the cause of the hangup (required)
+ * - playback: Playback - Playback control object (required)
  *
  * \retval NULL on error
  * \retval JSON (ast_json) describing the event
  */
-struct ast_json *stasis_json_event_channel_destroyed_create(
-	struct ast_channel_snapshot *channel_snapshot,
+struct ast_json *stasis_json_event_playback_finished_create(
 	struct ast_json *blob
 	);
 
@@ -112,18 +109,15 @@ struct ast_json *stasis_json_event_channel_caller_id_create(
 	);
 
 /*!
- * \brief A hangup was requested on the channel.
+ * \brief Event showing the start of a media playback operation.
  *
- * \param channel The channel on which the hangup was requested.
  * \param blob JSON blob containing the following parameters:
- * - soft: boolean - Whether the hangup request was a soft hangup request.
- * - cause: integer - Integer representation of the cause of the hangup.
+ * - playback: Playback - Playback control object (required)
  *
  * \retval NULL on error
  * \retval JSON (ast_json) describing the event
  */
-struct ast_json *stasis_json_event_channel_hangup_request_create(
-	struct ast_channel_snapshot *channel_snapshot,
+struct ast_json *stasis_json_event_playback_started_create(
 	struct ast_json *blob
 	);
 
@@ -153,6 +147,22 @@ struct ast_json *stasis_json_event_application_replaced_create(
 	);
 
 /*!
+ * \brief Notification that a channel has been destroyed.
+ *
+ * \param channel The channel to be used to generate this event
+ * \param blob JSON blob containing the following parameters:
+ * - cause: integer - Integer representation of the cause of the hangup (required)
+ * - cause_txt: string - Text representation of the cause of the hangup (required)
+ *
+ * \retval NULL on error
+ * \retval JSON (ast_json) describing the event
+ */
+struct ast_json *stasis_json_event_channel_destroyed_create(
+	struct ast_channel_snapshot *channel_snapshot,
+	struct ast_json *blob
+	);
+
+/*!
  * \brief Channel variable changed.
  *
  * \param channel The channel on which the variable was set.
@@ -238,6 +248,22 @@ struct ast_json *stasis_json_event_channel_state_change_create(
 	);
 
 /*!
+ * \brief A hangup was requested on the channel.
+ *
+ * \param channel The channel on which the hangup was requested.
+ * \param blob JSON blob containing the following parameters:
+ * - soft: boolean - Whether the hangup request was a soft hangup request.
+ * - cause: integer - Integer representation of the cause of the hangup.
+ *
+ * \retval NULL on error
+ * \retval JSON (ast_json) describing the event
+ */
+struct ast_json *stasis_json_event_channel_hangup_request_create(
+	struct ast_channel_snapshot *channel_snapshot,
+	struct ast_json *blob
+	);
+
+/*!
  * \brief Notification that a channel has entered a bridge.
  *
  * \param channel The channel to be used to generate this event
@@ -284,19 +310,20 @@ struct ast_json *stasis_json_event_stasis_end_create(
  * ChannelUserevent
  * - eventname: string (required)
  * BridgeCreated
- * ChannelDestroyed
- * - cause: integer (required)
- * - cause_txt: string (required)
+ * PlaybackFinished
+ * - playback: Playback (required)
  * ChannelSnapshot
  * ChannelCallerId
  * - caller_presentation_txt: string (required)
  * - caller_presentation: integer (required)
- * ChannelHangupRequest
- * - soft: boolean
- * - cause: integer
+ * PlaybackStarted
+ * - playback: Playback (required)
  * BridgeDestroyed
  * ApplicationReplaced
  * - application: string (required)
+ * ChannelDestroyed
+ * - cause: integer (required)
+ * - cause_txt: string (required)
  * ChannelVarset
  * - variable: string (required)
  * - value: string (required)
@@ -308,6 +335,9 @@ struct ast_json *stasis_json_event_stasis_end_create(
  * - application: string (required)
  * - application_data: string (required)
  * ChannelStateChange
+ * ChannelHangupRequest
+ * - soft: boolean
+ * - cause: integer
  * ChannelEnteredBridge
  * ChannelDtmfReceived
  * - digit: string (required)
@@ -325,10 +355,12 @@ struct ast_json *stasis_json_event_stasis_end_create(
  * - application: string (required)
  * - channel_hangup_request: ChannelHangupRequest
  * - channel_userevent: ChannelUserevent
+ * - playback_started: PlaybackStarted
  * - channel_snapshot: ChannelSnapshot
  * - channel_dtmf_received: ChannelDtmfReceived
  * - channel_caller_id: ChannelCallerId
  * - bridge_destroyed: BridgeDestroyed
+ * - playback_finished: PlaybackFinished
  * - stasis_end: StasisEnd
  * StasisEnd
  */