From 0c8451cae9c585793fa98fb99864d5228127bbf9 Mon Sep 17 00:00:00 2001
From: Dylan Van Assche <me@dylanvanassche.be>
Date: Tue, 5 Apr 2022 20:26:09 +0200
Subject: [PATCH 03/26] bluetooth: add UPower backend

UPower provides information about the power supply and battery
level of the host. Add a backend to retrieve the host battery level.
---
 src/modules/bluetooth/meson.build |   4 +-
 src/modules/bluetooth/upower.c    | 300 ++++++++++++++++++++++++++++++
 src/modules/bluetooth/upower.h    |  41 ++++
 3 files changed, 344 insertions(+), 1 deletion(-)
 create mode 100644 src/modules/bluetooth/upower.c
 create mode 100644 src/modules/bluetooth/upower.h

diff --git a/src/modules/bluetooth/meson.build b/src/modules/bluetooth/meson.build
index ca77ee6aa..0703d5086 100644
--- a/src/modules/bluetooth/meson.build
+++ b/src/modules/bluetooth/meson.build
@@ -16,6 +16,8 @@ libbluez5_util_headers = [
 
 if get_option('bluez5-native-headset')
   libbluez5_util_sources += [ 'backend-native.c' ]
+  libbluez5_util_sources += [ 'upower.c' ]
+  libbluez5_util_headers += [ 'upower.h' ]
 endif
 
 if get_option('bluez5-ofono-headset')
@@ -35,7 +37,7 @@ libbluez5_util = shared_library('bluez5-util',
   c_args : [pa_c_args, server_c_args],
   link_args : [nodelete_link_args],
   include_directories : [configinc, topinc],
-  dependencies : [libpulse_dep, libpulsecommon_dep, libpulsecore_dep, bluez_dep, dbus_dep, sbc_dep, libintl_dep, bluez5_gst_dep, bluez5_gstapp_dep],
+  dependencies : [libpulse_dep, libpulsecommon_dep, libpulsecore_dep, bluez_dep, dbus_dep, sbc_dep, libintl_dep, bluez5_gst_dep, bluez5_gstapp_dep, libm_dep],
   install : true,
   install_rpath : privlibdir,
   install_dir : modlibexecdir,
diff --git a/src/modules/bluetooth/upower.c b/src/modules/bluetooth/upower.c
new file mode 100644
index 000000000..b5cb89bfe
--- /dev/null
+++ b/src/modules/bluetooth/upower.c
@@ -0,0 +1,300 @@
+/***
+  This file is part of PulseAudio.
+
+  Copyrigth 2022 Dylan Van Assche <me@dylanvanassche.be>
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+***/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <math.h>
+#include <pulsecore/core-error.h>
+#include <pulsecore/core-util.h>
+#include <pulsecore/dbus-shared.h>
+#include <pulsecore/log.h>
+#include <pulse/timeval.h>
+#include <pulse/rtclock.h>
+
+#include "upower.h"
+
+static pa_dbus_pending* send_and_add_to_pending(pa_upower_backend *backend, DBusMessage *m,
+        DBusPendingCallNotifyFunction func, void *call_data) {
+
+    pa_dbus_pending *p;
+    DBusPendingCall *call;
+
+    pa_assert(backend);
+    pa_assert(m);
+
+    pa_assert_se(dbus_connection_send_with_reply(pa_dbus_connection_get(backend->connection), m, &call, -1));
+
+    p = pa_dbus_pending_new(pa_dbus_connection_get(backend->connection), m, call, backend, call_data);
+    PA_LLIST_PREPEND(pa_dbus_pending, backend->pending, p);
+    dbus_pending_call_set_notify(call, func, p, NULL);
+
+    return p;
+}
+
+static void parse_percentage(pa_upower_backend *b, DBusMessageIter *i) {
+    double percentage;
+    unsigned int battery_level;
+
+    pa_assert(i);
+    pa_assert(dbus_message_iter_get_arg_type(i) == DBUS_TYPE_DOUBLE);
+
+    dbus_message_iter_get_basic(i, &percentage);
+    battery_level = (unsigned int) round(percentage / 20.0);
+
+    if (battery_level != b->battery_level) {
+        b->battery_level = battery_level;
+        pa_log_debug("AG battery level updated (%d/5)", b->battery_level);
+        pa_hook_fire(pa_bluetooth_discovery_hook(b->discovery, PA_BLUETOOTH_HOOK_HOST_BATTERY_LEVEL_CHANGED), b);
+    }
+}
+
+static void get_percentage_reply(DBusPendingCall *pending, void *userdata) {
+    pa_dbus_pending *p;
+    pa_upower_backend *b;
+    DBusMessage *r;
+    DBusMessageIter arg_i, variant_i;
+
+    pa_assert(pending);
+    pa_assert_se(p = userdata);
+    pa_assert_se(b = p->context_data);
+    pa_assert_se(r = dbus_pending_call_steal_reply(pending));
+
+    if (dbus_message_is_error(r, DBUS_ERROR_UNKNOWN_METHOD)) {
+        pa_log_warn("UPower D-Bus Display Device not available");
+        goto finish;
+    }
+
+    if (dbus_message_get_type(r) == DBUS_MESSAGE_TYPE_ERROR) {
+        pa_log_error("Get() failed: %s: %s", dbus_message_get_error_name(r), pa_dbus_get_error_message(r));
+        goto finish;
+    }
+
+    if (!dbus_message_iter_init(r, &arg_i) || !pa_streq(dbus_message_get_signature(r), "v")) {
+        pa_log_error("Invalid reply signature for Get()");
+        goto finish;
+    }
+
+    dbus_message_iter_recurse(&arg_i, &variant_i);
+    parse_percentage(b, &variant_i);
+
+finish:
+    dbus_message_unref(r);
+
+    PA_LLIST_REMOVE(pa_dbus_pending, b->pending, p);
+    pa_dbus_pending_free(p);
+}
+
+static const char *check_variant_property(DBusMessageIter *i) {
+    const char *key;
+
+    pa_assert(i);
+
+    if (dbus_message_iter_get_arg_type(i) != DBUS_TYPE_STRING) {
+        pa_log_error("Property name not a string.");
+        return NULL;
+    }
+
+    dbus_message_iter_get_basic(i, &key);
+
+    if (!dbus_message_iter_next(i)) {
+        pa_log_error("Property value missing");
+        return NULL;
+    }
+
+    if (dbus_message_iter_get_arg_type(i) != DBUS_TYPE_VARIANT) {
+        pa_log_error("Property value not a variant.");
+        return NULL;
+    }
+
+    return key;
+}
+
+static DBusHandlerResult filter_cb(DBusConnection *bus, DBusMessage *m, void *data) {
+    DBusError err;
+    DBusMessage *m2;
+    static const char* upower_device_interface = UPOWER_SERVICE UPOWER_DEVICE_INTERFACE;
+    static const char* percentage_property = "Percentage";
+    pa_upower_backend *b = data;
+    const char *path, *interface, *member;
+
+    pa_assert(bus);
+    pa_assert(m);
+    pa_assert(b);
+
+    dbus_error_init(&err);
+
+    path = dbus_message_get_path(m);
+    interface = dbus_message_get_interface(m);
+    member = dbus_message_get_member(m);
+
+    pa_log_debug("dbus: path=%s, interface=%s, member=%s", path, interface, member);
+
+    /* UPower D-Bus status change */
+    if (dbus_message_is_signal(m, DBUS_INTERFACE_DBUS, "NameOwnerChanged")) {
+        const char *name, *old_owner, *new_owner;
+
+        if (!dbus_message_get_args(m, &err,
+                                   DBUS_TYPE_STRING, &name,
+                                   DBUS_TYPE_STRING, &old_owner,
+                                   DBUS_TYPE_STRING, &new_owner,
+                                   DBUS_TYPE_INVALID)) {
+            pa_log_error("Failed to parse " DBUS_INTERFACE_DBUS ".NameOwnerChanged: %s", err.message);
+            goto fail;
+        }
+
+        if (pa_streq(name, UPOWER_SERVICE)) {
+
+            /* UPower disappeared from D-Bus */
+            if (old_owner && *old_owner) {
+                pa_log_debug("UPower disappeared from D-Bus");
+                b->battery_level = 0;
+                pa_hook_fire(pa_bluetooth_discovery_hook(b->discovery, PA_BLUETOOTH_HOOK_HOST_BATTERY_LEVEL_CHANGED), b);
+            }
+
+            /* UPower appeared on D-Bus */
+            if (new_owner && *new_owner) {
+                pa_log_debug("UPower appeared on D-Bus");
+
+                /* Update battery level */
+                pa_assert_se(m2 = dbus_message_new_method_call(UPOWER_SERVICE, UPOWER_DISPLAY_DEVICE_OBJECT, DBUS_INTERFACE_PROPERTIES, "Get"));
+                pa_assert_se(dbus_message_append_args(m2,
+                    DBUS_TYPE_STRING, &upower_device_interface,
+                    DBUS_TYPE_STRING, &percentage_property,
+                    DBUS_TYPE_INVALID));
+                send_and_add_to_pending(b, m2, get_percentage_reply, NULL);
+            }
+        }
+
+        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+    /* UPower battery level property updates */
+    } else if (dbus_message_is_signal(m, DBUS_INTERFACE_PROPERTIES, "PropertiesChanged")) {
+        DBusMessageIter arg_i, element_i;
+
+        if (!dbus_message_iter_init(m, &arg_i) || !pa_streq(dbus_message_get_signature(m), "sa{sv}as")) {
+            pa_log_error("Invalid signature found in PropertiesChanged");
+            goto fail;
+        }
+
+        /* Skip interface name */
+        pa_assert_se(dbus_message_iter_next(&arg_i));
+        pa_assert(dbus_message_iter_get_arg_type(&arg_i) == DBUS_TYPE_ARRAY);
+
+        dbus_message_iter_recurse(&arg_i, &element_i);
+
+        /* Parse UPower property updates */
+        while (dbus_message_iter_get_arg_type(&element_i) == DBUS_TYPE_DICT_ENTRY) {
+            DBusMessageIter dict_i, variant_i;
+            const char *key;
+
+            dbus_message_iter_recurse(&element_i, &dict_i);
+
+            /* Retrieve property name */
+            key = check_variant_property(&dict_i);
+            if (key == NULL) {
+                pa_log_error("Received invalid property!");
+                break;
+            }
+
+            dbus_message_iter_recurse(&dict_i, &variant_i);
+
+            if(pa_streq(path, UPOWER_DISPLAY_DEVICE_OBJECT)) {
+                pa_log_debug("UPower Device property updated: %s", key);
+
+                if(pa_streq(key, "Percentage"))
+                    parse_percentage(b, &variant_i);
+            }
+
+            dbus_message_iter_next(&element_i);
+        }
+    }
+
+fail:
+    dbus_error_free(&err);
+    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
+}
+
+unsigned int pa_upower_get_battery_level(pa_upower_backend *backend) {
+    return backend->battery_level;
+}
+
+pa_upower_backend *pa_upower_backend_new(pa_core *c, pa_bluetooth_discovery *d) {
+    pa_upower_backend *backend;
+    DBusError err;
+    DBusMessage *m;
+    static const char* upower_device_interface = UPOWER_SERVICE UPOWER_DEVICE_INTERFACE;
+    static const char* percentage_property = "Percentage";
+
+    pa_log_debug("Native backend enabled UPower battery status reporting");
+
+    backend = pa_xnew0(pa_upower_backend, 1);
+    backend->core = c;
+    backend->discovery = d;
+
+    /* Get DBus connection */
+    dbus_error_init(&err);
+    if (!(backend->connection = pa_dbus_bus_get(c, DBUS_BUS_SYSTEM, &err))) {
+        pa_log("Failed to get D-Bus connection: %s", err.message);
+        dbus_error_free(&err);
+        pa_xfree(backend);
+        return NULL;
+    }
+
+    /* Add filter callback for DBus connection */
+    if (!dbus_connection_add_filter(pa_dbus_connection_get(backend->connection), filter_cb, backend, NULL)) {
+        pa_log_error("Failed to add filter function");
+        pa_dbus_connection_unref(backend->connection);
+        pa_xfree(backend);
+        return NULL;
+    }
+
+    /* Register for battery level changes from UPower */
+    if (pa_dbus_add_matches(pa_dbus_connection_get(backend->connection), &err,
+            "type='signal',sender='" DBUS_SERVICE_DBUS "',interface='" DBUS_INTERFACE_DBUS "',member='NameOwnerChanged',"
+            "arg0='" UPOWER_SERVICE "'",
+            "type='signal',sender='" UPOWER_SERVICE "',interface='" DBUS_INTERFACE_PROPERTIES "',member='PropertiesChanged'",
+            NULL) < 0) {
+        pa_log("Failed to add UPower D-Bus matches: %s", err.message);
+        dbus_connection_remove_filter(pa_dbus_connection_get(backend->connection), filter_cb, backend);
+        pa_dbus_connection_unref(backend->connection);
+        pa_xfree(backend);
+        return NULL;
+    }
+
+    /* Initialize battery level by requesting it from UPower */
+    pa_assert_se(m = dbus_message_new_method_call(UPOWER_SERVICE, UPOWER_DISPLAY_DEVICE_OBJECT, DBUS_INTERFACE_PROPERTIES, "Get"));
+    pa_assert_se(dbus_message_append_args(m,
+        DBUS_TYPE_STRING, &upower_device_interface,
+        DBUS_TYPE_STRING, &percentage_property,
+        DBUS_TYPE_INVALID));
+    send_and_add_to_pending(backend, m, get_percentage_reply, NULL);
+
+    return backend;
+}
+
+void pa_upower_backend_free(pa_upower_backend *backend) {
+    pa_assert(backend);
+
+    pa_dbus_free_pending_list(&backend->pending);
+
+    pa_dbus_connection_unref(backend->connection);
+
+    pa_xfree(backend);
+}
+
diff --git a/src/modules/bluetooth/upower.h b/src/modules/bluetooth/upower.h
new file mode 100644
index 000000000..3e9ee9291
--- /dev/null
+++ b/src/modules/bluetooth/upower.h
@@ -0,0 +1,41 @@
+#pragma once
+
+/***
+  This file is part of PulseAudio.
+
+  Copyrigth 2022 Dylan Van Assche <me@dylanvanassche.be>
+
+  PulseAudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+
+  PulseAudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "bluez5-util.h"
+
+#define UPOWER_SERVICE "org.freedesktop.UPower"
+#define UPOWER_DEVICE_INTERFACE ".Device"
+#define UPOWER_DISPLAY_DEVICE_OBJECT "/org/freedesktop/UPower/devices/DisplayDevice"
+
+struct pa_upower_backend {
+    pa_core *core;
+    pa_dbus_connection *connection;
+    pa_bluetooth_discovery *discovery;
+    unsigned int battery_level;
+
+    PA_LLIST_HEAD(pa_dbus_pending, pending);
+};
+
+pa_upower_backend *pa_upower_backend_new(pa_core *c, pa_bluetooth_discovery *d);
+void pa_upower_backend_free(pa_upower_backend *backend);
+void pa_upower_register_transport(pa_upower_backend *backend, pa_bluetooth_transport *t);
+void pa_upower_unregister_transport(pa_upower_backend *backend);
+unsigned int pa_upower_get_battery_level(pa_upower_backend *backend);
-- 
2.35.1

