/* GStreamer
 * Copyright (C) 2016 Hyunjun Ko <zzoon@igalia.com>
 *
 * gstosxaudiodeviceprovider.c: OSX audio device probing and monitoring
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gst/gst.h>
#include <gst/audio/audio.h>
#include "gstosxaudiosrc.h"
#include "gstosxaudiosink.h"
#include "gstosxaudiodeviceprovider.h"

GST_DEBUG_CATEGORY_STATIC (gst_osxaudio_device_debug);
#define GST_CAT_DEFAULT gst_osxaudio_device_debug

#if defined(MAC_OS_X_VERSION_MAX_ALLOWED) && MAC_OS_X_VERSION_MAX_ALLOWED < 120000
#define kAudioObjectPropertyElementMain kAudioObjectPropertyElementMaster
#endif

static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_OSX_AUDIO_SRC_CAPS)
    );

static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_OSX_AUDIO_SINK_CAPS)
    );

static GstOsxAudioDevice *gst_osx_audio_device_new (AudioDeviceID device_id,
    const gchar * device_name, GstOsxAudioDeviceType type,
    GstCoreAudio * core_audio);

G_DEFINE_TYPE (GstOsxAudioDeviceProvider, gst_osx_audio_device_provider,
    GST_TYPE_DEVICE_PROVIDER);
GST_DEVICE_PROVIDER_REGISTER_DEFINE (osxaudiodeviceprovider,
    "osxaudiodeviceprovider", GST_RANK_PRIMARY,
    GST_TYPE_OSX_AUDIO_DEVICE_PROVIDER);

static gboolean gst_osx_audio_device_provider_start (GstDeviceProvider *
    provider);
static void gst_osx_audio_device_provider_stop (GstDeviceProvider * provider);
static GList *gst_osx_audio_device_provider_probe (GstDeviceProvider *
    provider);
static void
gst_osx_audio_device_provider_update_devices (GstOsxAudioDeviceProvider * self);

static void
gst_osx_audio_device_provider_class_init (GstOsxAudioDeviceProviderClass *
    klass)
{
  GstDeviceProviderClass *dm_class = GST_DEVICE_PROVIDER_CLASS (klass);

  dm_class->start = gst_osx_audio_device_provider_start;
  dm_class->stop = gst_osx_audio_device_provider_stop;
  dm_class->probe = gst_osx_audio_device_provider_probe;

  gst_device_provider_class_set_static_metadata (dm_class,
      "OSX Audio Device Provider", "Source/Sink/Audio",
      "List and monitor OSX audio source and sink devices",
      "Hyunjun Ko <zzoon@igalia.com>");

  GST_DEBUG_CATEGORY_INIT (gst_osxaudio_device_debug, "osxaudio_device", 0,
      "Audio device provider for macOS");
}

static void
gst_osx_audio_device_provider_init (GstOsxAudioDeviceProvider * provider)
{
}

static GstOsxAudioDevice *
gst_osx_audio_device_provider_probe_device (GstOsxAudioDeviceProvider *
    provider, AudioDeviceID device_id, const gchar * device_name,
    GstOsxAudioDeviceType type, gboolean is_default)
{
  GstOsxAudioDevice *device = NULL;
  GstCoreAudio *core_audio;

  core_audio = gst_core_audio_new (NULL);
  core_audio->is_src = type == GST_OSX_AUDIO_DEVICE_TYPE_SOURCE ? TRUE : FALSE;
  core_audio->device_id = device_id;
  core_audio->is_default = is_default;

  if (!gst_core_audio_open (core_audio)) {
    GST_ERROR ("CoreAudio device could not be opened");
    goto done;
  }

  device = gst_osx_audio_device_new (device_id, device_name, type, core_audio);

  gst_core_audio_close (core_audio);

done:
  g_object_unref (core_audio);

  return device;
}

static inline gchar *
_audio_device_get_cfstring_prop (AudioDeviceID device_id, gboolean output,
    AudioObjectPropertyElement prop_id)
{
  OSStatus status = noErr;
  UInt32 propertySize = 0;
  CFStringRef prop_val;
  gchar *result = NULL;

  AudioObjectPropertyAddress propAddress = {
    prop_id,
    kAudioDevicePropertyScopeOutput,
    kAudioObjectPropertyElementMain
  };

  propAddress.mScope = output ? kAudioDevicePropertyScopeOutput :
      kAudioDevicePropertyScopeInput;

  /* Get the length of the device name */
  status = AudioObjectGetPropertyDataSize (device_id,
      &propAddress, 0, NULL, &propertySize);
  if (status != noErr) {
    goto beach;
  }

  /* Get the requested property */
  status = AudioObjectGetPropertyData (device_id,
      &propAddress, 0, NULL, &propertySize, &prop_val);
  if (status != noErr) {
    goto beach;
  }

  /* Convert to UTF-8 C String */
  CFIndex prop_len = CFStringGetLength (prop_val);
  CFIndex max_size =
      CFStringGetMaximumSizeForEncoding (prop_len, kCFStringEncodingUTF8) + 1;
  result = g_malloc (max_size);

  if (!CFStringGetCString (prop_val, result, max_size, kCFStringEncodingUTF8)) {
    g_free (result);
    result = NULL;
  }

  CFRelease (prop_val);

beach:
  return result;
}

static inline gchar *
_audio_device_get_name (AudioDeviceID device_id, gboolean output)
{
  return _audio_device_get_cfstring_prop (device_id, output,
      kAudioObjectPropertyName);
}

static inline gchar *
_audio_device_get_uid (AudioDeviceID device_id, gboolean output)
{
  return _audio_device_get_cfstring_prop (device_id, output,
      kAudioDevicePropertyDeviceUID);
}

static inline gboolean
_audio_device_has_output (AudioDeviceID device_id)
{
  OSStatus status = noErr;
  UInt32 propertySize;

  AudioObjectPropertyAddress streamsAddress = {
    kAudioDevicePropertyStreams,
    kAudioDevicePropertyScopeOutput,
    kAudioObjectPropertyElementMain
  };

  status = AudioObjectGetPropertyDataSize (device_id,
      &streamsAddress, 0, NULL, &propertySize);

  if (status != noErr) {
    GST_WARNING ("failed getting device property: %d", (int) status);
    return FALSE;
  }
  if (propertySize == 0) {
    GST_DEBUG ("property size was 0; device has no output channels");
    return FALSE;
  }

  return TRUE;
}

static inline gboolean
_audio_device_has_input (AudioDeviceID device_id)
{
  OSStatus status = noErr;
  UInt32 propertySize;

  AudioObjectPropertyAddress streamsAddress = {
    kAudioDevicePropertyStreams,
    kAudioDevicePropertyScopeInput,
    kAudioObjectPropertyElementMain
  };

  status = AudioObjectGetPropertyDataSize (device_id,
      &streamsAddress, 0, NULL, &propertySize);

  if (status != noErr) {
    GST_WARNING ("failed getting device property: %d", (int) status);
    return FALSE;
  }
  if (propertySize == 0) {
    GST_DEBUG ("property size was 0; device has no input channels");
    return FALSE;
  }

  return TRUE;
}


static inline AudioDeviceID
_audio_system_get_default_device (gboolean output)
{
  OSStatus status = noErr;
  UInt32 propertySize = sizeof (AudioDeviceID);
  AudioDeviceID device_id = kAudioDeviceUnknown;
  AudioObjectPropertySelector prop_selector;

  prop_selector = output ? kAudioHardwarePropertyDefaultOutputDevice :
      kAudioHardwarePropertyDefaultInputDevice;

  AudioObjectPropertyAddress defaultDeviceAddress = {
    prop_selector,
    kAudioObjectPropertyScopeGlobal,
    kAudioObjectPropertyElementMain
  };

  status = AudioObjectGetPropertyData (kAudioObjectSystemObject,
      &defaultDeviceAddress, 0, NULL, &propertySize, &device_id);
  if (status != noErr) {
    GST_ERROR ("failed getting default output device: %d", (int) status);
  }

  GST_DEBUG ("Default device id: %u", (unsigned) device_id);

  return device_id;
}

static inline AudioDeviceID *
_audio_system_get_devices (gint * ndevices)
{
  OSStatus status = noErr;
  UInt32 propertySize = 0;
  AudioDeviceID *devices = NULL;

  AudioObjectPropertyAddress audioDevicesAddress = {
    kAudioHardwarePropertyDevices,
    kAudioObjectPropertyScopeGlobal,
    kAudioObjectPropertyElementMain
  };

  status = AudioObjectGetPropertyDataSize (kAudioObjectSystemObject,
      &audioDevicesAddress, 0, NULL, &propertySize);
  if (status != noErr) {
    GST_WARNING ("failed getting number of devices: %d", (int) status);
    return NULL;
  }

  *ndevices = propertySize / sizeof (AudioDeviceID);

  devices = (AudioDeviceID *) g_malloc (propertySize);
  if (devices) {
    status = AudioObjectGetPropertyData (kAudioObjectSystemObject,
        &audioDevicesAddress, 0, NULL, &propertySize, devices);
    if (status != noErr) {
      GST_WARNING ("failed getting the list of devices: %d", (int) status);
      g_free (devices);
      *ndevices = 0;
      return NULL;
    }
  }

  return devices;
}

static OSStatus
_audio_devices_changed_cb (AudioObjectID inObjectID, UInt32 inNumberAddresses,
    const AudioObjectPropertyAddress * inAddresses,
    void *__nullable inClientData)
{
  GstOsxAudioDeviceProvider *self =
      GST_OSX_AUDIO_DEVICE_PROVIDER (inClientData);

  GST_DEBUG ("Audio devices changed");
  gst_osx_audio_device_provider_update_devices (self);

  return noErr;
}

static AudioObjectPropertyAddress
_get_devices_list_address ()
{
  AudioObjectPropertyAddress address = {
    .mSelector = kAudioHardwarePropertyDevices,
    .mScope = kAudioObjectPropertyScopeGlobal,
    .mElement = kAudioObjectPropertyElementMain
  };

  return address;
}

static gboolean
_start_audio_device_watcher (GstOsxAudioDeviceProvider * self)
{
  AudioObjectPropertyAddress propertyAddress = _get_devices_list_address ();
  OSStatus result = AudioObjectAddPropertyListener (kAudioObjectSystemObject,
      &propertyAddress, _audio_devices_changed_cb, self);

  if (result != noErr) {
    GST_WARNING ("Failed to add device list change listener: %d", result);
    return FALSE;
  }

  GST_DEBUG ("Audio device watcher started");
  return TRUE;
}

static gboolean
_stop_audio_device_watcher (GstOsxAudioDeviceProvider * self)
{
  AudioObjectPropertyAddress propertyAddress = _get_devices_list_address ();
  OSStatus result = AudioObjectRemovePropertyListener (kAudioObjectSystemObject,
      &propertyAddress, _audio_devices_changed_cb, self);

  if (result != noErr) {
    GST_WARNING ("Failed to remove device list change listener: %d", result);
    return FALSE;
  }

  GST_DEBUG ("Audio device watcher stopped");
  return TRUE;
}

static void
gst_osx_audio_device_provider_probe_internal (GstOsxAudioDeviceProvider * self,
    gboolean is_src, AudioDeviceID * osx_devices, gint ndevices,
    GList ** devices)
{
  gint i = 0;
  GstOsxAudioDeviceType type = GST_OSX_AUDIO_DEVICE_TYPE_INVALID;
  GstOsxAudioDevice *device = NULL;

  if (is_src) {
    type = GST_OSX_AUDIO_DEVICE_TYPE_SOURCE;
  } else {
    type = GST_OSX_AUDIO_DEVICE_TYPE_SINK;
  }

  AudioDeviceID default_device = _audio_system_get_default_device (!is_src);

  for (i = 0; i < ndevices; i++) {
    gchar *device_name;

    if ((device_name = _audio_device_get_name (osx_devices[i], FALSE))) {
      gboolean has_output = _audio_device_has_output (osx_devices[i]);
      gboolean has_input = _audio_device_has_input (osx_devices[i]);
      gboolean is_default = (default_device == osx_devices[i]);

      if (is_src && !has_input) {
        goto cleanup;
      } else if (!is_src && !has_output) {
        goto cleanup;
      }

      device =
          gst_osx_audio_device_provider_probe_device (self, osx_devices[i],
          device_name, type, is_default);
      if (device) {
        if (is_src) {
          GST_DEBUG ("Input Device ID: %u Name: %s",
              (unsigned) osx_devices[i], device_name);
        } else {
          GST_DEBUG ("Output Device ID: %u Name: %s",
              (unsigned) osx_devices[i], device_name);
        }
        gst_object_ref_sink (device);
        *devices = g_list_prepend (*devices, device);
      }

    cleanup:
      g_free (device_name);
    }
  }
}

static GList *
gst_osx_audio_device_provider_probe (GstDeviceProvider * provider)
{
  GstOsxAudioDeviceProvider *self = GST_OSX_AUDIO_DEVICE_PROVIDER (provider);
  GList *devices = NULL;
  AudioDeviceID *osx_devices = NULL;
  gint ndevices = 0;

  osx_devices = _audio_system_get_devices (&ndevices);

  if (ndevices < 1) {
    GST_WARNING ("no audio output devices found");
    goto done;
  }

  GST_INFO ("found %d audio device(s)", ndevices);

  gst_osx_audio_device_provider_probe_internal (self, TRUE, osx_devices,
      ndevices, &devices);
  gst_osx_audio_device_provider_probe_internal (self, FALSE, osx_devices,
      ndevices, &devices);

done:
  g_free (osx_devices);

  return devices;
}

static gboolean
gst_osx_audio_device_provider_start (GstDeviceProvider * provider)
{
  GstOsxAudioDeviceProvider *self = GST_OSX_AUDIO_DEVICE_PROVIDER (provider);
  GList *devices = NULL;
  GList *iter;

  devices = gst_osx_audio_device_provider_probe (provider);
  if (devices) {
    for (iter = devices; iter; iter = g_list_next (iter)) {
      gst_device_provider_device_add (provider, GST_DEVICE (iter->data));
    }

    g_list_free (devices);
  }

  return _start_audio_device_watcher (self);
}

static void
gst_osx_audio_device_provider_stop (GstDeviceProvider * provider)
{
  GstOsxAudioDeviceProvider *self = GST_OSX_AUDIO_DEVICE_PROVIDER (provider);
  _stop_audio_device_watcher (self);
}

static gboolean
gst_osx_audio_device_is_in_list (GList * list, GstDevice * gst_device)
{
  GstOsxAudioDevice *osx_device = GST_OSX_AUDIO_DEVICE (gst_device);
  gchar *name = gst_device_get_display_name (gst_device);
  GList *iter;
  gboolean found = FALSE;

  for (iter = list; iter; iter = g_list_next (iter)) {
    GstOsxAudioDevice *other_osx = GST_OSX_AUDIO_DEVICE (iter->data);
    gchar *other_name = gst_device_get_display_name (GST_DEVICE (iter->data));

    /* Only checking ID + class for now.
     * Should be enough to pick up changes when an existing output device
     * adds an input or vice versa */
    if (g_ascii_strcasecmp (name, other_name) == 0
        && osx_device->device_id == other_osx->device_id) {
      found = TRUE;
    }

    g_free (other_name);

    if (found)
      break;
  }

  g_free (name);
  return found;
}

static void
gst_osx_audio_device_provider_update_devices (GstOsxAudioDeviceProvider * self)
{
  GstDeviceProvider *provider = GST_DEVICE_PROVIDER_CAST (self);
  GList *prev_devices = NULL;
  GList *new_devices = NULL;
  GList *to_add = NULL;
  GList *to_remove = NULL;
  GList *iter;

  GST_OBJECT_LOCK (self);
  prev_devices = g_list_copy_deep (provider->devices,
      (GCopyFunc) gst_object_ref, NULL);
  GST_OBJECT_UNLOCK (self);

  new_devices = gst_osx_audio_device_provider_probe (provider);
  if (!new_devices)
    goto done;

  /* Ownership of GstDevice for gst_device_provider_device_add()
   * and gst_device_provider_device_remove() is a bit complicated.
   * Remove floating reference here for things to be clear */
  for (iter = new_devices; iter; iter = g_list_next (iter))
    gst_object_ref_sink (iter->data);

  /* Check added devices */
  for (iter = new_devices; iter; iter = g_list_next (iter)) {
    if (!gst_osx_audio_device_is_in_list
        (prev_devices, GST_DEVICE (iter->data))) {
      to_add = g_list_prepend (to_add, gst_object_ref (iter->data));
    }
  }

  /* Check removed devices */
  for (iter = prev_devices; iter; iter = g_list_next (iter)) {
    if (!gst_osx_audio_device_is_in_list (new_devices, GST_DEVICE (iter->data))) {
      to_remove = g_list_prepend (to_remove, gst_object_ref (iter->data));
    }
  }

  for (iter = to_remove; iter; iter = g_list_next (iter))
    gst_device_provider_device_remove (provider, GST_DEVICE (iter->data));

  for (iter = to_add; iter; iter = g_list_next (iter))
    gst_device_provider_device_add (provider, GST_DEVICE (iter->data));

done:
  if (prev_devices)
    g_list_free_full (prev_devices, (GDestroyNotify) gst_object_unref);

  if (to_add)
    g_list_free_full (to_add, (GDestroyNotify) gst_object_unref);

  if (to_remove)
    g_list_free_full (to_remove, (GDestroyNotify) gst_object_unref);

  if (new_devices)
    g_list_free (new_devices);
}

enum
{
  PROP_DEVICE_ID = 1,
};

G_DEFINE_TYPE (GstOsxAudioDevice, gst_osx_audio_device, GST_TYPE_DEVICE);

static void gst_osx_audio_device_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);
static void gst_osx_audio_device_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);
static GstElement *gst_osx_audio_device_create_element (GstDevice * device,
    const gchar * name);

static void
gst_osx_audio_device_class_init (GstOsxAudioDeviceClass * klass)
{
  GstDeviceClass *dev_class = GST_DEVICE_CLASS (klass);
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  dev_class->create_element = gst_osx_audio_device_create_element;

  object_class->get_property = gst_osx_audio_device_get_property;
  object_class->set_property = gst_osx_audio_device_set_property;

  g_object_class_install_property (object_class, PROP_DEVICE_ID,
      g_param_spec_int ("device-id", "Device ID", "Device ID of input device",
          0, G_MAXINT, 0, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
}

static void
gst_osx_audio_device_init (GstOsxAudioDevice * device)
{
}

static GstElement *
gst_osx_audio_device_create_element (GstDevice * device, const gchar * name)
{
  GstOsxAudioDevice *osxdev = GST_OSX_AUDIO_DEVICE (device);
  GstElement *elem;

  elem = gst_element_factory_make (osxdev->element, name);
  g_object_set (elem, "device", osxdev->device_id, NULL);

  return elem;
}

static GstOsxAudioDevice *
gst_osx_audio_device_new (AudioDeviceID device_id, const gchar * device_name,
    GstOsxAudioDeviceType type, GstCoreAudio * core_audio)
{
  GstOsxAudioDevice *gstdev;
  const gchar *element_name = NULL;
  const gchar *klass = NULL;
  GstCaps *template_caps, *caps;
  GstStructure *props = gst_structure_new_empty ("properties");

  g_return_val_if_fail (device_id > 0, NULL);
  g_return_val_if_fail (device_name, NULL);

  gst_structure_set (props, "is-default", G_TYPE_BOOLEAN,
      core_audio->is_default, NULL);

  gchar *uid = _audio_device_get_uid (device_id, !core_audio->is_src);
  if (uid != NULL) {
    gst_structure_set (props, "unique-id", G_TYPE_STRING, uid, NULL);
    g_free (uid);
  }

  switch (type) {
    case GST_OSX_AUDIO_DEVICE_TYPE_SOURCE:
      element_name = "osxaudiosrc";
      klass = "Audio/Source";

      template_caps = gst_static_pad_template_get_caps (&src_factory);
      caps = gst_core_audio_probe_caps (core_audio, template_caps);
      gst_caps_unref (template_caps);

      break;
    case GST_OSX_AUDIO_DEVICE_TYPE_SINK:
      element_name = "osxaudiosink";
      klass = "Audio/Sink";

      template_caps = gst_static_pad_template_get_caps (&sink_factory);
      caps = gst_core_audio_probe_caps (core_audio, template_caps);
      gst_caps_unref (template_caps);

      break;
    default:
      g_assert_not_reached ();
      break;
  }

  gstdev = g_object_new (GST_TYPE_OSX_AUDIO_DEVICE, "device-id",
      device_id, "display-name", device_name, "caps", caps,
      "properties", props, "device-class", klass, NULL);

  gstdev->element = element_name;


  return gstdev;
}

static void
gst_osx_audio_device_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstOsxAudioDevice *device;

  device = GST_OSX_AUDIO_DEVICE_CAST (object);

  switch (prop_id) {
    case PROP_DEVICE_ID:
      g_value_set_int (value, device->device_id);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}


static void
gst_osx_audio_device_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstOsxAudioDevice *device;

  device = GST_OSX_AUDIO_DEVICE_CAST (object);

  switch (prop_id) {
    case PROP_DEVICE_ID:
      device->device_id = g_value_get_int (value);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}