/*
 * Copyright (c) 2011- Osmo Antero.
*
* 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 3 of the License (GPL3), or 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 3 for more details.
*
* You should have received a copy of the GNU Library General Public
* License 3 along with this program; if not, see /usr/share/common-licenses/GPL file
* or <http://www.gnu.org/licenses/>.
*/
#include "gst-devices.h"
#include "support.h" // _(x)
#include "log.h"
#include "utility.h"
#include "rec-manager-struct.h"

#include <stdio.h>
#include <string.h>
#include <glib.h>

// Collect audio input devices and audio output devices w/ connected loudspeakers.
// This module is using gst_device_monitor_* functions that were introduced in GStreamer 1.4.

// You may also check the output of these pa (pulseaudio) commands.

// Get list of input devices:
// $ pactl list short sources | cut -f2
// $ pactl list | grep -A6  'Source #' | egrep "Name: |Description: "
//
// Get list of sink (output) devices:
// $ pactl list short sinks | cut -f2
// $ pactl list | grep -A6  'Sink #' | egrep "Name: |Description: "


// Audio source devices
G_LOCK_DEFINE_STATIC(g_source_list);
static GList *g_source_list = NULL;

static GstDeviceMonitor *g_dev_monitor = NULL;

static void gstdev_get_devices();
static void gstdev_read_fields(GstDevice *dev, gchar **dev_id, gchar **id_attrib, gchar **dev_descr, gchar **media_role, gchar **dev_class, gchar **icon_name);
static void gstdev_add_to_list(GstDevice *dev);
static void gstdev_remove_from_list(GstDevice *dev);
static void gstdev_clear_lists();

void gstdev_module_init() {
    LOG_DEBUG("Init gst-devices.c.\n");
    g_source_list = NULL;
    g_dev_monitor = NULL;
}

void gstdev_module_exit() {
    LOG_DEBUG("Clean up gst-devices.c.\n");

    if (GST_IS_DEVICE_MONITOR(g_dev_monitor)) {
        gst_device_monitor_stop(g_dev_monitor);
        gst_object_unref(g_dev_monitor);
    }

    g_dev_monitor = NULL;

    // Clear lists
    gstdev_clear_lists();
}

GList *gstdev_get_source_list() {
    // Return g_source_list to the caller

    gstdev_get_devices();

    return g_source_list;
}

static void gstdev_clear_lists() {
    LOG_DEBUG("gstdev_clear_lists(). Clear g_source_list.\n");

    G_LOCK(g_source_list);

    // Free g_source_list
    audio_sources_free_list(g_source_list);
    g_source_list = NULL;

    G_UNLOCK(g_source_list);
}

void gstdev_update_GUI() {
    // Device list changed. Update GUI.

    RecorderCommand *cmd = g_malloc0(sizeof(RecorderCommand));
    cmd->type = RECORDING_DEVICE_CHANGED;

    // Send command to rec-manager.c and GUI.
    // It will free the cmd structure after processing.
    rec_manager_send_command(cmd);
}

static gboolean message_func(GstBus *bus, GstMessage *message, gpointer user_data) {
    GstDevice *device = NULL;
    gchar *name = NULL;

    LOG_DEBUG("message_func(): function to add or remove device called.\n");

    switch (GST_MESSAGE_TYPE (message)) {
    case GST_MESSAGE_DEVICE_ADDED:
        gst_message_parse_device_added(message, &device);

        name = gst_device_get_display_name(device);

        LOG_DEBUG("Audio device added: %s\n", name);
        g_free (name);

        gstdev_add_to_list(device);

        gstdev_update_GUI();

        break;

    case GST_MESSAGE_DEVICE_REMOVED:
        gst_message_parse_device_removed(message, &device);

        name = gst_device_get_display_name(device);

        LOG_DEBUG("Audio device removed: %s\n", name);
        g_free (name);

        gstdev_remove_from_list(device);

        gstdev_update_GUI();

        break;

    default:
        break;
    }

    return G_SOURCE_CONTINUE;
}

GstDeviceMonitor *setup_raw_audio_source_device_monitor() {

    LOG_DEBUG("Setup monitor to detect new and unplugged devices.\n");

    GstDeviceMonitor *monitor = gst_device_monitor_new ();

    GstBus *bus = gst_device_monitor_get_bus(monitor);
    gst_bus_add_watch(bus, message_func, NULL);
    gst_object_unref(bus);

    GstCaps *caps = gst_caps_new_empty_simple ("audio/x-raw");
    gst_device_monitor_add_filter(monitor, NULL, caps); // "Audio/Source", "Audio/Sink"
    gst_caps_unref (caps);

    gst_device_monitor_start(monitor);

    return monitor;
}

static void gstdev_read_fields(GstDevice *dev, gchar **dev_id, gchar **id_attrib, gchar **dev_descr, gchar **media_role, gchar **dev_class, gchar **icon_name) {

	*dev_id = NULL;
    *id_attrib = NULL;
    *media_role = NULL;
    *icon_name = NULL;

    gchar *disp_name = gst_device_get_display_name(dev);

    // Cut it nicely
    *dev_descr = g_strdup(disp_name);
    str_cut_nicely(*dev_descr, 39/*to len*/, 25/*minimum len*/);

    g_free(disp_name);

    *dev_class = gst_device_get_device_class(dev);

	GstStructure *dev_props = gst_device_get_properties(dev);

	gchar *txt = gst_structure_to_string(dev_props);
	g_free(txt);
	
	gint nn = gst_structure_n_fields(dev_props);

	for (gint i=0; i < nn; i++) {
	
		const gchar *fname = gst_structure_nth_field_name (dev_props, i);

        const gchar *sval;

        sval = NULL;
        if (gst_structure_get_field_type(dev_props, fname) == G_TYPE_STRING) {
		    sval = gst_structure_get_string(dev_props, fname);  
	    }
	    
		if (g_strrstr0(fname, "object.id")) {
			*dev_id = g_strdup(sval);
			*id_attrib = g_strdup("path");
		
		} else if (g_strrstr0(fname, "media.class")) {
			// *dev_class = g_strdup(sval);

		} else if (g_strrstr0(fname, "device.icon_name")) {  // <-- Pulseaudio
			*icon_name = g_strdup(sval); 

		} else if (g_strrstr0(fname, "device.icon-name")) {  // <-- Pipewire
			*icon_name = g_strdup(sval); 

		} else if (g_strrstr0(fname, "device.form_factor")) { // <-- Pulseaudio
			*media_role = g_strdup(sval); 

		} else if (g_strrstr0(fname, "device.form-factor")) {  // <-- Pipewire
			*media_role = g_strdup(sval); 
		}
		
	} 
	
	gst_structure_free(dev_props);
 
// -----------

    // Read device id if Pulsesrc 
    // or read device's path number if Pipewiresrc
    GstElement *e = gst_device_create_element(dev, "this_elemnt");

	// Id or path number.		
    // In PulseAudio`s pulsesrc this field is a "device" id.
	// See:
 	// $ pactl list short sources | cut -f2
 	// $ pactl list | grep -A3 'Source #'
	//
	// In Pipewire's pipewiresrc this is a "path" number. 
	// See:
	// $ pw-cli dump short Node
	
	GObjectClass *oclass = G_OBJECT_GET_CLASS(e);
	guint n = 0;
	GParamSpec **props = g_object_class_list_properties(oclass, &n);

	GValue val = G_VALUE_INIT;

	for (guint i=0; i <n; i++) {

		g_value_init(&val, props[i]->value_type);
    	g_object_get_property(G_OBJECT(e), props[i]->name, &val);

	   	// g_print("%i:  prop name=%s   value=%s\n", i, props[i]->name, g_strdup_value_contents(&val)); 

		// 
		// prop name=name   value="elemntxx"
		// prop name=parent   value=NULL
		// prop name=blocksize   value=4096
		// prop name=num-buffers   value=-1
		// prop name=typefind   value=FALSE
		// prop name=do-timestamp   value=FALSE
		//
		// prop name=path   value="80"      <-- Pipewire
		//	or	
		// name=device   value="alsa_output.pci-0000_00_1f.3.analog-stereo"  <-- Pulseaudio
		//

		if (!g_strcmp0(props[i]->name, "role")) {
				// *media_role = g_value_dup_string(&val);
				
		} if (!g_strcmp0(props[i]->name, "device")) {
				*dev_id = g_value_dup_string(&val);
				*id_attrib = g_strdup("device");
				
		} else if (!g_strcmp0(props[i]->name, "path")) {

				if (*dev_id == NULL) {
					*dev_id = g_value_dup_string(&val);
					*id_attrib = g_strdup("path");
				}
		}		

		g_value_unset(&val);

	}
	
	g_free(props);
    gst_object_unref(GST_OBJECT(e));

}

GList *remove_item(GList *list, gchar *dev_id) {

    GList *item = g_list_first(list);
    while (item) {

        DeviceItem *rec = (DeviceItem*)item->data;
        if (rec) {
			if (rec->id && dev_id && g_strcmp0(rec->id, dev_id) == 0) {
				list = g_list_delete_link(list, item);
				device_item_free(rec);
				return list;
     		}
     	}	
     	
        item = g_list_next(item);
    }

    // Return unmodified list
    return list;
}

static void gstdev_remove_from_list(GstDevice *dev) {
    gchar *dev_id = NULL;
	gchar *id_attrib = NULL;
    gchar *dev_descr = NULL;
	gchar *media_role = NULL;
    gchar *dev_class = NULL;
    gchar *icon_name = NULL;

    LOG_DEBUG("Remove device from the list.\n");

    G_LOCK(g_source_list);

    gstdev_read_fields(dev, &dev_id, &id_attrib, &dev_descr, &media_role, &dev_class, &icon_name);

	g_source_list = remove_item(g_source_list, dev_id);


    g_free(dev_id);
    g_free(id_attrib);
    g_free(dev_descr);
    g_free(media_role);
    g_free(dev_class);
    g_free(icon_name);

    G_UNLOCK(g_source_list);
}

static void gstdev_add_to_list(GstDevice *dev) {
    gchar *dev_descr = NULL;
    gchar *dev_id = NULL;
    gchar *id_attrib = NULL;
    gchar *media_role = NULL;
    gchar *dev_class = NULL;
    gchar *icon_name = NULL;

    LOG_DEBUG("Add new (input or output) device to the list.\n");

    G_LOCK(g_source_list);

    gstdev_read_fields(dev, &dev_id, &id_attrib, &dev_descr, &media_role, &dev_class, &icon_name);

	gboolean add = FALSE;

    // Create new DeviceItem
    DeviceItem *item = device_item_create(dev_id, dev_descr);

	gchar *dev_class_l = g_ascii_strdown(dev_class, -1);
	item->dev_class = g_strdup(dev_class_l);

	item->id_attrib = g_strdup(id_attrib);
	item->media_role = g_strdup(media_role);

	// media.class == Audio/Source
	// media.class == Video/Source   ?and media.role == Camera    
	// media.class == Audio/Sink 

    item->type = AUDIO_INPUT;

    // Audio/Source
    if (g_strrstr(item->dev_class, "audio/source")) {

        // Webcam or video camera?
		if (g_strrstr0(item->media_role, "cam") || g_strrstr0(item->media_role, "webcam") || g_strrstr0(item->media_role, "camera") || g_strrstr0(item->media_role, "video")) {

            // Some suitable icon names      
            item->icon_name = g_strdup_printf("%s\n%s\n%s\n%s", "camera-web", icon_name, "audio-input-microphone", "microphone.png");
        
        } else {

            // Some suitable icon names      
            item->icon_name = g_strdup_printf("%s\n%s\n%s", icon_name, "audio-input-microphone", "microphone.png");
        }

        LOG_DEBUG("Add Audio/Source to g_source_list:%s, id_attrib:%s, decr:%s, role:%s class:%s icon:%s\n", 
                    dev_id, id_attrib, dev_descr, media_role, dev_class, item->icon_name);

        add = TRUE;
	} 
	
    // Video/Source (Cameras that capture audio and video)
    if (g_strrstr(item->dev_class, "video/source")) {

        // Some suitable icon names      
        item->icon_name = g_strdup_printf("%s\n%s\n%s\n%s", icon_name, "camera-web", "audio-input-microphone", "microphone.png");

        LOG_DEBUG("Add Video/Source to g_source_list:%s, id_attrib:%s, decr:%s, role:%s class:%s icon:%s\n", 
                    dev_id, id_attrib, dev_descr, media_role, dev_class, item->icon_name);
        
        add = TRUE;
	}

    // Audio/Sink (audio card, loudspeakers, mixed output)
    if (g_strrstr(item->dev_class, "audio/sink")) {

        // Some suitable icon names      
        item->icon_name = g_strdup_printf("%s\n%s\n%s\n%s", icon_name, "audio-card", "audio-speaker-center", "loudspeaker.png");

        LOG_DEBUG("Add Audio/Sink to g_source_list:%s, id_attrib:%s, decr:%s, role:%s class:%s icon:%s\n", 
                    dev_id, id_attrib, dev_descr, media_role, dev_class, item->icon_name);

        add = TRUE;
	}

	if (add) {
        g_source_list = g_list_append(g_source_list, item);
	} else {
	
		device_item_free(item);
		item = NULL;
	}

    g_free(dev_id);
    g_free(id_attrib);
    g_free(media_role);
    g_free(dev_descr);
    g_free(dev_class);
    g_free(dev_class_l);
    g_free(icon_name);

    G_UNLOCK(g_source_list);
}

void gstdev_fix_the_list() {
    // Note: Check listing of these commands (in Pulseaudio):
    //
    // Input devices:
    // pactl list | grep -A6  'Source #' | egrep "Name: |Description: "
    // pactl list short sources | cut -f2
    //
    // And sink (output) devices:
    // pactl list | grep -A6  'Sink #' | egrep "Name: |Description: "
    // pactl list short sinks | cut -f2

    // Remove obsolete DeviceItems
    // Keep the .monitor device, but delete its audio card listing (its Audio/Sink device). We cannot record from it.
    // Below, we delete the _item and keep _item2. 
    //  
    // _item->id: alsa_output.pci-0000_00_1f.3.analog-stereo.monitor  <-- keep this .monitor device
    // _item->description: Monitor of Built-in Audio Analog Stereo 
    // _item->dev_class: Audio/Source     <--  Replace this with "audio/sink" so we can find it later.

    // _item2->id: alsa_output.pci-0000_00_1f.3.analog-stereo <-- delete this (cannot record from /Sink)
    // _item2->description: Built-in Audio Analog Stereo
    // _item2->dev_class: Audio/Sink

    G_LOCK(g_source_list);

    GList *n = g_list_first(g_source_list);
    while (n) {

        DeviceItem *item = (DeviceItem*)n->data;
        if (g_strrstr0(item->dev_class, "audio/sink")) {
        
            gchar *dev_id = g_strdup_printf("%s.monitor", item->id);
        
            DeviceItem *found_item = audio_sources_find_in_list(g_source_list, dev_id);
            if (found_item && found_item != item) {

                g_free(found_item->dev_class);
                found_item->dev_class = g_strdup("audio/sink");
                
                g_free(found_item->icon_name);
                found_item->icon_name = g_strdup(item->icon_name);

                // Mark this to be deleted
                g_free(item->id); 
                item->id  = NULL;
            }
            
            g_free(dev_id);
        }

        n = g_list_next(n);
    }

    // Remove NULL items (traverse the list right way)
    n = g_list_first(g_source_list);
    while (n) {

        DeviceItem *item = (DeviceItem*)n->data;

        GList *next = g_list_next(n);

        if (item->id == NULL) {
            g_source_list = g_list_delete_link(g_source_list, n);
            device_item_free(item);
        }       

        n = next;
    }

    G_UNLOCK(g_source_list);
}

static void gstdev_get_devices() {

    LOG_DEBUG("Get list of audio input/output devices from GStreamer.\n");

    gstdev_clear_lists();

    // Set up device monitor
    if (!GST_IS_DEVICE_MONITOR(g_dev_monitor)) {
        g_dev_monitor = setup_raw_audio_source_device_monitor();
    }

    GList *list = gst_device_monitor_get_devices(g_dev_monitor);

    // Ref: http://code.metager.de/source/xref/freedesktop/gstreamer/gstreamer/gst/gstdevice.c

    GList *n = g_list_first(list);
    while (n) {
        GstDevice *dev = (GstDevice*)n->data;

        gstdev_add_to_list(dev);

        n = g_list_next(n);
    }

    g_list_free_full(list, (GDestroyNotify)gst_object_unref);

    // Fix the list if pulseaudio 
    gstdev_fix_the_list();
}