#include <math.h>
#include "gst-pipeline.h"
#include "audio-sources.h"

static GstElement *pipeline_create_simple(gchar *audio_source, GList *dev_list, gchar *enc_pipeline, gchar *output_sink, gchar **err_msg);
static GstElement *pipeline_create_complex(gchar *audio_source, GList *dev_list, gchar *enc_pipeline, gchar *output_sink, gchar **err_msg);

GstElement *pipeline_create(gchar *audio_source, GList *dev_list, gchar *enc_pipeline, gchar *output_sink, gchar **err_msg) {
    // Create a GStreamer pipeline for audio recording or listening
    GstElement *pipeline = NULL;

    // Wash the device list. User may have disconnected microphones and webcams.
    // Invalid devices will crash the GStreamer pipeline.
    // Remove invalid devices.
    GList *new_list = audio_sources_wash_device_list(dev_list);

    // Zero or one device?
    if (g_list_length(new_list) < 2) {

        // Create a simple pipeline that can record from/listen to max 1 device
        pipeline = pipeline_create_simple(audio_source, new_list, enc_pipeline, output_sink, err_msg);

    } else {

        // Create a complex pipeline that can record from/listen to 2 or more devices
        pipeline = pipeline_create_complex(audio_source, new_list, enc_pipeline, output_sink, err_msg);

    }

    // Free new_list
    str_list_free(new_list);
    new_list = NULL;

    return pipeline;
}

GstElement *pipeline_create_simple(gchar *audio_source, GList *dev_list, gchar *enc_pipeline, gchar *output_sink, gchar **err_msg) {
    // Create a simple pipeline that can record from 1 device.
    // Ref: http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-intro-basics-bins.html

    // Typical pipeline is:
    // gst-launch pulsesrc name=source0 device=alsa_input.usb-046d_089d-01-U0x46d0x89d.analog-mono !
    //    level name=level ! queue ! audioconvert ! audio/x-raw-float,rate=44100,channels=2 !
    //    vorbisenc name=enc quality=0.5 ! oggmux ! filesink name=output-sink location=test1.oga

    // Other pipeline samples.
    // OGG audio output:
    // $ gst-launch pulsesrc ! queue ! audioconvert ! vorbisenc ! oggmux ! filesink location=test.oga
    //
    // FLAC:
    // $ gst-launch pulsesrc ! queue ! audioconvert ! flacenc ! filesink location=test.flac
    //
    // WAV:
    // $ gst-launch pulsesrc ! queue ! audioconvert ! wavenc ! filesink location=test.wav
    //
    // MP3:
    // $ gst-launch pulsesrc ! queue ! audioconvert ! lame ! filesink location=test.mp3
    //
    // See also: gconf-editor, key: system -> gstreamer -> 0.10 -> audio -> profiles.

    GstElement *pipeline = NULL;

    // Build a pipeline string
    gchar *pipeline_cmd = g_strdup_printf ("%s name=source0"
                                           " ! level name=level"
                                           " ! queue"
                                           " ! audioconvert"
                                           " ! %s"
                                           " ! %s name=output-sink",
                                           audio_source,
                                           enc_pipeline,
                                           output_sink);

    LOG_DEBUG("\n\n");
    LOG_DEBUG("Going to create pipeline:\ngst-launch %s\n\n", pipeline_cmd);

    GError *err = NULL;
    pipeline = gst_parse_launch(pipeline_cmd, &err);
    g_free(pipeline_cmd);

    if (err) {
        // Set err_msg
        *err_msg = g_strdup_printf(_("Cannot create audio pipeline. %s.\n"), err->message);
        g_error_free(err);
        goto LBL_1;
    }

    // Get the "source0" element
    GstElement *source = gst_bin_get_by_name(GST_BIN(pipeline), "source0");

    if (!GST_IS_ELEMENT(source)) {
        // Set err_msg
        *err_msg = g_strdup_printf(_("Cannot find audio element %s.\n"), audio_source);
        goto LBL_1;
    }

    // Set audio device
    if (g_list_length(dev_list) > 0) {
        gchar *device = dev_list->data;
        g_object_set(G_OBJECT(source), "device", device, NULL);

        LOG_DEBUG("Setting device. %s device=%s\n", audio_source, device);
    }
    
    g_object_unref(source);

    // Ok
    return pipeline;

LBL_1:
    // Got an error
    return NULL;
}

static GstElement *pipeline_create_complex(gchar *audio_source, GList *dev_list, gchar *enc_pipeline, gchar *output_sink, gchar **err_msg) {
    // Create a complex pipeline using the GstAdder element.
    // Ref: http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-base-plugins/html/gst-plugins-base-plugins-adder.html
    // This can record from 2, 3 or more devices.

    // Typical pipeline is:
    // $ gst-launch-0.10 adder name=mix ! audioconvert ! vorbisenc ! oggmux ! filesink location=test1.ogg {
    //    pulsesrc device=alsa_output.pci-0000_04_02.0.analog-stereo.monitor ! queue ! mix. } {
    //    pulsesrc device=alsa_input.pci_8086_24c5_alsa_capture_0 ! queue ! mix. }

    GstElement *pipeline = NULL;

    // Build a pipeline string
    GString *str = g_string_new(NULL);
    g_string_printf(str, "adder name=mix"
                    " ! level name=level"
                    " ! audioconvert"
                    " ! %s"
                    " ! %s name=output-sink"
                    " ",
                    enc_pipeline,
                    output_sink);

    // Add all devices to the pipe:
    // { pulsesrc device=alsa_input.pci_8086_24c5_alsa_capture_0 ! queue ! mix. } {
    //   pulsesrc device=alsa_output.pci_8086_24c5_alsa_playback_0.monitor ! queue ! mix.
    // } { etc.}

    // For all devices in dev_list
    GList *n = g_list_first(dev_list);
    gint i = 0;
    while (n) {
        gchar *device = (gchar*)n->data;
        g_string_append_printf(str, "{ %s name=source%d device=%s ! queue ! mix. }", audio_source, i++, device);
        n = g_list_next(n);
    }

    // Take pipeline string
    gchar *pipeline_cmd = g_string_free(str, FALSE);

    LOG_DEBUG("\n\n");
    LOG_DEBUG("Going to create pipeline:\ngst-launch %s\n\n", pipeline_cmd);

    GError *err = NULL;
    pipeline = gst_parse_launch(pipeline_cmd, &err);
    g_free(pipeline_cmd);

    if (err) {
        *err_msg = g_strdup_printf(_("Cannot create audio pipeline. %s.\n"), err->message);
        g_error_free(err);
        goto LBL_1;
    }

    // Ok
    return pipeline;

LBL_1:
    // Got an error
    return NULL;
}