#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gst/gst.h>
#include <gst/app/gstappsrc.h>
#include <gst/video/video.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>


typedef struct {
 GstPipeline *pipeline;
 GstElement *appsrc;
 GstElement *src;
 GstElement *encoder;
 GstElement *streamer;
 GMainLoop *loop;
 GTimer* timer;
 guint sourceid;
} gst_app_t;

static gst_app_t gst_app;


static gboolean read_data(gst_app_t* app) {
    GstFlowReturn ret;
    gdouble ms;
    static gboolean white = FALSE;

    ms = g_timer_elapsed(app->timer, NULL);
    //GST_INFO("Entering read_data(app=%p), elapsed seconds=%f.", app, ms);

    if (ms > 1.0/15.0) {
        GstBuffer* buffer;
        gboolean ok = TRUE;

        buffer = gst_buffer_new();

        GST_INFO("Pushing new data into pipe, elapsed seconds=%f.", ms);

        // this makes the image black/white
        memset(GST_BUFFER_DATA(buffer), white ? 0xff : 0x0, GST_BUFFER_SIZE(buffer));
        GST_BUFFER_SIZE(buffer) = 320 * 240 * 3 * sizeof(guchar);

        white = !white;
        g_signal_emit_by_name(app->appsrc, "push-buffer", buffer, &ret);
        gst_buffer_unref(buffer);

        if (GST_FLOW_OK != ret) {
            // some error, stop sending data
            GST_INFO("some error: %d", ret);
            ok = FALSE;
        }

        g_timer_start(app->timer);
    }
    //GST_INFO("Exiting read_data(app=%p).", app);
    return TRUE;
}


static void start_feed(GstElement* pipeline, guint size, gst_app_t* app) {
    GST_INFO("Entering start_feed(pipeline=%p, size=%d, app=%p).", pipeline, size, app);
    if (0 == app->sourceid) {
        GST_INFO("Start feeding");
        app->sourceid = g_idle_add((GSourceFunc)read_data, app);
    }
}


static void stop_feed(GstElement* pipeline, gst_app_t* app) {
    GST_INFO("Entering stop_feed(pipeline=%p, app=%p).", pipeline, app);
    if (0 != app->sourceid) {
        GST_INFO("Stop feeding");
        g_source_remove(app->sourceid);
        app->sourceid = 0;
    }
}


static gboolean bus_message(GstBus* bus, GstMessage* message, gst_app_t* app) {
    GST_INFO("Entering bus_message(bus=%p, message=%s, app=%p).", bus, gst_message_type_get_name(GST_MESSAGE_TYPE(message)), app);
    switch(GST_MESSAGE_TYPE(message)) {
        case GST_MESSAGE_ERROR: {
            GError* err = NULL;
            gchar* dbg_info = NULL;

            gst_message_parse_error(message, &err, &dbg_info);
            g_printerr("ERROR from element %s: %s\n",
            GST_OBJECT_NAME(message->src), err->message);
            g_printerr("Debugging info: %s\n",(dbg_info) ? dbg_info : "none");
            g_error_free(err);
            g_free(dbg_info);
            g_main_loop_quit(app->loop);
            break;
        }
        case GST_MESSAGE_EOS:
            GST_INFO("End-of-stream message received, quitting main loop.");
            g_main_loop_quit(app->loop);
            break;
        default:
            break;
    }
    return TRUE;
}


int main(int argc, char* argv[]) {
    gst_app_t* app = &gst_app;
    GstBus* bus;
    GstCaps* caps;
    int USE_TESTSRC = 0;
    int i = 0;

    for (i = 0; i < argc; i++) {
        if (!strcmp(argv[i], "--testsrc")) {
            USE_TESTSRC = 1;
        }
    }

    gst_init(&argc, &argv);

    app->loop = g_main_loop_new(NULL, TRUE);
    app->timer = g_timer_new();

    if (USE_TESTSRC) {
        app->pipeline = (GstPipeline*)gst_parse_launch("videotestsrc      ! videorate ! ffmpegcolorspace ! videoscale method=1 ! video/x-raw-yuv,width=320,height=240,format=(fourcc)UYVY,framerate=\(fraction\)15/1 ! TIVidenc1 codecName=h264enc engineName=codecServer ! rtph264pay pt=96 ! udpsink host=192.168.1.112 port=5000", NULL);
    } else {
        app->pipeline = (GstPipeline*)gst_parse_launch("appsrc name=mysrc ! videorate ! ffmpegcolorspace ! videoscale method=1 ! video/x-raw-yuv,width=320,height=240,format=(fourcc)UYVY,framerate=\(fraction\)15/1 ! TIVidenc1 codecName=h264enc engineName=codecServer ! rtph264pay pt=96 ! udpsink host=192.168.1.112 port=5000", NULL);
    }

    g_assert (app->pipeline);

    bus = gst_pipeline_get_bus(GST_PIPELINE(app->pipeline));
    g_assert(bus);
    gst_bus_add_watch (bus, (GstBusFunc) bus_message, app);

    if (!USE_TESTSRC) {
        app->appsrc = gst_bin_get_by_name (GST_BIN(app->pipeline), "mysrc");
        g_assert(app->appsrc);
        g_assert(GST_IS_APP_SRC(app->appsrc));
        g_signal_connect (app->appsrc, "need-data",  G_CALLBACK (start_feed), app);
        g_signal_connect (app->appsrc, "enough-data", G_CALLBACK (stop_feed), app);

        caps = gst_video_format_new_caps(GST_VIDEO_FORMAT_UYVY, 320, 240, 0, 1, 4, 3);
        gst_app_src_set_caps(GST_APP_SRC(app->appsrc), caps);
        //gst_app_src_set_max_bytes(GST_APP_SRC(app->appsrc), 320 * 240 * 3 * 100);
    }

    GST_INFO("Setting pipeline %p to playing.", app->pipeline);
    gst_element_set_state ((GstElement*)app->pipeline, GST_STATE_PLAYING);

    g_main_loop_run (app->loop);

    GST_INFO("Stopping pipeline %p.", app->pipeline);

    gst_element_set_state ((GstElement*)app->pipeline, GST_STATE_NULL);

    gst_object_unref (bus);
    g_main_loop_unref (app->loop);

    return 0;
}