/*
 * Copyright (C) 2011-2024 Meltytech, LLC
 *
 * This library 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.
 *
 * 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <framework/mlt.h>
#include <limits.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Forward references
static int start(mlt_consumer consumer);
static int stop(mlt_consumer consumer);
static int is_stopped(mlt_consumer consumer);
static void *consumer_thread(void *arg);
static void consumer_close(mlt_consumer consumer);
static void purge(mlt_consumer consumer);

static mlt_properties normalizers = NULL;

/** Initialise the consumer.
*/

mlt_consumer consumer_multi_init(mlt_profile profile,
                                 mlt_service_type type,
                                 const char *id,
                                 char *arg)
{
    mlt_consumer consumer = mlt_consumer_new(profile);

    if (consumer) {
        mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);

        // Set defaults
        mlt_properties_set(properties, "resource", arg);
        mlt_properties_set_int(properties, "real_time", -1);
        mlt_properties_set_int(properties, "terminate_on_pause", 1);

        // Init state
        mlt_properties_set_int(properties, "joined", 1);

        // Assign callbacks
        consumer->close = consumer_close;
        consumer->start = start;
        consumer->stop = stop;
        consumer->is_stopped = is_stopped;
        consumer->purge = purge;
    }

    return consumer;
}

static mlt_consumer create_consumer(mlt_profile profile, char *id, char *arg)
{
    char *myid = id ? strdup(id) : NULL;
    char *myarg = (myid && !arg) ? strchr(myid, ':') : NULL;
    if (myarg)
        *myarg++ = '\0';
    else
        myarg = arg;
    mlt_consumer consumer = mlt_factory_consumer(profile, myid, myarg);
    free(myid);
    return consumer;
}

static void create_filter(mlt_profile profile, mlt_service service, char *effect, int *created)
{
    char *id = strdup(effect);
    char *arg = strchr(id, ':');
    if (arg != NULL)
        *arg++ = '\0';

    // We cannot use GLSL-based filters here.
    if (strncmp(effect, "movit.", 6) && strncmp(effect, "glsl.", 5)) {
        mlt_filter filter;
        // The swscale and avcolor_space filters require resolution as arg to test compatibility
        if (strncmp(effect, "swscale", 7) == 0 || strncmp(effect, "avcolo", 6) == 0) {
            int width = mlt_properties_get_int(MLT_SERVICE_PROPERTIES(service), "meta.media.width");
            filter = mlt_factory_filter(profile, id, &width);
        } else {
            filter = mlt_factory_filter(profile, id, arg);
        }
        if (filter) {
            mlt_properties_set_int(MLT_FILTER_PROPERTIES(filter), "_loader", 1);
            mlt_service_attach(service, filter);
            mlt_filter_close(filter);
            *created = 1;
        }
    }
    free(id);
}

static void attach_normalizers(mlt_profile profile, mlt_service service)
{
    // Loop variable
    int i;

    // Tokeniser
    mlt_tokeniser tokeniser = mlt_tokeniser_init();

    // We only need to load the normalizing properties once
    if (normalizers == NULL) {
        char temp[PATH_MAX];
        snprintf(temp, sizeof(temp), "%s/core/loader.ini", mlt_environment("MLT_DATA"));
        normalizers = mlt_properties_load(temp);
        mlt_factory_register_for_clean_up(normalizers, (mlt_destructor) mlt_properties_close);
    }

    // Apply normalizers
    for (i = 0; i < mlt_properties_count(normalizers); i++) {
        int j = 0;
        int created = 0;
        char *value = mlt_properties_get_value(normalizers, i);
        mlt_tokeniser_parse_new(tokeniser, value, ",");
        for (j = 0; !created && j < mlt_tokeniser_count(tokeniser); j++)
            create_filter(profile, service, mlt_tokeniser_get_string(tokeniser, j), &created);
    }

    // Close the tokeniser
    mlt_tokeniser_close(tokeniser);

    // Attach the audio and video format converters
    int created = 0;
    // movit.convert skips setting the frame->convert_image pointer if GLSL cannot be used.
    mlt_filter filter = mlt_factory_filter(profile, "movit.convert", NULL);
    if (filter != NULL) {
        mlt_properties_set_int(MLT_FILTER_PROPERTIES(filter), "_loader", 1);
        mlt_service_attach(service, filter);
        mlt_filter_close(filter);
        created = 1;
    }
    // avcolor_space and imageconvert only set frame->convert_image if it has not been set.
    create_filter(profile, service, "avcolor_space", &created);
    if (!created)
        create_filter(profile, service, "imageconvert", &created);
    create_filter(profile, service, "audioconvert", &created);
}

static void on_frame_show(void *dummy, mlt_properties properties, mlt_event_data event_data)
{
    mlt_events_fire(properties, "consumer-frame-show", event_data);
}

static mlt_consumer generate_consumer(mlt_consumer consumer, mlt_properties props, int index)
{
    mlt_profile profile = NULL;
    if (mlt_properties_get(props, "mlt_profile"))
        profile = mlt_profile_init(mlt_properties_get(props, "mlt_profile"));
    if (!profile)
        profile = mlt_profile_clone(mlt_service_profile(MLT_CONSUMER_SERVICE(consumer)));
    mlt_consumer nested = create_consumer(profile,
                                          mlt_properties_get(props, "mlt_service"),
                                          mlt_properties_get(props, "target"));

    if (nested) {
        mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
        mlt_properties nested_props = MLT_CONSUMER_PROPERTIES(nested);
        char key[30];

        snprintf(key, sizeof(key), "%d.consumer", index);
        mlt_properties_set_data(properties,
                                key,
                                nested,
                                0,
                                (mlt_destructor) mlt_consumer_close,
                                NULL);
        snprintf(key, sizeof(key), "%d.profile", index);
        mlt_properties_set_data(properties,
                                key,
                                profile,
                                0,
                                (mlt_destructor) mlt_profile_close,
                                NULL);

        mlt_properties_set_int(nested_props, "put_mode", 1);
        mlt_properties_pass_list(nested_props, properties, "terminate_on_pause");
        mlt_properties_set(props, "consumer", NULL);
        // set mlt_profile before other properties to facilitate presets
        mlt_properties_pass_list(nested_props, props, "mlt_profile");
        mlt_properties_inherit(nested_props, props);

        attach_normalizers(profile, MLT_CONSUMER_SERVICE(nested));

        // Relay the first available consumer-frame-show event
        mlt_event event = mlt_properties_get_data(properties, "frame-show-event", NULL);
        if (!event) {
            event = mlt_events_listen(nested_props,
                                      properties,
                                      "consumer-frame-show",
                                      (mlt_listener) on_frame_show);
            mlt_properties_set_data(properties,
                                    "frame-show-event",
                                    event,
                                    0,
                                    /*mlt_event_close*/ NULL,
                                    NULL);
        }
    } else {
        mlt_profile_close(profile);
    }
    return nested;
}

static void foreach_consumer_init(mlt_consumer consumer)
{
    const char *resource = mlt_properties_get(MLT_CONSUMER_PROPERTIES(consumer), "resource");
    mlt_properties properties = mlt_properties_parse_yaml(resource);
    char key[20];
    int index = 0;

    if (mlt_properties_get_data(MLT_CONSUMER_PROPERTIES(consumer), "0", NULL)) {
        // Properties set directly by application
        mlt_properties p;

        if (properties)
            mlt_properties_close(properties);
        properties = MLT_CONSUMER_PROPERTIES(consumer);
        do {
            snprintf(key, sizeof(key), "%d", index);
            if ((p = mlt_properties_get_data(properties, key, NULL)))
                generate_consumer(consumer, p, index++);
        } while (p);
    } else if (properties && mlt_properties_get_data(properties, "0", NULL)) {
        // YAML file supplied
        mlt_properties p;

        do {
            snprintf(key, sizeof(key), "%d", index);
            if ((p = mlt_properties_get_data(properties, key, NULL)))
                generate_consumer(consumer, p, index++);
        } while (p);
        mlt_properties_close(properties);
    } else {
        // properties file supplied or properties on this consumer
        const char *s;

        if (properties)
            mlt_properties_close(properties);
        if (resource)
            properties = mlt_properties_load(resource);
        else
            properties = MLT_CONSUMER_PROPERTIES(consumer);

        do {
            snprintf(key, sizeof(key), "%d", index);
            if ((s = mlt_properties_get(properties, key))) {
                mlt_properties p = mlt_properties_new();
                if (!p)
                    break;

                // Terminate mlt_service value at the argument delimiter if supplied.
                // Needed here instead of just relying upon create_consumer() so that
                // a properties preset is picked up correctly.
                char *service = strdup(mlt_properties_get(properties, key));
                char *arg = strchr(service, ':');
                if (arg) {
                    *arg++ = '\0';
                    mlt_properties_set(p, "target", arg);
                }
                mlt_properties_set(p, "mlt_service", service);
                free(service);

                snprintf(key, sizeof(key), "%d.", index);

                int i, count;
                count = mlt_properties_count(properties);
                for (i = 0; i < count; i++) {
                    char *name = mlt_properties_get_name(properties, i);
                    if (!strncmp(name, key, strlen(key)))
                        mlt_properties_set(p,
                                           name + strlen(key),
                                           mlt_properties_get_value(properties, i));
                }
                generate_consumer(consumer, p, index++);
                mlt_properties_close(p);
            }
        } while (s);
        if (resource)
            mlt_properties_close(properties);
    }
}

static void foreach_consumer_start(mlt_consumer consumer)
{
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    mlt_consumer nested = NULL;
    char key[30];
    int index = 0;

    do {
        snprintf(key, sizeof(key), "%d.consumer", index++);
        nested = mlt_properties_get_data(properties, key, NULL);
        if (nested) {
            mlt_properties nested_props = MLT_CONSUMER_PROPERTIES(nested);
            mlt_properties_set_position(nested_props,
                                        "_multi_position",
                                        mlt_properties_get_position(properties, "in"));
            mlt_properties_set_data(nested_props, "_multi_audio", NULL, 0, NULL, NULL);
            mlt_properties_set_int(nested_props, "_multi_samples", 0);
            mlt_consumer_start(nested);
        }
    } while (nested);
}

static void foreach_consumer_refresh(mlt_consumer consumer)
{
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    mlt_consumer nested = NULL;
    char key[30];
    int index = 0;

    do {
        snprintf(key, sizeof(key), "%d.consumer", index++);
        nested = mlt_properties_get_data(properties, key, NULL);
        if (nested)
            mlt_properties_set_int(MLT_CONSUMER_PROPERTIES(nested), "refresh", 1);
    } while (nested);
}

// Update certain properties on this consumer from the child consumers.
static void foreach_consumer_update(mlt_consumer consumer)
{
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    mlt_consumer nested = NULL;
    char key[30];
    int index = 0;

    do {
        snprintf(key, sizeof(key), "%d.consumer", index++);
        nested = mlt_properties_get_data(properties, key, NULL);
        if (nested) {
            mlt_properties_pass_list(
                properties,
                MLT_CONSUMER_PROPERTIES(nested),
                "color_trc color_range progressive deinterlacer mlt_image_format");
        }
    } while (nested);
}

static void foreach_consumer_put(mlt_consumer consumer, mlt_frame frame)
{
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    mlt_consumer nested = NULL;
    char key[30];
    int index = 0;

    do {
        snprintf(key, sizeof(key), "%d.consumer", index++);
        nested = mlt_properties_get_data(properties, key, NULL);
        if (nested) {
            mlt_properties nested_props = MLT_CONSUMER_PROPERTIES(nested);
            double self_fps = mlt_properties_get_double(properties, "fps");
            double nested_fps = mlt_properties_get_double(nested_props, "fps");
            mlt_position nested_pos = mlt_properties_get_position(nested_props, "_multi_position");
            mlt_position self_pos = mlt_frame_get_position(frame);
            double self_time = self_pos / self_fps;
            double nested_time = nested_pos / nested_fps;

            // get the audio for the current frame
            uint8_t *buffer = NULL;
            mlt_audio_format format = mlt_audio_s16;
            int channels = mlt_properties_get_int(properties, "channels");
            int frequency = mlt_properties_get_int(properties, "frequency");
            int current_samples = mlt_audio_calculate_frame_samples(self_fps, frequency, self_pos);
            mlt_frame_get_audio(frame,
                                (void **) &buffer,
                                &format,
                                &frequency,
                                &channels,
                                &current_samples);
            int current_size = mlt_audio_format_size(format, current_samples, channels);

            // get any leftover audio
            int prev_size = 0;
            uint8_t *prev_buffer = mlt_properties_get_data(nested_props, "_multi_audio", &prev_size);
            uint8_t *new_buffer = NULL;
            if (prev_size > 0) {
                new_buffer = mlt_pool_alloc(prev_size + current_size);
                memcpy(new_buffer, prev_buffer, prev_size);
                memcpy(new_buffer + prev_size, buffer, current_size);
                buffer = new_buffer;
            }
            current_size += prev_size;
            current_samples += mlt_properties_get_int(nested_props, "_multi_samples");

            // This log line somehow fixes a bug in release build on clang/macOS
            // https://forum.shotcut.org/t/shotcut-export-drops-frames/42676
            mlt_log_debug(MLT_CONSUMER_SERVICE(consumer),
                          "%d: nested_time %g self_time %g\n",
                          nested_pos,
                          nested_time,
                          self_time);
            while (nested_time <= self_time) {
                // put ideal number of samples into cloned frame
                int deeply = index > 1 ? 1 : 0;
                mlt_frame clone_frame = mlt_frame_clone(frame, deeply);
                mlt_properties clone_props = MLT_FRAME_PROPERTIES(clone_frame);
                int nested_samples = mlt_audio_calculate_frame_samples(nested_fps,
                                                                       frequency,
                                                                       nested_pos);
                // -10 is an optimization to avoid tiny amounts of leftover samples
                nested_samples = nested_samples > current_samples - 10 ? current_samples
                                                                       : nested_samples;
                int nested_size = mlt_audio_format_size(format, nested_samples, channels);
                if (nested_size > 0) {
                    prev_buffer = mlt_pool_alloc(nested_size);
                    memcpy(prev_buffer, buffer, nested_size);
                } else {
                    prev_buffer = NULL;
                    nested_size = 0;
                }
                mlt_frame_set_audio(clone_frame, prev_buffer, format, nested_size, mlt_pool_release);
                mlt_properties_set_int(clone_props, "audio_samples", nested_samples);
                mlt_properties_set_int(clone_props, "audio_frequency", frequency);
                mlt_properties_set_int(clone_props, "audio_channels", channels);

                // chomp the audio
                current_samples -= nested_samples;
                current_size -= nested_size;
                buffer += nested_size;

                // Fix some things
                mlt_properties_set_int(clone_props,
                                       "meta.media.width",
                                       mlt_properties_get_int(MLT_FRAME_PROPERTIES(frame), "width"));
                mlt_properties_set_int(clone_props,
                                       "meta.media.height",
                                       mlt_properties_get_int(MLT_FRAME_PROPERTIES(frame),
                                                              "height"));

                // send frame to nested consumer
                mlt_consumer_put_frame(nested, clone_frame);
                mlt_properties_set_position(nested_props, "_multi_position", ++nested_pos);
                nested_time = nested_pos / nested_fps;
            }

            // save any remaining audio
            if (current_size > 0) {
                prev_buffer = mlt_pool_alloc(current_size);
                memcpy(prev_buffer, buffer, current_size);
            } else {
                prev_buffer = NULL;
                current_size = 0;
            }
            mlt_pool_release(new_buffer);
            mlt_properties_set_data(nested_props,
                                    "_multi_audio",
                                    prev_buffer,
                                    current_size,
                                    mlt_pool_release,
                                    NULL);
            mlt_properties_set_int(nested_props, "_multi_samples", current_samples);
        }
    } while (nested);
}

static void foreach_consumer_stop(mlt_consumer consumer)
{
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    mlt_consumer nested = NULL;
    char key[30];
    int index = 0;
    struct timespec tm = {0, 1000 * 1000};

    do {
        snprintf(key, sizeof(key), "%d.consumer", index++);
        nested = mlt_properties_get_data(properties, key, NULL);
        if (nested) {
            // Let consumer with terminate_on_pause stop on their own
            if (mlt_properties_get_int(MLT_CONSUMER_PROPERTIES(nested), "terminate_on_pause")) {
                // Send additional dummy frame to unlatch nested consumer's threads
                mlt_consumer_put_frame(nested, mlt_frame_init(MLT_CONSUMER_SERVICE(consumer)));
                // wait for stop
                while (!mlt_consumer_is_stopped(nested))
                    nanosleep(&tm, NULL);
            } else {
                mlt_consumer_stop(nested);
            }
        }
    } while (nested);
}

/** Start the consumer.
*/

static int start(mlt_consumer consumer)
{
    // Check that we're not already running
    if (is_stopped(consumer)) {
        mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
        pthread_t *thread = calloc(1, sizeof(pthread_t));

        // Assign the thread to properties with automatic dealloc
        mlt_properties_set_data(properties, "thread", thread, sizeof(pthread_t), free, NULL);

        // Set the running state
        mlt_properties_set_int(properties, "running", 1);
        mlt_properties_set_int(properties, "joined", 0);

        // Construct and start nested consumers
        if (!mlt_properties_get_data(properties, "0.consumer", NULL))
            foreach_consumer_init(consumer);
        foreach_consumer_start(consumer);

        // Create the thread
        pthread_create(thread, NULL, consumer_thread, consumer);
    }
    return 0;
}

/** Stop the consumer.
*/

static int stop(mlt_consumer consumer)
{
    // Check that we're running
    if (!mlt_properties_get_int(MLT_CONSUMER_PROPERTIES(consumer), "joined")) {
        mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
        pthread_t *thread = mlt_properties_get_data(properties, "thread", NULL);

        // Stop the thread
        mlt_properties_set_int(properties, "running", 0);

        // Wait for termination
        if (thread) {
            foreach_consumer_refresh(consumer);
            pthread_join(*thread, NULL);
        }
        mlt_properties_set_int(properties, "joined", 1);

        // Stop nested consumers
        foreach_consumer_stop(consumer);
    }

    return 0;
}

/** Determine if the consumer is stopped.
*/

static int is_stopped(mlt_consumer consumer)
{
    return !mlt_properties_get_int(MLT_CONSUMER_PROPERTIES(consumer), "running");
}

/** Purge each of the child consumers.
*/

static void purge(mlt_consumer consumer)
{
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    if (mlt_properties_get_int(properties, "running")) {
        mlt_consumer nested = NULL;
        char key[30];
        int index = 0;

        do {
            snprintf(key, sizeof(key), "%d.consumer", index++);
            nested = mlt_properties_get_data(properties, key, NULL);
            mlt_consumer_purge(nested);
        } while (nested);
    }
}

/** The main thread - the argument is simply the consumer.
*/

static void *consumer_thread(void *arg)
{
    mlt_consumer consumer = arg;
    mlt_properties properties = MLT_CONSUMER_PROPERTIES(consumer);
    mlt_frame frame = NULL;

    // Determine whether to stop at end-of-media
    int terminate_on_pause = mlt_properties_get_int(properties, "terminate_on_pause");
    int terminated = 0;

    foreach_consumer_update(consumer);

    // Loop while running
    while (!terminated && !is_stopped(consumer)) {
        // Get the next frame
        frame = mlt_consumer_rt_frame(consumer);

        // Check for termination
        if (terminate_on_pause && frame)
            terminated = mlt_properties_get_double(MLT_FRAME_PROPERTIES(frame), "_speed") == 0.0;

        // Check that we have a frame to work with
        if (frame && !terminated && !is_stopped(consumer)) {
            if (mlt_properties_get_int(MLT_FRAME_PROPERTIES(frame), "rendered")) {
                if (mlt_properties_get_int(MLT_FRAME_PROPERTIES(frame), "_speed") == 0)
                    foreach_consumer_refresh(consumer);
                foreach_consumer_put(consumer, frame);
            } else {
                int dropped = mlt_properties_get_int(properties, "_dropped");
                mlt_log_info(MLT_CONSUMER_SERVICE(consumer), "dropped frame %d\n", ++dropped);
                mlt_properties_set_int(properties, "_dropped", dropped);
            }
            mlt_frame_close(frame);
        } else {
            if (frame && terminated) {
                // Send this termination frame to nested consumers for their cancellation
                foreach_consumer_put(consumer, frame);
            }
            if (frame)
                mlt_frame_close(frame);
            terminated = 1;
        }
    }

    // Indicate that the consumer is stopped
    mlt_consumer_stopped(consumer);

    return NULL;
}

/** Close the consumer.
*/

static void consumer_close(mlt_consumer consumer)
{
    mlt_consumer_stop(consumer);

    // Close the parent
    mlt_consumer_close(consumer);
    free(consumer);
}
