/* lv2_jack_host - SLV2 Jack Host
 * Copyright (C) 2007-2011 David Robillard <http://drobilla.net>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * This program 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 General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _XOPEN_SOURCE 500

#include <math.h>
#include <signal.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <jack/jack.h>
#include <jack/midiport.h>

#include "lv2/lv2plug.in/ns/ext/event/event-helpers.h"
#include "lv2/lv2plug.in/ns/ext/event/event.h"
#include "lv2/lv2plug.in/ns/ext/uri-map/uri-map.h"

#include "slv2/slv2.h"

#include "slv2-config.h"

#ifdef SLV2_JACK_SESSION
#include <jack/session.h>
#include <glib.h>

GMutex* exit_mutex;
GCond*  exit_cond;
#endif /* SLV2_JACK_SESSION */

#define MIDI_BUFFER_SIZE 1024

enum PortType {
	CONTROL,
	AUDIO,
	EVENT
};

struct Port {
	SLV2Port           slv2_port;
	enum PortType      type;
	jack_port_t*       jack_port; /**< For audio/MIDI ports, otherwise NULL */
	float              control;   /**< For control ports, otherwise 0.0f */
	LV2_Event_Buffer*  ev_buffer; /**< For MIDI ports, otherwise NULL */
	bool               is_input;
};

/** This program's data */
struct JackHost {
	jack_client_t* jack_client;   /**< Jack client */
	SLV2Plugin     plugin;        /**< Plugin "class" (actually just a few strings) */
	SLV2Instance   instance;      /**< Plugin "instance" (loaded shared lib) */
	uint32_t       num_ports;     /**< Size of the two following arrays: */
	struct Port*   ports;         /**< Port array of size num_ports */
	SLV2Value      input_class;   /**< Input port class (URI) */
	SLV2Value      output_class;  /**< Output port class (URI) */
	SLV2Value      control_class; /**< Control port class (URI) */
	SLV2Value      audio_class;   /**< Audio port class (URI) */
	SLV2Value      event_class;   /**< Event port class (URI) */
	SLV2Value      midi_class;    /**< MIDI event class (URI) */
	SLV2Value      optional;      /**< lv2:connectionOptional port property */
};

/** URI map feature, for event types (we use only MIDI) */
#define MIDI_EVENT_ID 1
uint32_t
uri_to_id(LV2_URI_Map_Callback_Data callback_data,
          const char*               map,
          const char*               uri)
{
	/* Note a non-trivial host needs to use an actual dictionary here */
	if (!strcmp(map, LV2_EVENT_URI) && !strcmp(uri, SLV2_EVENT_CLASS_MIDI))
		return MIDI_EVENT_ID;
	else
		return 0;  /* Refuse to map ID */
}

#define NS_EXT "http://lv2plug.in/ns/ext/"

static LV2_URI_Map_Feature uri_map         = { NULL, &uri_to_id };
static const LV2_Feature   uri_map_feature = { NS_EXT "uri-map", &uri_map };

const LV2_Feature* features[2] = { &uri_map_feature, NULL };

/** Abort and exit on error */
static void
die(const char* msg)
{
	fprintf(stderr, "%s\n", msg);
	exit(EXIT_FAILURE);
}

/** Creates a port and connects the plugin instance to its data location.
 *
 * For audio ports, creates a jack port and connects plugin port to buffer.
 *
 * For control ports, sets controls array to default value and connects plugin
 * port to that element.
 */
void
create_port(struct JackHost* host,
            uint32_t         port_index,
            float            default_value)
{
	struct Port* const port = &host->ports[port_index];

	port->slv2_port = slv2_plugin_get_port_by_index(host->plugin, port_index);
	port->jack_port = NULL;
	port->control   = 0.0f;
	port->ev_buffer = NULL;

	slv2_instance_connect_port(host->instance, port_index, NULL);

	/* Get the port symbol for console printing */
	SLV2Value symbol       = slv2_port_get_symbol(host->plugin, port->slv2_port);
	const char* symbol_str = slv2_value_as_string(symbol);

	enum JackPortFlags jack_flags = 0;
	if (slv2_port_is_a(host->plugin, port->slv2_port, host->input_class)) {
		jack_flags     = JackPortIsInput;
		port->is_input = true;
	} else if (slv2_port_is_a(host->plugin, port->slv2_port, host->output_class)) {
		jack_flags     = JackPortIsOutput;
		port->is_input = false;
	} else if (slv2_port_has_property(host->plugin, port->slv2_port, host->optional)) {
		slv2_instance_connect_port(host->instance, port_index, NULL);
	} else {
		die("Mandatory port has unknown type (neither input or output)");
	}

	/* Set control values */
	if (slv2_port_is_a(host->plugin, port->slv2_port, host->control_class)) {
		port->type    = CONTROL;
		port->control = isnan(default_value) ? 0.0 : default_value;
		printf("%s = %f\n", symbol_str, host->ports[port_index].control);
	} else if (slv2_port_is_a(host->plugin, port->slv2_port, host->audio_class)) {
		port->type = AUDIO;
	} else if (slv2_port_is_a(host->plugin, port->slv2_port, host->event_class)) {
		port->type = EVENT;
	}

	/* Connect the port based on its type */
	switch (port->type) {
	case CONTROL:
		slv2_instance_connect_port(host->instance, port_index, &port->control);
		break;
	case AUDIO:
		port->jack_port = jack_port_register(
			host->jack_client, symbol_str, JACK_DEFAULT_AUDIO_TYPE, jack_flags, 0);
		break;
	case EVENT:
		port->jack_port = jack_port_register(
			host->jack_client, symbol_str, JACK_DEFAULT_MIDI_TYPE, jack_flags, 0);
		port->ev_buffer = lv2_event_buffer_new(MIDI_BUFFER_SIZE, LV2_EVENT_AUDIO_STAMP);
		slv2_instance_connect_port(host->instance, port_index, port->ev_buffer);
		break;
	default:
		/* FIXME: check if port connection is optional and die if not */
		slv2_instance_connect_port(host->instance, port_index, NULL);
		fprintf(stderr, "WARNING: Unknown port type, port not connected.\n");
	}
}

/** Jack process callback. */
int
jack_process_cb(jack_nframes_t nframes, void* data)
{
	struct JackHost* const host = (struct JackHost*)data;

	/* Prepare port buffers */
	for (uint32_t p = 0; p < host->num_ports; ++p) {
		if (!host->ports[p].jack_port)
			continue;

		if (host->ports[p].type == AUDIO) {
			/* Connect plugin port directly to Jack port buffer. */
			slv2_instance_connect_port(
				host->instance, p,
				jack_port_get_buffer(host->ports[p].jack_port, nframes));

		} else if (host->ports[p].type == EVENT) {
			/* Clear Jack event port buffer. */
			lv2_event_buffer_reset(host->ports[p].ev_buffer,
			                       LV2_EVENT_AUDIO_STAMP,
			                       (uint8_t*)(host->ports[p].ev_buffer + 1));

			if (host->ports[p].is_input) {
				void* buf = jack_port_get_buffer(host->ports[p].jack_port,
				                                 nframes);

				LV2_Event_Iterator iter;
				lv2_event_begin(&iter, host->ports[p].ev_buffer);

				for (uint32_t i = 0; i < jack_midi_get_event_count(buf); ++i) {
					jack_midi_event_t ev;
					jack_midi_event_get(&ev, buf, i);
					lv2_event_write(&iter,
					                ev.time, 0,
					                MIDI_EVENT_ID, ev.size, ev.buffer);
				}
			}
		}
	}

	/* Run plugin for this cycle */
	slv2_instance_run(host->instance, nframes);

	/* Deliver MIDI output */
	for (uint32_t p = 0; p < host->num_ports; ++p) {
		if (host->ports[p].jack_port
		    && !host->ports[p].is_input
		    && host->ports[p].type == EVENT) {

			void* buf = jack_port_get_buffer(host->ports[p].jack_port,
			                                 nframes);

			jack_midi_clear_buffer(buf);

			LV2_Event_Iterator iter;
			lv2_event_begin(&iter, host->ports[p].ev_buffer);

			for (uint32_t i = 0; i < iter.buf->event_count; ++i) {
				uint8_t*   data;
				LV2_Event* ev = lv2_event_get(&iter, &data);
				jack_midi_event_write(buf, ev->frames, data, ev->size);
				lv2_event_increment(&iter);
			}
		}
	}

	return 0;
}

#ifdef SLV2_JACK_SESSION
void
jack_session_cb(jack_session_event_t* event, void* arg)
{
	struct JackHost* host = (struct JackHost*)arg;

	char cmd[256];
	snprintf(cmd, sizeof(cmd), "lv2_jack_host %s %s",
	         slv2_value_as_uri(slv2_plugin_get_uri(host->plugin)),
	         event->client_uuid);

	event->command_line = strdup(cmd);
	jack_session_reply(host->jack_client, event);

	switch (event->type) {
	case JackSessionSave:
		break;
	case JackSessionSaveAndQuit:
		g_mutex_lock(exit_mutex);
		g_cond_signal(exit_cond);
		g_mutex_unlock(exit_mutex);
		break;
	case JackSessionSaveTemplate:
		break;
	}

	jack_session_event_free(event);
}
#endif /* SLV2_JACK_SESSION */

static void
signal_handler(int ignored)
{
#ifdef SLV2_JACK_SESSION
	g_mutex_lock(exit_mutex);
	g_cond_signal(exit_cond);
	g_mutex_unlock(exit_mutex);
#endif
}

int
main(int argc, char** argv)
{
	struct JackHost host;
	host.jack_client = NULL;
	host.num_ports   = 0;
	host.ports       = NULL;

#ifdef SLV2_JACK_SESSION
	if (!g_thread_supported()) {
		g_thread_init(NULL);
	}
	exit_mutex = g_mutex_new();
	exit_cond  = g_cond_new();
#endif

	signal(SIGINT, signal_handler);
	signal(SIGTERM, signal_handler);

	/* Find all installed plugins */
	SLV2World world = slv2_world_new();
	slv2_world_load_all(world);
	SLV2Plugins plugins = slv2_world_get_all_plugins(world);

	/* Set up the port classes this app supports */
	host.input_class   = slv2_value_new_uri(world, SLV2_PORT_CLASS_INPUT);
	host.output_class  = slv2_value_new_uri(world, SLV2_PORT_CLASS_OUTPUT);
	host.control_class = slv2_value_new_uri(world, SLV2_PORT_CLASS_CONTROL);
	host.audio_class   = slv2_value_new_uri(world, SLV2_PORT_CLASS_AUDIO);
	host.event_class   = slv2_value_new_uri(world, SLV2_PORT_CLASS_EVENT);
	host.midi_class    = slv2_value_new_uri(world, SLV2_EVENT_CLASS_MIDI);
	host.optional      = slv2_value_new_uri(world, SLV2_NAMESPACE_LV2
	                                        "connectionOptional");

#ifdef SLV2_JACK_SESSION
	if (argc != 2 && argc != 3) {
		fprintf(stderr, "Usage: %s PLUGIN_URI [JACK_UUID]\n", argv[0]);
#else
	if (argc != 2) {
		fprintf(stderr, "Usage: %s PLUGIN_URI\n", argv[0]);
#endif
		slv2_world_free(world);
		return EXIT_FAILURE;
	}

	const char* const plugin_uri_str = argv[1];

	printf("Plugin:    %s\n", plugin_uri_str);

	SLV2Value plugin_uri = slv2_value_new_uri(world, plugin_uri_str);
	host.plugin = slv2_plugins_get_by_uri(plugins, plugin_uri);
	slv2_value_free(plugin_uri);

	if (!host.plugin) {
		fprintf(stderr, "Failed to find plugin %s.\n", plugin_uri_str);
		slv2_world_free(world);
		return EXIT_FAILURE;
	}

	/* Get the plugin's name */
	SLV2Value   name     = slv2_plugin_get_name(host.plugin);
	const char* name_str = slv2_value_as_string(name);

	/* Truncate plugin name to suit JACK (if necessary) */
	char* jack_name = NULL;
	if (strlen(name_str) >= (unsigned)jack_client_name_size() - 1) {
		jack_name = calloc(jack_client_name_size(), sizeof(char));
		strncpy(jack_name, name_str, jack_client_name_size() - 1);
	} else {
		jack_name = strdup(name_str);
	}

	/* Connect to JACK */
	printf("JACK Name: %s\n\n", jack_name);
#ifdef SLV2_JACK_SESSION
	const char* const jack_uuid_str = (argc > 2) ? argv[2] : NULL;
	if (jack_uuid_str) {
		host.jack_client = jack_client_open(jack_name, JackSessionID, NULL,
		                                    jack_uuid_str);
	}
#endif

	if (!host.jack_client) {
		host.jack_client = jack_client_open(jack_name, JackNullOption, NULL);
	}

	free(jack_name);
	slv2_value_free(name);

	if (!host.jack_client)
		die("Failed to connect to JACK.\n");

	/* Instantiate the plugin */
	host.instance = slv2_plugin_instantiate(
		host.plugin, jack_get_sample_rate(host.jack_client), features);
	if (!host.instance)
		die("Failed to instantiate plugin.\n");

	jack_set_process_callback(host.jack_client, &jack_process_cb, (void*)(&host));
#ifdef SLV2_JACK_SESSION
	jack_set_session_callback(host.jack_client, &jack_session_cb, (void*)(&host));
#endif

	/* Create ports */
	host.num_ports = slv2_plugin_get_num_ports(host.plugin);
	host.ports     = calloc((size_t)host.num_ports, sizeof(struct Port));
	float* default_values = calloc(slv2_plugin_get_num_ports(host.plugin),
	                               sizeof(float));
	slv2_plugin_get_port_ranges_float(host.plugin, NULL, NULL, default_values);

	for (uint32_t i = 0; i < host.num_ports; ++i)
		create_port(&host, i, default_values[i]);

	free(default_values);

	/* Activate plugin and JACK */
	slv2_instance_activate(host.instance);
	jack_activate(host.jack_client);

	/* Run */
#ifdef SLV2_JACK_SESSION
	printf("\nPress Ctrl-C to quit: ");
	fflush(stdout);
	g_cond_wait(exit_cond, exit_mutex);
#else
	printf("\nPress enter to quit: ");
	fflush(stdout);
	getc(stdin);
#endif
	printf("\n");

	/* Deactivate JACK */
	jack_deactivate(host.jack_client);

	for (uint32_t i = 0; i < host.num_ports; ++i) {
		if (host.ports[i].jack_port != NULL) {
			jack_port_unregister(host.jack_client, host.ports[i].jack_port);
			host.ports[i].jack_port = NULL;
		}
		if (host.ports[i].ev_buffer != NULL) {
			free(host.ports[i].ev_buffer);
		}
	}
	jack_client_close(host.jack_client);

	/* Deactivate plugin */
	slv2_instance_deactivate(host.instance);
	slv2_instance_free(host.instance);

	/* Clean up */
	free(host.ports);
	slv2_value_free(host.input_class);
	slv2_value_free(host.output_class);
	slv2_value_free(host.control_class);
	slv2_value_free(host.audio_class);
	slv2_value_free(host.event_class);
	slv2_value_free(host.midi_class);
	slv2_value_free(host.optional);
	slv2_plugins_free(world, plugins);
	slv2_world_free(world);

#ifdef SLV2_JACK_SESSION
	g_mutex_free(exit_mutex);
	g_cond_free(exit_cond);
#endif

	return 0;
}