#include <stdint.h>
#include <stdio.h>
#include <math.h>
#include <lv2.h>
#include "lv2_event.h"
#include "lv2_event_helpers.h"
#include "lv2_uri_map.h"
#include "osc.h"
#include "filter.h"
#include "voice.h"
#include "engine.h"
#include "psyn.h"

double _sample_rate;

struct psyn_t
{
	LV2_Event_Buffer *events;
	LV2_Event_Feature *event_ref;
	int midi_event_id;
	float *out_l;
	float *out_r;

	struct engine_t eng;
};

static void psyn_init(struct psyn_t *psyn, uint32_t sample_rate)
{
	_sample_rate = sample_rate;

	engine_init();
}

static LV2_Handle instantiate(
	const LV2_Descriptor *descriptor,
	double sample_rate,
	const char *bundle_path,
	const LV2_Feature * const *host_features)
{
	struct psyn_t *psyn;
	LV2_URI_Map_Feature *map_feature;
	int i;

	psyn = malloc(sizeof *psyn);
	memset(psyn, 0, sizeof *psyn);

	psyn_init(psyn, sample_rate);

	for (i = 0; host_features[i]; i++) {
		if (!strcmp(host_features[i]->URI, "http://lv2plug.in/ns/ext/uri-map")) {
			map_feature = host_features[i]->data;

			psyn->midi_event_id = map_feature->uri_to_id(map_feature->callback_data, "http://lv2plug.in/ns/ext/event", "http://lv2plug.in/ns/ext/midi#MidiEvent");
		} else if (!strcmp(host_features[i]->URI, "http://lv2plug.in/ns/ext/event")) {
			psyn->event_ref = host_features[i]->data;
		}
	}

	if (psyn->midi_event_id == 0 || psyn->event_ref == NULL) {
		printf("psyn instantiate failed, leaving\n");
		return NULL;
	}

	return (LV2_Handle)psyn;
}

static void connect_port(LV2_Handle lv2instance, uint32_t port, void *data)
{
	struct psyn_t *psyn = (struct psyn_t *)lv2instance;

	switch (port) {
		case 0:
			psyn->events = data;
			break;
		case 1:
			psyn->out_l = data;
			break;
		case 2:
			psyn->out_r = data;
			break;
	}
}

static void cleanup(LV2_Handle lv2instance)
{
	struct psyn_t *psyn = (struct psyn_t *)lv2instance;
	free(psyn);
}

static void run(LV2_Handle lv2instance, uint32_t sample_count)
{
	struct psyn_t *psyn = (struct psyn_t *)lv2instance;
	uint32_t frame = 0;
	LV2_Event *ev = NULL;
	LV2_Event_Iterator iterator;

	lv2_event_begin(&iterator, psyn->events);

	if (lv2_event_is_valid(&iterator)) ev = lv2_event_get(&iterator, NULL);

	while (frame < sample_count) {
		uint32_t to;

		if (ev != NULL) {
			to = ev->frames;
		} else {
			to = sample_count;
		}

		engine_run(&psyn->eng, to - frame, psyn->out_l + frame, psyn->out_r + frame);
		frame = to;

		if (ev != NULL) {
			if (ev->type == 0) {
				psyn->event_ref->lv2_event_unref(psyn->event_ref->callback_data, ev);
			} else if (ev->type == psyn->midi_event_id && ev->size == 3) {
				uint8_t *data = (uint8_t *)(ev + 1);

				switch (data[0] & 0xF0) {
					case 0x80:
						engine_endvoice(&psyn->eng, data[1], data[2]);
						break;

					case 0x90:
						engine_startvoice(&psyn->eng, data[1], data[2]);
						break;
				}
			}

			lv2_event_increment(&iterator);
			if (lv2_event_is_valid(&iterator)) {
				ev = lv2_event_get(&iterator, NULL);
			} else {
				ev = NULL;
			}
		}
	}
}

static LV2_Descriptor g_lv2descriptor =
{
	.URI = "http://fuzzle.org/~petern/psyn/1",
	.instantiate = &instantiate,
	.connect_port = &connect_port,
	.run = &run,
	.cleanup = &cleanup,
};

const LV2_Descriptor *lv2_descriptor(uint32_t index)
{
	if (index == 0) {
		return &g_lv2descriptor;
	}

	return NULL;
}