/*
 * Copyright (c) 2012 Jan Vesely
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup dplay
 * @{
 */
/**
 * @file PCM playback audio devices
 */

#include <assert.h>
#include <errno.h>
#include <str_error.h>
#include <str.h>
#include <audio_pcm_iface.h>
#include <fibril_synch.h>
#include <pcm/format.h>
#include <sys/mman.h>
#include <sys/time.h>
#include <inttypes.h>

#include <stdio.h>
#include <macros.h>

#include "wave.h"
#include "dplay.h"

#define DEFAULT_FRAGMENTS 2

/** Playback helper structure */
typedef struct {
	struct {
		void *base;
		size_t size;
		void* write_ptr;
	} buffer;
	pcm_format_t f;
	FILE* source;
	volatile bool playing;
	fibril_mutex_t mutex;
	fibril_condvar_t cv;
	audio_pcm_sess_t *device;
} playback_t;

/**
 * Initialize playback helper structure.
 * @param pb Pointer to helper structure to initialize
 * @param sess Pointer to audio device IPC session
 * @return
 */
static void playback_initialize(playback_t *pb, audio_pcm_sess_t *sess)
{
	assert(sess);
	assert(pb);
	pb->buffer.base = NULL;
	pb->buffer.size = 0;
	pb->buffer.write_ptr = NULL;
	pb->playing = false;
	pb->source = NULL;
	pb->device = sess;
	fibril_mutex_initialize(&pb->mutex);
	fibril_condvar_initialize(&pb->cv);
}

/**
 * Fragment playback callback function.
 * @param iid IPC call id.
 * @param icall Pointer to the call structure
 * @param arg Argument, pointer to the playback helper function
 */
static void device_event_callback(ipc_callid_t iid, ipc_call_t *icall, void* arg)
{
	async_answer_0(iid, EOK);
	playback_t *pb = arg;
	const size_t fragment_size = pb->buffer.size / DEFAULT_FRAGMENTS;
	while (1) {
		ipc_call_t call;
		ipc_callid_t callid = async_get_call(&call);
		switch(IPC_GET_IMETHOD(call)) {
		case PCM_EVENT_PLAYBACK_STARTED:
		case PCM_EVENT_FRAMES_PLAYED:
			printf("%" PRIun " frames: ", IPC_GET_ARG1(call));
			async_answer_0(callid, EOK);
			break;
		case PCM_EVENT_PLAYBACK_TERMINATED:
			printf("Playback terminated\n");
			fibril_mutex_lock(&pb->mutex);
			pb->playing = false;
			fibril_condvar_signal(&pb->cv);
			async_answer_0(callid, EOK);
			fibril_mutex_unlock(&pb->mutex);
			return;
		default:
			printf("Unknown event %" PRIun ".\n", IPC_GET_IMETHOD(call));
			async_answer_0(callid, ENOTSUP);
			continue;

		}
		const size_t bytes = fread(pb->buffer.write_ptr,
		   sizeof(uint8_t), fragment_size, pb->source);
		printf("Copied from position %p size %zu/%zu\n",
		    pb->buffer.write_ptr, bytes, fragment_size);
		if (bytes == 0) {
			audio_pcm_last_playback_fragment(pb->device);
		}
		/* any constant is silence */
		memset(pb->buffer.write_ptr + bytes, 0, fragment_size - bytes);
		pb->buffer.write_ptr += fragment_size;

		if (pb->buffer.write_ptr >= (pb->buffer.base + pb->buffer.size))
			pb->buffer.write_ptr -= pb->buffer.size;
	}
}

/**
 * Start event based playback.
 * @param pb Playback helper structure.
 */
static void play_fragment(playback_t *pb)
{
	assert(pb);
	assert(pb->device);
	const size_t fragment_size = pb->buffer.size / DEFAULT_FRAGMENTS;
	printf("Registering event callback\n");
	int ret = audio_pcm_register_event_callback(pb->device,
	    device_event_callback, pb);
	if (ret != EOK) {
		printf("Failed to register event callback.\n");
		return;
	}
	printf("Playing: %dHz, %s, %d channel(s).\n", pb->f.sampling_rate,
	    pcm_sample_format_str(pb->f.sample_format), pb->f.channels);
	const size_t bytes = fread(pb->buffer.base, sizeof(uint8_t),
	    fragment_size, pb->source);
	if (bytes != fragment_size)
		memset(pb->buffer.base + bytes, 0, fragment_size - bytes);
	printf("Initial: Copied from position %p size %zu/%zu\n",
	    pb->buffer.base, bytes, fragment_size);
	pb->buffer.write_ptr = pb->buffer.base + fragment_size;
	fibril_mutex_lock(&pb->mutex);
	const unsigned frames =
	    pcm_format_size_to_frames(fragment_size, &pb->f);
	ret = audio_pcm_start_playback_fragment(pb->device, frames,
	    pb->f.channels, pb->f.sampling_rate, pb->f.sample_format);
	if (ret != EOK) {
		fibril_mutex_unlock(&pb->mutex);
		printf("Failed to start playback: %s.\n", str_error(ret));
		audio_pcm_unregister_event_callback(pb->device);
		return;
	}

	for (pb->playing = true; pb->playing;
	    fibril_condvar_wait(&pb->cv, &pb->mutex));

	fibril_mutex_unlock(&pb->mutex);
	printf("\n");
	audio_pcm_unregister_event_callback(pb->device);
}

/**
 * Count occupied space in a cyclic buffer.
 * @param pb Playback helper structure.
 * @param pos read pointer position.
 * @return Occupied space size.
 */
static size_t buffer_occupied(const playback_t *pb, size_t pos)
{
	assert(pb);
	void *read_ptr = pb->buffer.base + pos;
	if (read_ptr > pb->buffer.write_ptr)
		return pb->buffer.write_ptr + pb->buffer.size - read_ptr;
	return pb->buffer.write_ptr - read_ptr;

}

/**
 * Count available space in a cyclic buffer.
 * @param pb Playback helper structure.
 * @param pos read pointer position.
 * @return Free space size.
 */
static size_t buffer_avail(const playback_t *pb, size_t pos)
{
	assert(pb);
	void *read_ptr = pb->buffer.base + pos;
	if (read_ptr <= pb->buffer.write_ptr)
		return read_ptr + pb->buffer.size - pb->buffer.write_ptr - 1;
	return (read_ptr - pb->buffer.write_ptr) - 1;
}

/**
 * Size of the space between write pointer and the end of a cyclic buffer
 * @param pb Playback helper structure.
 */
static size_t buffer_remain(const playback_t *pb)
{
	assert(pb);
	return (pb->buffer.base + pb->buffer.size) - pb->buffer.write_ptr;
}

/**
 * Move write pointer forward. Wrap around the end.
 * @param pb Playback helper structure.
 * @param bytes NUmber of bytes to advance.
 */
static void buffer_advance(playback_t *pb, size_t bytes)
{
	assert(pb);
	pb->buffer.write_ptr += bytes;
	while (pb->buffer.write_ptr >= (pb->buffer.base + pb->buffer.size))
		pb->buffer.write_ptr -= pb->buffer.size;
}

#define DPRINTF(f, ...) \
	printf("%.2lu:%.6lu   "f, time.tv_sec % 100, time.tv_usec, __VA_ARGS__)

/**
 * Start playback using buffer position api.
 * @param pb Playback helper function.
 */
static void play(playback_t *pb)
{
	assert(pb);
	assert(pb->device);
	pb->buffer.write_ptr = pb->buffer.base;
	printf("Playing: %dHz, %s, %d channel(s).\n", pb->f.sampling_rate,
	    pcm_sample_format_str(pb->f.sample_format), pb->f.channels);
	useconds_t work_time = 20000; /* 20 ms */
	bool started = false;
	size_t pos = 0;
	struct timeval time = { 0 };
	getuptime(&time);
	do {
		size_t available = buffer_avail(pb, pos);
		/* Writing might need wrap around the end,
		 * read directly to device buffer */
		size_t bytes = fread(pb->buffer.write_ptr, sizeof(uint8_t),
		    min(available, buffer_remain(pb)), pb->source);
		buffer_advance(pb, bytes);
		DPRINTF("POS %zu: %zu bytes free in buffer, read %zu, wp %zu\n",
		    pos, available, bytes,
		    pb->buffer.write_ptr - pb->buffer.base);
		available -= bytes;

		/* continue if we wrapped around the end */
		if (available) {
			bytes = fread(pb->buffer.write_ptr,
			    sizeof(uint8_t), min(available, buffer_remain(pb)),
			    pb->source);
			buffer_advance(pb, bytes);
			DPRINTF("POS %zu: %zu bytes still free in buffer, "
			    "read %zu, wp %zu\n", pos, available, bytes,
			    pb->buffer.write_ptr - pb->buffer.base);
			available -= bytes;
		}

		if (!started) {
			int ret = audio_pcm_start_playback(pb->device,
			    pb->f.channels, pb->f.sampling_rate,
			    pb->f.sample_format);
			if (ret != EOK) {
				printf("Failed to start playback\n");
				return;
			}
			started = true;
			ret = audio_pcm_get_buffer_pos(pb->device, &pos);
			if (ret != EOK) {
				printf("Failed to update position indicator\n");
			}
		}
		const size_t to_play = buffer_occupied(pb, pos);
		const useconds_t usecs =
		    pcm_format_size_to_usec(to_play, &pb->f);

		/* Compute delay time */
		const useconds_t real_delay = (usecs > work_time)
		    ? usecs - work_time : 0;
		DPRINTF("POS %zu: %u usecs (%u) to play %zu bytes.\n",
		    pos, usecs, real_delay, to_play);
		if (real_delay)
			async_usleep(real_delay);
		/* update buffer position */
		const int ret = audio_pcm_get_buffer_pos(pb->device, &pos);
		if (ret != EOK) {
			printf("Failed to update position indicator\n");
		}
		getuptime(&time);

		/* we did not use all the space we had,
		 * that is the end */
		if (available)
			break;

	} while (1);
	audio_pcm_stop_playback(pb->device);
}

/**
 * Play audio file usign direct device access.
 * @param device The device.
 * @param file The file.
 * @return Error code.
 */
int dplay(const char *device, const char *file)
{
	int ret = EOK;
	audio_pcm_sess_t *session = NULL;
	if (str_cmp(device, "default") == 0) {
		session = audio_pcm_open_default();
	} else {
		session = audio_pcm_open(device);
	}
	if (!session) {
		printf("Failed to connect to device %s.\n", device);
		return 1;
	}
	printf("Playing on device: %s.\n", device);
	if (audio_pcm_query_cap(session, AUDIO_CAP_PLAYBACK) <= 0) {
		printf("Device %s does not support playback\n", device);
		ret = ENOTSUP;
		goto close_session;
	}

	const char* info = NULL;
	ret = audio_pcm_get_info_str(session, &info);
	if (ret != EOK) {
		printf("Failed to get PCM info.\n");
		goto close_session;
	}
	printf("Playing on %s.\n", info);
	free(info);

	playback_t pb;
	playback_initialize(&pb, session);

	ret = audio_pcm_get_buffer(pb.device, &pb.buffer.base, &pb.buffer.size);
	if (ret != EOK) {
		printf("Failed to get PCM buffer: %s.\n", str_error(ret));
		goto close_session;
	}
	printf("Buffer: %p %zu.\n", pb.buffer.base, pb.buffer.size);

	pb.source = fopen(file, "rb");
	if (pb.source == NULL) {
		ret = ENOENT;
		printf("Failed to open file: %s.\n", file);
		goto cleanup;
	}

	wave_header_t header;
	fread(&header, sizeof(header), 1, pb.source);
	const char *error;
	ret = wav_parse_header(&header, NULL, NULL,
	    &pb.f.channels, &pb.f.sampling_rate, &pb.f.sample_format, &error);
	if (ret != EOK) {
		printf("Error parsing wav header: %s.\n", error);
		goto cleanup;
	}
	if (audio_pcm_query_cap(pb.device, AUDIO_CAP_BUFFER_POS) > 0) {
		play(&pb);
	} else {
		if (audio_pcm_query_cap(pb.device, AUDIO_CAP_INTERRUPT) > 0)
			play_fragment(&pb);
		else
			printf("Neither playing method is supported");
	}

cleanup:
	fclose(pb.source);
	munmap(pb.buffer.base, pb.buffer.size);
	audio_pcm_release_buffer(pb.device);
close_session:
	audio_pcm_close(session);
	return ret == EOK ? 0 : 1;
}
/**
 * @}
 */