/**
 * FreeRDP: A Remote Desktop Protocol Implementation
 * Audio Output Virtual Channel
 *
 * Copyright (c) 2015 Rozhuk Ivan <rozhuk.im@gmail.com>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <winpr/crt.h>
#include <winpr/cmdline.h>
#include <winpr/sysinfo.h>
#include <winpr/collections.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <unistd.h>
#include <sys/soundcard.h>

#include <freerdp/types.h>
#include <freerdp/codec/dsp.h>
#include <freerdp/channels/log.h>

#include "rdpsnd_main.h"

typedef struct rdpsnd_oss_plugin rdpsndOssPlugin;

struct rdpsnd_oss_plugin {
	rdpsndDevicePlugin device;

	int pcm_handle;
	int mixer_handle;
	int dev_unit;

	int supported_formats;

	int latency;
	AUDIO_FORMAT format;

	FREERDP_DSP_CONTEXT *dsp_context;
};

#define OSS_LOG_ERR(_text, _error) \
	if (_error != 0) \
		WLog_ERR(TAG, "%s: %i - %s\n", _text, _error, strerror(_error));


static int rdpsnd_oss_get_format(AUDIO_FORMAT *format) {

	switch (format->wFormatTag) {
	case WAVE_FORMAT_PCM:
		switch (format->wBitsPerSample) {
		case 8:
			return AFMT_S8;
		case 16:
			return AFMT_S16_LE;
		}
		break;
	case WAVE_FORMAT_ALAW:
		return AFMT_A_LAW;
#if 0 /* This does not work on my desktop. */
	case WAVE_FORMAT_MULAW:
		return AFMT_MU_LAW;
#endif
	case WAVE_FORMAT_ADPCM:
	case WAVE_FORMAT_DVI_ADPCM:
		return AFMT_S16_LE;
	}

	return 0;
}

static BOOL rdpsnd_oss_format_supported(rdpsndDevicePlugin *device, AUDIO_FORMAT *format) {
	int req_fmt = 0;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL || format == NULL)
		return FALSE;

	switch (format->wFormatTag) {
	case WAVE_FORMAT_PCM:
		if (format->cbSize != 0 ||
		    format->nSamplesPerSec > 48000 ||
		    (format->wBitsPerSample != 8 && format->wBitsPerSample != 16) ||
		    (format->nChannels != 1 && format->nChannels != 2))
			return FALSE;
		break;
	case WAVE_FORMAT_ADPCM:
	case WAVE_FORMAT_DVI_ADPCM:
		if (format->nSamplesPerSec > 48000 ||
		    format->wBitsPerSample != 4 ||
		    (format->nChannels != 1 && format->nChannels != 2))
			return FALSE;
		break;
	}
	
	req_fmt = rdpsnd_oss_get_format(format);
	if (oss->pcm_handle != -1) { /* Check really supported formats by dev. */
		if ((req_fmt & oss->supported_formats) == 0)
			return FALSE;
		if ((AFMT_STEREO & oss->supported_formats) == 0 && format->nChannels == 2)
			return FALSE;
	} else {
		if (req_fmt == 0)
			return FALSE;
	}

	return TRUE;
}

static void rdpsnd_oss_set_format(rdpsndDevicePlugin *device, AUDIO_FORMAT *format, int latency) {
	int tmp;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL || oss->pcm_handle == -1 || format == NULL)
		return;
	
	oss->latency = latency;
	CopyMemory(&(oss->format), format, sizeof(AUDIO_FORMAT));

	tmp = rdpsnd_oss_get_format(format);
	if (ioctl(oss->pcm_handle, SNDCTL_DSP_SETFMT, &tmp) == -1)
		OSS_LOG_ERR("SNDCTL_DSP_SETFMT failed.", errno);
	tmp = format->nChannels;
	if (ioctl(oss->pcm_handle, SNDCTL_DSP_CHANNELS, &tmp) == -1)
		OSS_LOG_ERR("SNDCTL_DSP_CHANNELS failed.", errno);
	tmp = format->nSamplesPerSec;
	if (ioctl(oss->pcm_handle, SNDCTL_DSP_SPEED, &tmp) == -1)
		OSS_LOG_ERR("SNDCTL_DSP_SPEED failed.", errno);
	tmp = format->nBlockAlign;
	if (ioctl(oss->pcm_handle, SNDCTL_DSP_SETFRAGMENT, &tmp) == -1)
		OSS_LOG_ERR("SNDCTL_DSP_SETFRAGMENT failed.", errno);
}

static void rdpsnd_oss_open_mixer(rdpsndOssPlugin *oss) {
	int devmask = 0;
	char mixer[PATH_MAX] = "/dev/mixer";

	if (oss->mixer_handle != -1)
		return;

	if (oss->dev_unit != -1)
		snprintf(mixer, PATH_MAX - 1, "/dev/mixer%i", oss->dev_unit);
	if ((oss->mixer_handle = open(mixer, O_RDWR)) < 0) {
		OSS_LOG_ERR("mixer open failed", errno);
		oss->mixer_handle = -1;
		return;
	}
	if (ioctl(oss->mixer_handle, SOUND_MIXER_READ_DEVMASK, &devmask) == -1) {
		OSS_LOG_ERR("SOUND_MIXER_READ_DEVMASK failed", errno);
		close(oss->mixer_handle);
		oss->mixer_handle = -1;
		return;
	}
}

static void rdpsnd_oss_open(rdpsndDevicePlugin *device, AUDIO_FORMAT *format, int latency) {
	int mask = 0;
	char dev_name[PATH_MAX] = "/dev/dsp";
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL || oss->pcm_handle != -1)
		return;

	if (oss->dev_unit != -1)
		snprintf(dev_name, PATH_MAX - 1, "/dev/dsp%i", oss->dev_unit);
	if ((oss->pcm_handle = open(dev_name, O_WRONLY)) < 0) {
		OSS_LOG_ERR("sound dev open failed", errno);
		oss->pcm_handle = -1;
		return;
	}
#if 0 /* FreeBSD OSS implementation at this moment (2015.03) does not set PCM_CAP_OUTPUT flag. */
	if (ioctl(oss->pcm_handle, SNDCTL_DSP_GETCAPS, &mask) == -1) {
		OSS_LOG_ERR("SNDCTL_DSP_GETCAPS failed, try ignory.", errno);
	} else if ((mask & PCM_CAP_OUTPUT) == 0) {
		OSS_LOG_ERR("Device does not supports playback", EOPNOTSUPP);
		close(oss->pcm_handle);
		oss->pcm_handle = -1;
		return;
	}
#endif
	if (ioctl(oss->pcm_handle, SNDCTL_DSP_GETFMTS, &oss->supported_formats) == -1) {
		OSS_LOG_ERR("SNDCTL_DSP_GETFMTS failed.", errno);
		close(oss->pcm_handle);
		oss->pcm_handle = -1;
		return;
	}
	freerdp_dsp_context_reset_adpcm(oss->dsp_context);
	rdpsnd_oss_set_format(device, format, latency);
	rdpsnd_oss_open_mixer(oss);
}

static void rdpsnd_oss_close(rdpsndDevicePlugin *device) {
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL)
		return;

	if (oss->pcm_handle != -1) {
		close(oss->pcm_handle);
		oss->pcm_handle = -1;
	}

	if (oss->mixer_handle != -1) {
		close(oss->mixer_handle);
		oss->mixer_handle = -1;
	}
}

static void rdpsnd_oss_free(rdpsndDevicePlugin *device) {
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL)
		return;

	rdpsnd_oss_close(device);
	freerdp_dsp_context_free(oss->dsp_context);

	free(oss);
}

static UINT32 rdpsnd_oss_get_volume(rdpsndDevicePlugin *device) {
	int vol;
	UINT32 dwVolume;
	UINT16 dwVolumeLeft, dwVolumeRight;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	/* On error return 50% volume. */
	dwVolumeLeft = ((50 * 0xFFFF) / 100); /* 50% */
	dwVolumeRight = ((50 * 0xFFFF) / 100); /* 50% */
	dwVolume = ((dwVolumeLeft << 16) | dwVolumeRight);
	
	if (device == NULL || oss->mixer_handle == -1)
		return dwVolume;
	
	if (ioctl(oss->mixer_handle, MIXER_READ(SOUND_MIXER_VOLUME), &vol) == -1) {
		OSS_LOG_ERR("MIXER_READ", errno);
		return dwVolume;
	}
	
	dwVolumeLeft = (((vol & 0x7f) * 0xFFFF) / 100);
	dwVolumeRight = ((((vol >> 8) & 0x7f) * 0xFFFF) / 100);
	dwVolume = ((dwVolumeLeft << 16) | dwVolumeRight);

	return dwVolume;
}

static void rdpsnd_oss_set_volume(rdpsndDevicePlugin *device, UINT32 value) {
	int left, right;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL || oss->mixer_handle == -1)
		return;

	left = (value & 0xFFFF);
	right = ((value >> 16) & 0xFFFF);

	if (left < 0)
		left = 0;
	else if (left > 100)
		left = 100;
	if (right < 0)
		right = 0;
	else if (right > 100)
		right = 100;

	left |= (right << 8);
	if (ioctl(oss->mixer_handle, MIXER_WRITE(SOUND_MIXER_VOLUME), &left) == -1)
		OSS_LOG_ERR("WRITE_MIXER", errno);
}

static void rdpsnd_oss_wave_decode(rdpsndDevicePlugin *device, RDPSND_WAVE *wave) {
	int size;
	BYTE *data;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL || wave == NULL)
		return;

	switch (oss->format.wFormatTag) {
	case WAVE_FORMAT_ADPCM:
		oss->dsp_context->decode_ms_adpcm(oss->dsp_context,
			wave->data, wave->length, oss->format.nChannels, oss->format.nBlockAlign);
		size = oss->dsp_context->adpcm_size;
		data = oss->dsp_context->adpcm_buffer;
		break;
	case WAVE_FORMAT_DVI_ADPCM:
		oss->dsp_context->decode_ima_adpcm(oss->dsp_context,
			wave->data, wave->length, oss->format.nChannels, oss->format.nBlockAlign);
		size = oss->dsp_context->adpcm_size;
		data = oss->dsp_context->adpcm_buffer;
		break;
	default:
		size = wave->length;
		data = wave->data;
	}

	wave->data = (BYTE*)malloc(size);
	CopyMemory(wave->data, data, size);
	if (wave->length != size)
		WLog_ERR(TAG, "wave->length = %i, size = %i!!!\n", wave->length, size);
	wave->length = size;
}

static void rdpsnd_oss_wave_play(rdpsndDevicePlugin *device, RDPSND_WAVE *wave) {
	BYTE *data;
	int offset, size, status;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	if (device == NULL || wave == NULL)
		return;

	offset = 0;
	data = wave->data;
	size = wave->length;

	while (offset < size) {
		status = write(oss->pcm_handle, &data[offset], (size - offset));
		if (status < 0) {
			OSS_LOG_ERR("write fail", errno);
			rdpsnd_oss_close(device);
			rdpsnd_oss_open(device, NULL, 0);
			break;
		}
		offset += status;
	}
	/* From rdpsnd_main.c */
	wave->wTimeStampB = wave->wTimeStampA + wave->wAudioLength + 65;
	wave->wLocalTimeB = wave->wLocalTimeA + wave->wAudioLength + 65;

	free(data);
}


static COMMAND_LINE_ARGUMENT_A rdpsnd_oss_args[] = {
	{ "dev", COMMAND_LINE_VALUE_REQUIRED, "<device>", NULL, NULL, -1, NULL, "device" },
	{ NULL, 0, NULL, NULL, NULL, -1, NULL, NULL }
};

static int rdpsnd_oss_parse_addin_args(rdpsndDevicePlugin *device, ADDIN_ARGV *args) {
	int status;
	char *str_num, *eptr;
	DWORD flags;
	COMMAND_LINE_ARGUMENT_A *arg;
	rdpsndOssPlugin *oss = (rdpsndOssPlugin*)device;

	flags = COMMAND_LINE_SIGIL_NONE | COMMAND_LINE_SEPARATOR_COLON;

	status = CommandLineParseArgumentsA(args->argc, (const char**)args->argv, rdpsnd_oss_args, flags, oss, NULL, NULL);
	if (status < 0)
		return status;

	arg = rdpsnd_oss_args;

	do {
		WLog_ERR(TAG, "arg: %s\n", arg->Name);
		if (!(arg->Flags & COMMAND_LINE_VALUE_PRESENT))
			continue;

		CommandLineSwitchStart(arg)

		CommandLineSwitchCase(arg, "dev") {
			str_num = _strdup(arg->Value);
			oss->dev_unit = strtol(str_num, &eptr, 10);
			if (oss->dev_unit < 0 || *eptr != '\0')
				oss->dev_unit = -1;
			free(str_num);
		}

		CommandLineSwitchEnd(arg)
	}
	while ((arg = CommandLineFindNextArgumentA(arg)) != NULL);

	return status;
}

#ifdef STATIC_CHANNELS
#define freerdp_rdpsnd_client_subsystem_entry	oss_freerdp_rdpsnd_client_subsystem_entry
#endif

int freerdp_rdpsnd_client_subsystem_entry(PFREERDP_RDPSND_DEVICE_ENTRY_POINTS pEntryPoints) {
	ADDIN_ARGV *args;
	rdpsndOssPlugin *oss;

	oss = (rdpsndOssPlugin*)malloc(sizeof(rdpsndOssPlugin));
	ZeroMemory(oss, sizeof(rdpsndOssPlugin));

	oss->device.Open = rdpsnd_oss_open;
	oss->device.FormatSupported = rdpsnd_oss_format_supported;
	oss->device.SetFormat = rdpsnd_oss_set_format;
	oss->device.GetVolume = rdpsnd_oss_get_volume;
	oss->device.SetVolume = rdpsnd_oss_set_volume;
	oss->device.WaveDecode = rdpsnd_oss_wave_decode;
	oss->device.WavePlay = rdpsnd_oss_wave_play;
	oss->device.Close = rdpsnd_oss_close;
	oss->device.Free = rdpsnd_oss_free;

	oss->pcm_handle = -1;
	oss->mixer_handle = -1;
	oss->dev_unit = -1;

	args = pEntryPoints->args;
	rdpsnd_oss_parse_addin_args((rdpsndDevicePlugin*)oss, args);

	oss->dsp_context = freerdp_dsp_context_new();

	pEntryPoints->pRegisterRdpsndDevice(pEntryPoints->rdpsnd, (rdpsndDevicePlugin*)oss);

	return 0;
}