#include "configuration.h"

#ifdef SHR3D_LIBSAMPLERATE

/*
** Copyright (c) 2002-2016, Erik de Castro Lopo <erikd@mega-nerd.com>
** All rights reserved.
**
** This code is released under 2-clause BSD license. Please see the
** file at : https://github.com/libsndfile/libsamplerate/blob/master/COPYING
*/

//#ifdef HAVE_CONFIG_H
#include	"samplerateconfig.h"
//#endif

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

#include	"samplerate.h"
#include	"sampleratecommon.h"

static SRC_STATE* psrc_set_converter(int converter_type, int channels, int* error);


SRC_STATE*
src_new(int converter_type, int channels, int* error)
{
	return psrc_set_converter(converter_type, channels, error);
} /* src_new */

SRC_STATE*
src_clone(SRC_STATE* orig, int* error)
{
	if (!orig)
	{
		if (error)
			*error = SRC_ERR_BAD_STATE;
		return NULL;
	}
	if (error)
		*error = SRC_ERR_NO_ERROR;

	SRC_STATE* state = orig->vt->copy(orig);
	if (!state)
		if (error)
			*error = SRC_ERR_MALLOC_FAILED;

	return state;
}

SRC_STATE*
src_callback_new(src_callback_t func, int converter_type, int channels, int* error, void* cb_data)
{
	SRC_STATE* state;

	if (func == NULL)
	{
		if (error)
			*error = SRC_ERR_BAD_CALLBACK;
		return NULL;
	};

	if (error != NULL)
		*error = 0;

	if ((state = src_new(converter_type, channels, error)) == NULL)
		return NULL;

	src_reset(state);

	state->mode = SRC_MODE_CALLBACK;
	state->callback_func = func;
	state->user_callback_data = cb_data;

	return state;
} /* src_callback_new */

SRC_STATE*
src_delete(SRC_STATE* state)
{
	if (state)
		state->vt->close(state);

	return NULL;
} /* src_state */

int
src_process(SRC_STATE* state, SRC_DATA* data)
{
	int error;

	if (state == NULL)
		return SRC_ERR_BAD_STATE;

	if (state->mode != SRC_MODE_PROCESS)
		return SRC_ERR_BAD_MODE;

	/* Check for valid SRC_DATA first. */
	if (data == NULL)
		return SRC_ERR_BAD_DATA;

	/* And that data_in and data_out are valid. */
	if ((data->data_in == NULL && data->input_frames > 0)
		|| (data->data_out == NULL && data->output_frames > 0))
		return SRC_ERR_BAD_DATA_PTR;

	/* Check src_ratio is in range. */
	if (is_bad_src_ratio(data->src_ratio))
		return SRC_ERR_BAD_SRC_RATIO;

	if (data->input_frames < 0)
		data->input_frames = 0;
	if (data->output_frames < 0)
		data->output_frames = 0;

	if (data->data_in < data->data_out)
	{
		if (data->data_in + data->input_frames * state->channels > data->data_out)
		{	/*-printf ("\n\ndata_in: %p    data_out: %p\n",
				(void*) (data->data_in + data->input_frames * psrc->channels), (void*) data->data_out) ;-*/
			return SRC_ERR_DATA_OVERLAP;
		};
	}
	else if (data->data_out + data->output_frames * state->channels > data->data_in)
	{	/*-printf ("\n\ndata_in : %p   ouput frames: %ld    data_out: %p\n", (void*) data->data_in, data->output_frames, (void*) data->data_out) ;

		printf ("data_out: %p (%p)    data_in: %p\n", (void*) data->data_out,
			(void*) (data->data_out + data->input_frames * psrc->channels), (void*) data->data_in) ;-*/
		return SRC_ERR_DATA_OVERLAP;
	};

	/* Set the input and output counts to zero. */
	data->input_frames_used = 0;
	data->output_frames_gen = 0;

	/* Special case for when last_ratio has not been set. */
	if (state->last_ratio < (1.0 / SRC_MAX_RATIO))
		state->last_ratio = data->src_ratio;

	/* Now process. */
	if (fabs(state->last_ratio - data->src_ratio) < 1e-15)
		error = state->vt->const_process(state, data);
	else
		error = state->vt->vari_process(state, data);

	return error;
} /* src_process */

long
src_callback_read(SRC_STATE* state, double src_ratio, long frames, float* data)
{
	SRC_DATA	src_data;

	long	output_frames_gen;
	int		error = 0;

	if (state == NULL)
		return 0;

	if (frames <= 0)
		return 0;

	if (state->mode != SRC_MODE_CALLBACK)
	{
		state->error = SRC_ERR_BAD_MODE;
		return 0;
	};

	if (state->callback_func == NULL)
	{
		state->error = SRC_ERR_NULL_CALLBACK;
		return 0;
	};

	memset(&src_data, 0, sizeof(src_data));

	/* Check src_ratio is in range. */
	if (is_bad_src_ratio(src_ratio))
	{
		state->error = SRC_ERR_BAD_SRC_RATIO;
		return 0;
	};

	/* Switch modes temporarily. */
	src_data.src_ratio = src_ratio;
	src_data.data_out = data;
	src_data.output_frames = frames;

	src_data.data_in = state->saved_data;
	src_data.input_frames = state->saved_frames;

	output_frames_gen = 0;
	while (output_frames_gen < frames)
	{	/*	Use a dummy array for the case where the callback function
		**	returns without setting the ptr.
		*/
		float dummy[1];

		if (src_data.input_frames == 0)
		{
			float* ptr = dummy;

			src_data.input_frames = state->callback_func(state->user_callback_data, &ptr);
			src_data.data_in = ptr;

			if (src_data.input_frames == 0)
				src_data.end_of_input = 1;
		};

		/*
		** Now call process function. However, we need to set the mode
		** to SRC_MODE_PROCESS first and when we return set it back to
		** SRC_MODE_CALLBACK.
		*/
		state->mode = SRC_MODE_PROCESS;
		error = src_process(state, &src_data);
		state->mode = SRC_MODE_CALLBACK;

		if (error != 0)
			break;

		src_data.data_in += src_data.input_frames_used * state->channels;
		src_data.input_frames -= src_data.input_frames_used;

		src_data.data_out += src_data.output_frames_gen * state->channels;
		src_data.output_frames -= src_data.output_frames_gen;

		output_frames_gen += src_data.output_frames_gen;

		if (src_data.end_of_input == SRC_TRUE && src_data.output_frames_gen == 0)
			break;
	};

	state->saved_data = src_data.data_in;
	state->saved_frames = src_data.input_frames;

	if (error != 0)
	{
		state->error = (SRC_ERROR)error;
		return 0;
	};

	return output_frames_gen;
} /* src_callback_read */

/*==========================================================================
*/

int
src_set_ratio(SRC_STATE* state, double new_ratio)
{
	if (state == NULL)
		return SRC_ERR_BAD_STATE;

	if (is_bad_src_ratio(new_ratio))
		return SRC_ERR_BAD_SRC_RATIO;

	state->last_ratio = new_ratio;

	return SRC_ERR_NO_ERROR;
} /* src_set_ratio */

int
src_get_channels(SRC_STATE* state)
{
	if (state == NULL)
		return -SRC_ERR_BAD_STATE;

	return state->channels;
} /* src_get_channels */

int
src_reset(SRC_STATE* state)
{
	if (state == NULL)
		return SRC_ERR_BAD_STATE;

	state->vt->reset(state);

	state->last_position = 0.0;
	state->last_ratio = 0.0;

	state->saved_data = NULL;
	state->saved_frames = 0;

	state->error = SRC_ERR_NO_ERROR;

	return SRC_ERR_NO_ERROR;
} /* src_reset */

/*==============================================================================
**	Control functions.
*/

const char*
src_get_name(int converter_type)
{
	const char* desc;

	if ((desc = sinc_get_name(converter_type)) != NULL)
		return desc;

	if ((desc = zoh_get_name(converter_type)) != NULL)
		return desc;

	if ((desc = linear_get_name(converter_type)) != NULL)
		return desc;

	return NULL;
} /* src_get_name */

const char*
src_get_description(int converter_type)
{
	const char* desc;

	if ((desc = sinc_get_description(converter_type)) != NULL)
		return desc;

	if ((desc = zoh_get_description(converter_type)) != NULL)
		return desc;

	if ((desc = linear_get_description(converter_type)) != NULL)
		return desc;

	return NULL;
} /* src_get_description */

const char*
src_get_version(void)
{
	return PACKAGE "-" VERSION " (c) 2002-2008 Erik de Castro Lopo";
} /* src_get_version */

int
src_is_valid_ratio(double ratio)
{
	if (is_bad_src_ratio(ratio))
		return SRC_FALSE;

	return SRC_TRUE;
} /* src_is_valid_ratio */

/*==============================================================================
**	Error reporting functions.
*/

int
src_error(SRC_STATE* state)
{
	if (state)
		return state->error;
	return SRC_ERR_NO_ERROR;
} /* src_error */

const char*
src_strerror(int error)
{
	switch (error)
	{
	case SRC_ERR_NO_ERROR:
		return "No error.";
	case SRC_ERR_MALLOC_FAILED:
		return "Malloc failed.";
	case SRC_ERR_BAD_STATE:
		return "SRC_STATE pointer is NULL.";
	case SRC_ERR_BAD_DATA:
		return "SRC_DATA pointer is NULL.";
	case SRC_ERR_BAD_DATA_PTR:
		return "SRC_DATA->data_out or SRC_DATA->data_in is NULL.";
	case SRC_ERR_NO_PRIVATE:
		return "Internal error. No private data.";

	case SRC_ERR_BAD_SRC_RATIO:
		return "SRC ratio outside [1/" SRC_MAX_RATIO_STR ", " SRC_MAX_RATIO_STR "] range.";

	case SRC_ERR_BAD_SINC_STATE:
		return "src_process() called without reset after end_of_input.";
	case SRC_ERR_BAD_PROC_PTR:
		return "Internal error. No process pointer.";
	case SRC_ERR_SHIFT_BITS:
		return "Internal error. SHIFT_BITS too large.";
	case SRC_ERR_FILTER_LEN:
		return "Internal error. Filter length too large.";
	case SRC_ERR_BAD_CONVERTER:
		return "Bad converter number.";
	case SRC_ERR_BAD_CHANNEL_COUNT:
		return "Channel count must be >= 1.";
	case SRC_ERR_SINC_BAD_BUFFER_LEN:
		return "Internal error. Bad buffer length. Please report this.";
	case SRC_ERR_SIZE_INCOMPATIBILITY:
		return "Internal error. Input data / internal buffer size difference. Please report this.";
	case SRC_ERR_BAD_PRIV_PTR:
		return "Internal error. Private pointer is NULL. Please report this.";
	case SRC_ERR_DATA_OVERLAP:
		return "Input and output data arrays overlap.";
	case SRC_ERR_BAD_CALLBACK:
		return "Supplied callback function pointer is NULL.";
	case SRC_ERR_BAD_MODE:
		return "Calling mode differs from initialisation mode (ie process v callback).";
	case SRC_ERR_NULL_CALLBACK:
		return "Callback function pointer is NULL in src_callback_read ().";
	case SRC_ERR_NO_VARIABLE_RATIO:
		return "This converter only allows constant conversion ratios.";
	case SRC_ERR_SINC_PREPARE_DATA_BAD_LEN:
		return "Internal error : Bad length in prepare_data ().";
	case SRC_ERR_BAD_INTERNAL_STATE:
		return "Error : Someone is trampling on my internal state.";

	case SRC_ERR_MAX_ERROR:
		return "Placeholder. No error defined for this error number.";

	default: 						break;
	}

	return NULL;
} /* src_strerror */

/*==============================================================================
**	Simple interface for performing a single conversion from input buffer to
**	output buffer at a fixed conversion ratio.
*/

int
src_simple(SRC_DATA* src_data, int converter, int channels)
{
	SRC_STATE* src_state;
	int 		error;

	if ((src_state = src_new(converter, channels, &error)) == NULL)
		return error;

	src_data->end_of_input = 1; /* Only one buffer worth of input. */

	error = src_process(src_state, src_data);

	src_delete(src_state);

	return error;
} /* src_simple */

void
src_short_to_float_array(const short* in, float* out, int len)
{
	for (int i = 0; i < len; i++)
	{
		out[i] = (float)(in[i] / (1.0 * 0x8000));
	};

	return;
} /* src_short_to_float_array */

void
src_float_to_short_array(const float* in, short* out, int len)
{
	for (int i = 0; i < len; i++)
	{
		float scaled_value;
		scaled_value = in[i] * 32768.f;
		if (scaled_value >= 32767.f)
			out[i] = 32767;
		else if (scaled_value <= -32768.f)
			out[i] = -32768;
		else
			out[i] = (short)(lrintf(scaled_value));
	}
} /* src_float_to_short_array */

void
src_int_to_float_array(const int* in, float* out, int len)
{
	for (int i = 0; i < len; i++)
	{
		out[i] = (float)(in[i] / (8.0 * 0x10000000));
	};

	return;
} /* src_int_to_float_array */

void
src_float_to_int_array(const float* in, int* out, int len)
{
	double scaled_value;

	for (int i = 0; i < len; i++)
	{
		scaled_value = in[i] * (8.0 * 0x10000000);
#if CPU_CLIPS_POSITIVE == 0
		if (scaled_value >= (1.0 * 0x7FFFFFFF))
		{
			out[i] = 0x7fffffff;
			continue;
		};
#endif
#if CPU_CLIPS_NEGATIVE == 0
		if (scaled_value <= (-8.0 * 0x10000000))
		{
			out[i] = -1 - 0x7fffffff;
			continue;
		};
#endif
		out[i] = (int)lrint(scaled_value);
	};

} /* src_float_to_int_array */

/*==============================================================================
**	Private functions.
*/

static SRC_STATE*
psrc_set_converter(int converter_type, int channels, int* error)
{
	SRC_ERROR temp_error;
	SRC_STATE* state;
	switch (converter_type)
	{
#ifdef ENABLE_SINC_BEST_CONVERTER
	case SRC_SINC_BEST_QUALITY:
		state = sinc_state_new(converter_type, channels, &temp_error);
		break;
#endif
#ifdef ENABLE_SINC_MEDIUM_CONVERTER
	case SRC_SINC_MEDIUM_QUALITY:
		state = sinc_state_new(converter_type, channels, &temp_error);
		break;
#endif
#ifdef ENABLE_SINC_FAST_CONVERTER
	case SRC_SINC_FASTEST:
		state = sinc_state_new(converter_type, channels, &temp_error);
		break;
#endif
	case SRC_ZERO_ORDER_HOLD:
		state = zoh_state_new(channels, &temp_error);
		break;
	case SRC_LINEAR:
		state = linear_state_new(channels, &temp_error);
		break;
	default:
		temp_error = SRC_ERR_BAD_CONVERTER;
		state = NULL;
		break;
	}

	if (error)
		*error = (int)temp_error;

	return state;
} /* psrc_set_converter */

#endif // SHR3D_LIBSAMPLERATE
