/*
** 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    "config.h"
#endif

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

#include    "samplerate.h"
#include    "common.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) (psf_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) psf_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 */
