#include "riscv_const_structs.h"
#include "ref.h"

void ref_rfft_f32(riscv_rfft_instance_f32 *S, float32_t *pSrc, float32_t *pDst)
{
    uint32_t i;

    if (S->ifftFlagR) {
        for (i = 0; i < S->fftLenReal * 2; i++) {
            pDst[i] = pSrc[i];
        }
    } else {
        for (i = 0; i < S->fftLenReal; i++) {
            pDst[2 * i + 0] = pSrc[i];
            pDst[2 * i + 1] = 0.0f;
        }
    }

    switch (S->fftLenReal) {
        case 128:
            ref_cfft_f32(&riscv_cfft_sR_f32_len128, pDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 512:
            ref_cfft_f32(&riscv_cfft_sR_f32_len512, pDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 2048:
            ref_cfft_f32(&riscv_cfft_sR_f32_len2048, pDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 8192:
            ref_cfft_f32(&ref_cfft_sR_f32_len8192, pDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;
    }

    if (S->ifftFlagR) {
        // throw away the imaginary part which should be all zeros
        for (i = 0; i < S->fftLenReal; i++) {
            pDst[i] = pDst[2 * i];
        }
    }
}

void ref_rfft_fast_f32(riscv_rfft_fast_instance_f32 *S, float32_t *p,
                       float32_t *pOut, uint8_t ifftFlag)
{
    uint32_t i, j;

    if (ifftFlag) {
        for (i = 0; i < S->fftLenRFFT; i++) {
            pOut[i] = p[i];
        }
        // unpack first sample's complex part into middle sample's real part
        pOut[S->fftLenRFFT] = pOut[1];
        pOut[S->fftLenRFFT + 1] = 0;
        pOut[1] = 0;
        j = 4;
        for (i = S->fftLenRFFT / 2 + 1; i < S->fftLenRFFT; i++) {
            pOut[2 * i + 0] = p[2 * i + 0 - j];
            pOut[2 * i + 1] = -p[2 * i + 1 - j];
            j += 4;
        }
    } else {
        for (i = 0; i < S->fftLenRFFT; i++) {
            pOut[2 * i + 0] = p[i];
            pOut[2 * i + 1] = 0.0f;
        }
    }

    switch (S->fftLenRFFT) {
        case 32:
            ref_cfft_f32(&riscv_cfft_sR_f32_len32, pOut, ifftFlag, 1);
            break;

        case 64:
            ref_cfft_f32(&riscv_cfft_sR_f32_len64, pOut, ifftFlag, 1);
            break;

        case 128:
            ref_cfft_f32(&riscv_cfft_sR_f32_len128, pOut, ifftFlag, 1);
            break;

        case 256:
            ref_cfft_f32(&riscv_cfft_sR_f32_len256, pOut, ifftFlag, 1);
            break;

        case 512:
            ref_cfft_f32(&riscv_cfft_sR_f32_len512, pOut, ifftFlag, 1);
            break;

        case 1024:
            ref_cfft_f32(&riscv_cfft_sR_f32_len1024, pOut, ifftFlag, 1);
            break;

        case 2048:
            ref_cfft_f32(&riscv_cfft_sR_f32_len2048, pOut, ifftFlag, 1);
            break;

        case 4096:
            ref_cfft_f32(&riscv_cfft_sR_f32_len4096, pOut, ifftFlag, 1);
            break;
    }

    if (ifftFlag) {
        // throw away the imaginary part which should be all zeros
        for (i = 0; i < S->fftLenRFFT; i++) {
            pOut[i] = pOut[2 * i];
        }
    } else {
        // pack last sample's real part into first sample's complex part
        pOut[1] = pOut[S->fftLenRFFT];
    }
}

void ref_rfft_q31(const riscv_rfft_instance_q31 *S, q31_t *pSrc, q31_t *pDst)
{
    uint32_t i;
    // float32_t *fDst = (float32_t*)pDst;
    float32_t fDst[S->fftLenReal * 2];
    riscv_q31_to_float(pSrc, fDst, S->fftLenReal * 2);

    if (S->ifftFlagR) {
        for (i = 0; i < S->fftLenReal * 2; i++) {
            fDst[i] = (float32_t)pSrc[i] / 2147483648.0f;
        }
    } else {
        for (i = 0; i < S->fftLenReal; i++) {
            fDst[2 * i + 0] = (float32_t)pSrc[i] / 2147483648.0f;
            fDst[2 * i + 1] = 0.0f;
        }
    }

    switch (S->fftLenReal) {
        case 32:
            ref_cfft_f32(&riscv_cfft_sR_f32_len32, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 64:
            ref_cfft_f32(&riscv_cfft_sR_f32_len64, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 128:
            ref_cfft_f32(&riscv_cfft_sR_f32_len128, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 256:
            ref_cfft_f32(&riscv_cfft_sR_f32_len256, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 512:
            ref_cfft_f32(&riscv_cfft_sR_f32_len512, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 1024:
            ref_cfft_f32(&riscv_cfft_sR_f32_len1024, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 2048:
            ref_cfft_f32(&riscv_cfft_sR_f32_len2048, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 4096:
            ref_cfft_f32(&riscv_cfft_sR_f32_len4096, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 8192:
            ref_cfft_f32(&ref_cfft_sR_f32_len8192, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;
    }

    if (S->ifftFlagR) {
        // throw away the imaginary part which should be all zeros
        for (i = 0; i < S->fftLenReal; i++) {
            // read the float data, scale up for q31, cast to q31
            pDst[i] = (q31_t)(fDst[2 * i] * 2147483648.0f);
        }
    } else {
        for (i = 0; i < S->fftLenReal; i++) {
            // read the float data, scale up for q31, cast to q31
            pDst[i] =
                (q31_t)(fDst[i] * 2147483648.0f / (float32_t)S->fftLenReal);
        }
    }
}

void ref_rfft_q15(const riscv_rfft_instance_q15 *S, q15_t *pSrc, q15_t *pDst)
{
    uint32_t i;
    // float32_t *fDst = (float32_t*)pDst;
    float32_t fDst[S->fftLenReal * 2];
    riscv_q15_to_float(pSrc, fDst, S->fftLenReal * 2);

    if (S->ifftFlagR) {
        for (i = 0; i < S->fftLenReal * 2; i++) {
            fDst[i] = (float32_t)pSrc[i] / 32768.0f;
        }
    } else {
        for (i = 0; i < S->fftLenReal; i++) {
            // read the q15 data, cast to float, scale down for float
            fDst[2 * i + 0] = (float32_t)pSrc[i] / 32768.0f;
            fDst[2 * i + 1] = 0.0f;
        }
    }

    switch (S->fftLenReal) {
        case 32:
            ref_cfft_f32(&riscv_cfft_sR_f32_len32, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 64:
            ref_cfft_f32(&riscv_cfft_sR_f32_len64, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 128:
            ref_cfft_f32(&riscv_cfft_sR_f32_len128, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 256:
            ref_cfft_f32(&riscv_cfft_sR_f32_len256, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 512:
            ref_cfft_f32(&riscv_cfft_sR_f32_len512, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 1024:
            ref_cfft_f32(&riscv_cfft_sR_f32_len1024, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 2048:
            ref_cfft_f32(&riscv_cfft_sR_f32_len2048, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 4096:
            ref_cfft_f32(&riscv_cfft_sR_f32_len4096, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;

        case 8192:
            ref_cfft_f32(&ref_cfft_sR_f32_len8192, fDst, S->ifftFlagR,
                         S->bitReverseFlagR);
            break;
    }

    if (S->ifftFlagR) {
        // throw away the imaginary part which should be all zeros
        for (i = 0; i < S->fftLenReal; i++) {
            pDst[i] = (q15_t)(fDst[2 * i] * 32768.0f);
        }
    } else {
        for (i = 0; i < S->fftLenReal; i++) {
            pDst[i] = (q15_t)(fDst[i] * 32768.0f / (float32_t)S->fftLenReal);
        }
    }
}