/*
 * Copyright © 2018, VideoLAN and dav1d authors
 * Copyright © 2018, Two Orioles, LLC
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS 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.
 */

#include "config.h"

#include <stdio.h>

#include "common/intops.h"

#include "src/lr_apply.h"


enum LrRestorePlanes {
    LR_RESTORE_Y = 1 << 0,
    LR_RESTORE_U = 1 << 1,
    LR_RESTORE_V = 1 << 2,
};

// The loop filter buffer stores 12 rows of pixels. A superblock block will
// contain at most 2 stripes. Each stripe requires 4 rows pixels (2 above
// and 2 below) the final 4 rows are used to swap the bottom of the last
// stripe with the top of the next super block row.
static void backup_lpf(pixel *dst, ptrdiff_t dst_stride,
                       const pixel *src, ptrdiff_t src_stride,
                       const int ss_ver, const int sb128,
                       int row, const int row_h, const int w)
{
    src_stride = PXSTRIDE(src_stride);
    dst_stride = PXSTRIDE(dst_stride);

    // The first stripe of the frame is shorter by 8 luma pixel rows.
    int stripe_h = (64 - 8 * !row) >> ss_ver;

    if (row) {
        const int top = 4 << sb128;
        // Copy the top part of the stored loop filtered pixels from the
        // previous sb row needed above the first stripe of this sb row.
        pixel_copy(&dst[dst_stride *  0], &dst[dst_stride *  top], w);
        pixel_copy(&dst[dst_stride *  1], &dst[dst_stride * (top + 1)], w);
        pixel_copy(&dst[dst_stride *  2], &dst[dst_stride * (top + 2)], w);
        pixel_copy(&dst[dst_stride *  3], &dst[dst_stride * (top + 3)], w);
    }

    dst += 4 * dst_stride;
    src += (stripe_h - 2) * src_stride;

    for (; row + stripe_h <= row_h; row += stripe_h) {
        for (int i = 0; i < 4; i++) {
            pixel_copy(dst, src, w);
            dst += dst_stride;
            src += src_stride;
        }
        stripe_h = 64 >> ss_ver;
        src += (stripe_h - 4) * src_stride;
    }
}

void bytefn(dav1d_lr_copy_lpf)(Dav1dFrameContext *const f,
                               /*const*/ pixel *const src[3], const int sby)
{
    const ptrdiff_t offset = 8 * !!sby;
    const ptrdiff_t *const src_stride = f->cur.p.stride;

    // TODO Also check block level restore type to reduce copying.
    const int restore_planes =
        ((f->frame_hdr.restoration.type[0] != RESTORATION_NONE) << 0) +
        ((f->frame_hdr.restoration.type[1] != RESTORATION_NONE) << 1) +
        ((f->frame_hdr.restoration.type[2] != RESTORATION_NONE) << 2);

    if (restore_planes & LR_RESTORE_Y) {
        const int h = f->bh << 2;
        const int w = f->bw << 2;
        const int row_h = imin((sby + 1) << (6 + f->seq_hdr.sb128), h);
        const int y_stripe = (sby << (6 + f->seq_hdr.sb128)) - offset;
        backup_lpf(f->lf.lr_lpf_line_ptr[0], sizeof(pixel) * f->b4_stride * 4,
                   src[0] - offset * PXSTRIDE(src_stride[0]), src_stride[0],
                   0, f->seq_hdr.sb128, y_stripe, row_h, w);
    }
    if (restore_planes & (LR_RESTORE_U | LR_RESTORE_V)) {
        const int ss_ver = f->cur.p.p.layout == DAV1D_PIXEL_LAYOUT_I420;
        const int ss_hor = f->cur.p.p.layout != DAV1D_PIXEL_LAYOUT_I444;
        const int h = f->bh << (2 - ss_ver);
        const int w = f->bw << (2 - ss_hor);
        const int row_h = imin((sby + 1) << ((6 - ss_ver) + f->seq_hdr.sb128), h);
        const ptrdiff_t offset_uv = offset >> ss_ver;
        const int y_stripe =
            (sby << ((6 - ss_ver) + f->seq_hdr.sb128)) - offset_uv;

        if (restore_planes & LR_RESTORE_U) {
            backup_lpf(f->lf.lr_lpf_line_ptr[1], sizeof(pixel) * f->b4_stride * 4,
                       src[1] - offset_uv * PXSTRIDE(src_stride[1]), src_stride[1],
                       ss_ver, f->seq_hdr.sb128, y_stripe, row_h, w);
        }
        if (restore_planes & LR_RESTORE_V) {
            backup_lpf(f->lf.lr_lpf_line_ptr[2], sizeof(pixel) * f->b4_stride * 4,
                       src[2] - offset_uv * PXSTRIDE(src_stride[1]), src_stride[1],
                       ss_ver, f->seq_hdr.sb128, y_stripe, row_h, w);
        }
    }
}


static void lr_stripe(const Dav1dFrameContext *const f, pixel *p,
                      const pixel (*left)[4], int x, int y,
                      const int plane, const int unit_w, const int row_h,
                      const Av1RestorationUnit *const lr, enum LrEdgeFlags edges)
{
    const Dav1dDSPContext *const dsp = f->dsp;
    const int chroma = !!plane;
    const int ss_ver = chroma & (f->cur.p.p.layout == DAV1D_PIXEL_LAYOUT_I420);
    const int sbrow_has_bottom = (edges & LR_HAVE_BOTTOM);
    const pixel *lpf = f->lf.lr_lpf_line_ptr[plane] + x;
    const ptrdiff_t p_stride = f->cur.p.stride[chroma];
    const ptrdiff_t lpf_stride = sizeof(pixel) * f->b4_stride * 4;

    // The first stripe of the frame is shorter by 8 luma pixel rows.
    int stripe_h = imin((64 - 8 * !y) >> ss_ver, row_h - y);

    // FIXME [8] might be easier for SIMD
    int16_t filterh[7], filterv[7];
    if (lr->type == RESTORATION_WIENER) {
        filterh[0] = filterh[6] = lr->filter_h[0];
        filterh[1] = filterh[5] = lr->filter_h[1];
        filterh[2] = filterh[4] = lr->filter_h[2];
        filterh[3] = -((filterh[0] + filterh[1] + filterh[2]) * 2);

        filterv[0] = filterv[6] = lr->filter_v[0];
        filterv[1] = filterv[5] = lr->filter_v[1];
        filterv[2] = filterv[4] = lr->filter_v[2];
        filterv[3] = -((filterv[0] + filterv[1] + filterv[2]) * 2);
    }

    while (y + stripe_h <= row_h) {
        // TODO Look into getting rid of the this if
        if (y + stripe_h == row_h) {
            edges &= ~LR_HAVE_BOTTOM;
        } else {
            edges |= LR_HAVE_BOTTOM;
        }
        if (lr->type == RESTORATION_WIENER) {
            dsp->lr.wiener(p, p_stride, left, lpf, lpf_stride, unit_w, stripe_h,
                           filterh, filterv, edges);
        } else {
            assert(lr->type == RESTORATION_SGRPROJ);
            dsp->lr.selfguided(p, p_stride, left, lpf, lpf_stride, unit_w, stripe_h,
                               lr->sgr_idx, lr->sgr_weights, edges);
        }

        left += stripe_h;
        y += stripe_h;
        if (y + stripe_h > row_h && sbrow_has_bottom) break;
        p += stripe_h * PXSTRIDE(p_stride);
        edges |= LR_HAVE_TOP;
        stripe_h = imin(64 >> ss_ver, row_h - y);
        if (stripe_h == 0) break;
        lpf += 4 * PXSTRIDE(lpf_stride);
    }
}

static void backup4xU(pixel (*dst)[4], const pixel *src, const ptrdiff_t src_stride,
                      int u)
{
    for (; u > 0; u--, dst++, src += PXSTRIDE(src_stride))
        pixel_copy(dst, src, 4);
}

static void lr_sbrow(const Dav1dFrameContext *const f, pixel *p, const int y,
                     const int w, const int h, const int row_h, const int plane)
{
    const int chroma = !!plane;
    const int ss_ver = chroma & (f->cur.p.p.layout == DAV1D_PIXEL_LAYOUT_I420);
    const int ss_hor = chroma & (f->cur.p.p.layout != DAV1D_PIXEL_LAYOUT_I444);
    const ptrdiff_t p_stride = f->cur.p.stride[chroma];

    const int unit_size_log2 = f->frame_hdr.restoration.unit_size[!!plane];
    const int unit_size = 1 << unit_size_log2;
    const int half_unit_size = unit_size >> 1;
    const int max_unit_size = unit_size + half_unit_size;

    // Y coordinate of the sbrow (y is 8 luma pixel rows above row_y)
    const int row_y = y + ((8 >> ss_ver) * !!y);

    // FIXME This is an ugly hack to lookup the proper AV1Filter unit for
    // chroma planes. Question: For Multithreaded decoding, is it better
    // to store the chroma LR information with collocated Luma information?
    // In other words. For a chroma restoration unit locate at 128,128 and
    // with a 4:2:0 chroma subsampling, do we store the filter information at
    // the AV1Filter unit located at (128,128) or (256,256)
    // TODO Support chroma subsampling.
    const int shift_ver = 7 - ss_ver;
    const int shift_hor = 7 - ss_hor;

    int ruy = (row_y >> unit_size_log2);
    // Merge last restoration unit if its height is < half_unit_size
    if (ruy > 0) ruy -= (ruy << unit_size_log2) + half_unit_size > h;

    // The first stripe of the frame is shorter by 8 luma pixel rows.
    const int filter_h =
        imin(((1 << (6 + f->seq_hdr.sb128)) - 8 * !y) >> ss_ver, h - y);

    pixel pre_lr_border[2][128 + 8 /* maximum sbrow height is 128 + 8 rows offset */][4];

    int unit_w = unit_size, bit = 0;

    enum LrEdgeFlags edges = (y > 0 ? LR_HAVE_TOP : 0) |
                             (row_h < h ? LR_HAVE_BOTTOM : 0);

    for (int x = 0, rux = 0; x < w; x+= unit_w, rux++, edges |= LR_HAVE_LEFT, bit ^= 1) {
        // TODO Clean up this if statement.
        if (x + max_unit_size > w) {
            unit_w = w - x;
            edges &= ~LR_HAVE_RIGHT;
        } else {
            edges |= LR_HAVE_RIGHT;
        }

        // Based on the position of the restoration unit, find the corresponding
        // AV1Filter unit.
        const int unit_idx = ((ruy & 16) >> 3) + ((rux & 16) >> 4);
        const Av1RestorationUnit *const lr =
            &f->lf.mask[(((ruy << (unit_size_log2)) >> shift_ver) * f->sb128w) +
                        (x >> shift_hor)].lr[plane][unit_idx];

        // FIXME Don't backup if the next restoration unit is RESTORE_NONE
        // This also requires not restoring in the same conditions.
        if (edges & LR_HAVE_RIGHT) {
            backup4xU(pre_lr_border[bit], p + unit_w - 4, p_stride, filter_h);
        }
        if (lr->type != RESTORATION_NONE) {
            lr_stripe(f, p, pre_lr_border[!bit], x, y, plane, unit_w, row_h, lr, edges);
        }
        p += unit_w;
    }
}

void bytefn(dav1d_lr_sbrow)(Dav1dFrameContext *const f, pixel *const dst[3],
                            const int sby)
{
    const ptrdiff_t offset_y = 8 * !!sby;
    const ptrdiff_t *const dst_stride = f->cur.p.stride;

    const int restore_planes =
        ((f->frame_hdr.restoration.type[0] != RESTORATION_NONE) << 0) +
        ((f->frame_hdr.restoration.type[1] != RESTORATION_NONE) << 1) +
        ((f->frame_hdr.restoration.type[2] != RESTORATION_NONE) << 2);

    if (restore_planes & LR_RESTORE_Y) {
        const int h = f->cur.p.p.h;
        const int w = f->cur.p.p.w;
        const int row_h = imin((sby + 1) << (6 + f->seq_hdr.sb128), h);
        const int y_stripe = (sby << (6 + f->seq_hdr.sb128)) - offset_y;
        lr_sbrow(f, dst[0] - offset_y * PXSTRIDE(dst_stride[0]), y_stripe, w,
                 h, row_h, 0);
    }
    if (restore_planes & (LR_RESTORE_U | LR_RESTORE_V)) {
        const int ss_ver = f->cur.p.p.layout == DAV1D_PIXEL_LAYOUT_I420;
        const int ss_hor = f->cur.p.p.layout != DAV1D_PIXEL_LAYOUT_I444;
        const int h = (f->cur.p.p.h + ss_ver) >> ss_ver;
        const int w = (f->cur.p.p.w + ss_hor) >> ss_hor;
        const int row_h = imin((sby + 1) << ((6 - ss_ver) + f->seq_hdr.sb128), h);
        const ptrdiff_t offset_uv = offset_y >> ss_ver;
        const int y_stripe =
            (sby << ((6 - ss_ver) + f->seq_hdr.sb128)) - offset_uv;
        if (restore_planes & LR_RESTORE_U)
            lr_sbrow(f, dst[1] - offset_uv * PXSTRIDE(dst_stride[1]), y_stripe,
                     w, h, row_h, 1);

        if (restore_planes & LR_RESTORE_V)
            lr_sbrow(f, dst[2] - offset_uv * PXSTRIDE(dst_stride[1]), y_stripe,
                     w, h, row_h, 2);
    }
}