/*
 * Copyright (c) 2016, Alliance for Open Media. All rights reserved
 *
 * This source code is subject to the terms of the BSD 2 Clause License and
 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
 * was not distributed with this source code in the LICENSE file, you can
 * obtain it at www.aomedia.org/license/software. If the Alliance for Open
 * Media Patent License 1.0 was not distributed with this source code in the
 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 */

#include "./aom_config.h"
#include "aom_mem/aom_mem.h"
#include "aom_ports/mem.h"
#include "av1/common/blockd.h"
#include "av1/decoder/detokenize.h"

#define ACCT_STR __func__

#include "av1/common/common.h"
#include "av1/common/entropy.h"
#include "av1/common/idct.h"

static INLINE int read_coeff(const aom_cdf_prob *const *cdf, int n,
                             aom_reader *r) {
  int val = 0;
  int i = 0;
  int count = 0;
  while (count < n) {
    const int size = AOMMIN(n - count, 4);
    val |= aom_read_cdf(r, cdf[i++], 1 << size, ACCT_STR) << count;
    count += size;
  }
  return val;
}

static int token_to_value(aom_reader *const r, int token, TX_SIZE tx_size,
                          int bit_depth) {
  switch (token) {
    case ZERO_TOKEN:
    case ONE_TOKEN:
    case TWO_TOKEN:
    case THREE_TOKEN:
    case FOUR_TOKEN: return token;
    case CATEGORY1_TOKEN: return CAT1_MIN_VAL + read_coeff(av1_cat1_cdf, 1, r);
    case CATEGORY2_TOKEN: return CAT2_MIN_VAL + read_coeff(av1_cat2_cdf, 2, r);
    case CATEGORY3_TOKEN: return CAT3_MIN_VAL + read_coeff(av1_cat3_cdf, 3, r);
    case CATEGORY4_TOKEN: return CAT4_MIN_VAL + read_coeff(av1_cat4_cdf, 4, r);
    case CATEGORY5_TOKEN: return CAT5_MIN_VAL + read_coeff(av1_cat5_cdf, 5, r);
    case CATEGORY6_TOKEN: {
      const int skip_bits =
          CAT6_BIT_SIZE - av1_get_cat6_extrabits_size(tx_size, bit_depth);
      return CAT6_MIN_VAL + read_coeff(av1_cat6_cdf, 18 - skip_bits, r);
    }
    default:
      assert(0);  // Invalid token.
      return -1;
  }
}

static int decode_coefs(MACROBLOCKD *xd, PLANE_TYPE type, tran_low_t *dqcoeff,
                        TX_SIZE tx_size, TX_TYPE tx_type, const int16_t *dq,
                        qm_val_t *iqm[TX_SIZES_ALL], int ctx,
                        const int16_t *scan, const int16_t *nb,
                        int16_t *max_scan_line, aom_reader *r) {
  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
  const int max_eob = av1_get_max_eob(tx_size);
  const int ref = is_inter_block(&xd->mi[0]->mbmi);
  const qm_val_t *iqmatrix = iqm[tx_size];
  (void)tx_type;
  int band, c = 0;
  const TX_SIZE tx_size_ctx = get_txsize_entropy_ctx(tx_size);
  aom_cdf_prob(*coef_head_cdfs)[COEFF_CONTEXTS][CDF_SIZE(ENTROPY_TOKENS)] =
      ec_ctx->coef_head_cdfs[tx_size_ctx][type][ref];
  aom_cdf_prob(*coef_tail_cdfs)[COEFF_CONTEXTS][CDF_SIZE(ENTROPY_TOKENS)] =
      ec_ctx->coef_tail_cdfs[tx_size_ctx][type][ref];
  int val = 0;

  uint8_t token_cache[MAX_TX_SQUARE];
  const uint8_t *band_translate = get_band_translate(tx_size);
  int v, token;
  int32_t dqv = dq[0];

  int dq_shift = av1_get_tx_scale(tx_size);

  band = *band_translate++;

  int more_data = 1;
  while (more_data) {
    int comb_token;
    int last_pos = (c + 1 == max_eob);
    int first_pos = (c == 0);

    comb_token = last_pos ? 2 * aom_read_bit(r, ACCT_STR) + 2
                          : aom_read_symbol(r, coef_head_cdfs[band][ctx],
                                            HEAD_TOKENS + first_pos, ACCT_STR) +
                                !first_pos;
    if (first_pos) {
      if (comb_token == 0) return 0;
    }
    token = comb_token >> 1;

    while (!token) {
      *max_scan_line = AOMMAX(*max_scan_line, scan[c]);
      token_cache[scan[c]] = 0;
      ++c;
      dqv = dq[1];
      ctx = get_coef_context(nb, token_cache, c);
      band = *band_translate++;

      last_pos = (c + 1 == max_eob);

      comb_token = last_pos ? 2 * aom_read_bit(r, ACCT_STR) + 2
                            : aom_read_symbol(r, coef_head_cdfs[band][ctx],
                                              HEAD_TOKENS, ACCT_STR) +
                                  1;
      token = comb_token >> 1;
    }

    more_data = comb_token & 1;

    if (token > ONE_TOKEN)
      token +=
          aom_read_symbol(r, coef_tail_cdfs[band][ctx], TAIL_TOKENS, ACCT_STR);

    *max_scan_line = AOMMAX(*max_scan_line, scan[c]);
    token_cache[scan[c]] = av1_pt_energy_class[token];

    val = token_to_value(r, token, tx_size, xd->bd);
    // Apply quant matrix only for 2D transforms
    if (IS_2D_TRANSFORM(tx_type) && iqmatrix != NULL)
      dqv = ((iqmatrix[scan[c]] * (int)dqv) + (1 << (AOM_QM_BITS - 1))) >>
            AOM_QM_BITS;
    v = (int)(((int64_t)val * dqv) >> dq_shift);

    v = (int)check_range(aom_read_bit(r, ACCT_STR) ? -v : v, xd->bd);

    dqcoeff[scan[c]] = v;

    ++c;
    more_data &= (c < max_eob);
    if (!more_data) break;
    dqv = dq[1];
    ctx = get_coef_context(nb, token_cache, c);
    band = *band_translate++;
  }

  return c;
}

static void decode_color_map_tokens(Av1ColorMapParam *param, aom_reader *r) {
  uint8_t color_order[PALETTE_MAX_SIZE];
  const int n = param->n_colors;
  uint8_t *const color_map = param->color_map;
  MapCdf color_map_cdf = param->map_cdf;
  int plane_block_width = param->plane_width;
  int plane_block_height = param->plane_height;
  int rows = param->rows;
  int cols = param->cols;

  // The first color index.
  color_map[0] = av1_read_uniform(r, n);
  assert(color_map[0] < n);

  // Run wavefront on the palette map index decoding.
  for (int i = 1; i < rows + cols - 1; ++i) {
    for (int j = AOMMIN(i, cols - 1); j >= AOMMAX(0, i - rows + 1); --j) {
      const int color_ctx = av1_get_palette_color_index_context(
          color_map, plane_block_width, (i - j), j, n, color_order, NULL);
      const int color_idx = aom_read_symbol(
          r, color_map_cdf[n - PALETTE_MIN_SIZE][color_ctx], n, ACCT_STR);
      assert(color_idx >= 0 && color_idx < n);
      color_map[(i - j) * plane_block_width + j] = color_order[color_idx];
    }
  }
  // Copy last column to extra columns.
  if (cols < plane_block_width) {
    for (int i = 0; i < rows; ++i) {
      memset(color_map + i * plane_block_width + cols,
             color_map[i * plane_block_width + cols - 1],
             (plane_block_width - cols));
    }
  }
  // Copy last row to extra rows.
  for (int i = rows; i < plane_block_height; ++i) {
    memcpy(color_map + i * plane_block_width,
           color_map + (rows - 1) * plane_block_width, plane_block_width);
  }
}

static void get_palette_params(const MACROBLOCKD *const xd, int plane,
                               BLOCK_SIZE bsize, Av1ColorMapParam *params) {
  assert(plane == 0 || plane == 1);
  const MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
  const PALETTE_MODE_INFO *const pmi = &mbmi->palette_mode_info;
  params->color_map = xd->plane[plane].color_index_map;
  params->map_cdf = plane ? xd->tile_ctx->palette_uv_color_index_cdf
                          : xd->tile_ctx->palette_y_color_index_cdf;
  params->n_colors = pmi->palette_size[plane];
  av1_get_block_dimensions(bsize, plane, xd, &params->plane_width,
                           &params->plane_height, &params->rows, &params->cols);
}

void av1_decode_palette_tokens(MACROBLOCKD *const xd, int plane,
                               aom_reader *r) {
  const MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
  assert(plane == 0 || plane == 1);
  Av1ColorMapParam color_map_params;
  memset(&color_map_params, 0, sizeof(color_map_params));
  get_palette_params(xd, plane, mbmi->sb_type, &color_map_params);
  decode_color_map_tokens(&color_map_params, r);
}

int av1_decode_block_tokens(MACROBLOCKD *const xd, int plane,
                            const SCAN_ORDER *sc, int x, int y, TX_SIZE tx_size,
                            TX_TYPE tx_type, int16_t *max_scan_line,
                            aom_reader *r, int seg_id) {
  struct macroblockd_plane *const pd = &xd->plane[plane];
  const int16_t *const dequant = pd->seg_dequant_QTX[seg_id];
  const int ctx =
      get_entropy_context(tx_size, pd->above_context + x, pd->left_context + y);

  const int eob = decode_coefs(xd, pd->plane_type, pd->dqcoeff, tx_size,
                               tx_type, dequant, pd->seg_iqmatrix[seg_id], ctx,
                               sc->scan, sc->neighbors, max_scan_line, r);
  av1_set_contexts(xd, pd, plane, tx_size, eob > 0, x, y);
  return eob;
}