/*
 *                             The MIT License
 *
 * Wavefront Alignment Algorithms
 * Copyright (c) 2017 by Santiago Marco-Sola  <santiagomsola@gmail.com>
 *
 * This file is part of Wavefront Alignment Algorithms.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * PROJECT: Wavefront Alignment Algorithms
 * AUTHOR(S): Santiago Marco-Sola <santiagomsola@gmail.com>
 * DESCRIPTION: WaveFront alignment module for computing wavefronts
 */

#include "utils/commons.h"
#include "system/mm_allocator.h"
#include "alignment/affine2p_penalties.h"
#include "wavefront_compute.h"

/*
 * Compute limits
 */
void wavefront_compute_limits_input(
    wavefront_aligner_t* const wf_aligner,
    const wavefront_set_t* const wavefront_set,
    int* const lo,
    int* const hi) {
  // Parameters
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  const wavefront_t* const m_misms = wavefront_set->in_mwavefront_misms;
  const wavefront_t* const m_open1 = wavefront_set->in_mwavefront_open1;
  // Init
  int min_lo = m_misms->lo;
  int max_hi = m_misms->hi;
  // Gap-linear
  if (min_lo > m_open1->lo-1) min_lo = m_open1->lo-1;
  if (max_hi < m_open1->hi+1) max_hi = m_open1->hi+1;
  if (distance_metric == gap_linear) {
    *lo = min_lo;
    *hi = max_hi;
    return;
  }
  // Parameters
  const wavefront_t* const i1_ext = wavefront_set->in_i1wavefront_ext;
  const wavefront_t* const d1_ext = wavefront_set->in_d1wavefront_ext;
  // Gap-affine
  if (min_lo > i1_ext->lo+1) min_lo = i1_ext->lo+1;
  if (max_hi < i1_ext->hi+1) max_hi = i1_ext->hi+1;
  if (min_lo > d1_ext->lo-1) min_lo = d1_ext->lo-1;
  if (max_hi < d1_ext->hi-1) max_hi = d1_ext->hi-1;
  if (distance_metric == gap_affine) {
    *lo = min_lo;
    *hi = max_hi;
    return;
  }
  // Parameters
  const wavefront_t* const m_open2 = wavefront_set->in_mwavefront_open2;
  const wavefront_t* const i2_ext = wavefront_set->in_i2wavefront_ext;
  const wavefront_t* const d2_ext = wavefront_set->in_d2wavefront_ext;
  // Gap-affine-2p
  if (min_lo > m_open2->lo-1) min_lo = m_open2->lo-1;
  if (max_hi < m_open2->hi+1) max_hi = m_open2->hi+1;
  if (min_lo > i2_ext->lo+1) min_lo = i2_ext->lo+1;
  if (max_hi < i2_ext->hi+1) max_hi = i2_ext->hi+1;
  if (min_lo > d2_ext->lo-1) min_lo = d2_ext->lo-1;
  if (max_hi < d2_ext->hi-1) max_hi = d2_ext->hi-1;
  *lo = min_lo;
  *hi = max_hi;
}
void wavefront_compute_limits_output(
    wavefront_aligner_t* const wf_aligner,
    const int lo,
    const int hi,
    int* const effective_lo,
    int* const effective_hi) {
  // Parameters
  wavefront_components_t* const wf_components = &wf_aligner->wf_components;
  const int max_score_scope = wf_components->max_score_scope;
  // Add padding to avoid compute-kernel peeling
  const int eff_lo = lo - (max_score_scope + 1);
  const int eff_hi = hi + (max_score_scope + 1);
  // Consider historic (to avoid errors using heuristics)
  *effective_lo = MIN(eff_lo,wf_components->historic_min_lo);
  *effective_hi = MAX(eff_hi,wf_components->historic_max_hi);
  wf_components->historic_min_lo = *effective_lo;
  wf_components->historic_max_hi = *effective_hi;
}
/*
 * Score translation
 */
int wavefront_compute_classic_score(
    wavefront_aligner_t* const wf_aligner,
    const int pattern_length,
    const int text_length,
    const int wf_score) {
  // Parameters
  const int swg_match = -(wf_aligner->penalties.match);
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  // Adapt score
  if (distance_metric <= edit) return wf_score;
  if (swg_match == 0) return -wf_score;
  return WF_SCORE_TO_SW_SCORE(swg_match,pattern_length,text_length,wf_score);
}
/*
 * Compute ends-free init conditions
 */
bool wavefront_compute_endsfree_required(
    wavefront_aligner_t* const wf_aligner,
    const int score) {
  // Parameters
  alignment_form_t* const alg_form = &wf_aligner->alignment_form;
  wavefront_penalties_t* const penalties = &wf_aligner->penalties;
  // Return if ends-free initialization is required
  if (penalties->match == 0) return false;
  if (alg_form->span != alignment_endsfree) return false;
  if (alg_form->text_begin_free == 0 &&
      alg_form->pattern_begin_free == 0) return false;
  if (score % (-penalties->match) != 0) return false;
  // Check boundary conditions for ends-free
  const int endsfree_k = score/(-penalties->match); // (h/v)-coordinate for boundary conditions
  const bool text_begin_free = (alg_form->text_begin_free >= endsfree_k);
  const bool pattern_begin_free = (alg_form->pattern_begin_free >= endsfree_k);
  if (!text_begin_free && !pattern_begin_free) return false;
  // Ok
  return true;
}
void wavefront_compute_endsfree_limits(
    wavefront_aligner_t* const wf_aligner,
    const int score,
    int* const lo,
    int* const hi) {
  // Parameters
  alignment_form_t* const alg_form = &wf_aligner->alignment_form;
  wavefront_penalties_t* const penalties = &wf_aligner->penalties;
  // Consider ends-free conditions
  const int endsfree_k = score/(-penalties->match);
  *hi = (alg_form->text_begin_free >= endsfree_k) ? endsfree_k : INT_MIN;
  *lo = (alg_form->pattern_begin_free >= endsfree_k) ? -endsfree_k : INT_MAX;
}
void wavefront_compute_endsfree_init_offset(
    wavefront_aligner_t* const wf_aligner,
    wavefront_t* const wavefront,
    const int k,
    const int v,
    const int h) {
  // Parameters
  wavefront_components_t* const wf_components = &wf_aligner->wf_components;
  wf_offset_t* const offsets = wavefront->offsets;
  // Set offset
  offsets[k] = DPMATRIX_OFFSET(h,v);
  if (wf_components->bt_piggyback) {
    wavefront->bt_pcigar[k] = 0;
    wavefront->bt_prev[k] =
        wf_backtrace_buffer_init_block(wf_components->bt_buffer,v,h);
  }
}
void wavefront_compute_endsfree_init(
    wavefront_aligner_t* const wf_aligner,
    wavefront_t* const wavefront,
    const int score) {
  // Parameters
  alignment_form_t* const alg_form = &wf_aligner->alignment_form;
  wavefront_penalties_t* const penalties = &wf_aligner->penalties;
  const int lo = wavefront->lo;
  const int hi = wavefront->hi;
  // Consider ends-free conditions
  int endsfree_k = score/(-penalties->match);
  wf_offset_t* const offsets = wavefront->offsets;
  // Consider text begin-free
  int k;
  if (alg_form->text_begin_free >= endsfree_k) {
    if (hi >= endsfree_k) {
      if (offsets[endsfree_k] <= DPMATRIX_OFFSET(endsfree_k,0)) {
        wavefront_compute_endsfree_init_offset(wf_aligner,wavefront,endsfree_k,0,endsfree_k);
      }
    } else {
      for (k=hi+1;k<endsfree_k;++k) {
        offsets[k] = WAVEFRONT_OFFSET_NULL;
      }
      wavefront_compute_endsfree_init_offset(wf_aligner,wavefront,endsfree_k,0,endsfree_k);
      wavefront->hi = endsfree_k;
    }
  }
  // Consider pattern begin-free
  if (alg_form->pattern_begin_free >= endsfree_k) {
    endsfree_k = -endsfree_k;
    if (lo <= endsfree_k) {
      if (offsets[endsfree_k] <= DPMATRIX_OFFSET(0,endsfree_k)) {
        wavefront_compute_endsfree_init_offset(wf_aligner,wavefront,endsfree_k,-endsfree_k,0);
      }
    } else {
      wavefront_compute_endsfree_init_offset(wf_aligner,wavefront,endsfree_k,-endsfree_k,0);
      for (k=endsfree_k+1;k<lo;k++) {
        offsets[k] = WAVEFRONT_OFFSET_NULL;
      }
      wavefront->lo = endsfree_k;
    }
  }
}
wavefront_t* wavefront_compute_endsfree_allocate_null(
    wavefront_aligner_t* const wf_aligner,
    const int score) {
  // Parameters
  wavefront_slab_t* const wavefront_slab = wf_aligner->wavefront_slab;
  alignment_form_t* const alg_form = &wf_aligner->alignment_form;
  wavefront_penalties_t* const penalties = &wf_aligner->penalties;
  // Consider ends-free conditions
  const int endsfree_k = score/(-penalties->match);
  const bool text_begin_free = (alg_form->text_begin_free >= endsfree_k);
  const bool pattern_begin_free = (alg_form->pattern_begin_free >= endsfree_k);
  int lo = 0, hi = 0;
  if (text_begin_free && pattern_begin_free) {
    lo = -endsfree_k;
    hi = endsfree_k;
  } else if (text_begin_free) {
    lo = endsfree_k;
    hi = endsfree_k;
  } else if (pattern_begin_free) {
    lo = -endsfree_k;
    hi = -endsfree_k;
  }
  // Compute effective hi/lo dimensions
  int effective_lo, effective_hi;
  wavefront_compute_limits_output(wf_aligner,lo,hi,&effective_lo,&effective_hi);
  // Allocate & initialize
  wavefront_t* const wavefront = wavefront_slab_allocate(wavefront_slab,effective_lo,effective_hi);
  wf_offset_t* const offsets = wavefront->offsets;
  int k;
  for (k=lo;k<=hi;k++) {
    offsets[k] = WAVEFRONT_OFFSET_NULL;
  }
  if (text_begin_free) {
    wavefront_compute_endsfree_init_offset(wf_aligner,wavefront,endsfree_k,0,endsfree_k);
  }
  if (pattern_begin_free) {
    wavefront_compute_endsfree_init_offset(wf_aligner,wavefront,-endsfree_k,endsfree_k,0);
  }
  wavefront->lo = lo;
  wavefront->hi = hi;
  // Set max/min init elements
  wavefront->wf_elements_init_min = lo;
  wavefront->wf_elements_init_max = hi;
  // Return
  return wavefront;
}
/*
 * Input wavefronts (fetch)
 */
wavefront_t* wavefront_compute_get_mwavefront(
    wavefront_components_t* const wf_components,
    const int score_mod) {
  return (score_mod < 0 ||
          wf_components->mwavefronts[score_mod] == NULL ||
          wf_components->mwavefronts[score_mod]->null) ?
      wf_components->wavefront_null : wf_components->mwavefronts[score_mod];
}
wavefront_t* wavefront_compute_get_i1wavefront(
    wavefront_components_t* const wf_components,
    const int score_mod) {
  return (score_mod < 0 ||
          wf_components->i1wavefronts[score_mod] == NULL ||
          wf_components->i1wavefronts[score_mod]->null) ?
      wf_components->wavefront_null : wf_components->i1wavefronts[score_mod];
}
wavefront_t* wavefront_compute_get_i2wavefront(
    wavefront_components_t* const wf_components,
    const int score_mod) {
  return (score_mod < 0 ||
          wf_components->i2wavefronts[score_mod] == NULL ||
          wf_components->i2wavefronts[score_mod]->null) ?
      wf_components->wavefront_null : wf_components->i2wavefronts[score_mod];
}
wavefront_t* wavefront_compute_get_d1wavefront(
    wavefront_components_t* const wf_components,
    const int score_mod) {
  return (score_mod < 0 ||
          wf_components->d1wavefronts[score_mod] == NULL ||
          wf_components->d1wavefronts[score_mod]->null) ?
      wf_components->wavefront_null : wf_components->d1wavefronts[score_mod];
}
wavefront_t* wavefront_compute_get_d2wavefront(
    wavefront_components_t* const wf_components,
    const int score_mod) {
  return (score_mod < 0 ||
          wf_components->d2wavefronts[score_mod] == NULL ||
          wf_components->d2wavefronts[score_mod]->null) ?
      wf_components->wavefront_null : wf_components->d2wavefronts[score_mod];
}
void wavefront_compute_fetch_input(
    wavefront_aligner_t* const wf_aligner,
    wavefront_set_t* const wavefront_set,
    const int score) {
  // Parameters
  wavefront_components_t* const wf_components = &wf_aligner->wf_components;
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  // Compute scores
  const wavefront_penalties_t* const penalties = &(wf_aligner->penalties);
  if (distance_metric == gap_linear) {
    int mismatch = score - penalties->mismatch;
    int gap_open1 = score - penalties->gap_opening1;
    // Modular wavefront
    if (wf_components->memory_modular) {
      const int max_score_scope = wf_components->max_score_scope;
      if (mismatch > 0) mismatch =  mismatch % max_score_scope;
      if (gap_open1 > 0) gap_open1 = gap_open1 % max_score_scope;
    }
    // Fetch wavefronts
    wavefront_set->in_mwavefront_misms = wavefront_compute_get_mwavefront(wf_components,mismatch);
    wavefront_set->in_mwavefront_open1 = wavefront_compute_get_mwavefront(wf_components,gap_open1);
  } else { // distance_metric == gap_affine || distance_metric == gap_affine_2p
    int mismatch = score - penalties->mismatch;
    int gap_open1 = score - penalties->gap_opening1 - penalties->gap_extension1;
    int gap_extend1 = score - penalties->gap_extension1;
    int gap_open2 = score - penalties->gap_opening2 - penalties->gap_extension2;
    int gap_extend2 = score - penalties->gap_extension2;
    // Modular wavefront
    if (wf_components->memory_modular) {
      const int max_score_scope = wf_components->max_score_scope;
      if (mismatch > 0) mismatch =  mismatch % max_score_scope;
      if (gap_open1 > 0) gap_open1 = gap_open1 % max_score_scope;
      if (gap_extend1 > 0) gap_extend1 = gap_extend1 % max_score_scope;
      if (gap_open2 > 0) gap_open2 = gap_open2 % max_score_scope;
      if (gap_extend2 > 0) gap_extend2 = gap_extend2 % max_score_scope;
    }
    // Fetch wavefronts
    wavefront_set->in_mwavefront_misms = wavefront_compute_get_mwavefront(wf_components,mismatch);
    wavefront_set->in_mwavefront_open1 = wavefront_compute_get_mwavefront(wf_components,gap_open1);
    wavefront_set->in_i1wavefront_ext = wavefront_compute_get_i1wavefront(wf_components,gap_extend1);
    wavefront_set->in_d1wavefront_ext = wavefront_compute_get_d1wavefront(wf_components,gap_extend1);
    if (distance_metric == gap_affine) return;
    wavefront_set->in_mwavefront_open2 = wavefront_compute_get_mwavefront(wf_components,gap_open2);
    wavefront_set->in_i2wavefront_ext = wavefront_compute_get_i2wavefront(wf_components,gap_extend2);
    wavefront_set->in_d2wavefront_ext = wavefront_compute_get_d2wavefront(wf_components,gap_extend2);
  }
}
/*
 * Output wavefronts (allocate)
 */
void wavefront_compute_free_output(
    wavefront_aligner_t* const wf_aligner,
    const int score_mod) {
  // Parameters
  wavefront_components_t* const wf_components = &wf_aligner->wf_components;
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  wavefront_slab_t* const wavefront_slab = wf_aligner->wavefront_slab;
  // Free
  if (wf_components->mwavefronts[score_mod]) {
    wavefront_slab_free(wavefront_slab,wf_components->mwavefronts[score_mod]);
  }
  if (distance_metric == gap_linear) return;
  if (wf_components->i1wavefronts[score_mod]) {
    wavefront_slab_free(wavefront_slab,wf_components->i1wavefronts[score_mod]);
  }
  if (wf_components->d1wavefronts[score_mod]) {
    wavefront_slab_free(wavefront_slab,wf_components->d1wavefronts[score_mod]);
  }
  if (distance_metric == gap_affine) return;
  if (wf_components->i2wavefronts[score_mod]) {
    wavefront_slab_free(wavefront_slab,wf_components->i2wavefronts[score_mod]);
  }
  if (wf_components->d2wavefronts[score_mod]) {
    wavefront_slab_free(wavefront_slab,wf_components->d2wavefronts[score_mod]);
  }
}
void wavefront_compute_allocate_output_null(
    wavefront_aligner_t* const wf_aligner,
    const int score) {
  // Parameters
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  wavefront_components_t* const wf_components = &wf_aligner->wf_components;
  // Modular wavefront
  int score_mod = score;
  if (wf_components->memory_modular) {
    score_mod = score % wf_components->max_score_scope;
    wavefront_compute_free_output(wf_aligner,score_mod);
  }
  // Consider ends-free (M!=0)
  if (wavefront_compute_endsfree_required(wf_aligner,score)) {
    wf_components->mwavefronts[score_mod] =
        wavefront_compute_endsfree_allocate_null(wf_aligner,score);
  } else {
    wf_components->mwavefronts[score_mod] = NULL;
  }
  // Nullify Wavefronts
  if (distance_metric == gap_linear) return;
  wf_components->i1wavefronts[score_mod] = NULL;
  wf_components->d1wavefronts[score_mod] = NULL;
  if (distance_metric == gap_affine) return;
  wf_components->i2wavefronts[score_mod] = NULL;
  wf_components->d2wavefronts[score_mod] = NULL;
}
void wavefront_compute_allocate_output(
    wavefront_aligner_t* const wf_aligner,
    wavefront_set_t* const wavefront_set,
    const int score,
    const int lo,
    const int hi) {
  // Parameters
  wavefront_components_t* const wf_components = &wf_aligner->wf_components;
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  wavefront_slab_t* const wavefront_slab = wf_aligner->wavefront_slab;
  // Consider ends-free (M!=0)
  int effective_lo, effective_hi;
  if (wavefront_compute_endsfree_required(wf_aligner,score)) {
    int endsfree_lo, endsfree_hi;
    wavefront_compute_endsfree_limits(wf_aligner,score,&endsfree_lo,&endsfree_hi);
    effective_lo = MIN(lo,endsfree_lo);
    effective_hi = MAX(hi,endsfree_hi);
  } else {
    effective_lo = lo;
    effective_hi = hi;
  }
  // Compute effective hi/lo dimensions
  wavefront_compute_limits_output(
      wf_aligner,effective_lo,effective_hi,
      &effective_lo,&effective_hi);
  // Resize null/victim wavefronts
  wavefront_components_resize_null__victim(wf_components,effective_lo,effective_hi);
  // Modular wavefront
  int score_mod = score;
  if (wf_components->memory_modular) {
    score_mod = score % wf_components->max_score_scope;
    wavefront_compute_free_output(wf_aligner,score_mod);
  }
  // Check
  if (score_mod >= wf_components->num_wavefronts) {
    fprintf(stderr,"[WFA::Compute] Maximum allocated wavefronts reached\n");
    exit(1);
  }
  // Allocate M-Wavefront
  wavefront_set->out_mwavefront = wavefront_slab_allocate(wavefront_slab,effective_lo,effective_hi);
  wf_components->mwavefronts[score_mod] = wavefront_set->out_mwavefront;
  wf_components->mwavefronts[score_mod]->lo = lo;
  wf_components->mwavefronts[score_mod]->hi = hi;
  if (distance_metric == gap_linear) return;
  // Allocate I1-Wavefront
  if (!wavefront_set->in_mwavefront_open1->null || !wavefront_set->in_i1wavefront_ext->null) {
    wavefront_set->out_i1wavefront = wavefront_slab_allocate(wavefront_slab,effective_lo,effective_hi);
    wf_components->i1wavefronts[score_mod] = wavefront_set->out_i1wavefront;
    wf_components->i1wavefronts[score_mod]->lo = lo;
    wf_components->i1wavefronts[score_mod]->hi = hi;
  } else {
    wavefront_set->out_i1wavefront = wf_components->wavefront_victim;
    wf_components->i1wavefronts[score_mod] = NULL;
  }
  // Allocate D1-Wavefront
  if (!wavefront_set->in_mwavefront_open1->null || !wavefront_set->in_d1wavefront_ext->null) {
    wavefront_set->out_d1wavefront = wavefront_slab_allocate(wavefront_slab,effective_lo,effective_hi);
    wf_components->d1wavefronts[score_mod] = wavefront_set->out_d1wavefront;
    wf_components->d1wavefronts[score_mod]->lo = lo;
    wf_components->d1wavefronts[score_mod]->hi = hi;
  } else {
    wavefront_set->out_d1wavefront = wf_components->wavefront_victim;
    wf_components->d1wavefronts[score_mod] = NULL;
  }
  if (distance_metric == gap_affine) return;
  // Allocate I2-Wavefront
  if (!wavefront_set->in_mwavefront_open2->null || !wavefront_set->in_i2wavefront_ext->null) {
    wavefront_set->out_i2wavefront = wavefront_slab_allocate(wavefront_slab,effective_lo,effective_hi);
    wf_components->i2wavefronts[score_mod] = wavefront_set->out_i2wavefront;
    wf_components->i2wavefronts[score_mod]->lo = lo;
    wf_components->i2wavefronts[score_mod]->hi = hi;
  } else {
    wavefront_set->out_i2wavefront = wf_components->wavefront_victim;
    wf_components->i2wavefronts[score_mod] = NULL;
  }
  // Allocate D2-Wavefront
  if (!wavefront_set->in_mwavefront_open2->null || !wavefront_set->in_d2wavefront_ext->null) {
    wavefront_set->out_d2wavefront = wavefront_slab_allocate(wavefront_slab,effective_lo,effective_hi);
    wf_components->d2wavefronts[score_mod] = wavefront_set->out_d2wavefront;
    wf_components->d2wavefronts[score_mod]->lo = lo;
    wf_components->d2wavefronts[score_mod]->hi = hi;
  } else {
    wavefront_set->out_d2wavefront = wf_components->wavefront_victim;
    wf_components->d2wavefronts[score_mod] = NULL;
  }
}
/*
 * Initialize wavefronts ends
 */
void wavefront_compute_init_ends_wf_lower(
    wavefront_t* const wavefront,
    const int min_lo) {
  // Check initialization (lowest element)
  if (wavefront->wf_elements_init_min <= min_lo) return;
  // Initialize lower elements
  wf_offset_t* const offsets = wavefront->offsets;
  const int min_init = MIN(wavefront->wf_elements_init_min,wavefront->lo);
  int k;
  for (k=min_lo;k<min_init;++k) {
    offsets[k] = WAVEFRONT_OFFSET_NULL;
  }
  // Set new minimum
  wavefront->wf_elements_init_min = min_lo;
}
void wavefront_compute_init_ends_wf_higher(
    wavefront_t* const wavefront,
    const int max_hi) {
  // Check initialization (highest element)
  if (wavefront->wf_elements_init_max >= max_hi) return;
  // Initialize lower elements
  wf_offset_t* const offsets = wavefront->offsets;
  const int max_init = MAX(wavefront->wf_elements_init_max,wavefront->hi);
  int k;
  for (k=max_init+1;k<=max_hi;++k) {
    offsets[k] = WAVEFRONT_OFFSET_NULL;
  }
  // Set new maximum
  wavefront->wf_elements_init_max = max_hi;
}
void wavefront_compute_init_ends(
    wavefront_aligner_t* const wf_aligner,
    wavefront_set_t* const wavefront_set,
    const int lo,
    const int hi) {
  // Parameters
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  // Init missing elements, instead of loop peeling (M)
  const bool m_misms_null = wavefront_set->in_mwavefront_misms->null;
  const bool m_gap1_null = wavefront_set->in_mwavefront_open1->null;
  if (!m_misms_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_mwavefront_misms,hi);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_mwavefront_misms,lo);
  }
  if (!m_gap1_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_mwavefront_open1,hi+1);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_mwavefront_open1,lo-1);
  }
  if (distance_metric == gap_linear) return;
  // Init missing elements, instead of loop peeling (Open1/I1/D1)
  const bool i1_ext_null = wavefront_set->in_i1wavefront_ext->null;
  const bool d1_ext_null = wavefront_set->in_d1wavefront_ext->null;
  if (!i1_ext_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_i1wavefront_ext,hi);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_i1wavefront_ext,lo-1);
  }
  if (!d1_ext_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_d1wavefront_ext,hi+1);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_d1wavefront_ext,lo);
  }
  if (distance_metric == gap_affine) return;
  // Init missing elements, instead of loop peeling (Open2/I2/D2)
  const bool m_gap2_null = wavefront_set->in_mwavefront_open2->null;
  const bool i2_ext_null = wavefront_set->in_i2wavefront_ext->null;
  const bool d2_ext_null = wavefront_set->in_d2wavefront_ext->null;
  if (!m_gap2_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_mwavefront_open2,hi+1);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_mwavefront_open2,lo-1);
  }
  if (!i2_ext_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_i2wavefront_ext,hi);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_i2wavefront_ext,lo-1);
  }
  if (!d2_ext_null) {
    wavefront_compute_init_ends_wf_higher(wavefront_set->in_d2wavefront_ext,hi+1);
    wavefront_compute_init_ends_wf_lower(wavefront_set->in_d2wavefront_ext,lo);
  }
}
/*
 * Trim wavefronts ends
 */
void wavefront_compute_trim_ends(
    wavefront_aligner_t* const wf_aligner,
    wavefront_t* const wavefront) {
  // Parameters
  wavefront_sequences_t* const sequences = &wf_aligner->sequences;
  const int pattern_length = sequences->pattern_length;
  const int text_length = sequences->text_length;
  wf_offset_t* const offsets = wavefront->offsets;
  // Trim from hi
  int k;
  const int lo = wavefront->lo;
  for (k=wavefront->hi;k>=lo;--k) {
    // Fetch offset
    const wf_offset_t offset = offsets[k];
    // Check boundaries
    const uint32_t h = WAVEFRONT_H(k,offset); // Make unsigned to avoid checking negative
    const uint32_t v = WAVEFRONT_V(k,offset); // Make unsigned to avoid checking negative
    if (h <= text_length && v <= pattern_length) break;
  }
  wavefront->hi = k; // Set new hi
  wavefront->wf_elements_init_max = k;
  // Trim from lo
  const int hi = wavefront->hi;
  for (k=wavefront->lo;k<=hi;++k) {
    // Fetch offset
    const wf_offset_t offset = offsets[k];
    // Check boundaries
    const uint32_t h = WAVEFRONT_H(k,offset); // Make unsigned to avoid checking negative
    const uint32_t v = WAVEFRONT_V(k,offset); // Make unsigned to avoid checking negative
    if (h <= text_length && v <= pattern_length) break;
  }
  wavefront->lo = k; // Set new lo
  wavefront->wf_elements_init_min = k;
  wavefront->null = (wavefront->lo > wavefront->hi);
}
void wavefront_compute_process_ends(
    wavefront_aligner_t* const wf_aligner,
    wavefront_set_t* const wavefront_set,
    const int score) {
  // Parameters
  const distance_metric_t distance_metric = wf_aligner->penalties.distance_metric;
  // Consider ends-free (M!=0)
  if (wavefront_compute_endsfree_required(wf_aligner,score)) {
    wavefront_compute_endsfree_init(wf_aligner,wavefront_set->out_mwavefront,score);
  }
  // Trim ends from non-null WFs
  if (wavefront_set->out_mwavefront) wavefront_compute_trim_ends(wf_aligner,wavefront_set->out_mwavefront);
  if (distance_metric == gap_linear) return;
  if (wavefront_set->out_i1wavefront) wavefront_compute_trim_ends(wf_aligner,wavefront_set->out_i1wavefront);
  if (wavefront_set->out_d1wavefront) wavefront_compute_trim_ends(wf_aligner,wavefront_set->out_d1wavefront);
  if (distance_metric == gap_affine) return;
  if (wavefront_set->out_i2wavefront) wavefront_compute_trim_ends(wf_aligner,wavefront_set->out_i2wavefront);
  if (wavefront_set->out_d2wavefront) wavefront_compute_trim_ends(wf_aligner,wavefront_set->out_d2wavefront);
}
/*
 * Multithread dispatcher
 */
#ifdef WFA_PARALLEL
int wavefront_compute_num_threads(
    wavefront_aligner_t* const wf_aligner,
    const int lo,
    const int hi) {
  // Parameters
  const int max_num_threads = wf_aligner->system.max_num_threads;
  if (max_num_threads == 1) return 1;
  const int min_offsets_per_thread = wf_aligner->system.min_offsets_per_thread;
  // Compute minimum work-chunks worth spawning threads
  const int num_chunks = WAVEFRONT_LENGTH(lo,hi)/min_offsets_per_thread;
  const int max_workers = MIN(num_chunks,max_num_threads);
  return MAX(max_workers,1);
}
void wavefront_compute_thread_limits(
    const int thread_id,
    const int num_theads,
    const int lo,
    const int hi,
    int* const thread_lo,
    int* const thread_hi) {
  const int chunk_size = WAVEFRONT_LENGTH(lo,hi)/num_theads;
  const int t_lo = lo + thread_id*chunk_size;
  const int t_hi = (thread_id+1 == num_theads) ? hi : t_lo + chunk_size - 1;
  *thread_lo = t_lo;
  *thread_hi = t_hi;
}
#endif