/*
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software  Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2018, Blender Foundation
 * This is a new part of Blender
 */

/** \file
 * \ingroup modifiers
 */

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

#include "BLI_utildefines.h"

#include "DNA_meshdata_types.h"
#include "DNA_scene_types.h"
#include "DNA_object_types.h"
#include "DNA_gpencil_types.h"
#include "DNA_gpencil_modifier_types.h"

#include "BKE_colortools.h"
#include "BKE_deform.h"
#include "BKE_gpencil.h"
#include "BKE_gpencil_modifier.h"

#include "DEG_depsgraph.h"

#include "MOD_gpencil_util.h"
#include "MOD_gpencil_modifiertypes.h"

static void initData(GpencilModifierData *md)
{
  TimeGpencilModifierData *gpmd = (TimeGpencilModifierData *)md;
  gpmd->layername[0] = '\0';
  gpmd->offset = 1;
  gpmd->frame_scale = 1.0f;
  gpmd->flag |= GP_TIME_KEEP_LOOP;
  gpmd->sfra = 1;
  gpmd->efra = 250;
}

static void copyData(const GpencilModifierData *md, GpencilModifierData *target)
{
  BKE_gpencil_modifier_copyData_generic(md, target);
}

static int remapTime(struct GpencilModifierData *md,
                     struct Depsgraph *UNUSED(depsgraph),
                     struct Scene *scene,
                     struct Object *UNUSED(ob),
                     struct bGPDlayer *gpl,
                     int cfra)
{
  TimeGpencilModifierData *mmd = (TimeGpencilModifierData *)md;
  const bool custom = mmd->flag & GP_TIME_CUSTOM_RANGE;
  const bool invgpl = mmd->flag & GP_TIME_INVERT_LAYER;
  const bool invpass = mmd->flag & GP_TIME_INVERT_LAYERPASS;
  int sfra = custom ? mmd->sfra : scene->r.sfra;
  int efra = custom ? mmd->efra : scene->r.efra;
  CLAMP_MIN(sfra, 0);
  CLAMP_MIN(efra, 0);

  /* Avoid inverse ranges. */
  if (efra < sfra) {
    return cfra;
  }

  const int time_range = efra - sfra + 1;
  int offset = mmd->offset;
  int segments = 0;

  /* omit if filter by layer */
  if (mmd->layername[0] != '\0') {
    if (invgpl == false) {
      if (!STREQ(mmd->layername, gpl->info)) {
        return cfra;
      }
    }
    else {
      if (STREQ(mmd->layername, gpl->info)) {
        return cfra;
      }
    }
  }
  /* verify pass */
  if (mmd->layer_pass > 0) {
    if (invpass == false) {
      if (gpl->pass_index != mmd->layer_pass) {
        return cfra;
      }
    }
    else {
      if (gpl->pass_index == mmd->layer_pass) {
        return cfra;
      }
    }
  }

  /* if fix mode, return predefined frame number */
  if (mmd->mode == GP_TIME_MODE_FIX) {
    return offset;
  }

  /* invert current frame number */
  if (mmd->mode == GP_TIME_MODE_REVERSE) {
    cfra = efra - cfra + sfra;
  }

  /* apply frame scale */
  cfra *= mmd->frame_scale;

  /* verify offset never is greater than frame range */
  if (abs(offset) > time_range) {
    offset = offset - ((offset / time_range) * time_range);
  }

  /* verify not outside range if loop is disabled */
  if ((mmd->flag & GP_TIME_KEEP_LOOP) == 0) {
    if (cfra + offset < sfra) {
      return sfra;
    }
    if (cfra + offset > efra) {
      return efra;
    }
  }

  /* check frames before start */
  if (cfra < sfra) {
    segments = ((cfra + sfra) / time_range);
    cfra = cfra + (segments * time_range);
  }

  /* check frames after end */
  if (cfra > efra) {
    segments = ((cfra - sfra) / time_range);
    cfra = cfra - (segments * time_range);
  }

  if (mmd->flag & GP_TIME_KEEP_LOOP) {
    const int nfra = cfra + offset;

    /* if the sum of the cfra is out scene frame range, recalc */
    if (cfra + offset < sfra) {
      const int delta = abs(sfra - nfra);
      return efra - delta + 1;
    }
    else if (cfra + offset > efra) {
      return nfra - efra + sfra - 1;
    }
  }

  return cfra + offset;
}

GpencilModifierTypeInfo modifierType_Gpencil_Time = {
    /* name */ "Time Offset",
    /* structName */ "TimeGpencilModifierData",
    /* structSize */ sizeof(TimeGpencilModifierData),
    /* type */ eGpencilModifierTypeType_Gpencil,
    /* flags */ eGpencilModifierTypeFlag_NoApply,

    /* copyData */ copyData,

    /* deformStroke */ NULL,
    /* generateStrokes */ NULL,
    /* bakeModifier */ NULL,
    /* remapTime */ remapTime,

    /* initData */ initData,
    /* freeData */ NULL,
    /* isDisabled */ NULL,
    /* updateDepsgraph */ NULL,
    /* dependsOnTime */ NULL,
    /* foreachObjectLink */ NULL,
    /* foreachIDLink */ NULL,
    /* foreachTexLink */ NULL,
};