/* SPDX-License-Identifier: GPL-2.0-or-later
 * Copyright 2008 Blender Foundation. */

/** \file
 * \ingroup spaction
 */

#include <float.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_dlrbTree.h"
#include "BLI_lasso_2d.h"
#include "BLI_utildefines.h"

#include "DNA_anim_types.h"
#include "DNA_gpencil_types.h"
#include "DNA_mask_types.h"
#include "DNA_object_types.h"
#include "DNA_scene_types.h"

#include "RNA_access.h"
#include "RNA_define.h"

#include "BKE_context.h"
#include "BKE_fcurve.h"
#include "BKE_gpencil.h"
#include "BKE_nla.h"

#include "UI_interface.h"
#include "UI_view2d.h"

#include "ED_anim_api.h"
#include "ED_gpencil.h"
#include "ED_keyframes_edit.h"
#include "ED_keyframes_keylist.h"
#include "ED_markers.h"
#include "ED_mask.h"
#include "ED_screen.h"
#include "ED_select_utils.h"

#include "WM_api.h"
#include "WM_types.h"

#include "action_intern.h"

/* ************************************************************************** */
/* KEYFRAMES STUFF */

static bAnimListElem *actkeys_find_list_element_at_position(bAnimContext *ac,
                                                            int filter,
                                                            float region_x,
                                                            float region_y)
{
  View2D *v2d = &ac->region->v2d;

  float view_x, view_y;
  int channel_index;
  UI_view2d_region_to_view(v2d, region_x, region_y, &view_x, &view_y);
  UI_view2d_listview_view_to_cell(
      0, ACHANNEL_STEP(ac), 0, ACHANNEL_FIRST_TOP(ac), view_x, view_y, NULL, &channel_index);

  ListBase anim_data = {NULL, NULL};
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  bAnimListElem *ale = BLI_findlink(&anim_data, channel_index);
  if (ale != NULL) {
    BLI_remlink(&anim_data, ale);
    ale->next = ale->prev = NULL;
  }
  ANIM_animdata_freelist(&anim_data);

  return ale;
}

static void actkeys_list_element_to_keylist(bAnimContext *ac,
                                            struct AnimKeylist *keylist,
                                            bAnimListElem *ale)
{
  AnimData *adt = ANIM_nla_mapping_get(ac, ale);

  bDopeSheet *ads = NULL;
  if (ELEM(ac->datatype, ANIMCONT_DOPESHEET, ANIMCONT_TIMELINE)) {
    ads = ac->data;
  }

  if (ale->key_data) {
    switch (ale->datatype) {
      case ALE_SCE: {
        Scene *scene = (Scene *)ale->key_data;
        scene_to_keylist(ads, scene, keylist, 0);
        break;
      }
      case ALE_OB: {
        Object *ob = (Object *)ale->key_data;
        ob_to_keylist(ads, ob, keylist, 0);
        break;
      }
      case ALE_ACT: {
        bAction *act = (bAction *)ale->key_data;
        action_to_keylist(adt, act, keylist, 0);
        break;
      }
      case ALE_FCURVE: {
        FCurve *fcu = (FCurve *)ale->key_data;
        fcurve_to_keylist(adt, fcu, keylist, 0);
        break;
      }
    }
  }
  else if (ale->type == ANIMTYPE_SUMMARY) {
    /* dopesheet summary covers everything */
    summary_to_keylist(ac, keylist, 0);
  }
  else if (ale->type == ANIMTYPE_GROUP) {
    /* TODO: why don't we just give groups key_data too? */
    bActionGroup *agrp = (bActionGroup *)ale->data;
    agroup_to_keylist(adt, agrp, keylist, 0);
  }
  else if (ale->type == ANIMTYPE_GPLAYER) {
    /* TODO: why don't we just give gplayers key_data too? */
    bGPDlayer *gpl = (bGPDlayer *)ale->data;
    gpl_to_keylist(ads, gpl, keylist);
  }
  else if (ale->type == ANIMTYPE_MASKLAYER) {
    /* TODO: why don't we just give masklayers key_data too? */
    MaskLayer *masklay = (MaskLayer *)ale->data;
    mask_to_keylist(ads, masklay, keylist);
  }
}

static void actkeys_find_key_in_list_element(bAnimContext *ac,
                                             bAnimListElem *ale,
                                             float region_x,
                                             float *r_selx,
                                             float *r_frame,
                                             bool *r_found,
                                             bool *r_is_selected)
{
  *r_found = false;

  View2D *v2d = &ac->region->v2d;

  struct AnimKeylist *keylist = ED_keylist_create();
  actkeys_list_element_to_keylist(ac, keylist, ale);
  ED_keylist_prepare_for_direct_access(keylist);

  AnimData *adt = ANIM_nla_mapping_get(ac, ale);

  /* standard channel height (to allow for some slop) */
  float key_hsize = ACHANNEL_HEIGHT(ac) * 0.8f;
  /* half-size (for either side), but rounded up to nearest int (for easier targeting) */
  key_hsize = roundf(key_hsize / 2.0f);

  const Range2f range = {UI_view2d_region_to_view_x(v2d, region_x - (int)key_hsize),
                         UI_view2d_region_to_view_x(v2d, region_x + (int)key_hsize)};
  const ActKeyColumn *ak = ED_keylist_find_any_between(keylist, range);
  if (ak) {

    /* set the frame to use, and apply inverse-correction for NLA-mapping
     * so that the frame will get selected by the selection functions without
     * requiring to map each frame once again...
     */
    *r_selx = BKE_nla_tweakedit_remap(adt, ak->cfra, NLATIME_CONVERT_UNMAP);
    *r_frame = ak->cfra;
    *r_found = true;
    *r_is_selected = (ak->sel & SELECT) != 0;
  }

  /* cleanup temporary lists */
  ED_keylist_free(keylist);
}

static void actkeys_find_key_at_position(bAnimContext *ac,
                                         int filter,
                                         float region_x,
                                         float region_y,
                                         bAnimListElem **r_ale,
                                         float *r_selx,
                                         float *r_frame,
                                         bool *r_found,
                                         bool *r_is_selected)

{
  *r_found = false;
  *r_ale = actkeys_find_list_element_at_position(ac, filter, region_x, region_y);

  if (*r_ale != NULL) {
    actkeys_find_key_in_list_element(
        ac, *r_ale, region_x, r_selx, r_frame, r_found, r_is_selected);
  }
}

static bool actkeys_is_key_at_position(bAnimContext *ac, float region_x, float region_y)
{
  bAnimListElem *ale;
  float selx, frame;
  bool found;
  bool is_selected;

  int filter = ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS;
  actkeys_find_key_at_position(
      ac, filter, region_x, region_y, &ale, &selx, &frame, &found, &is_selected);

  if (ale != NULL) {
    MEM_freeN(ale);
  }
  return found;
}

/* ******************** Deselect All Operator ***************************** */
/* This operator works in one of three ways:
 * 1) (de)select all (AKEY) - test if select all or deselect all
 * 2) invert all (CTRL-IKEY) - invert selection of all keyframes
 * 3) (de)select all - no testing is done; only for use internal tools as normal function...
 */

/* Deselects keyframes in the action editor
 * - This is called by the deselect all operator, as well as other ones!
 *
 * - test: check if select or deselect all
 * - sel: how to select keyframes (SELECT_*)
 */
static void deselect_action_keys(bAnimContext *ac, short test, short sel)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  KeyframeEditData ked = {{NULL}};
  KeyframeEditFunc test_cb, sel_cb;

  /* determine type-based settings */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);

  /* filter data */
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  /* init BezTriple looping data */
  test_cb = ANIM_editkeyframes_ok(BEZT_OK_SELECTED);

  /* See if we should be selecting or deselecting */
  if (test) {
    for (ale = anim_data.first; ale; ale = ale->next) {
      if (ale->type == ANIMTYPE_GPLAYER) {
        if (ED_gpencil_layer_frame_select_check(ale->data)) {
          sel = SELECT_SUBTRACT;
          break;
        }
      }
      else if (ale->type == ANIMTYPE_MASKLAYER) {
        if (ED_masklayer_frame_select_check(ale->data)) {
          sel = SELECT_SUBTRACT;
          break;
        }
      }
      else {
        if (ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, test_cb, NULL)) {
          sel = SELECT_SUBTRACT;
          break;
        }
      }
    }
  }

  /* convert sel to selectmode, and use that to get editor */
  sel_cb = ANIM_editkeyframes_select(sel);

  /* Now set the flags */
  for (ale = anim_data.first; ale; ale = ale->next) {
    if (ale->type == ANIMTYPE_GPLAYER) {
      ED_gpencil_layer_frame_select_set(ale->data, sel);
      ale->update |= ANIM_UPDATE_DEPS;
    }
    else if (ale->type == ANIMTYPE_MASKLAYER) {
      ED_masklayer_frame_select_set(ale->data, sel);
    }
    else {
      ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, sel_cb, NULL);
    }
  }

  /* Cleanup */
  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* ------------------- */

static int actkeys_deselectall_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* 'standard' behavior - check if selected, then apply relevant selection */
  const int action = RNA_enum_get(op->ptr, "action");
  switch (action) {
    case SEL_TOGGLE:
      deselect_action_keys(&ac, 1, SELECT_ADD);
      break;
    case SEL_SELECT:
      deselect_action_keys(&ac, 0, SELECT_ADD);
      break;
    case SEL_DESELECT:
      deselect_action_keys(&ac, 0, SELECT_SUBTRACT);
      break;
    case SEL_INVERT:
      deselect_action_keys(&ac, 0, SELECT_INVERT);
      break;
    default:
      BLI_assert(0);
      break;
  }

  /* set notifier that keyframe selection have changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_all(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Select All";
  ot->idname = "ACTION_OT_select_all";
  ot->description = "Toggle selection of all keyframes";

  /* api callbacks */
  ot->exec = actkeys_deselectall_exec;
  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

  /* properties */
  WM_operator_properties_select_all(ot);
}

/* ******************** Box Select Operator **************************** */
/**
 * This operator currently works in one of three ways:
 * - BKEY     - 1) all keyframes within region are selected #ACTKEYS_BORDERSEL_ALLKEYS.
 * - ALT-BKEY - depending on which axis of the region was larger...
 *   - 2) x-axis, so select all frames within frame range #ACTKEYS_BORDERSEL_FRAMERANGE.
 *   - 3) y-axis, so select all frames within channels that region included
 *     #ACTKEYS_BORDERSEL_CHANNELS.
 */

/* defines for box_select mode */
enum {
  ACTKEYS_BORDERSEL_ALLKEYS = 0,
  ACTKEYS_BORDERSEL_FRAMERANGE,
  ACTKEYS_BORDERSEL_CHANNELS,
} /*eActKeys_BoxSelect_Mode*/;

typedef struct BoxSelectData {
  bAnimContext *ac;
  short selectmode;

  KeyframeEditData ked;
  KeyframeEditFunc ok_cb, select_cb;
} BoxSelectData;

static void box_select_elem(
    BoxSelectData *sel_data, bAnimListElem *ale, float xmin, float xmax, bool summary)
{
  bAnimContext *ac = sel_data->ac;

  switch (ale->type) {
#if 0 /* XXX: Keyframes are not currently shown here */
    case ANIMTYPE_GPDATABLOCK: {
      bGPdata *gpd = ale->data;
      bGPDlayer *gpl;
      for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
        ED_gpencil_layer_frames_select_box(gpl, xmin, xmax, data->selectmode);
      }
      ale->update |= ANIM_UPDATE_DEPS;
      break;
    }
#endif
    case ANIMTYPE_GPLAYER: {
      ED_gpencil_layer_frames_select_box(ale->data, xmin, xmax, sel_data->selectmode);
      ale->update |= ANIM_UPDATE_DEPS;
      break;
    }
    case ANIMTYPE_MASKDATABLOCK: {
      Mask *mask = ale->data;
      MaskLayer *masklay;
      for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
        ED_masklayer_frames_select_box(masklay, xmin, xmax, sel_data->selectmode);
      }
      break;
    }
    case ANIMTYPE_MASKLAYER: {
      ED_masklayer_frames_select_box(ale->data, xmin, xmax, sel_data->selectmode);
      break;
    }
    default: {
      if (summary) {
        break;
      }

      if (ale->type == ANIMTYPE_SUMMARY) {
        ListBase anim_data = {NULL, NULL};
        ANIM_animdata_filter(ac, &anim_data, ANIMFILTER_DATA_VISIBLE, ac->data, ac->datatype);

        LISTBASE_FOREACH (bAnimListElem *, ale2, &anim_data) {
          box_select_elem(sel_data, ale2, xmin, xmax, true);
        }

        ANIM_animdata_update(ac, &anim_data);
        ANIM_animdata_freelist(&anim_data);
      }

      if (!ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK)) {
        ANIM_animchannel_keyframes_loop(
            &sel_data->ked, ac->ads, ale, sel_data->ok_cb, sel_data->select_cb, NULL);
      }
    }
  }
}

static void box_select_action(bAnimContext *ac, const rcti rect, short mode, short selectmode)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  BoxSelectData sel_data = {.ac = ac, .selectmode = selectmode};
  View2D *v2d = &ac->region->v2d;
  rctf rectf;

  /* Convert mouse coordinates to frame ranges and channel
   * coordinates corrected for view pan/zoom. */
  UI_view2d_region_to_view(v2d, rect.xmin, rect.ymin + 2, &rectf.xmin, &rectf.ymin);
  UI_view2d_region_to_view(v2d, rect.xmax, rect.ymax - 2, &rectf.xmax, &rectf.ymax);

  /* filter data */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  /* Get beztriple editing/validation funcs. */
  sel_data.select_cb = ANIM_editkeyframes_select(selectmode);

  if (ELEM(mode, ACTKEYS_BORDERSEL_FRAMERANGE, ACTKEYS_BORDERSEL_ALLKEYS)) {
    sel_data.ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAMERANGE);
  }
  else {
    sel_data.ok_cb = NULL;
  }

  /* init editing data */
  memset(&sel_data.ked, 0, sizeof(KeyframeEditData));

  float ymax = ACHANNEL_FIRST_TOP(ac);

  /* loop over data, doing box select */
  for (ale = anim_data.first; ale; ale = ale->next, ymax -= ACHANNEL_STEP(ac)) {
    AnimData *adt = ANIM_nla_mapping_get(ac, ale);

    /* get new vertical minimum extent of channel */
    float ymin = ymax - ACHANNEL_STEP(ac);

    /* set horizontal range (if applicable) */
    if (ELEM(mode, ACTKEYS_BORDERSEL_FRAMERANGE, ACTKEYS_BORDERSEL_ALLKEYS)) {
      /* if channel is mapped in NLA, apply correction */
      if (adt) {
        sel_data.ked.iterflags &= ~(KED_F1_NLA_UNMAP | KED_F2_NLA_UNMAP);
        sel_data.ked.f1 = BKE_nla_tweakedit_remap(adt, rectf.xmin, NLATIME_CONVERT_UNMAP);
        sel_data.ked.f2 = BKE_nla_tweakedit_remap(adt, rectf.xmax, NLATIME_CONVERT_UNMAP);
      }
      else {
        sel_data.ked.iterflags |= (KED_F1_NLA_UNMAP | KED_F2_NLA_UNMAP); /* for summary tracks */
        sel_data.ked.f1 = rectf.xmin;
        sel_data.ked.f2 = rectf.xmax;
      }
    }

    /* perform vertical suitability check (if applicable) */
    if ((mode == ACTKEYS_BORDERSEL_FRAMERANGE) || !((ymax < rectf.ymin) || (ymin > rectf.ymax))) {
      box_select_elem(&sel_data, ale, rectf.xmin, rectf.xmax, false);
    }
  }

  /* cleanup */
  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* ------------------- */

static int actkeys_box_select_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
  bAnimContext ac;
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  bool tweak = RNA_boolean_get(op->ptr, "tweak");
  if (tweak) {
    int mval[2];
    WM_event_drag_start_mval(event, ac.region, mval);
    if (actkeys_is_key_at_position(&ac, mval[0], mval[1])) {
      return OPERATOR_CANCELLED | OPERATOR_PASS_THROUGH;
    }
  }

  return WM_gesture_box_invoke(C, op, event);
}

static int actkeys_box_select_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;
  rcti rect;
  short mode = 0;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  const eSelectOp sel_op = RNA_enum_get(op->ptr, "mode");
  const int selectmode = (sel_op != SEL_OP_SUB) ? SELECT_ADD : SELECT_SUBTRACT;
  if (SEL_OP_USE_PRE_DESELECT(sel_op)) {
    deselect_action_keys(&ac, 1, SELECT_SUBTRACT);
  }

  /* get settings from operator */
  WM_operator_properties_border_to_rcti(op, &rect);

  /* selection 'mode' depends on whether box_select region only matters on one axis */
  if (RNA_boolean_get(op->ptr, "axis_range")) {
    /* Mode depends on which axis of the range is larger to determine which axis to use:
     * - checking this in region-space is fine,
     *   as it's fundamentally still going to be a different rect size.
     * - the frame-range select option is favored over the channel one (x over y),
     *   as frame-range one is often used for tweaking timing when "blocking",
     *   while channels is not that useful...
     */
    if (BLI_rcti_size_x(&rect) >= BLI_rcti_size_y(&rect)) {
      mode = ACTKEYS_BORDERSEL_FRAMERANGE;
    }
    else {
      mode = ACTKEYS_BORDERSEL_CHANNELS;
    }
  }
  else {
    mode = ACTKEYS_BORDERSEL_ALLKEYS;
  }

  /* apply box_select action */
  box_select_action(&ac, rect, mode, selectmode);

  /* set notifier that keyframe selection have changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_box(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Box Select";
  ot->idname = "ACTION_OT_select_box";
  ot->description = "Select all keyframes within the specified region";

  /* api callbacks */
  ot->invoke = actkeys_box_select_invoke;
  ot->exec = actkeys_box_select_exec;
  ot->modal = WM_gesture_box_modal;
  ot->cancel = WM_gesture_box_cancel;

  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_UNDO;

  /* rna */
  ot->prop = RNA_def_boolean(ot->srna, "axis_range", 0, "Axis Range", "");

  /* properties */
  WM_operator_properties_gesture_box(ot);
  WM_operator_properties_select_operation_simple(ot);

  PropertyRNA *prop = RNA_def_boolean(
      ot->srna, "tweak", 0, "Tweak", "Operator has been activated using a click-drag event");
  RNA_def_property_flag(prop, PROP_SKIP_SAVE);
}

/* ******************** Region Select Operators ***************************** */
/* "Region Select" operators include the Lasso and Circle Select operators.
 * These two ended up being lumped together, as it was easier in the
 * original Graph Editor implementation of these to do it this way.
 */

typedef struct RegionSelectData {
  bAnimContext *ac;
  short mode;
  short selectmode;

  KeyframeEditData ked;
  KeyframeEditFunc ok_cb, select_cb;
} RegionSelectData;

static void region_select_elem(RegionSelectData *sel_data, bAnimListElem *ale, bool summary)
{
  bAnimContext *ac = sel_data->ac;

  switch (ale->type) {
#if 0 /* XXX: Keyframes are not currently shown here */
    case ANIMTYPE_GPDATABLOCK: {
      bGPdata *gpd = ale->data;
      bGPDlayer *gpl;
      for (gpl = gpd->layers.first; gpl; gpl = gpl->next) {
        ED_gpencil_layer_frames_select_region(&rdata->ked, ale->data, rdata->mode, rdata->selectmode);
      }
      break;
    }
#endif
    case ANIMTYPE_GPLAYER: {
      ED_gpencil_layer_frames_select_region(
          &sel_data->ked, ale->data, sel_data->mode, sel_data->selectmode);
      ale->update |= ANIM_UPDATE_DEPS;
      break;
    }
    case ANIMTYPE_MASKDATABLOCK: {
      Mask *mask = ale->data;
      MaskLayer *masklay;
      for (masklay = mask->masklayers.first; masklay; masklay = masklay->next) {
        ED_masklayer_frames_select_region(
            &sel_data->ked, masklay, sel_data->mode, sel_data->selectmode);
      }
      break;
    }
    case ANIMTYPE_MASKLAYER: {
      ED_masklayer_frames_select_region(
          &sel_data->ked, ale->data, sel_data->mode, sel_data->selectmode);
      break;
    }
    default: {
      if (summary) {
        break;
      }

      if (ale->type == ANIMTYPE_SUMMARY) {
        ListBase anim_data = {NULL, NULL};
        ANIM_animdata_filter(ac, &anim_data, ANIMFILTER_DATA_VISIBLE, ac->data, ac->datatype);

        LISTBASE_FOREACH (bAnimListElem *, ale2, &anim_data) {
          region_select_elem(sel_data, ale2, true);
        }

        ANIM_animdata_update(ac, &anim_data);
        ANIM_animdata_freelist(&anim_data);
      }

      if (!ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK)) {
        ANIM_animchannel_keyframes_loop(
            &sel_data->ked, ac->ads, ale, sel_data->ok_cb, sel_data->select_cb, NULL);
      }
    }
  }
}

static void region_select_action_keys(
    bAnimContext *ac, const rctf *rectf_view, short mode, short selectmode, void *data)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  RegionSelectData sel_data = {.ac = ac, .mode = mode, .selectmode = selectmode};
  View2D *v2d = &ac->region->v2d;
  rctf rectf, scaled_rectf;

  /* Convert mouse coordinates to frame ranges and channel
   * coordinates corrected for view pan/zoom. */
  UI_view2d_region_to_view_rctf(v2d, rectf_view, &rectf);

  /* filter data */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  /* Get beztriple editing/validation funcs. */
  sel_data.select_cb = ANIM_editkeyframes_select(selectmode);
  sel_data.ok_cb = ANIM_editkeyframes_ok(mode);

  /* init editing data */
  memset(&sel_data.ked, 0, sizeof(KeyframeEditData));
  if (mode == BEZT_OK_CHANNEL_LASSO) {
    KeyframeEdit_LassoData *data_lasso = data;
    data_lasso->rectf_scaled = &scaled_rectf;
    sel_data.ked.data = data_lasso;
  }
  else if (mode == BEZT_OK_CHANNEL_CIRCLE) {
    KeyframeEdit_CircleData *data_circle = data;
    data_circle->rectf_scaled = &scaled_rectf;
    sel_data.ked.data = data;
  }
  else {
    sel_data.ked.data = &scaled_rectf;
  }

  float ymax = ACHANNEL_FIRST_TOP(ac);

  /* loop over data, doing region select */
  for (ale = anim_data.first; ale; ale = ale->next, ymax -= ACHANNEL_STEP(ac)) {
    AnimData *adt = ANIM_nla_mapping_get(ac, ale);

    /* get new vertical minimum extent of channel */
    float ymin = ymax - ACHANNEL_STEP(ac);

    /* compute midpoint of channel (used for testing if the key is in the region or not) */
    sel_data.ked.channel_y = (ymin + ymax) / 2.0f;

    /* if channel is mapped in NLA, apply correction
     * - Apply to the bounds being checked, not all the keyframe points,
     *   to avoid having scaling everything
     * - Save result to the scaled_rect, which is all that these operators
     *   will read from
     */
    if (adt) {
      sel_data.ked.iterflags &= ~(KED_F1_NLA_UNMAP | KED_F2_NLA_UNMAP);
      sel_data.ked.f1 = BKE_nla_tweakedit_remap(adt, rectf.xmin, NLATIME_CONVERT_UNMAP);
      sel_data.ked.f2 = BKE_nla_tweakedit_remap(adt, rectf.xmax, NLATIME_CONVERT_UNMAP);
    }
    else {
      sel_data.ked.iterflags |= (KED_F1_NLA_UNMAP | KED_F2_NLA_UNMAP); /* for summary tracks */
      sel_data.ked.f1 = rectf.xmin;
      sel_data.ked.f2 = rectf.xmax;
    }

    /* Update values for scaled_rectf - which is used to compute the mapping in the callbacks
     * NOTE: Since summary tracks need late-binding remapping, the callbacks may overwrite these
     *       with the properly remapped ked.f1/f2 values, when needed
     */
    scaled_rectf.xmin = sel_data.ked.f1;
    scaled_rectf.xmax = sel_data.ked.f2;
    scaled_rectf.ymin = ymin;
    scaled_rectf.ymax = ymax;

    /* perform vertical suitability check (if applicable) */
    if ((mode == ACTKEYS_BORDERSEL_FRAMERANGE) || !((ymax < rectf.ymin) || (ymin > rectf.ymax))) {
      region_select_elem(&sel_data, ale, false);
    }
  }

  /* cleanup */
  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* ----------------------------------- */

static int actkeys_lassoselect_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;

  KeyframeEdit_LassoData data_lasso;
  rcti rect;
  rctf rect_fl;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  data_lasso.rectf_view = &rect_fl;
  data_lasso.mcoords = WM_gesture_lasso_path_to_array(C, op, &data_lasso.mcoords_len);
  if (data_lasso.mcoords == NULL) {
    return OPERATOR_CANCELLED;
  }

  const eSelectOp sel_op = RNA_enum_get(op->ptr, "mode");
  const int selectmode = (sel_op != SEL_OP_SUB) ? SELECT_ADD : SELECT_SUBTRACT;
  if (SEL_OP_USE_PRE_DESELECT(sel_op)) {
    deselect_action_keys(&ac, 1, SELECT_SUBTRACT);
  }

  /* get settings from operator */
  BLI_lasso_boundbox(&rect, data_lasso.mcoords, data_lasso.mcoords_len);
  BLI_rctf_rcti_copy(&rect_fl, &rect);

  /* apply box_select action */
  region_select_action_keys(&ac, &rect_fl, BEZT_OK_CHANNEL_LASSO, selectmode, &data_lasso);

  MEM_freeN((void *)data_lasso.mcoords);

  /* send notifier that keyframe selection has changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_lasso(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Lasso Select";
  ot->description = "Select keyframe points using lasso selection";
  ot->idname = "ACTION_OT_select_lasso";

  /* api callbacks */
  ot->invoke = WM_gesture_lasso_invoke;
  ot->modal = WM_gesture_lasso_modal;
  ot->exec = actkeys_lassoselect_exec;
  ot->poll = ED_operator_action_active;
  ot->cancel = WM_gesture_lasso_cancel;

  /* flags */
  ot->flag = OPTYPE_UNDO | OPTYPE_DEPENDS_ON_CURSOR;

  /* properties */
  WM_operator_properties_gesture_lasso(ot);
  WM_operator_properties_select_operation_simple(ot);
}

/* ------------------- */

static int action_circle_select_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;

  KeyframeEdit_CircleData data = {0};
  rctf rect_fl;

  float x = RNA_int_get(op->ptr, "x");
  float y = RNA_int_get(op->ptr, "y");
  float radius = RNA_int_get(op->ptr, "radius");

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  const eSelectOp sel_op = ED_select_op_modal(RNA_enum_get(op->ptr, "mode"),
                                              WM_gesture_is_modal_first(op->customdata));
  const short selectmode = (sel_op != SEL_OP_SUB) ? SELECT_ADD : SELECT_SUBTRACT;
  if (SEL_OP_USE_PRE_DESELECT(sel_op)) {
    deselect_action_keys(&ac, 0, SELECT_SUBTRACT);
  }

  data.mval[0] = x;
  data.mval[1] = y;
  data.radius_squared = radius * radius;
  data.rectf_view = &rect_fl;

  rect_fl.xmin = x - radius;
  rect_fl.xmax = x + radius;
  rect_fl.ymin = y - radius;
  rect_fl.ymax = y + radius;

  /* apply region select action */
  region_select_action_keys(&ac, &rect_fl, BEZT_OK_CHANNEL_CIRCLE, selectmode, &data);

  /* send notifier that keyframe selection has changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_circle(wmOperatorType *ot)
{
  ot->name = "Circle Select";
  ot->description = "Select keyframe points using circle selection";
  ot->idname = "ACTION_OT_select_circle";

  ot->invoke = WM_gesture_circle_invoke;
  ot->modal = WM_gesture_circle_modal;
  ot->exec = action_circle_select_exec;
  ot->poll = ED_operator_action_active;
  ot->cancel = WM_gesture_circle_cancel;
  ot->get_name = ED_select_circle_get_name;

  /* flags */
  ot->flag = OPTYPE_UNDO;

  /* properties */
  WM_operator_properties_gesture_circle(ot);
  WM_operator_properties_select_operation_simple(ot);
}

/* ******************** Column Select Operator **************************** */
/* This operator works in one of four ways:
 * - 1) select all keyframes in the same frame as a selected one  (KKEY)
 * - 2) select all keyframes in the same frame as the current frame marker (CTRL-KKEY)
 * - 3) select all keyframes in the same frame as a selected markers (SHIFT-KKEY)
 * - 4) select all keyframes that occur between selected markers (ALT-KKEY)
 */

/* defines for column-select mode */
static const EnumPropertyItem prop_column_select_types[] = {
    {ACTKEYS_COLUMNSEL_KEYS, "KEYS", 0, "On Selected Keyframes", ""},
    {ACTKEYS_COLUMNSEL_CFRA, "CFRA", 0, "On Current Frame", ""},
    {ACTKEYS_COLUMNSEL_MARKERS_COLUMN, "MARKERS_COLUMN", 0, "On Selected Markers", ""},
    {ACTKEYS_COLUMNSEL_MARKERS_BETWEEN,
     "MARKERS_BETWEEN",
     0,
     "Between Min/Max Selected Markers",
     ""},
    {0, NULL, 0, NULL, NULL},
};

/* ------------------- */

/* Selects all visible keyframes between the specified markers */
/* TODO(campbell): this is almost an _exact_ duplicate of a function of the same name in
 * graph_select.c should de-duplicate. */
static void markers_selectkeys_between(bAnimContext *ac)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  KeyframeEditFunc ok_cb, select_cb;
  KeyframeEditData ked = {{NULL}};
  float min, max;

  /* get extreme markers */
  ED_markers_get_minmax(ac->markers, 1, &min, &max);
  min -= 0.5f;
  max += 0.5f;

  /* get editing funcs + data */
  ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAMERANGE);
  select_cb = ANIM_editkeyframes_select(SELECT_ADD);

  ked.f1 = min;
  ked.f2 = max;

  /* filter data */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  /* select keys in-between */
  for (ale = anim_data.first; ale; ale = ale->next) {
    switch (ale->type) {
      case ANIMTYPE_GPLAYER:
        ED_gpencil_layer_frames_select_box(ale->data, min, max, SELECT_ADD);
        ale->update |= ANIM_UPDATE_DEPS;
        break;

      case ANIMTYPE_MASKLAYER:
        ED_masklayer_frames_select_box(ale->data, min, max, SELECT_ADD);
        break;

      case ANIMTYPE_FCURVE: {
        AnimData *adt = ANIM_nla_mapping_get(ac, ale);
        if (adt) {
          ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 0, 1);
          ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
          ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 1, 1);
        }
        else {
          ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
        }
        break;
      }

      default:
        BLI_assert_msg(false, "Keys cannot be selected into this animation type.");
    }
  }

  /* Cleanup */
  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* Selects all visible keyframes in the same frames as the specified elements */
static void columnselect_action_keys(bAnimContext *ac, short mode)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  Scene *scene = ac->scene;
  CfraElem *ce;
  KeyframeEditFunc select_cb, ok_cb;
  KeyframeEditData ked = {{NULL}};

  /* build list of columns */
  switch (mode) {
    case ACTKEYS_COLUMNSEL_KEYS: /* list of selected keys */
      if (ac->datatype == ANIMCONT_GPENCIL) {
        filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE);
        ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

        for (ale = anim_data.first; ale; ale = ale->next) {
          ED_gpencil_layer_make_cfra_list(ale->data, &ked.list, 1);
        }
      }
      else {
        filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE);
        ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

        for (ale = anim_data.first; ale; ale = ale->next) {
          if (ale->datatype == ALE_GPFRAME) {
            ED_gpencil_layer_make_cfra_list(ale->data, &ked.list, 1);
          }
          else {
            ANIM_fcurve_keyframes_loop(&ked, ale->key_data, NULL, bezt_to_cfraelem, NULL);
          }
        }
      }
      ANIM_animdata_freelist(&anim_data);
      break;

    case ACTKEYS_COLUMNSEL_CFRA: /* current frame */
      /* make a single CfraElem for storing this */
      ce = MEM_callocN(sizeof(CfraElem), "cfraElem");
      BLI_addtail(&ked.list, ce);

      ce->cfra = (float)scene->r.cfra;
      break;

    case ACTKEYS_COLUMNSEL_MARKERS_COLUMN: /* list of selected markers */
      ED_markers_make_cfra_list(ac->markers, &ked.list, SELECT);
      break;

    default: /* invalid option */
      return;
  }

  /* set up BezTriple edit callbacks */
  select_cb = ANIM_editkeyframes_select(SELECT_ADD);
  ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAME);

  /* loop through all of the keys and select additional keyframes
   * based on the keys found to be selected above
   */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  for (ale = anim_data.first; ale; ale = ale->next) {
    AnimData *adt = ANIM_nla_mapping_get(ac, ale);

    /* loop over cfraelems (stored in the KeyframeEditData->list)
     * - we need to do this here, as we can apply fewer NLA-mapping conversions
     */
    for (ce = ked.list.first; ce; ce = ce->next) {
      /* set frame for validation callback to refer to */
      if (adt) {
        ked.f1 = BKE_nla_tweakedit_remap(adt, ce->cfra, NLATIME_CONVERT_UNMAP);
      }
      else {
        ked.f1 = ce->cfra;
      }

      /* select elements with frame number matching cfraelem */
      if (ale->type == ANIMTYPE_GPLAYER) {
        ED_gpencil_select_frame(ale->data, ce->cfra, SELECT_ADD);
        ale->update |= ANIM_UPDATE_DEPS;
      }
      else if (ale->type == ANIMTYPE_MASKLAYER) {
        ED_mask_select_frame(ale->data, ce->cfra, SELECT_ADD);
      }
      else {
        ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
      }
    }
  }

  /* free elements */
  BLI_freelistN(&ked.list);

  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* ------------------- */

static int actkeys_columnselect_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;
  short mode;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* action to take depends on the mode */
  mode = RNA_enum_get(op->ptr, "mode");

  if (mode == ACTKEYS_COLUMNSEL_MARKERS_BETWEEN) {
    markers_selectkeys_between(&ac);
  }
  else {
    columnselect_action_keys(&ac, mode);
  }

  /* set notifier that keyframe selection have changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_column(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Select All";
  ot->idname = "ACTION_OT_select_column";
  ot->description = "Select all keyframes on the specified frame(s)";

  /* api callbacks */
  ot->exec = actkeys_columnselect_exec;
  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

  /* props */
  ot->prop = RNA_def_enum(ot->srna, "mode", prop_column_select_types, 0, "Mode", "");
  RNA_def_property_flag(ot->prop, PROP_HIDDEN);
}

/* ******************** Select Linked Operator *********************** */

static int actkeys_select_linked_exec(bContext *C, wmOperator *UNUSED(op))
{
  bAnimContext ac;

  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  KeyframeEditFunc ok_cb = ANIM_editkeyframes_ok(BEZT_OK_SELECTED);
  KeyframeEditFunc sel_cb = ANIM_editkeyframes_select(SELECT_ADD);

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* loop through all of the keys and select additional keyframes based on these */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FCURVESONLY |
            ANIMFILTER_NODUPLIS);
  ANIM_animdata_filter(&ac, &anim_data, filter, ac.data, ac.datatype);

  for (ale = anim_data.first; ale; ale = ale->next) {
    FCurve *fcu = (FCurve *)ale->key_data;

    /* check if anything selected? */
    if (ANIM_fcurve_keyframes_loop(NULL, fcu, NULL, ok_cb, NULL)) {
      /* select every keyframe in this curve then */
      ANIM_fcurve_keyframes_loop(NULL, fcu, NULL, sel_cb, NULL);
    }
  }

  /* Cleanup */
  ANIM_animdata_freelist(&anim_data);

  /* set notifier that keyframe selection has changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_linked(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Select Linked";
  ot->idname = "ACTION_OT_select_linked";
  ot->description = "Select keyframes occurring in the same F-Curves as selected ones";

  /* api callbacks */
  ot->exec = actkeys_select_linked_exec;
  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ******************** Select More/Less Operators *********************** */

/* Common code to perform selection */
static void select_moreless_action_keys(bAnimContext *ac, short mode)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  KeyframeEditData ked = {{NULL}};
  KeyframeEditFunc build_cb;

  /* init selmap building data */
  build_cb = ANIM_editkeyframes_buildselmap(mode);

  /* loop through all of the keys and select additional keyframes based on these */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_FCURVESONLY |
            ANIMFILTER_NODUPLIS);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  for (ale = anim_data.first; ale; ale = ale->next) {

    /* TODO: other types. */
    if (ale->datatype != ALE_FCURVE) {
      continue;
    }

    /* only continue if F-Curve has keyframes */
    FCurve *fcu = (FCurve *)ale->key_data;
    if (fcu->bezt == NULL) {
      continue;
    }

    /* build up map of whether F-Curve's keyframes should be selected or not */
    ked.data = MEM_callocN(fcu->totvert, "selmap actEdit more");
    ANIM_fcurve_keyframes_loop(&ked, fcu, NULL, build_cb, NULL);

    /* based on this map, adjust the selection status of the keyframes */
    ANIM_fcurve_keyframes_loop(&ked, fcu, NULL, bezt_selmap_flush, NULL);

    /* free the selmap used here */
    MEM_freeN(ked.data);
    ked.data = NULL;
  }

  /* Cleanup */
  ANIM_animdata_freelist(&anim_data);
}

/* ----------------- */

static int actkeys_select_more_exec(bContext *C, wmOperator *UNUSED(op))
{
  bAnimContext ac;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* perform select changes */
  select_moreless_action_keys(&ac, SELMAP_MORE);

  /* set notifier that keyframe selection has changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_more(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Select More";
  ot->idname = "ACTION_OT_select_more";
  ot->description = "Select keyframes beside already selected ones";

  /* api callbacks */
  ot->exec = actkeys_select_more_exec;
  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ----------------- */

static int actkeys_select_less_exec(bContext *C, wmOperator *UNUSED(op))
{
  bAnimContext ac;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* perform select changes */
  select_moreless_action_keys(&ac, SELMAP_LESS);

  /* set notifier that keyframe selection has changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  if (ac.datatype == ANIMCONT_GPENCIL) {
    WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);
  }
  return OPERATOR_FINISHED;
}

void ACTION_OT_select_less(wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Select Less";
  ot->idname = "ACTION_OT_select_less";
  ot->description = "Deselect keyframes on ends of selection islands";

  /* api callbacks */
  ot->exec = actkeys_select_less_exec;
  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;
}

/* ******************** Select Left/Right Operator ************************* */
/* Select keyframes left/right of the current frame indicator */

/* defines for left-right select tool */
static const EnumPropertyItem prop_actkeys_leftright_select_types[] = {
    {ACTKEYS_LRSEL_TEST, "CHECK", 0, "Check if Select Left or Right", ""},
    {ACTKEYS_LRSEL_LEFT, "LEFT", 0, "Before Current Frame", ""},
    {ACTKEYS_LRSEL_RIGHT, "RIGHT", 0, "After Current Frame", ""},
    {0, NULL, 0, NULL, NULL},
};

/* --------------------------------- */

static void actkeys_select_leftright(bAnimContext *ac, short leftright, short select_mode)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  KeyframeEditFunc ok_cb, select_cb;
  KeyframeEditData ked = {{NULL}};
  Scene *scene = ac->scene;

  /* if select mode is replace, deselect all keyframes (and channels) first */
  if (select_mode == SELECT_REPLACE) {
    select_mode = SELECT_ADD;

    /* - deselect all other keyframes, so that just the newly selected remain
     * - channels aren't deselected, since we don't re-select any as a consequence
     */
    deselect_action_keys(ac, 0, SELECT_SUBTRACT);
  }

  /* set callbacks and editing data */
  ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAMERANGE);
  select_cb = ANIM_editkeyframes_select(select_mode);

  if (leftright == ACTKEYS_LRSEL_LEFT) {
    ked.f1 = MINAFRAMEF;
    ked.f2 = (float)(scene->r.cfra + 0.1f);
  }
  else {
    ked.f1 = (float)(scene->r.cfra - 0.1f);
    ked.f2 = MAXFRAMEF;
  }

  /* filter data */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  /* select keys */
  for (ale = anim_data.first; ale; ale = ale->next) {
    switch (ale->type) {
      case ANIMTYPE_GPLAYER:
        ED_gpencil_layer_frames_select_box(ale->data, ked.f1, ked.f2, select_mode);
        ale->update |= ANIM_UPDATE_DEPS;
        break;

      case ANIMTYPE_MASKLAYER:
        ED_masklayer_frames_select_box(ale->data, ked.f1, ked.f2, select_mode);
        break;

      case ANIMTYPE_FCURVE: {
        AnimData *adt = ANIM_nla_mapping_get(ac, ale);
        if (adt) {
          ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 0, 1);
          ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
          ANIM_nla_mapping_apply_fcurve(adt, ale->key_data, 1, 1);
        }
        else {
          ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
        }
        break;
      }

      default:
        BLI_assert_msg(false, "Keys cannot be selected into this animation type.");
    }
  }

  /* Sync marker support */
  if (select_mode == SELECT_ADD) {
    SpaceAction *saction = (SpaceAction *)ac->sl;

    if ((saction) && (saction->flag & SACTION_MARKERS_MOVE)) {
      ListBase *markers = ED_animcontext_get_markers(ac);
      TimeMarker *marker;

      for (marker = markers->first; marker; marker = marker->next) {
        if (((leftright == ACTKEYS_LRSEL_LEFT) && (marker->frame < scene->r.cfra)) ||
            ((leftright == ACTKEYS_LRSEL_RIGHT) && (marker->frame >= scene->r.cfra))) {
          marker->flag |= SELECT;
        }
        else {
          marker->flag &= ~SELECT;
        }
      }
    }
  }

  /* Cleanup */
  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* ----------------- */

static int actkeys_select_leftright_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;
  short leftright = RNA_enum_get(op->ptr, "mode");
  short selectmode;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* select mode is either replace (deselect all, then add) or add/extend */
  if (RNA_boolean_get(op->ptr, "extend")) {
    selectmode = SELECT_INVERT;
  }
  else {
    selectmode = SELECT_REPLACE;
  }

  /* if "test" mode is set, we don't have any info to set this with */
  if (leftright == ACTKEYS_LRSEL_TEST) {
    return OPERATOR_CANCELLED;
  }

  /* do the selecting now */
  actkeys_select_leftright(&ac, leftright, selectmode);

  /* set notifier that keyframe selection (and channels too) have changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);

  return OPERATOR_FINISHED;
}

static int actkeys_select_leftright_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
  bAnimContext ac;
  short leftright = RNA_enum_get(op->ptr, "mode");

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* handle mode-based testing */
  if (leftright == ACTKEYS_LRSEL_TEST) {
    Scene *scene = ac.scene;
    ARegion *region = ac.region;
    View2D *v2d = &region->v2d;
    float x;

    /* determine which side of the current frame mouse is on */
    x = UI_view2d_region_to_view_x(v2d, event->mval[0]);
    if (x < scene->r.cfra) {
      RNA_enum_set(op->ptr, "mode", ACTKEYS_LRSEL_LEFT);
    }
    else {
      RNA_enum_set(op->ptr, "mode", ACTKEYS_LRSEL_RIGHT);
    }
  }

  /* perform selection */
  return actkeys_select_leftright_exec(C, op);
}

void ACTION_OT_select_leftright(wmOperatorType *ot)
{
  PropertyRNA *prop;

  /* identifiers */
  ot->name = "Select Left/Right";
  ot->idname = "ACTION_OT_select_leftright";
  ot->description = "Select keyframes to the left or the right of the current frame";

  /* api callbacks */
  ot->invoke = actkeys_select_leftright_invoke;
  ot->exec = actkeys_select_leftright_exec;
  ot->poll = ED_operator_action_active;

  /* flags */
  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO;

  /* properties */
  ot->prop = RNA_def_enum(
      ot->srna, "mode", prop_actkeys_leftright_select_types, ACTKEYS_LRSEL_TEST, "Mode", "");
  RNA_def_property_flag(ot->prop, PROP_SKIP_SAVE);

  prop = RNA_def_boolean(ot->srna, "extend", 0, "Extend Select", "");
  RNA_def_property_flag(prop, PROP_SKIP_SAVE);
}

/* ******************** Mouse-Click Select Operator *********************** */
/* This operator works in one of three ways:
 * - 1) keyframe under mouse - no special modifiers
 * - 2) all keyframes on the same side of current frame indicator as mouse - ALT modifier
 * - 3) column select all keyframes in frame under mouse - CTRL modifier
 * - 4) all keyframes in channel under mouse - CTRL+ALT modifiers
 *
 * In addition to these basic options, the SHIFT modifier can be used to toggle the
 * selection mode between replacing the selection (without) and inverting the selection (with).
 */

/* ------------------- */

/* option 1) select keyframe directly under mouse */
static void actkeys_mselect_single(bAnimContext *ac,
                                   bAnimListElem *ale,
                                   short select_mode,
                                   float selx)
{
  KeyframeEditData ked = {{NULL}};
  KeyframeEditFunc select_cb, ok_cb;

  /* get functions for selecting keyframes */
  select_cb = ANIM_editkeyframes_select(select_mode);
  ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAME);
  ked.f1 = selx;
  ked.iterflags |= KED_F1_NLA_UNMAP;

  /* select the nominated keyframe on the given frame */
  if (ale->type == ANIMTYPE_GPLAYER) {
    ED_gpencil_select_frame(ale->data, selx, select_mode);
    ale->update |= ANIM_UPDATE_DEPS;
  }
  else if (ale->type == ANIMTYPE_MASKLAYER) {
    ED_mask_select_frame(ale->data, selx, select_mode);
  }
  else {
    if (ale->type == ANIMTYPE_SUMMARY && ale->datatype == ALE_ALL) {
      ListBase anim_data = {NULL, NULL};
      int filter;

      filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
      ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

      /* Loop over all keys that are represented by this summary key. */
      LISTBASE_FOREACH (bAnimListElem *, ale2, &anim_data) {
        if (ale2->type == ANIMTYPE_GPLAYER) {
          ED_gpencil_select_frame(ale2->data, selx, select_mode);
          ale2->update |= ANIM_UPDATE_DEPS;
        }
        else if (ale2->type == ANIMTYPE_MASKLAYER) {
          ED_mask_select_frame(ale2->data, selx, select_mode);
        }
      }

      ANIM_animdata_update(ac, &anim_data);
      ANIM_animdata_freelist(&anim_data);
    }

    if (!ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK)) {
      ANIM_animchannel_keyframes_loop(&ked, ac->ads, ale, ok_cb, select_cb, NULL);
    }
  }
}

/* Option 2) Selects all the keyframes on either side of the current frame
 * (depends on which side the mouse is on) */
/* (see actkeys_select_leftright) */

/* Option 3) Selects all visible keyframes in the same frame as the mouse click */
static void actkeys_mselect_column(bAnimContext *ac, short select_mode, float selx)
{
  ListBase anim_data = {NULL, NULL};
  bAnimListElem *ale;
  int filter;

  KeyframeEditFunc select_cb, ok_cb;
  KeyframeEditData ked = {{NULL}};

  /* set up BezTriple edit callbacks */
  select_cb = ANIM_editkeyframes_select(select_mode);
  ok_cb = ANIM_editkeyframes_ok(BEZT_OK_FRAME);

  /* loop through all of the keys and select additional keyframes
   * based on the keys found to be selected above
   */
  filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
  ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

  for (ale = anim_data.first; ale; ale = ale->next) {
    /* select elements with frame number matching cfra */
    if (ale->type == ANIMTYPE_GPLAYER) {
      ED_gpencil_select_frame(ale->data, selx, select_mode);
      ale->update |= ANIM_UPDATE_DEPS;
    }
    else if (ale->type == ANIMTYPE_MASKLAYER) {
      ED_mask_select_frame(ale->data, selx, select_mode);
    }
    else {
      AnimData *adt = ANIM_nla_mapping_get(ac, ale);

      /* set frame for validation callback to refer to */
      if (adt) {
        ked.f1 = BKE_nla_tweakedit_remap(adt, selx, NLATIME_CONVERT_UNMAP);
      }
      else {
        ked.f1 = selx;
      }

      ANIM_fcurve_keyframes_loop(&ked, ale->key_data, ok_cb, select_cb, NULL);
    }
  }

  /* free elements */
  BLI_freelistN(&ked.list);

  ANIM_animdata_update(ac, &anim_data);
  ANIM_animdata_freelist(&anim_data);
}

/* option 4) select all keyframes in same channel */
static void actkeys_mselect_channel_only(bAnimContext *ac, bAnimListElem *ale, short select_mode)
{
  KeyframeEditFunc select_cb;

  /* get functions for selecting keyframes */
  select_cb = ANIM_editkeyframes_select(select_mode);

  /* select all keyframes in this channel */
  if (ale->type == ANIMTYPE_GPLAYER) {
    ED_gpencil_select_frames(ale->data, select_mode);
    ale->update = ANIM_UPDATE_DEPS;
  }
  else if (ale->type == ANIMTYPE_MASKLAYER) {
    ED_mask_select_frames(ale->data, select_mode);
  }
  else {
    if (ale->type == ANIMTYPE_SUMMARY && ale->datatype == ALE_ALL) {
      ListBase anim_data = {NULL, NULL};
      int filter;

      filter = (ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_NODUPLIS);
      ANIM_animdata_filter(ac, &anim_data, filter, ac->data, ac->datatype);

      LISTBASE_FOREACH (bAnimListElem *, ale2, &anim_data) {
        if (ale2->type == ANIMTYPE_GPLAYER) {
          ED_gpencil_select_frames(ale2->data, select_mode);
          ale2->update |= ANIM_UPDATE_DEPS;
        }
        else if (ale2->type == ANIMTYPE_MASKLAYER) {
          ED_mask_select_frames(ale2->data, select_mode);
        }
      }

      ANIM_animdata_update(ac, &anim_data);
      ANIM_animdata_freelist(&anim_data);
    }

    if (!ELEM(ac->datatype, ANIMCONT_GPENCIL, ANIMCONT_MASK)) {
      ANIM_animchannel_keyframes_loop(NULL, ac->ads, ale, NULL, select_cb, NULL);
    }
  }
}

/* ------------------- */

static int mouse_action_keys(bAnimContext *ac,
                             const int mval[2],
                             short select_mode,
                             const bool deselect_all,
                             const bool column,
                             const bool same_channel,
                             bool wait_to_deselect_others)
{
  int filter = ANIMFILTER_DATA_VISIBLE | ANIMFILTER_LIST_VISIBLE | ANIMFILTER_LIST_CHANNELS;

  bAnimListElem *ale = NULL;
  bool found = false;
  bool is_selected = false;
  float frame = 0.0f; /* frame of keyframe under mouse - NLA corrections not applied/included */
  float selx = 0.0f;  /* frame of keyframe under mouse */
  int ret_value = OPERATOR_FINISHED;

  actkeys_find_key_at_position(
      ac, filter, mval[0], mval[1], &ale, &selx, &frame, &found, &is_selected);

  if (select_mode != SELECT_REPLACE) {
    wait_to_deselect_others = false;
  }

  /* For replacing selection, if we have something to select, we have to clear existing selection.
   * The same goes if we found nothing to select, and deselect_all is true
   * (deselect on nothing behavior). */
  if ((select_mode == SELECT_REPLACE && found) || (!found && deselect_all)) {
    /* reset selection mode for next steps */
    select_mode = SELECT_ADD;

    /* Rather than deselecting others, users may want to drag to box-select (drag from empty space)
     * or tweak-translate an already selected item. If these cases may apply, delay deselection. */
    if (wait_to_deselect_others && (!found || is_selected)) {
      ret_value = OPERATOR_RUNNING_MODAL;
    }
    else {
      /* deselect all keyframes */
      deselect_action_keys(ac, 0, SELECT_SUBTRACT);

      /* highlight channel clicked on */
      if (ELEM(ac->datatype, ANIMCONT_ACTION, ANIMCONT_DOPESHEET, ANIMCONT_TIMELINE)) {
        /* deselect all other channels first */
        ANIM_anim_channels_select_set(ac, ACHANNEL_SETFLAG_CLEAR);

        /* Highlight Action-Group or F-Curve? */
        if (ale != NULL && ale->data) {
          if (ale->type == ANIMTYPE_GROUP) {
            bActionGroup *agrp = ale->data;

            agrp->flag |= AGRP_SELECTED;
            ANIM_set_active_channel(ac, ac->data, ac->datatype, filter, agrp, ANIMTYPE_GROUP);
          }
          else if (ELEM(ale->type, ANIMTYPE_FCURVE, ANIMTYPE_NLACURVE)) {
            FCurve *fcu = ale->data;

            fcu->flag |= FCURVE_SELECTED;
            ANIM_set_active_channel(ac, ac->data, ac->datatype, filter, fcu, ale->type);
          }
          else if (ale->type == ANIMTYPE_GPLAYER) {
            bGPdata *gpd = (bGPdata *)ale->id;
            bGPDlayer *gpl = ale->data;

            ED_gpencil_set_active_channel(gpd, gpl);
          }
        }
      }
      else if (ac->datatype == ANIMCONT_GPENCIL) {
        /* deselect all other channels first */
        ANIM_anim_channels_select_set(ac, ACHANNEL_SETFLAG_CLEAR);

        /* Highlight GPencil Layer */
        if (ale != NULL && ale->data != NULL && ale->type == ANIMTYPE_GPLAYER) {
          bGPdata *gpd = (bGPdata *)ale->id;
          bGPDlayer *gpl = ale->data;

          ED_gpencil_set_active_channel(gpd, gpl);
        }
      }
      else if (ac->datatype == ANIMCONT_MASK) {
        /* deselect all other channels first */
        ANIM_anim_channels_select_set(ac, ACHANNEL_SETFLAG_CLEAR);

        if (ale != NULL && ale->data != NULL && ale->type == ANIMTYPE_MASKLAYER) {
          MaskLayer *masklay = ale->data;

          masklay->flag |= MASK_LAYERFLAG_SELECT;
        }
      }
    }
  }

  /* only select keyframes if we clicked on a valid channel and hit something */
  if (ale != NULL) {
    if (found) {
      /* apply selection to keyframes */
      if (column) {
        /* select all keyframes in the same frame as the one we hit on the active channel
         * [T41077]: "frame" not "selx" here (i.e. no NLA corrections yet) as the code here
         *            does that itself again as it needs to work on multiple data-blocks.
         */
        actkeys_mselect_column(ac, select_mode, frame);
      }
      else if (same_channel) {
        /* select all keyframes in the active channel */
        actkeys_mselect_channel_only(ac, ale, select_mode);
      }
      else {
        /* select the nominated keyframe on the given frame */
        actkeys_mselect_single(ac, ale, select_mode, selx);
      }
    }

    /* flush tagged updates
     * NOTE: We temporarily add this channel back to the list so that this can happen
     */
    ListBase anim_data = {ale, ale};
    ANIM_animdata_update(ac, &anim_data);

    /* free this channel */
    MEM_freeN(ale);
  }

  return ret_value;
}

/* handle clicking */
static int actkeys_clickselect_exec(bContext *C, wmOperator *op)
{
  bAnimContext ac;
  int ret_value;

  /* get editor data */
  if (ANIM_animdata_get_context(C, &ac) == 0) {
    return OPERATOR_CANCELLED;
  }

  /* get useful pointers from animation context data */
  /* region = ac.region; */ /* UNUSED */

  /* select mode is either replace (deselect all, then add) or add/extend */
  const short selectmode = RNA_boolean_get(op->ptr, "extend") ? SELECT_INVERT : SELECT_REPLACE;
  const bool deselect_all = RNA_boolean_get(op->ptr, "deselect_all");
  const bool wait_to_deselect_others = RNA_boolean_get(op->ptr, "wait_to_deselect_others");
  int mval[2];

  /* column selection */
  const bool column = RNA_boolean_get(op->ptr, "column");
  const bool channel = RNA_boolean_get(op->ptr, "channel");

  mval[0] = RNA_int_get(op->ptr, "mouse_x");
  mval[1] = RNA_int_get(op->ptr, "mouse_y");

  /* Select keyframe(s) based upon mouse position. */
  ret_value = mouse_action_keys(
      &ac, mval, selectmode, deselect_all, column, channel, wait_to_deselect_others);

  /* set notifier that keyframe selection (and channels too) have changed */
  WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_SELECTED, NULL);
  WM_event_add_notifier(C, NC_ANIMATION | ND_ANIMCHAN | NA_SELECTED, NULL);

  /* for tweak grab to work */
  return ret_value | OPERATOR_PASS_THROUGH;
}

void ACTION_OT_clickselect(wmOperatorType *ot)
{
  PropertyRNA *prop;

  /* identifiers */
  ot->name = "Select Keyframes";
  ot->idname = "ACTION_OT_clickselect";
  ot->description = "Select keyframes by clicking on them";

  /* callbacks */
  ot->poll = ED_operator_action_active;
  ot->exec = actkeys_clickselect_exec;
  ot->invoke = WM_generic_select_invoke;
  ot->modal = WM_generic_select_modal;

  /* flags */
  ot->flag = OPTYPE_UNDO;

  /* properties */
  WM_operator_properties_generic_select(ot);
  /* Key-map: Enable with `Shift`. */
  prop = RNA_def_boolean(
      ot->srna,
      "extend",
      0,
      "Extend Select",
      "Toggle keyframe selection instead of leaving newly selected keyframes only");
  RNA_def_property_flag(prop, PROP_SKIP_SAVE);

  prop = RNA_def_boolean(ot->srna,
                         "deselect_all",
                         false,
                         "Deselect On Nothing",
                         "Deselect all when nothing under the cursor");
  RNA_def_property_flag(prop, PROP_SKIP_SAVE);

  /* Key-map: Enable with `Alt`. */
  prop = RNA_def_boolean(
      ot->srna,
      "column",
      0,
      "Column Select",
      "Select all keyframes that occur on the same frame as the one under the mouse");
  RNA_def_property_flag(prop, PROP_SKIP_SAVE);

  /* Key-map: Enable with `Ctrl-Alt`. */
  prop = RNA_def_boolean(ot->srna,
                         "channel",
                         0,
                         "Only Channel",
                         "Select all the keyframes in the channel under the mouse");
  RNA_def_property_flag(prop, PROP_SKIP_SAVE);
}

/* ************************************************************************** */