/*
 * 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.
 */

/** \file
 * \ingroup spview3d
 */

#include "BLI_math.h"
#include "BLI_utildefines.h"

#include "BKE_context.h"
#include "BKE_object.h"

#include "DNA_object_types.h"

#include "ED_screen.h"
#include "ED_gizmo_library.h"

#include "UI_interface.h"
#include "UI_resources.h"

#include "MEM_guardedalloc.h"

#include "RNA_access.h"

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

#include "view3d_intern.h" /* own include */

/* -------------------------------------------------------------------- */
/** \name View3D Navigation Gizmo Group
 * \{ */

/* Offset from screen edge. */
#define GIZMO_OFFSET_FAC 1.2f
/* Size of main icon. */
#define GIZMO_SIZE 80
/* Factor for size of smaller button. */
#define GIZMO_MINI_FAC 0.35f
/* How much mini buttons offset from the primary. */
#define GIZMO_MINI_OFFSET_FAC 0.38f

enum {
  GZ_INDEX_MOVE = 0,
  GZ_INDEX_ROTATE = 1,
  GZ_INDEX_ZOOM = 2,

  /* just buttons */
  /* overlaps GZ_INDEX_ORTHO (switch between) */
  GZ_INDEX_PERSP = 3,
  GZ_INDEX_ORTHO = 4,
  GZ_INDEX_CAMERA = 5,

  GZ_INDEX_TOTAL = 6,
};

struct NavigateGizmoInfo {
  const char *opname;
  const char *gizmo;
  uint icon;
};

static struct NavigateGizmoInfo g_navigate_params[GZ_INDEX_TOTAL] = {
    {
        .opname = "VIEW3D_OT_move",
        .gizmo = "GIZMO_GT_button_2d",
        ICON_VIEW_PAN,
    },
    {
        .opname = "VIEW3D_OT_rotate",
        .gizmo = "VIEW3D_GT_navigate_rotate",
        0,
    },
    {
        .opname = "VIEW3D_OT_zoom",
        .gizmo = "GIZMO_GT_button_2d",
        ICON_VIEW_ZOOM,
    },
    {
        .opname = "VIEW3D_OT_view_persportho",
        .gizmo = "GIZMO_GT_button_2d",
        ICON_VIEW_PERSPECTIVE,
    },
    {
        .opname = "VIEW3D_OT_view_persportho",
        .gizmo = "GIZMO_GT_button_2d",
        ICON_VIEW_ORTHO,
    },
    {
        .opname = "VIEW3D_OT_view_camera",
        .gizmo = "GIZMO_GT_button_2d",
        ICON_VIEW_CAMERA,
    },
};

struct NavigateWidgetGroup {
  wmGizmo *gz_array[GZ_INDEX_TOTAL];
  /* Store the view state to check for changes. */
  struct {
    rcti rect_visible;
    struct {
      char is_persp;
      char is_camera;
      char viewlock;
    } rv3d;
  } state;
  int region_size[2];
};

static bool WIDGETGROUP_navigate_poll(const bContext *C, wmGizmoGroupType *UNUSED(gzgt))
{
  View3D *v3d = CTX_wm_view3d(C);
  if ((((U.uiflag & USER_SHOW_GIZMO_NAVIGATE) == 0) &&
       (U.mini_axis_type != USER_MINI_AXIS_TYPE_GIZMO)) ||
      (v3d->gizmo_flag & (V3D_GIZMO_HIDE | V3D_GIZMO_HIDE_NAVIGATE))) {
    return false;
  }
  return true;
}

static void WIDGETGROUP_navigate_setup(const bContext *C, wmGizmoGroup *gzgroup)
{
  struct NavigateWidgetGroup *navgroup = MEM_callocN(sizeof(struct NavigateWidgetGroup), __func__);

  navgroup->region_size[0] = -1;
  navgroup->region_size[1] = -1;

  wmOperatorType *ot_view_axis = WM_operatortype_find("VIEW3D_OT_view_axis", true);
  wmOperatorType *ot_view_camera = WM_operatortype_find("VIEW3D_OT_view_camera", true);

  for (int i = 0; i < GZ_INDEX_TOTAL; i++) {
    const struct NavigateGizmoInfo *info = &g_navigate_params[i];
    navgroup->gz_array[i] = WM_gizmo_new(info->gizmo, gzgroup, NULL);
    wmGizmo *gz = navgroup->gz_array[i];
    gz->flag |= WM_GIZMO_MOVE_CURSOR | WM_GIZMO_DRAW_MODAL;

    if (i == GZ_INDEX_ROTATE) {
      gz->color[3] = 0.0f;
      copy_v3_fl(gz->color_hi, 0.5f);
      gz->color_hi[3] = 0.5f;
    }
    else {
      uchar icon_color[3];
      UI_GetThemeColor3ubv(TH_TEXT, icon_color);
      int color_tint, color_tint_hi;
      if (icon_color[0] > 128) {
        color_tint = -40;
        color_tint_hi = 60;
        gz->color[3] = 0.5f;
        gz->color_hi[3] = 0.5f;
      }
      else {
        color_tint = 60;
        color_tint_hi = 60;
        gz->color[3] = 0.5f;
        gz->color_hi[3] = 0.75f;
      }
      UI_GetThemeColorShade3fv(TH_HEADER, color_tint, gz->color);
      UI_GetThemeColorShade3fv(TH_HEADER, color_tint_hi, gz->color_hi);
    }

    /* may be overwritten later */
    gz->scale_basis = (GIZMO_SIZE * GIZMO_MINI_FAC) / 2;
    if (info->icon != 0) {
      PropertyRNA *prop = RNA_struct_find_property(gz->ptr, "icon");
      RNA_property_enum_set(gz->ptr, prop, info->icon);
      RNA_enum_set(
          gz->ptr, "draw_options", ED_GIZMO_BUTTON_SHOW_OUTLINE | ED_GIZMO_BUTTON_SHOW_BACKDROP);
    }

    wmOperatorType *ot = WM_operatortype_find(info->opname, true);
    WM_gizmo_operator_set(gz, 0, ot, NULL);
  }

  {
    wmGizmo *gz = navgroup->gz_array[GZ_INDEX_CAMERA];
    WM_gizmo_operator_set(gz, 0, ot_view_camera, NULL);
  }

  /* Click only buttons (not modal). */
  {
    int gz_ids[] = {GZ_INDEX_PERSP, GZ_INDEX_ORTHO, GZ_INDEX_CAMERA};
    for (int i = 0; i < ARRAY_SIZE(gz_ids); i++) {
      wmGizmo *gz = navgroup->gz_array[gz_ids[i]];
      RNA_boolean_set(gz->ptr, "show_drag", false);
    }
  }

  /* Modal operators, don't use initial mouse location since we're clicking on a button. */
  {
    int gz_ids[] = {GZ_INDEX_MOVE, GZ_INDEX_ROTATE, GZ_INDEX_ZOOM};
    for (int i = 0; i < ARRAY_SIZE(gz_ids); i++) {
      wmGizmo *gz = navgroup->gz_array[gz_ids[i]];
      wmGizmoOpElem *gzop = WM_gizmo_operator_get(gz, 0);
      RNA_boolean_set(&gzop->ptr, "use_cursor_init", false);
    }
  }

  {
    wmGizmo *gz = navgroup->gz_array[GZ_INDEX_ROTATE];
    gz->scale_basis = GIZMO_SIZE / 2;
    char mapping[6] = {
        RV3D_VIEW_LEFT,
        RV3D_VIEW_RIGHT,
        RV3D_VIEW_FRONT,
        RV3D_VIEW_BACK,
        RV3D_VIEW_BOTTOM,
        RV3D_VIEW_TOP,
    };

    for (int part_index = 0; part_index < 6; part_index += 1) {
      PointerRNA *ptr = WM_gizmo_operator_set(gz, part_index + 1, ot_view_axis, NULL);
      RNA_enum_set(ptr, "type", mapping[part_index]);
    }

    /* When dragging an axis, use this instead. */
    wmWindowManager *wm = CTX_wm_manager(C);
    gz->keymap = WM_gizmo_keymap_generic_click_drag(wm);
    gz->drag_part = 0;
  }

  gzgroup->customdata = navgroup;
}

static void WIDGETGROUP_navigate_draw_prepare(const bContext *C, wmGizmoGroup *gzgroup)
{
  struct NavigateWidgetGroup *navgroup = gzgroup->customdata;
  ARegion *ar = CTX_wm_region(C);
  const RegionView3D *rv3d = ar->regiondata;

  for (int i = 0; i < 3; i++) {
    copy_v3_v3(navgroup->gz_array[GZ_INDEX_ROTATE]->matrix_offset[i], rv3d->viewmat[i]);
  }

  rcti rect_visible;
  ED_region_visible_rect(ar, &rect_visible);

  if ((navgroup->state.rect_visible.xmax == rect_visible.xmax) &&
      (navgroup->state.rect_visible.ymax == rect_visible.ymax) &&
      (navgroup->state.rv3d.is_persp == rv3d->is_persp) &&
      (navgroup->state.rv3d.is_camera == (rv3d->persp == RV3D_CAMOB)) &&
      (navgroup->state.rv3d.viewlock == rv3d->viewlock)) {
    return;
  }

  navgroup->state.rect_visible = rect_visible;
  navgroup->state.rv3d.is_persp = rv3d->is_persp;
  navgroup->state.rv3d.is_camera = (rv3d->persp == RV3D_CAMOB);
  navgroup->state.rv3d.viewlock = rv3d->viewlock;

  const bool show_navigate = (U.uiflag & USER_SHOW_GIZMO_NAVIGATE) != 0;
  const bool show_rotate_gizmo = (U.mini_axis_type == USER_MINI_AXIS_TYPE_GIZMO);
  const float icon_size = GIZMO_SIZE;
  const float icon_offset = (icon_size * 0.52f) * GIZMO_OFFSET_FAC * UI_DPI_FAC;
  const float icon_offset_mini = icon_size * GIZMO_MINI_OFFSET_FAC * UI_DPI_FAC;
  const float co_rotate[2] = {
      rect_visible.xmax - icon_offset,
      rect_visible.ymax - icon_offset,
  };

  float icon_offset_from_axis = 0.0f;
  switch ((eUserpref_MiniAxisType)U.mini_axis_type) {
    case USER_MINI_AXIS_TYPE_GIZMO:
      icon_offset_from_axis = icon_offset * 2.0f;
      break;
    case USER_MINI_AXIS_TYPE_MINIMAL:
      icon_offset_from_axis = (UI_UNIT_X * 2.5) + ((U.rvisize * U.pixelsize * 2.0f));
      break;
    case USER_MINI_AXIS_TYPE_NONE:
      icon_offset_from_axis = icon_offset_mini * 0.75f;
      break;
  }

  const float co[2] = {
      rect_visible.xmax - icon_offset_from_axis,
      rect_visible.ymax - icon_offset_mini * 0.75f,
  };

  wmGizmo *gz;

  for (uint i = 0; i < ARRAY_SIZE(navgroup->gz_array); i++) {
    gz = navgroup->gz_array[i];
    WM_gizmo_set_flag(gz, WM_GIZMO_HIDDEN, true);
  }

  /* RV3D_LOCKED or Camera: only show supported buttons. */
  if (show_rotate_gizmo) {
    gz = navgroup->gz_array[GZ_INDEX_ROTATE];
    gz->matrix_basis[3][0] = co_rotate[0];
    gz->matrix_basis[3][1] = co_rotate[1];
    WM_gizmo_set_flag(gz, WM_GIZMO_HIDDEN, false);
  }

  if (show_navigate) {
    int icon_mini_slot = 0;
    gz = navgroup->gz_array[GZ_INDEX_ZOOM];
    gz->matrix_basis[3][0] = co[0] - (icon_offset_mini * icon_mini_slot++);
    gz->matrix_basis[3][1] = co[1];
    WM_gizmo_set_flag(gz, WM_GIZMO_HIDDEN, false);

    gz = navgroup->gz_array[GZ_INDEX_MOVE];
    gz->matrix_basis[3][0] = co[0] - (icon_offset_mini * icon_mini_slot++);
    gz->matrix_basis[3][1] = co[1];
    WM_gizmo_set_flag(gz, WM_GIZMO_HIDDEN, false);

    if ((rv3d->viewlock & RV3D_LOCKED) == 0) {
      gz = navgroup->gz_array[GZ_INDEX_CAMERA];
      gz->matrix_basis[3][0] = co[0] - (icon_offset_mini * icon_mini_slot++);
      gz->matrix_basis[3][1] = co[1];
      WM_gizmo_set_flag(gz, WM_GIZMO_HIDDEN, false);

      if (navgroup->state.rv3d.is_camera == false) {
        gz = navgroup->gz_array[rv3d->is_persp ? GZ_INDEX_PERSP : GZ_INDEX_ORTHO];
        gz->matrix_basis[3][0] = co[0] - (icon_offset_mini * icon_mini_slot++);
        gz->matrix_basis[3][1] = co[1];
        WM_gizmo_set_flag(gz, WM_GIZMO_HIDDEN, false);
      }
    }
  }
}

void VIEW3D_GGT_navigate(wmGizmoGroupType *gzgt)
{
  gzgt->name = "View3D Navigate";
  gzgt->idname = "VIEW3D_GGT_navigate";

  gzgt->flag |= (WM_GIZMOGROUPTYPE_PERSISTENT | WM_GIZMOGROUPTYPE_SCALE |
                 WM_GIZMOGROUPTYPE_DRAW_MODAL_ALL);

  gzgt->poll = WIDGETGROUP_navigate_poll;
  gzgt->setup = WIDGETGROUP_navigate_setup;
  gzgt->draw_prepare = WIDGETGROUP_navigate_draw_prepare;
}

/** \} */