/*
 * 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) 2008 Blender Foundation.
 * All rights reserved.
 */

/** \file
 * \ingroup edrend
 */

#include <string.h>
#include <stddef.h>

#include "BLI_utildefines.h"

#include "DNA_scene_types.h"
#include "DNA_userdef_types.h"

#include "BKE_context.h"
#include "BKE_image.h"
#include "BKE_global.h"
#include "BKE_main.h"
#include "BKE_screen.h"
#include "BKE_report.h"

#include "BLT_translation.h"

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

#include "ED_screen.h"
#include "UI_interface.h"

#include "wm_window.h"

#include "render_intern.h"

/*********************** utilities for finding areas *************************/

/* returns biggest area that is not uv/image editor. Note that it uses buttons */
/* window as the last possible alternative.                                    */
/* would use BKE_screen_find_big_area(...) but this is too specific            */
static ScrArea *biggest_non_image_area(bContext *C)
{
  bScreen *sc = CTX_wm_screen(C);
  ScrArea *sa, *big = NULL;
  int size, maxsize = 0, bwmaxsize = 0;
  short foundwin = 0;

  for (sa = sc->areabase.first; sa; sa = sa->next) {
    if (sa->winx > 30 && sa->winy > 30) {
      size = sa->winx * sa->winy;
      if (!sa->full && sa->spacetype == SPACE_PROPERTIES) {
        if (foundwin == 0 && size > bwmaxsize) {
          bwmaxsize = size;
          big = sa;
        }
      }
      else if (sa->spacetype != SPACE_IMAGE && size > maxsize) {
        maxsize = size;
        big = sa;
        foundwin = 1;
      }
    }
  }

  return big;
}

static ScrArea *find_area_showing_r_result(bContext *C, Scene *scene, wmWindow **win)
{
  wmWindowManager *wm = CTX_wm_manager(C);
  ScrArea *sa = NULL;
  SpaceImage *sima;

  /* find an imagewindow showing render result */
  for (*win = wm->windows.first; *win; *win = (*win)->next) {
    if (WM_window_get_active_scene(*win) == scene) {
      const bScreen *screen = WM_window_get_active_screen(*win);

      for (sa = screen->areabase.first; sa; sa = sa->next) {
        if (sa->spacetype == SPACE_IMAGE) {
          sima = sa->spacedata.first;
          if (sima->image && sima->image->type == IMA_TYPE_R_RESULT) {
            break;
          }
        }
      }
      if (sa) {
        break;
      }
    }
  }

  return sa;
}

static ScrArea *find_area_image_empty(bContext *C)
{
  bScreen *sc = CTX_wm_screen(C);
  ScrArea *sa;
  SpaceImage *sima;

  /* find an imagewindow showing render result */
  for (sa = sc->areabase.first; sa; sa = sa->next) {
    if (sa->spacetype == SPACE_IMAGE) {
      sima = sa->spacedata.first;
      if (!sima->image) {
        break;
      }
    }
  }

  return sa;
}

/********************** open image editor for render *************************/

/* new window uses x,y to set position */
ScrArea *render_view_open(bContext *C, int mx, int my, ReportList *reports)
{
  Main *bmain = CTX_data_main(C);
  Scene *scene = CTX_data_scene(C);
  wmWindow *win = NULL;
  ScrArea *sa = NULL;
  SpaceImage *sima;
  bool area_was_image = false;

  if (U.render_display_type == USER_RENDER_DISPLAY_NONE) {
    return NULL;
  }

  if (U.render_display_type == USER_RENDER_DISPLAY_WINDOW) {
    int sizex = 30 * UI_DPI_FAC + (scene->r.xsch * scene->r.size) / 100;
    int sizey = 60 * UI_DPI_FAC + (scene->r.ysch * scene->r.size) / 100;

    /* arbitrary... miniature image window views don't make much sense */
    if (sizex < 320) {
      sizex = 320;
    }
    if (sizey < 256) {
      sizey = 256;
    }

    /* changes context! */
    if (WM_window_open_temp(
            C, IFACE_("Blender Render"), mx, my, sizex, sizey, SPACE_IMAGE, false) == NULL) {
      BKE_report(reports, RPT_ERROR, "Failed to open window!");
      return NULL;
    }

    sa = CTX_wm_area(C);
  }
  else if (U.render_display_type == USER_RENDER_DISPLAY_SCREEN) {
    sa = CTX_wm_area(C);

    /* if the active screen is already in fullscreen mode, skip this and
     * unset the area, so that the fullscreen area is just changed later */
    if (sa && sa->full) {
      sa = NULL;
    }
    else {
      if (sa && sa->spacetype == SPACE_IMAGE) {
        area_was_image = true;
      }

      /* this function returns with changed context */
      sa = ED_screen_full_newspace(C, sa, SPACE_IMAGE);
    }
  }

  if (!sa) {
    sa = find_area_showing_r_result(C, scene, &win);
    if (sa == NULL) {
      sa = find_area_image_empty(C);
    }

    /* if area found in other window, we make that one show in front */
    if (win && win != CTX_wm_window(C)) {
      wm_window_raise(win);
    }

    if (sa == NULL) {
      /* find largest open non-image area */
      sa = biggest_non_image_area(C);
      if (sa) {
        ED_area_newspace(C, sa, SPACE_IMAGE, true);
        sima = sa->spacedata.first;

        /* makes ESC go back to prev space */
        sima->flag |= SI_PREVSPACE;

        /* we already had a fullscreen here -> mark new space as a stacked fullscreen */
        if (sa->full) {
          sa->flag |= (AREA_FLAG_STACKED_FULLSCREEN | AREA_FLAG_TEMP_TYPE);
        }
      }
      else {
        /* use any area of decent size */
        sa = BKE_screen_find_big_area(CTX_wm_screen(C), SPACE_TYPE_ANY, 0);
        if (sa->spacetype != SPACE_IMAGE) {
          // XXX newspace(sa, SPACE_IMAGE);
          sima = sa->spacedata.first;

          /* makes ESC go back to prev space */
          sima->flag |= SI_PREVSPACE;
        }
      }
    }
  }
  sima = sa->spacedata.first;

  /* get the correct image, and scale it */
  sima->image = BKE_image_verify_viewer(bmain, IMA_TYPE_R_RESULT, "Render Result");

  /* If we're rendering to full screen, set appropriate hints on image editor
   * so it can restore properly on pressing escape. */
  if (sa->full) {
    sima->flag |= SI_FULLWINDOW;

    /* Tell the image editor to revert to previous space in space list on close
     * _only_ if it wasn't already an image editor when the render was invoked */
    if (area_was_image == 0) {
      sima->flag |= SI_PREVSPACE;
    }
    else {
      /* Leave it alone so the image editor will just go back from
       * full screen to the original tiled setup */
    }
  }

  return sa;
}

/*************************** cancel render viewer **********************/

static int render_view_cancel_exec(bContext *C, wmOperator *UNUSED(op))
{
  wmWindow *win = CTX_wm_window(C);
  ScrArea *sa = CTX_wm_area(C);
  SpaceImage *sima = sa->spacedata.first;

  /* ensure image editor fullscreen and area fullscreen states are in sync */
  if ((sima->flag & SI_FULLWINDOW) && !sa->full) {
    sima->flag &= ~SI_FULLWINDOW;
  }

  /* test if we have a temp screen in front */
  if (WM_window_is_temp_screen(win)) {
    wm_window_lower(win);
    return OPERATOR_FINISHED;
  }
  /* determine if render already shows */
  else if (sima->flag & SI_PREVSPACE) {
    sima->flag &= ~SI_PREVSPACE;

    if (sima->flag & SI_FULLWINDOW) {
      sima->flag &= ~SI_FULLWINDOW;
      ED_screen_full_prevspace(C, sa);
    }
    else {
      ED_area_prevspace(C, sa);
    }

    return OPERATOR_FINISHED;
  }
  else if (sima->flag & SI_FULLWINDOW) {
    sima->flag &= ~SI_FULLWINDOW;
    ED_screen_state_toggle(C, win, sa, SCREENMAXIMIZED);
    return OPERATOR_FINISHED;
  }

  return OPERATOR_PASS_THROUGH;
}

void RENDER_OT_view_cancel(struct wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Cancel Render View";
  ot->description = "Cancel show render view";
  ot->idname = "RENDER_OT_view_cancel";

  /* api callbacks */
  ot->exec = render_view_cancel_exec;
  ot->poll = ED_operator_image_active;
}

/************************* show render viewer *****************/

static int render_view_show_invoke(bContext *C, wmOperator *op, const wmEvent *event)
{
  wmWindow *wincur = CTX_wm_window(C);

  /* test if we have currently a temp screen active */
  if (WM_window_is_temp_screen(wincur)) {
    wm_window_lower(wincur);
  }
  else {
    wmWindow *win, *winshow;
    ScrArea *sa = find_area_showing_r_result(C, CTX_data_scene(C), &winshow);

    /* is there another window on current scene showing result? */
    for (win = CTX_wm_manager(C)->windows.first; win; win = win->next) {
      const bScreen *sc = WM_window_get_active_screen(win);

      if ((WM_window_is_temp_screen(win) &&
           ((ScrArea *)sc->areabase.first)->spacetype == SPACE_IMAGE) ||
          (win == winshow && winshow != wincur)) {
        wm_window_raise(win);
        return OPERATOR_FINISHED;
      }
    }

    /* determine if render already shows */
    if (sa) {
      /* but don't close it when rendering */
      if (G.is_rendering == false) {
        SpaceImage *sima = sa->spacedata.first;

        if (sima->flag & SI_PREVSPACE) {
          sima->flag &= ~SI_PREVSPACE;

          if (sima->flag & SI_FULLWINDOW) {
            sima->flag &= ~SI_FULLWINDOW;
            ED_screen_full_prevspace(C, sa);
          }
          else {
            ED_area_prevspace(C, sa);
          }
        }
      }
    }
    else {
      render_view_open(C, event->x, event->y, op->reports);
    }
  }

  return OPERATOR_FINISHED;
}

void RENDER_OT_view_show(struct wmOperatorType *ot)
{
  /* identifiers */
  ot->name = "Show/Hide Render View";
  ot->description = "Toggle show render view";
  ot->idname = "RENDER_OT_view_show";

  /* api callbacks */
  ot->invoke = render_view_show_invoke;
  ot->poll = ED_operator_screenactive;
}