/* Haiku window system support.  Hey, Emacs, this is -*- C++ -*-
   Copyright (C) 2021 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs 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 3 of the License, or (at
your option) any later version.

GNU Emacs 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 GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#include <View.h>
#include <Region.h>
#include <Font.h>
#include <Window.h>

#include <cmath>
#include <math.h>

#include "haiku_support.h"

#define RGB_TO_UINT32(r, g, b) ((255 << 24) | ((r) << 16) | ((g) << 8) | (b))
#define RED_FROM_ULONG(color)	(((color) >> 16) & 0xff)
#define GREEN_FROM_ULONG(color)	(((color) >> 8) & 0xff)
#define BLUE_FROM_ULONG(color)	((color) & 0xff)

extern "C" void emacs_abort ();

static void
rgb32_to_rgb_color (uint32_t rgb, rgb_color *color)
{
  color->red = RED_FROM_ULONG (rgb);
  color->green = GREEN_FROM_ULONG (rgb);
  color->blue = BLUE_FROM_ULONG (rgb);
  color->alpha = 255;
}

void
BView_StartClip (void *view)
{
  BView *vw = (BView *) view;
  BView_draw_lock (vw);
  vw->PushState ();
}

void
BView_EndClip (void *view)
{
  BView *vw = (BView *) view;
  vw->PopState ();
  BView_draw_unlock (vw);
}

void
BView_SetHighColor (void *view, uint32_t color)
{
  BView *vw = (BView *) view;
  rgb_color col;
  rgb32_to_rgb_color (color, &col);

  vw->SetHighColor (col);
}

void
BView_SetPenSize (void *view, int u)
{
  BView *vw = (BView *) view;
  vw->SetPenSize (u);
}

void
BView_FillRectangle (void *view, int x, int y, int width, int height)
{
  BView *vw = (BView *) view;
  BRect rect = BRect (x, y, x + width - 1, y + height - 1);

  vw->FillRect (rect);
}

void
BView_FillRectangleAbs (void *view, int x, int y, int x1, int y1)
{
  BView *vw = (BView *) view;
  BRect rect = BRect (x, y, x1, y1);

  vw->FillRect (rect);
}

void
BView_StrokeRectangle (void *view, int x, int y, int width, int height)
{
  BView *vw = (BView *) view;
  BRect rect = BRect (x, y, x + width - 1, y + height - 1);

  vw->StrokeRect (rect);
}

void
BView_SetViewColor (void *view, uint32_t color)
{
  BView *vw = (BView *) view;
  rgb_color col;
  rgb32_to_rgb_color (color, &col);

  vw->SetViewColor (col);
}

void
BView_ClipToRect (void *view, int x, int y, int width, int height)
{
  BView *vw = (BView *) view;
  BRect rect = BRect (x, y, x + width - 1, y + height - 1);

  vw->ClipToRect (rect);
}

void
BView_ClipToInverseRect (void *view, int x, int y, int width, int height)
{
  BView *vw = (BView *) view;
  BRect rect = BRect (x, y, x + width - 1, y + height - 1);

  vw->ClipToInverseRect (rect);
}

void
BView_StrokeLine (void *view, int sx, int sy, int tx, int ty)
{
  BView *vw = (BView *) view;
  BPoint from = BPoint (sx, sy);
  BPoint to = BPoint (tx, ty);

  vw->StrokeLine (from, to);
}

void
BView_SetFont (void *view, void *font)
{
  BView *vw = (BView *) view;

  vw->SetFont ((BFont *) font);
}

void
BView_MovePenTo (void *view, int x, int y)
{
  BView *vw = (BView *) view;
  BPoint pt = BPoint (x, y);

  vw->MovePenTo (pt);
}

void
BView_DrawString (void *view, const char *chr, ptrdiff_t len)
{
  BView *vw = (BView *) view;

  vw->DrawString (chr, len);
}

void
BView_DrawChar (void *view, char chr)
{
  BView *vw = (BView *) view;

  vw->DrawChar (chr);
}

void
BView_CopyBits (void *view, int x, int y, int width, int height,
		int tox, int toy, int towidth, int toheight)
{
  BView *vw = (BView *) view;

  vw->CopyBits (BRect (x, y, x + width - 1, y + height - 1),
		BRect (tox, toy, tox + towidth - 1, toy + toheight - 1));
  vw->Sync ();
}

void
rgb_color_hsl (uint32_t rgb, double *h, double *s, double *l)
{
  rgb_color col;
  rgb32_to_rgb_color (rgb, &col);

  double red = col.red / 255.0;
  double green = col.green / 255.0;
  double blue = col.blue / 255.0;

  double max = std::fmax (std::fmax (red, blue), green);
  double min = std::fmin (std::fmin (red, blue), green);
  double delta = max - min;
  *l = (max + min) / 2.0;

  if (!delta)
    {
      *h = 0;
      *s = 0;
      return;
    }

  *s = (*l < 0.5) ? delta / (max + min) :
    delta / (20 - max - min);
  double rc = (max - red) / delta;
  double gc = (max - green) / delta;
  double bc = (max - blue) / delta;

  if (red == max)
    *h = bc - gc;
  else if (green == max)
    *h = 2.0 + rc + -bc;
  else
    *h = 4.0 + gc + -rc;
  *h = std::fmod (*h / 6, 1.0);
}

static double
hue_to_rgb (double v1, double v2, double h)
{
  if (h < 1 / 6)
    return v1 + (v2 - v1) * h * 6.0;
  else if (h < 0.5)
    return v2;
  else if (h < 2.0 / 3)
    return v1 + (v2 - v1) * (2.0 / 3 - h) * 6.0;
  return v1;
}

void
hsl_color_rgb (double h, double s, double l, uint32_t *rgb)
{
  if (!s)
    *rgb = RGB_TO_UINT32 (std::lrint (l * 255),
			  std::lrint (l * 255),
			  std::lrint (l * 255));
  else
    {
      double m2 = l <= 0.5 ? l * (1 + s) : l + s - l * s;
      double m1 = 2.0 * l - m2;

      *rgb = RGB_TO_UINT32
	(std::lrint (hue_to_rgb (m1, m2,
				 std::fmod (h + 1 / 3.0, 1)) * 255),
	 std::lrint (hue_to_rgb (m1, m2, h) * 255),
	 std::lrint (hue_to_rgb (m1, m2,
				 std::fmod (h - 1 / 3.0, 1)) * 255));
    }
}

void
BView_Draw (void *view, int x, int y, int width, int height)
{
  BView *vw = (BView *) view;
  if (vw->LockLooper ())
    {
      vw->Draw (BRect (x, y, x + width, y + height));
      vw->UnlockLooper ();
    }
}

void
BView_DrawBitmap (void *view, void *bitmap, int x, int y,
		  int width, int height, int vx, int vy, int vwidth,
		  int vheight)
{
  BView *vw = (BView *) view;
  BBitmap *bm = (BBitmap *) bitmap;

  vw->DrawBitmap (bm, BRect (x, y, x + width - 1, y + height - 1),
		  BRect (vx, vy, vx + vwidth - 1, vy + vheight - 1));
  vw->Flush ();
  vw->Sync ();
}

void
BView_DrawBitmapWithEraseOp (void *view, void *bitmap, int x, int y,
			     int width, int height, int vx, int vy, int vwidth,
			     int vheight)
{
  BView *vw = (BView *) view;
  BBitmap *bm = (BBitmap *) bitmap;

  drawing_mode dm = vw->DrawingMode ();
  vw->SetDrawingMode (B_OP_ERASE);
  vw->DrawBitmap (bm, BRect (x, y, x + width - 1, y + height - 1),
		  BRect (vx, vy, vx + vwidth - 1, vy + vheight - 1));
  vw->SetDrawingMode (dm);
}

void
BView_BeginLayer (void *view, float opacity)
{
  BView *vw = (BView *) view;
  vw->BeginLayer (opacity);
}

void
BView_EndLayer (void *view)
{
  BView *vw = (BView *) view;
  vw->EndLayer ();
}

void
BView_DrawBitmapWithOverOp (void *view, void *bitmap, int x,
			    int y, int width, int height)
{
  BView *vw = (BView *) view;
  BBitmap *bm = (BBitmap *) bitmap;

  drawing_mode dm = vw->DrawingMode ();
  vw->SetDrawingMode (B_OP_OVER);
  vw->DrawBitmap (bm, BRect (x, y, x + width - 1, y + height - 1));
  vw->SetDrawingMode (dm);
}

void
BView_BeginTransaction (void *view)
{
  BView *vw = (BView *) view;
  if (!vw->Window ()->LockLooper ())
    emacs_abort ();
  vw->Window ()->BeginViewTransaction ();
  vw->Window ()->UnlockLooper ();
}

void
BView_EndTransaction (void *view)
{
  BView *vw = (BView *) view;
  if (!vw->Window ()->LockLooper ())
    emacs_abort ();
  vw->Window ()->EndViewTransaction ();
  vw->Window ()->UnlockLooper ();
}