/*
  Copyright 2012-2019 David Robillard <http://drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/**
   @file win_cairo.c Cairo graphics backend for Windows.
*/

#include "pugl/detail/types.h"
#include "pugl/detail/win.h"
#include "pugl/pugl_cairo_backend.h"

#include <cairo-win32.h>
#include <cairo.h>

#include <stdlib.h>

typedef struct  {
	cairo_surface_t* surface;
	cairo_t*         cr;
	HDC              drawDc;
	HBITMAP          drawBitmap;
} PuglWinCairoSurface;

static int
puglWinCairoCreateDrawContext(PuglView* view)
{
	PuglInternals* const       impl    = view->impl;
	PuglWinCairoSurface* const surface = (PuglWinCairoSurface*)impl->surface;

	surface->drawDc     = CreateCompatibleDC(impl->hdc);
	surface->drawBitmap = CreateCompatibleBitmap(
		impl->hdc, (int)view->frame.width, (int)view->frame.height);

	DeleteObject(SelectObject(surface->drawDc, surface->drawBitmap));

	cairo_status_t st = CAIRO_STATUS_SUCCESS;
	if (!(surface->surface = cairo_win32_surface_create(surface->drawDc)) ||
	    (st = cairo_surface_status(surface->surface)) ||
	    !(surface->cr = cairo_create(surface->surface)) ||
	    (st = cairo_status(surface->cr))) {
		return PUGL_ERR_CREATE_CONTEXT;
	}

	cairo_save(surface->cr);
	return 0;
}

static int
puglWinCairoDestroyDrawContext(PuglView* view)
{
	PuglInternals* const       impl    = view->impl;
	PuglWinCairoSurface* const surface = (PuglWinCairoSurface*)impl->surface;

	DeleteDC(surface->drawDc);
	DeleteObject(surface->drawBitmap);
	cairo_destroy(surface->cr);
	cairo_surface_destroy(surface->surface);

	surface->surface    = NULL;
	surface->cr         = NULL;
	surface->drawDc     = NULL;
	surface->drawBitmap = NULL;

	return 0;
}

static int
puglWinCairoConfigure(PuglView* view)
{
	PuglInternals* const impl = view->impl;
	PuglStatus           st   = PUGL_SUCCESS;

	if ((st = puglWinCreateWindow(view, "Pugl", &impl->hwnd, &impl->hdc))) {
		return st;
	}

	impl->pfd  = puglWinGetPixelFormatDescriptor(view->hints);
	impl->pfId = ChoosePixelFormat(impl->hdc, &impl->pfd);

	if (!SetPixelFormat(impl->hdc, impl->pfId, &impl->pfd)) {
		ReleaseDC(impl->hwnd, impl->hdc);
		DestroyWindow(impl->hwnd);
		impl->hwnd = NULL;
		impl->hdc  = NULL;
		return PUGL_ERR_SET_FORMAT;
	}

	impl->surface = (PuglWinCairoSurface*)calloc(
		1, sizeof(PuglWinCairoSurface));

	return 0;
}

static int
puglWinCairoCreate(PuglView* view)
{
	return puglWinCairoCreateDrawContext(view);
}

static int
puglWinCairoDestroy(PuglView* view)
{
	PuglInternals* const       impl    = view->impl;
	PuglWinCairoSurface* const surface = (PuglWinCairoSurface*)impl->surface;

	puglWinCairoDestroyDrawContext(view);
	free(surface);
	impl->surface = NULL;

	return 0;
}

static int
puglWinCairoEnter(PuglView* view, bool drawing)
{
	PuglInternals* const       impl    = view->impl;
	PuglWinCairoSurface* const surface = (PuglWinCairoSurface*)impl->surface;
	if (!drawing) {
		return 0;
	}

	PAINTSTRUCT ps;
	BeginPaint(view->impl->hwnd, &ps);
	cairo_save(surface->cr);

	return 0;
}

static int
puglWinCairoLeave(PuglView* view, bool drawing)
{
	PuglInternals* const       impl    = view->impl;
	PuglWinCairoSurface* const surface = (PuglWinCairoSurface*)impl->surface;
	if (!drawing) {
		return 0;
	}

	cairo_restore(surface->cr);
	cairo_surface_flush(surface->surface);
	BitBlt(impl->hdc,
	       0, 0, (int)view->frame.width, (int)view->frame.height,
	       surface->drawDc, 0, 0, SRCCOPY);

	PAINTSTRUCT ps;
	EndPaint(view->impl->hwnd, &ps);
	SwapBuffers(view->impl->hdc);

	return 0;
}

static int
puglWinCairoResize(PuglView* view,
                   int       PUGL_UNUSED(width),
                   int       PUGL_UNUSED(height))
{
	int st = 0;
	if ((st = puglWinCairoDestroyDrawContext(view)) ||
	    (st = puglWinCairoCreateDrawContext(view))) {
		return st;
	}

	return 0;
}

static void*
puglWinCairoGetContext(PuglView* view)
{
	return ((PuglWinCairoSurface*)view->impl->surface)->cr;
}

const PuglBackend*
puglCairoBackend()
{
	static const PuglBackend backend = {
		puglWinCairoConfigure,
		puglWinCairoCreate,
		puglWinCairoDestroy,
		puglWinCairoEnter,
		puglWinCairoLeave,
		puglWinCairoResize,
		puglWinCairoGetContext
	};

	return &backend;
}