/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * Contributor(s): Blender Foundation
 *
 * ***** END GPL LICENSE BLOCK *****
 * Making screendumps.
 */

/** \file blender/editors/screen/screendump.c
 *  \ingroup edscr
 */


#include <string.h>
#include <errno.h>

#include "MEM_guardedalloc.h"

#include "BLI_blenlib.h"
#include "BLI_utildefines.h"

#include "IMB_imbuf_types.h"
#include "IMB_imbuf.h"

#include "DNA_scene_types.h"
#include "DNA_screen_types.h"
#include "DNA_space_types.h"

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

#include "BIF_gl.h"

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

#include "UI_interface.h"

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

#include "screen_intern.h"

typedef struct ScreenshotData {
	unsigned int *dumprect;
	int dumpsx, dumpsy;
	rcti crop;

	ImageFormatData im_format;
} ScreenshotData;

static void screenshot_read_pixels(int x, int y, int w, int h, unsigned char *rect)
{
	int i;

	glReadPixels(x, y, w, h, GL_RGBA, GL_UNSIGNED_BYTE, rect);
	glFinish();

	/* clear alpha, it is not set to a meaningful value in opengl */
	for (i = 0, rect += 3; i < w * h; i++, rect += 4)
		*rect = 255;
}

/* get shot from frontbuffer */
static unsigned int *screenshot(bContext *C, int *dumpsx, int *dumpsy)
{
	wmWindow *win = CTX_wm_window(C);
	int x = 0, y = 0;
	unsigned int *dumprect = NULL;

	x = 0;
	y = 0;
	*dumpsx = WM_window_pixels_x(win);
	*dumpsy = WM_window_pixels_y(win);

	if (*dumpsx && *dumpsy) {

		dumprect = MEM_mallocN(sizeof(int) * (*dumpsx) * (*dumpsy), "dumprect");
		glReadBuffer(GL_FRONT);
		screenshot_read_pixels(x, y, *dumpsx, *dumpsy, (unsigned char *)dumprect);
		glReadBuffer(GL_BACK);
	}

	return dumprect;
}

/* call from both exec and invoke */
static int screenshot_data_create(bContext *C, wmOperator *op)
{
	unsigned int *dumprect;
	int dumpsx, dumpsy;

	/* do redraw so we don't show popups/menus */
	WM_redraw_windows(C);

	dumprect = screenshot(C, &dumpsx, &dumpsy);

	if (dumprect) {
		ScreenshotData *scd = MEM_callocN(sizeof(ScreenshotData), "screenshot");
		ScrArea *sa = CTX_wm_area(C);

		scd->dumpsx = dumpsx;
		scd->dumpsy = dumpsy;
		scd->dumprect = dumprect;
		if (sa) {
			scd->crop = sa->totrct;
		}

		BKE_imformat_defaults(&scd->im_format);

		op->customdata = scd;

		return true;
	}
	else {
		op->customdata = NULL;
		return false;
	}
}

static void screenshot_data_free(wmOperator *op)
{
	ScreenshotData *scd = op->customdata;

	if (scd) {
		if (scd->dumprect)
			MEM_freeN(scd->dumprect);
		MEM_freeN(scd);
		op->customdata = NULL;
	}
}

static void screenshot_crop(ImBuf *ibuf, rcti crop)
{
	unsigned int *to = ibuf->rect;
	unsigned int *from = ibuf->rect + crop.ymin * ibuf->x + crop.xmin;
	int crop_x = BLI_rcti_size_x(&crop);
	int crop_y = BLI_rcti_size_y(&crop);
	int y;

	if (crop_x > 0 && crop_y > 0) {
		for (y = 0; y < crop_y; y++, to += crop_x, from += ibuf->x)
			memmove(to, from, sizeof(unsigned int) * crop_x);

		ibuf->x = crop_x;
		ibuf->y = crop_y;
	}
}

static int screenshot_exec(bContext *C, wmOperator *op)
{
	ScreenshotData *scd = op->customdata;
	bool ok = false;

	if (scd == NULL) {
		/* when running exec directly */
		screenshot_data_create(C, op);
		scd = op->customdata;
	}

	if (scd) {
		if (scd->dumprect) {
			ImBuf *ibuf;
			char path[FILE_MAX];

			RNA_string_get(op->ptr, "filepath", path);
			BLI_path_abs(path, BKE_main_blendfile_path_from_global());

			/* operator ensures the extension */
			ibuf = IMB_allocImBuf(scd->dumpsx, scd->dumpsy, 24, 0);
			ibuf->rect = scd->dumprect;

			/* crop to show only single editor */
			if (!RNA_boolean_get(op->ptr, "full"))
				screenshot_crop(ibuf, scd->crop);

			if (scd->im_format.planes == R_IMF_PLANES_BW) {
				/* bw screenshot? - users will notice if it fails! */
				IMB_color_to_bw(ibuf);
			}
			if (BKE_imbuf_write(ibuf, path, &scd->im_format)) {
				ok = true;
			}
			else {
				BKE_reportf(op->reports, RPT_ERROR, "Could not write image: %s", strerror(errno));
			}

			IMB_freeImBuf(ibuf);
		}
	}

	screenshot_data_free(op);

	return ok ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
}

static int screenshot_invoke(bContext *C, wmOperator *op, const wmEvent *UNUSED(event))
{
	if (screenshot_data_create(C, op)) {
		if (RNA_struct_property_is_set(op->ptr, "filepath"))
			return screenshot_exec(C, op);

		/* extension is added by 'screenshot_check' after */
		char filepath[FILE_MAX] = "//screen";
		if (G.relbase_valid) {
			BLI_strncpy(filepath, BKE_main_blendfile_path_from_global(), sizeof(filepath));
			BLI_path_extension_replace(filepath, sizeof(filepath), "");  /* strip '.blend' */
		}
		RNA_string_set(op->ptr, "filepath", filepath);

		WM_event_add_fileselect(C, op);

		return OPERATOR_RUNNING_MODAL;
	}
	return OPERATOR_CANCELLED;
}

static bool screenshot_check(bContext *UNUSED(C), wmOperator *op)
{
	ScreenshotData *scd = op->customdata;
	return WM_operator_filesel_ensure_ext_imtype(op, &scd->im_format);
}

static void screenshot_cancel(bContext *UNUSED(C), wmOperator *op)
{
	screenshot_data_free(op);
}

static bool screenshot_draw_check_prop(PointerRNA *UNUSED(ptr), PropertyRNA *prop, void *UNUSED(user_data))
{
	const char *prop_id = RNA_property_identifier(prop);

	return !(STREQ(prop_id, "filepath"));
}

static void screenshot_draw(bContext *UNUSED(C), wmOperator *op)
{
	uiLayout *layout = op->layout;
	ScreenshotData *scd = op->customdata;
	PointerRNA ptr;

	/* image template */
	RNA_pointer_create(NULL, &RNA_ImageFormatSettings, &scd->im_format, &ptr);
	uiTemplateImageSettings(layout, &ptr, false);

	/* main draw call */
	RNA_pointer_create(NULL, op->type->srna, op->properties, &ptr);
	uiDefAutoButsRNA(layout, &ptr, screenshot_draw_check_prop, NULL, UI_BUT_LABEL_ALIGN_NONE, false);
}

static bool screenshot_poll(bContext *C)
{
	if (G.background)
		return false;

	return WM_operator_winactive(C);
}

void SCREEN_OT_screenshot(wmOperatorType *ot)
{
	ot->name = "Save Screenshot"; /* weak: opname starting with 'save' makes filewindow give save-over */
	ot->idname = "SCREEN_OT_screenshot";
	ot->description = "Capture a picture of the active area or whole Blender window";

	ot->invoke = screenshot_invoke;
	ot->check = screenshot_check;
	ot->exec = screenshot_exec;
	ot->cancel = screenshot_cancel;
	ot->ui = screenshot_draw;
	ot->poll = screenshot_poll;

	ot->flag = 0;

	WM_operator_properties_filesel(
	        ot, FILE_TYPE_FOLDER | FILE_TYPE_IMAGE, FILE_SPECIAL, FILE_SAVE,
	        WM_FILESEL_FILEPATH, FILE_DEFAULTDISPLAY, FILE_SORT_ALPHA);
	RNA_def_boolean(ot->srna, "full", 1, "Full Screen",
	                "Capture the whole window (otherwise only capture the active area)");
}