/*
 *  Roo/E, the Kangaroo Punch Portable GUI Toolkit
 *  Copyright (C) 2022 Scott Duensing
 *
 *  http://kangaroopunch.com
 *
 *
 *  This file is part of Roo/E.
 *
 *  Roo/E is free software: you can redistribute it and/or modify it under the
 *  terms of the GNU Affero General Public License as published by the Free
 *  Software Foundation, either version 3 of the License, or (at your option)
 *  any later version.
 *
 *  Roo/E 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 Affero General Public License
 *  along with Roo/E. If not, see <https://www.gnu.org/licenses/>.
 *
 */


#include "../wmwindow.h"
#include "../font.h"

#include "hscroll.h"


uint8_t  __MAGIC_HSCROLL = 0;


static void hscrollClick(WidgetT *widget, uint16_t x, uint16_t y, uint8_t event, void *data);
static void hscrollDestroy(struct WidgetS *widget, ...);
static void hscrollPaint(struct WidgetS *widget, ...);


static void hscrollClick(WidgetT *widget, uint16_t x, uint16_t y, uint8_t event, void *data) {
	HscrollT *h = (HscrollT *)widget;

	(void)data;

	// Clicking in left arrow?
	if (x <= GADGET_SIZE) {
		// Move content left.
		h->value -= SCROLL_SPEED_SLOW;
		// Clip.
		if (h->value < h->min) h->value = h->min;
		// Update.
		widgetDirtySet(widget, 1);
		// Call the actual click event.
		if (h->handler) h->handler(widget, x, y, event, h->base.data);
		return;
	}

	// Clicking in right arrow?
	if (x >= h->base.r.w - GADGET_SIZE) {
		// Move content right.
		h->value += SCROLL_SPEED_SLOW;
		// Clip.
		if (h->value > h->max - h->base.r.w) h->value = h->max - h->base.r.w;
		// Update.
		widgetDirtySet(widget, 1);
		// Call the actual click event.
		if (h->handler) h->handler(widget, x, y, event, h->base.data);
		return;
	}

	// Clicking left of thumb?  Also fakes dragging.
	if (x < h->thumb.x) {
		// Move content left.
		h->value -= SCROLL_SPEED_FAST;
		// Clip.
		if (h->value < h->min) h->value = h->min;
		// Update.
		widgetDirtySet(widget, 1);
		// Call the actual click event.
		if (h->handler) h->handler(widget, x, y, event, h->base.data);
		return;
	}

	// Clicking right of thumb?  Also fakes dragging.
	if (x > h->thumb.x2) {
		// Move content right.
		h->value += SCROLL_SPEED_FAST;
		// Clip.
		if (h->value > h->max - h->base.r.w) h->value = h->max - h->base.r.w;
		// Update.
		widgetDirtySet(widget, 1);
		// Call the actual click event.
		if (h->handler) h->handler(widget, x, y, event, h->base.data);
		return;
	}
}


void hscrollClickSet(HscrollT *hscroll, ClickHandlerT handler, void *data) {
	hscroll->handler   = handler;
	hscroll->base.data = data;
}


HscrollT *hscrollCreate(int16_t w, ClickHandlerT handler, void *data, ...) {
	HscrollT *h = NULL;

	NEW(HscrollT, h);
	memset(h, 0, sizeof(HscrollT));

	h->min   = 1;
	h->max   = 100;
	h->value = 1;

	widgetBaseSet(W(h), __MAGIC_HSCROLL, w, GADGET_SIZE);

	hscrollWidthSet(h, w);

	h->handler   = handler;
	h->base.data = data;

	widgetInputSetRaw(W(h), 1);

	return h;
}


static void hscrollDestroy(struct WidgetS *widget, ...) {
	HscrollT *h = (HscrollT *)widget;

	DEL(h);
}


static void hscrollPaint(struct WidgetS *widget, ...) {
	HscrollT *h = (HscrollT *)widget;
	ColorT    scrollBackgroundColor;
	ColorT    widgetColor;
	RectT     r;
	int16_t   i;
	double    d;

	if (widgetDirtyGet(widget)) {
		widgetDirtySet(widget, 0);
		// Find some colors.
		if (widgetIsInWidget(widget, W(wmWindowOnTopGet()))) {
			scrollBackgroundColor = GUI_DARKGRAY;
			widgetColor           = GUI_LIGHTGRAY;
		} else {
			scrollBackgroundColor = GUI_LIGHTGRAY;
			widgetColor           = GUI_DARKGRAY;
		}
		// Find coordinates.
		r    = h->base.r;
		r.x2 = r.x + h->base.r.w - 1;
		r.y2 = r.y + h->base.r.h - 1;
		// Paint scrollbar.
		surfaceBoxFilled(r.x + 1, r.y + 1, r.x2 - 1, r.y2 - 1, scrollBackgroundColor);
		surfaceBoxHighlight(r.x, r.y, r.x2, r.y2, GUI_WHITE, GUI_BLACK);
		surfaceLineV(r.x + (GADGET_SIZE - 1), r.y + 1, r.y2, GUI_BLACK);
		surfaceLineV(r.x2 - (GADGET_SIZE - 1), r.y + 1, r.y2, GUI_WHITE);
		// Prepare font.
		fontSet(__guiFontVGA8x8);
		fontColorSet(widgetColor, scrollBackgroundColor);
		// ***TODO***
		/*
		// If we have both horizontal and vertical scroll bars, we need to fix a shadow.
		if (w->flags & WIN_SCROLL_V) {
			surfaceLineV(w->scrollh.x2 - 1, w->scrollh.y, w->scrollh.y2, GUI_BLACK);
			surfaceLineV(w->scrollh.x2, w->scrollh.y, w->scrollh.y2, GUI_WHITE);
		}
		*/
		// Draw arrows.
		fontRender("\x11", r.x + 7, r.y + 7);
		fontRender("\x10", r.x2 - 12, r.y + 7);
		// Distance between arrow buttons on scroll bar.
		i = r.x2 - r.x - (GADGET_SIZE * 2 - 2) - 2;
		// Percentage to scale content height to scroll bar height.
		d = (double)i / (double)(h->max - h->min);
		// Find position and size of thumb.
		h->thumb.x  = r.x + GADGET_SIZE + (h->value * d);
		h->thumb.x2 = h->thumb.x + (h->base.r.w * d);
		h->thumb.y  = r.y  + 1;
		h->thumb.y2 = r.y2 - 1;
		// Clamp overflow due to doubles and my off-by-one brain.
		if (h->thumb.x2 >= h->thumb.x + i - 1) h->thumb.x2 = h->thumb.x + i - 1;
		// Draw thumb.
		surfaceBoxFilled(h->thumb.x + 1, h->thumb.y + 1, h->thumb.x2 - 1, h->thumb.y2 - 1, GUI_LIGHTGRAY);
		surfaceBoxHighlight(h->thumb.x, h->thumb.y, h->thumb.x2, h->thumb.y2, GUI_WHITE, GUI_BLACK);
		// Adjust thumb values from window space to widget space for click handler.
		h->thumb.x  -= h->base.r.x;
		h->thumb.x2 -= h->base.r.x;
		h->thumb.y  -= h->base.r.y;
		h->thumb.y2 -= h->base.r.y;
	}
}


void hscrollRangeSet(HscrollT *hscroll, int32_t min, int32_t max) {
	hscroll->min = min;
	hscroll->max = max;
	hscrollValueSet(hscroll, min);
}


RegisterT *hscrollRegister(uint8_t magic) {
	static RegisterT reg = {
		"Hscroll",
		hscrollClick,
		hscrollDestroy,
		hscrollPaint,
		NULL           // No unregister handler.
	};

	// One-time widget startup code.
	__MAGIC_HSCROLL = magic;

	return &reg;
}


int32_t hscrollValueGet(HscrollT *hscroll) {
	return hscroll->value;
}


void hscrollValueSet(HscrollT *hscroll, int32_t value) {
	if (value < hscroll->min) value = hscroll->min;
	if (value > hscroll->max) value = hscroll->max;
	if (hscroll->value != value) {
		hscroll->value = value;
		widgetDirtySet(W(hscroll), 1);
	}
}


void hscrollWidthSet(HscrollT *hscroll, int16_t w) {
	// Make sure it's at least wide enough to draw.
	if (w < GADGET_SIZE * 3) w = GADGET_SIZE * 3;

	hscroll->base.r.w = w;

	widgetDirtySet(W(hscroll), 1);
}