/**************************************************************************
*
* Copyright (C) 2009 Andreas.Fink (Andreas.Fink85@gmail.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* 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.
**************************************************************************/

#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <cairo.h>
#include <cairo-xlib.h>

#include "server.h"
#include "tooltip.h"
#include "panel.h"
#include "timer.h"

static int x, y, width, height;

// the next functions are helper functions for tooltip handling
void start_show_timeout();
void start_hide_timeout();
void stop_tooltip_timeout();

Tooltip g_tooltip;


void default_tooltip()
{
	// give the tooltip some reasonable default values
	memset(&g_tooltip, 0, sizeof(Tooltip));

	g_tooltip.font_color.color[0] = 1;
	g_tooltip.font_color.color[1] = 1;
	g_tooltip.font_color.color[2] = 1;
	g_tooltip.font_color.alpha = 1;
}

void cleanup_tooltip()
{
	stop_tooltip_timeout();
	tooltip_hide(0);
	tooltip_copy_text(0);
	if (g_tooltip.window) XDestroyWindow(server.dsp, g_tooltip.window);
	if (g_tooltip.font_desc) pango_font_description_free(g_tooltip.font_desc);
}


void init_tooltip()
{
	if (!g_tooltip.font_desc)
		g_tooltip.font_desc = pango_font_description_from_string("sans 10");
	if (g_tooltip.bg == 0)
		g_tooltip.bg = &g_array_index(backgrounds, Background, 0);

	XSetWindowAttributes attr;
	attr.override_redirect = True;
	attr.event_mask = StructureNotifyMask;
	attr.colormap = server.colormap;
	attr.background_pixel = 0;
	attr.border_pixel = 0;
	unsigned long mask = CWEventMask|CWColormap|CWBorderPixel|CWBackPixel|CWOverrideRedirect;
	if (g_tooltip.window) XDestroyWindow(server.dsp, g_tooltip.window);
	g_tooltip.window = XCreateWindow(server.dsp, server.root_win, 0, 0, 100, 20, 0, server.depth, InputOutput, server.visual, mask, &attr);
}


void tooltip_trigger_show(Area* area, Panel* p, XEvent *e)
{
	// Position the tooltip in the center of the area
	x = area->posx + area->width / 2 + e->xmotion.x_root - e->xmotion.x;
	y = area->posy + area->height / 2 + e->xmotion.y_root - e->xmotion.y;
	if (!panel_horizontal)
		y -= height/2;
	g_tooltip.panel = p;
	if (g_tooltip.mapped && g_tooltip.area != area) {
		tooltip_copy_text(area);
		tooltip_update();
		stop_tooltip_timeout();
	}
	else if (!g_tooltip.mapped) {
		start_show_timeout();
	}
}


void tooltip_show(void* arg)
{
	int mx, my;
	Window w;
	XTranslateCoordinates( server.dsp, server.root_win, g_tooltip.panel->main_win, x, y, &mx, &my, &w);
	Area* area;
	if (!panel_horizontal)
		my += height/2; /* we adjusted y in tooltip_trigger_show, revert or we won't find the correct area anymore */
	area = click_area(g_tooltip.panel, mx, my);
	stop_tooltip_timeout();
	if (!g_tooltip.mapped && area->_get_tooltip_text) {
		tooltip_copy_text(area);
		g_tooltip.mapped = True;
		XMapWindow(server.dsp, g_tooltip.window);
		tooltip_update();
		XFlush(server.dsp);
	}
}


void tooltip_update_geometry()
{
	cairo_surface_t *cs;
	cairo_t *c;
	PangoLayout* layout;
	cs = cairo_xlib_surface_create(server.dsp, g_tooltip.window, server.visual, width, height);
	c = cairo_create(cs);
	layout = pango_cairo_create_layout(c);
	pango_layout_set_font_description(layout, g_tooltip.font_desc);
	pango_layout_set_text(layout, g_tooltip.tooltip_text, -1);
	PangoRectangle r1, r2;
	pango_layout_get_pixel_extents(layout, &r1, &r2);
	width = 2*g_tooltip.bg->border.width + 2*g_tooltip.paddingx + r2.width;
	height = 2*g_tooltip.bg->border.width + 2*g_tooltip.paddingy + r2.height;

	Panel* panel = g_tooltip.panel;
	if (panel_horizontal && panel_position & BOTTOM)
		y = panel->posy-height;
	else if (panel_horizontal && panel_position & TOP)
		y = panel->posy + panel->area.height;
	else if (panel_position & LEFT)
		x = panel->posx + panel->area.width;
	else
		x = panel->posx - width;

	g_object_unref(layout);
	cairo_destroy(c);
	cairo_surface_destroy(cs);
}


void tooltip_adjust_geometry()
{
	// adjust coordinates and size to not go offscreen
	// it seems quite impossible that the height needs to be adjusted, but we do it anyway.

	int min_x, min_y, max_width, max_height;
	Panel* panel = g_tooltip.panel;
	int screen_width = server.monitor[panel->monitor].x + server.monitor[panel->monitor].width;
	int screen_height = server.monitor[panel->monitor].y + server.monitor[panel->monitor].height;
	if ( x+width <= screen_width && y+height <= screen_height && x>=server.monitor[panel->monitor].x && y>=server.monitor[panel->monitor].y )
		return;    // no adjustment needed

	if (panel_horizontal) {
		min_x=0;
		max_width=server.monitor[panel->monitor].width;
		max_height=server.monitor[panel->monitor].height-panel->area.height;
		if (panel_position & BOTTOM)
			min_y=0;
		else
			min_y=panel->area.height;
	}
	else {
		max_width=server.monitor[panel->monitor].width-panel->area.width;
		min_y=0;
		max_height=server.monitor[panel->monitor].height;
		if (panel_position & LEFT)
			min_x=panel->area.width;
		else
			min_x=0;
	}

	if (x+width > server.monitor[panel->monitor].x + server.monitor[panel->monitor].width)
		x = server.monitor[panel->monitor].x + server.monitor[panel->monitor].width - width;
	if ( y+height > server.monitor[panel->monitor].y + server.monitor[panel->monitor].height)
		y = server.monitor[panel->monitor].y + server.monitor[panel->monitor].height - height;

	if (x<min_x)
		x=min_x;
	if (width>max_width)
		width = max_width;
	if (y<min_y)
		y=min_y;
	if (height>max_height)
		height=max_height;
}

void tooltip_update()
{
	if (!g_tooltip.tooltip_text) {
		tooltip_hide(0);
		return;
	}

	tooltip_update_geometry();
	tooltip_adjust_geometry();
	XMoveResizeWindow(server.dsp, g_tooltip.window, x, y, width, height);

	// Stuff for drawing the tooltip
	cairo_surface_t *cs;
	cairo_t *c;
	PangoLayout* layout;
	cs = cairo_xlib_surface_create(server.dsp, g_tooltip.window, server.visual, width, height);
	c = cairo_create(cs);
	Color bc = g_tooltip.bg->back;
	Border b = g_tooltip.bg->border;
	if (server.real_transparency) {
		clear_pixmap(g_tooltip.window, 0, 0, width, height);
		draw_rect(c, b.width, b.width, width-2*b.width, height-2*b.width, b.rounded-b.width/1.571);
		cairo_set_source_rgba(c, bc.color[0], bc.color[1], bc.color[2], bc.alpha);
	}
	else {
		cairo_rectangle(c, 0., 0, width, height);
		cairo_set_source_rgb(c, bc.color[0], bc.color[1], bc.color[2]);
	}
	cairo_fill(c);
	cairo_set_line_width(c, b.width);
	if (server.real_transparency)
		draw_rect(c, b.width/2.0, b.width/2.0, width - b.width, height - b.width, b.rounded);
	else
		cairo_rectangle(c, b.width/2.0, b.width/2.0, width-b.width, height-b.width);
	cairo_set_source_rgba(c, b.color[0], b.color[1], b.color[2], b.alpha);
	cairo_stroke(c);

	Color fc = g_tooltip.font_color;
	cairo_set_source_rgba(c, fc.color[0], fc.color[1], fc.color[2], fc.alpha);
	layout = pango_cairo_create_layout(c);
	pango_layout_set_font_description(layout, g_tooltip.font_desc);
	pango_layout_set_text(layout, g_tooltip.tooltip_text, -1);
	PangoRectangle r1, r2;
	pango_layout_get_pixel_extents(layout, &r1, &r2);
	pango_layout_set_width(layout, width*PANGO_SCALE);
	pango_layout_set_height(layout, height*PANGO_SCALE);
	pango_layout_set_ellipsize(layout, PANGO_ELLIPSIZE_END);
	// I do not know why this is the right way, but with the below cairo_move_to it seems to be centered (horiz. and vert.)
	cairo_move_to(c, -r1.x/2+g_tooltip.bg->border.width+g_tooltip.paddingx, -r1.y/2+g_tooltip.bg->border.width+g_tooltip.paddingy);
	pango_cairo_show_layout (c, layout);

	g_object_unref (layout);
	cairo_destroy (c);
	cairo_surface_destroy (cs);
}


void tooltip_trigger_hide(Tooltip* tooltip)
{
	if (g_tooltip.mapped) {
		tooltip_copy_text(0);
		start_hide_timeout();
	}
	else {
		// tooltip not visible yet, but maybe a timeout is still pending
		stop_tooltip_timeout();
	}
}


void tooltip_hide(void* arg)
{
	stop_tooltip_timeout();
	if (g_tooltip.mapped) {
		g_tooltip.mapped = False;
		XUnmapWindow(server.dsp, g_tooltip.window);
		XFlush(server.dsp);
	}
}


void start_show_timeout()
{
	if (g_tooltip.timeout)
		change_timeout(g_tooltip.timeout, g_tooltip.show_timeout_msec, 0, tooltip_show, 0);
	else
		g_tooltip.timeout = add_timeout(g_tooltip.show_timeout_msec, 0, tooltip_show, 0);
}


void start_hide_timeout()
{
	if (g_tooltip.timeout)
		change_timeout(g_tooltip.timeout, g_tooltip.hide_timeout_msec, 0, tooltip_hide, 0);
	else
		g_tooltip.timeout = add_timeout(g_tooltip.hide_timeout_msec, 0, tooltip_hide, 0);
}


void stop_tooltip_timeout()
{
	if (g_tooltip.timeout) {
		stop_timeout(g_tooltip.timeout);
		g_tooltip.timeout = 0;
	}
}


void tooltip_copy_text(Area* area)
{
	free(g_tooltip.tooltip_text);
	if (area && area->_get_tooltip_text)
		g_tooltip.tooltip_text = strdup(area->_get_tooltip_text(area));
	else
		g_tooltip.tooltip_text = 0;
	g_tooltip.area = area;
}