/**************************************************************************
*
* 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;
static gboolean just_shown;

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

void tooltip_init_fonts();

Tooltip g_tooltip;

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

	g_tooltip.font_color.rgb[0] = 1;
	g_tooltip.font_color.rgb[1] = 1;
	g_tooltip.font_color.rgb[2] = 1;
	g_tooltip.font_color.alpha = 1;
	just_shown = FALSE;
}

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

void init_tooltip()
{
	if (!g_tooltip.bg)
		g_tooltip.bg = &g_array_index(backgrounds, Background, 0);
	tooltip_init_fonts();

	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.display, g_tooltip.window);
	g_tooltip.window = XCreateWindow(server.display,
	                                 server.root_win,
	                                 0,
	                                 0,
	                                 100,
	                                 20,
	                                 0,
	                                 server.depth,
	                                 InputOutput,
	                                 server.visual,
	                                 mask,
	                                 &attr);
}

void tooltip_init_fonts()
{
	if (!g_tooltip.font_desc)
		g_tooltip.font_desc = pango_font_description_from_string(get_default_font());
}

void tooltip_default_font_changed()
{
	if (g_tooltip.has_font)
		return;
	if (!g_tooltip.has_font) {
		pango_font_description_free(g_tooltip.font_desc);
		g_tooltip.font_desc = NULL;
	}
	tooltip_init_fonts();
	tooltip_update();
}

void tooltip_trigger_show(Area *area, Panel *p, XEvent *e)
{
	// Position the tooltip in the center of the area
	x = area->posx + MIN(area->width / 3, 22) + e->xmotion.x_root - e->xmotion.x;
	y = area->posy + area->height / 2 + e->xmotion.y_root - e->xmotion.y;
	just_shown = TRUE;
	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.display, server.root_win, g_tooltip.panel->main_win, x, y, &mx, &my, &w);
	Area *area = find_area_under_mouse(g_tooltip.panel, mx, my);
	if (!g_tooltip.mapped && area->_get_tooltip_text) {
		tooltip_copy_text(area);
		g_tooltip.mapped = True;
		XMapWindow(server.display, g_tooltip.window);
		tooltip_update();
		XFlush(server.display);
	}
}

void tooltip_update_geometry()
{
	Panel *panel = g_tooltip.panel;
	int screen_width = server.monitors[panel->monitor].x + server.monitors[panel->monitor].width;

	cairo_surface_t *cs = cairo_xlib_surface_create(server.display, g_tooltip.window, server.visual, width, height);
	cairo_t *c = cairo_create(cs);
	PangoLayout *layout = pango_cairo_create_layout(c);

	pango_layout_set_font_description(layout, g_tooltip.font_desc);
	PangoRectangle r1, r2;
	pango_layout_set_text(layout, "1234567890", -1);
	pango_layout_get_pixel_extents(layout, &r1, &r2);
	int max_width = MIN(r2.width * 7, screen_width * 2 / 3);
	pango_layout_set_width(layout, max_width * PANGO_SCALE);

	pango_layout_set_text(layout, g_tooltip.tooltip_text, -1);
	pango_layout_set_wrap(layout, PANGO_WRAP_WORD);
	pango_layout_get_pixel_extents(layout, &r1, &r2);
	width = left_right_bg_border_width(g_tooltip.bg) + 2 * g_tooltip.paddingx + r2.width;
	height = top_bottom_bg_border_width(g_tooltip.bg) + 2 * g_tooltip.paddingy + r2.height;

	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.

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

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

	if (x + width > server.monitors[panel->monitor].x + server.monitors[panel->monitor].width)
		x = server.monitors[panel->monitor].x + server.monitors[panel->monitor].width - width;
	if (y + height > server.monitors[panel->monitor].y + server.monitors[panel->monitor].height)
		y = server.monitors[panel->monitor].y + server.monitors[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();
	if (just_shown) {
		if (!panel_horizontal)
			y -= height / 2; // center vertically
		just_shown = FALSE;
	}
	tooltip_adjust_geometry();
	XMoveResizeWindow(server.display, g_tooltip.window, x, y, width, height);

	// Stuff for drawing the tooltip
	cairo_surface_t *cs = cairo_xlib_surface_create(server.display, g_tooltip.window, server.visual, width, height);
	cairo_t *c = cairo_create(cs);
	Color bc = g_tooltip.bg->fill_color;
	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.radius - b.width / 1.571);
		cairo_set_source_rgba(c, bc.rgb[0], bc.rgb[1], bc.rgb[2], bc.alpha);
	} else {
		cairo_rectangle(c, 0., 0, width, height);
		cairo_set_source_rgb(c, bc.rgb[0], bc.rgb[1], bc.rgb[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.radius);
	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.rgb[0], b.color.rgb[1], b.color.rgb[2], b.color.alpha);
	cairo_stroke(c);

	Color fc = g_tooltip.font_color;
	cairo_set_source_rgba(c, fc.rgb[0], fc.rgb[1], fc.rgb[2], fc.alpha);
	PangoLayout *layout = pango_cairo_create_layout(c);
	pango_layout_set_font_description(layout, g_tooltip.font_desc);
	pango_layout_set_wrap(layout, PANGO_WRAP_WORD);
	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 + left_bg_border_width(g_tooltip.bg) + g_tooltip.paddingx,
				  -r1.y / 2 + 1 + top_bg_border_width(g_tooltip.bg) + g_tooltip.paddingy);
	pango_cairo_show_layout(c, layout);

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

void tooltip_trigger_hide()
{
	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)
{
	if (g_tooltip.mapped) {
		g_tooltip.mapped = False;
		XUnmapWindow(server.display, g_tooltip.window);
		XFlush(server.display);
	}
}

void start_show_timeout()
{
	change_timeout(&g_tooltip.timeout, g_tooltip.show_timeout_msec, 0, tooltip_show, 0);
}

void start_hide_timeout()
{
	change_timeout(&g_tooltip.timeout, g_tooltip.hide_timeout_msec, 0, tooltip_hide, 0);
}

void stop_tooltip_timeout()
{
	stop_timeout(g_tooltip.timeout);
}

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