/**************************************************************************
*
* Tint2 : battery
*
* Copyright (C) 2009 Sebastian Reichel <elektranox@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
* or any later version 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 <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <cairo.h>
#include <cairo-xlib.h>
#include <pango/pangocairo.h>

#include "window.h"
#include "server.h"
#include "taskbar.h"
#include "panel.h"
#include "area.h"
#include "battery.h"
#include "clock.h"

PangoFontDescription *bat1_font_desc;
PangoFontDescription *bat2_font_desc;
struct batstate battery_state;

static char buf_bat_percentage[10];
static char buf_bat_time[20];

int8_t battery_low_status;
char *battery_low_cmd;
char *path_energy_now, *path_energy_full, *path_current_now, *path_status;


void init_battery()
{
	// check battery
	GDir *directory;
	GError *error = NULL;
	const char *entryname;
	char *battery_dir = 0;

	path_energy_now = path_energy_full = path_current_now = path_status = 0;
	directory = g_dir_open("/sys/class/power_supply", 0, &error);
	if (error)
		g_error_free(error);
	else {
		while ((entryname=g_dir_read_name(directory))) {
			if (strncmp(entryname,"AC", 2) == 0) continue;

			char *path1 = g_build_filename("/sys/class/power_supply", entryname, "present", NULL);
			if (g_file_test (path1, G_FILE_TEST_EXISTS)) {
				g_free(path1);
				battery_dir = g_build_filename("/sys/class/power_supply", entryname, NULL);
				break;
			}
			g_free(path1);
		}
	}
	if (battery_dir != 0) {
		char *path1 = g_build_filename(battery_dir, "energy_now", NULL);
		if (g_file_test (path1, G_FILE_TEST_EXISTS)) {
			path_energy_now = g_build_filename(battery_dir, "energy_now", NULL);
			path_energy_full = g_build_filename(battery_dir, "energy_full", NULL);
		}
		else {
			char *path2 = g_build_filename(battery_dir, "charge_now", NULL);
			if (g_file_test (path2, G_FILE_TEST_EXISTS)) {
				path_energy_now = g_build_filename(battery_dir, "charge_now", NULL);
				path_energy_full = g_build_filename(battery_dir, "charge_full", NULL);
			}
			else {
				g_free(battery_dir);
				battery_dir = 0;
				fprintf(stderr, "ERROR: can't found energy_* or charge_*\n");
			}
			g_free(path2);
		}
		path_current_now = g_build_filename(battery_dir, "current_now", NULL);
		path_status = g_build_filename(battery_dir, "status", NULL);
		g_free(path1);
	}

	FILE *fp;
   Panel *panel;
   Battery *battery;
   int i, bat_percentage_height, bat_percentage_height_ink, bat_time_height, bat_time_height_ink;

	for (i=0 ; i < nb_panel ; i++) {
		panel = &panel1[i];
		battery = &panel->battery;

		if (battery_dir == 0) battery->area.on_screen = 0;
		if (!battery->area.on_screen) continue;

		battery->area.parent = panel;
		battery->area.panel = panel;
		battery->area._draw_foreground = draw_battery;
		battery->area._resize = resize_battery;

		if((fp = fopen(path_energy_now, "r")) == NULL) {
			fprintf(stderr, "ERROR: battery applet can't open energy_now\n");
			panel->battery.area.on_screen = 0;
			continue;
		}
		fclose(fp);
		if((fp = fopen(path_energy_full, "r")) == NULL) {
			fprintf(stderr, "ERROR: battery applet can't open energy_full\n");
			panel->battery.area.on_screen = 0;
			continue;
		}
		fclose(fp);
		if((fp = fopen(path_current_now, "r")) == NULL) {
			fprintf(stderr, "ERROR: battery applet can't open current_now\n");
			panel->battery.area.on_screen = 0;
			continue;
		}
		fclose(fp);
		if((fp = fopen(path_status, "r")) == NULL) {
			fprintf(stderr, "ERROR: battery applet can't open status");
			panel->battery.area.on_screen = 0;
			continue;
		}
		fclose(fp);

		battery->area.posy = panel->area.pix.border.width + panel->area.paddingy;
		battery->area.height = panel->area.height - (2 * battery->area.posy);
		battery->area.resize = 1;
		battery->area.redraw = 1;

		update_battery(&battery_state);
		snprintf(buf_bat_percentage, sizeof(buf_bat_percentage), "%d%%", battery_state.percentage);
		snprintf(buf_bat_time, sizeof(buf_bat_time), "%02d:%02d", battery_state.time.hours, battery_state.time.minutes);

		get_text_size(bat1_font_desc, &bat_percentage_height_ink, &bat_percentage_height, panel->area.height, buf_bat_percentage, strlen(buf_bat_percentage));
		battery->bat1_posy = (battery->area.height - bat_percentage_height) / 2;

		get_text_size(bat2_font_desc, &bat_time_height_ink, &bat_time_height, panel->area.height, buf_bat_time, strlen(buf_bat_time));

		battery->bat1_posy -= ((bat_time_height_ink + 2) / 2);
		battery->bat2_posy = battery->bat1_posy + bat_percentage_height + 2 - (bat_percentage_height - bat_percentage_height_ink)/2 - (bat_time_height - bat_time_height_ink)/2;
	}
}


void update_battery() {
	FILE *fp;
	char tmp[25];
	int64_t energy_now = 0, energy_full = 0, current_now = 0;
	int seconds = 0;
	int8_t new_percentage = 0;

	fp = fopen(path_energy_now, "r");
	if(fp != NULL) {
		fgets(tmp, sizeof tmp, fp);
		energy_now = atoi(tmp);
		fclose(fp);
	}

	fp = fopen(path_energy_full, "r");
	if(fp != NULL) {
		fgets(tmp, sizeof tmp, fp);
		energy_full = atoi(tmp);
		fclose(fp);
	}

	fp = fopen(path_current_now, "r");
	if(fp != NULL) {
		fgets(tmp, sizeof tmp, fp);
		current_now = atoi(tmp);
		fclose(fp);
	}

	fp = fopen(path_status, "r");
	if(fp != NULL) {
		fgets(tmp, sizeof tmp, fp);
		fclose(fp);
	}

	battery_state.state = BATTERY_UNKNOWN;
	if(strcasecmp(tmp, "Charging\n")==0) battery_state.state = BATTERY_CHARGING;
	if(strcasecmp(tmp, "Discharging\n")==0) battery_state.state = BATTERY_DISCHARGING;

	if(current_now > 0) {
		switch(battery_state.state) {
			case BATTERY_CHARGING:
				seconds = 3600 * (energy_full - energy_now) / current_now;
				break;
			case BATTERY_DISCHARGING:
				seconds = 3600 * energy_now / current_now;
				break;
			default:
				seconds = 0;
				break;
		}
	} else seconds = 0;

	battery_state.time.hours = seconds / 3600;
	seconds -= 3600 * battery_state.time.hours;
	battery_state.time.minutes = seconds / 60;
	seconds -= 60 * battery_state.time.minutes;
	battery_state.time.seconds = seconds;

	if(energy_full > 0)
		new_percentage = (energy_now*100)/energy_full;

	if(battery_low_status != 0 && battery_low_status == new_percentage && battery_state.percentage > new_percentage) {
		printf("battery low, executing: %s\n", battery_low_cmd);
		if(battery_low_cmd) system(battery_low_cmd);
	}

	battery_state.percentage = new_percentage;
}


void draw_battery (void *obj, cairo_t *c, int active)
{
	Battery *battery = obj;
	PangoLayout *layout;

	layout = pango_cairo_create_layout (c);

	// draw layout
	pango_layout_set_font_description(layout, bat1_font_desc);
	pango_layout_set_width(layout, battery->area.width * PANGO_SCALE);
	pango_layout_set_alignment(layout, PANGO_ALIGN_CENTER);
	pango_layout_set_text(layout, buf_bat_percentage, strlen(buf_bat_percentage));

	cairo_set_source_rgba(c, battery->font.color[0], battery->font.color[1], battery->font.color[2], battery->font.alpha);

	pango_cairo_update_layout(c, layout);
	cairo_move_to(c, 0, battery->bat1_posy);
	pango_cairo_show_layout(c, layout);

	pango_layout_set_font_description(layout, bat2_font_desc);
	pango_layout_set_indent(layout, 0);
	pango_layout_set_text(layout, buf_bat_time, strlen(buf_bat_time));
	pango_layout_set_width(layout, battery->area.width * PANGO_SCALE);

	pango_cairo_update_layout(c, layout);
	cairo_move_to(c, 0, battery->bat2_posy);
	pango_cairo_show_layout(c, layout);

	g_object_unref(layout);
}


void resize_battery(void *obj)
{
  	Battery *battery = obj;
	PangoLayout *layout;
	int percentage_width, time_width, new_width;

	percentage_width = time_width = 0;
	battery->area.redraw = 1;

	snprintf(buf_bat_percentage, sizeof(buf_bat_percentage), "%d%%", battery_state.percentage);
	snprintf(buf_bat_time, sizeof(buf_bat_time), "%02d:%02d", battery_state.time.hours, battery_state.time.minutes);

	cairo_surface_t *cs;
	cairo_t *c;
	Pixmap pmap;
	pmap = XCreatePixmap(server.dsp, server.root_win, battery->area.width, battery->area.height, server.depth);

	cs = cairo_xlib_surface_create(server.dsp, pmap, server.visual, battery->area.width, battery->area.height);
	c = cairo_create(cs);
	layout = pango_cairo_create_layout(c);

	// check width
	pango_layout_set_font_description(layout, bat1_font_desc);
	pango_layout_set_indent(layout, 0);
	pango_layout_set_text(layout, buf_bat_percentage, strlen(buf_bat_percentage));
	pango_layout_get_pixel_size(layout, &percentage_width, NULL);

	pango_layout_set_font_description(layout, bat2_font_desc);
	pango_layout_set_indent(layout, 0);
	pango_layout_set_text(layout, buf_bat_time, strlen(buf_bat_time));
	pango_layout_get_pixel_size(layout, &time_width, NULL);

	if(percentage_width > time_width) new_width = percentage_width;
	else new_width = time_width;

	new_width += (2*battery->area.paddingxlr) + (2*battery->area.pix.border.width);

	int old_width = battery->area.width;

	Panel *panel = ((Area*)obj)->panel;
	battery->area.width = new_width + 1;
	battery->area.posx = panel->area.width - battery->area.width - panel->area.paddingxlr - panel->area.pix.border.width;
	if (panel->clock.area.on_screen)
		battery->area.posx -= (panel->clock.area.width + panel->area.paddingx);

	if(new_width > old_width || new_width < (old_width-6)) {
		// refresh and resize other objects on panel
		// we try to limit the number of refresh
		printf("battery_width %d, new_width %d\n", battery->area.width, new_width);
		panel->area.resize = 1;
		systray.area.resize = 1;
		panel_refresh = 1;
	}

	g_object_unref (layout);
	cairo_destroy (c);
	cairo_surface_destroy (cs);
	XFreePixmap (server.dsp, pmap);
}