#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>

#ifdef USE_SYSLOG
#include <syslog.h>
#endif

#include "main.h"

#ifdef USE_LIBNOTIFY
#include <libnotify/notify.h>
#endif

int run_verbose = 0;
int run_terse = 0;
int run_continuously = 0;
int interval = DEFAULT_LOG_INTERVAL;
int run_unsafe = 0;
int force_print_parameters = 0;

int warn_level = 10;

int warned = 0; /* Set if already warned */

const char * delimiter = "\n";

void print_help(void){
	printf("%s %s\n", TITLE, VERSION);
	printf("%s %s %s\n", USAGE0, PROGNAME, USAGE1);
	printf("%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n%s\n",
	       OPTIONS0, OPTIONS1, OPTIONS2, OPTIONS3, OPTIONS4,
	       OPTIONS5, OPTIONS6, OPTIONS7, OPTIONS8, OPTIONS9,
	       OPTIONS10);
}

int get_percentage
(FILE * fd_now, FILE * fd_full, int * c_now, int * c_full, float * frac, int *pct)
{
	int vals_read = fscanf(fd_now, "%d", c_now);
	if(vals_read != 1){
		if(errno != 0){
			perror("Error reading full battery charge: ");
		} else if(vals_read == EOF){
			printf("End-of-file reached while reading current battery charge(?)");
		} else {
			printf("Invalid number of arguments (%d) returned while reading full battery charge", vals_read);
		}
		return 1;
	}
	vals_read = fscanf(fd_full, "%d", c_full);
	if(vals_read != 1){
		if(errno != 0){
			perror("Error reading full battery charge: ");
		} else if(vals_read == EOF){
			printf("End-of-file reached while reading full battery charge(?)");
		} else {
			printf("Invalid number of arguments (%d) returned while reading full battery charge", vals_read);
		}
		return 1;
	}
	(*frac) = ((float)(*c_now)) / ((float)(*c_full));
	(*pct) = (int)((*frac) * 100);
	return 0;
}

void warn(int pct){
	if(!warned){

		printf("Battery Low\n");

#ifdef USE_SYSLOG
		syslog(LOG_WARNING, "Battery Low");
#endif
		
#ifdef USE_LIBNOTIFY
		char warnmesg[MESGLEN];
		snprintf(warnmesg, MESGLEN, "Battery is at %d percent", pct);
		notify_init(PROGNAME);
		NotifyNotification * levelwarn = notify_notification_new("Battery Low", warnmesg, "dialog-information");
		notify_notification_show(levelwarn, NULL);
		g_object_unref(G_OBJECT(levelwarn));
		notify_uninit();
#endif
	}
	warned = 1;
}

int main(int argc, char *const argv[]){

	int opt;
	while((opt = getopt(argc, argv, "vhtli:uw:p")) != -1) {
		switch(opt){
		case 'v':
			run_verbose = 1;
			break;
		case 'h':
			print_help();
			return 0;
		case 't':
			run_terse = 1;
			break;
		case 'l':
			run_continuously = 1;
			break;
		case 'i':
			interval = atoi(optarg);
			run_continuously = 1;
			break;
		case 'u':
			run_unsafe = 1;
			break;
		case 'w':
			warn_level = atoi(optarg);
			break;
		case 'p':
			force_print_parameters = 1;
			break;
		default:
			printf("Literally how could you pass an unspecified argument to this program");
		}
	}

	/**
	   Print run parameters at startup
	*/
	if(force_print_parameters) {
		if(run_terse && run_verbose){
			printf(PROGNAME " called with arguments to run both tersely and verbosely, the author legitimately cannot tell what you want her to do\n");
		} else if(run_terse) {
			printf(PROGNAME " will run tersely\n");
		} else if(run_verbose) {
			printf(PROGNAME " will run verbosely\n");
		}
		printf(PROGNAME " will poll every %d seconds\n", interval);
		if(!run_terse){
			printf(PROGNAME " will warn at %d%% battery\n", warn_level);
		}
		
		
	}
	
	if(warn_level <= 0 && !run_terse){
		fprintf(stderr, "Warn level set to %d. " PROGNAME " will not send warning on low battery.\n", warn_level);
	}

	if(interval < 15 && !run_unsafe){
		fprintf(stderr, "Update interval less than 15 seconds, refusing to run. Specify -u to override this check.\n");
		return 1;
	}

	
#ifdef USE_SYSLOG
        openlog(PROGNAME, 0, LOG_USER);
#endif
	
	FILE * fd_now = fopen(CHARGE_NOW_PATH, "r");
	FILE * fd_full = fopen(CHARGE_FULL_PATH, "r");

	int c_now;
	int c_full;
	float frac;
	int pct;

	do{
		int rval = get_percentage(fd_now, fd_full, &c_now, &c_full, &frac, &pct);
		if (rval){
			printf("Um, problem\n");
			return 1;
		}
		if(run_verbose){
			printf("Current charge: %d\n microampere-hours\n", c_now);
			printf("Full charge: %d\n microampere-hours\n", c_full);
		}
		
		if(!run_terse) {
			printf("Battery percentage: ");
		}
		
		if(pct > warn_level){
			warned = 0;
		}
		
		if(pct <= warn_level && !warned){
			warn(pct);
		}
		printf("%d%s", pct, delimiter);
#ifdef USE_SYSLOG
		syslog(LOG_INFO, "%d%%%s", pct, delimiter);
#endif
		if(run_continuously){
			sleep(interval);/*
			errno = 0;
			rewind(fd_now);
			if(errno != 0){
				perror("Error rewinding " CHARGE_NOW_PATH);
				return 1;
			}
			rewind(fd_full); //just for the hecc of it
			if(errno != 0){
				perror("Error rewinding " CHARGE_FULL_PATH);
				return 1;
			}*/
			fclose(fd_now);
			fclose(fd_full);
			fd_now = fopen(CHARGE_NOW_PATH, "r");
			fd_full = fopen(CHARGE_FULL_PATH, "r");
		}
	} while (run_continuously);


#ifdef USE_SYSLOG
	closelog();
#endif
	
	return 0;
}