#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

int main(int argc, char** argv)
{
// command manual
	if(argc < 2) {
		printf("Usage: %s [OPTION] \"command1[;command2][;command3][..]\"\n",argv[0]);
        printf("Description:\n");
        printf("\tExecute a command at a time define by the user.Press ctrl+z to quit.Then enter: ps to find the PID and kill the PID.Please notice:When there are more than 1 command to execute, please include them in a pair of double quation marks(\"\")\n");
        printf("Options:\n");
        printf("\t-t TIME\n");
        printf("\t\tdefine the time, format of TIME must be:HH:MM. default time is 5:59 \n");
        printf("\t-n 0|1\n");
        printf("\t\tdefine the execution times of the command.0 check every day and do not quit, 1 only execute one time. Default=0\n");
        printf("\t-iw DAY\n");
        printf("\t\tThe day to idel the work, format of DAY must be one of:Mon,Tue,Wed,Thu,Fri,Sat,Sun.No a day will be idel in the default setting\n");
        printf("Example:\n");
        printf("\t%s -t 5:59 -n 0 -iw Sat \"ls ..;ls \"\n",argv[0]);
        exit(0);
    }

//check the user's command
	char cmdstr[BUFSIZ];
	int cmdlen=0;
	int i;
	for(i=1;i<argc;i++) {
		cmdlen=strlen(argv[i]);
		cmdlen ++; 
	}	
	if(cmdlen > BUFSIZ-10) {
        printf("***Error: comand_string is too long (>%d)\n",BUFSIZ-10);
        exit(0);
	}
	
//get information from user command	
	char target_time[BUFSIZ]="5:59";
	int loop_time=0;
	char idel_day[BUFSIZ]="NaN";
	char NaN[BUFSIZ]="NaN";
	int argc_no=1;
	char string1[]="-t";
	char string2[]="-n";
	char string3[]="-iw";
	char aweek[BUFSIZ]="Week:Mon,Tue,Wed,Thu,Fri,Sat,Sun";
	struct tm tm2;
	for(i=1;i<argc;i++) {
		if(!strcmp(argv[i-1],string1)){
			sscanf(argv[i], "%d:%d",&(tm2.tm_hour),&(tm2.tm_min));
			if(tm2.tm_hour>23||tm2.tm_hour<0){
				printf("ERROR:The hour should between 0~23 but now %d\n",tm2.tm_hour);
				exit(0);
			}
			if(tm2.tm_min>59||tm2.tm_min<0){
				printf("ERROR:The minute should between 0~59 but now %d\n",tm2.tm_min);
				exit(0);
			}
			sprintf(target_time, argv[i]);
			argc_no=argc_no+2;
			i++;
			continue;
		}	
		else if(!strcmp(argv[i-1],string2)){
			sscanf(argv[i],"%d",&loop_time );
			if(!((loop_time == 0) || (loop_time == 1))){
				printf("\nERROR:loop time should be 0 or 1 but now %d\n",loop_time);
				exit(0);
		    }
			argc_no=argc_no+2;	
			i++;
			continue;
		}
		else if(!strcmp(argv[i-1],string3)){
			sscanf(argv[i],"%s",idel_day );
			for(int k=1;k<8;k++){
				if (!strstr(aweek,idel_day)){
				printf("ERROR:The date format is incorrect,should be one of %s but now %s",aweek,idel_day);
			    exit(0);
				}
			}	
			argc_no=argc_no+2;	
			i++;
			continue;
		}

   }

//show the command to be excuted
	printf("target_time is %s\n",target_time);
	printf("loop_time is %d\n",loop_time);
	printf("idel day is %s\n",idel_day);
	cmdstr[0]='\0';
	for(argc_no;argc_no<argc;argc_no++) {
		sprintf(&cmdstr[strlen(cmdstr)],"%s ",argv[argc_no]);
	}
	cmdstr[strlen(cmdstr)]='\0';
	printf("\nuser command string=%s\n",cmdstr);

//excute the command if it's not weekend and the time is match.
	sscanf(target_time, "%d:%d",&(tm2.tm_hour),&(tm2.tm_min));
	while((loop_time ==0)||(loop_time == 1)){ 
		while(1){
			time_t t;
			struct tm *tm1;
			char buf[BUFSIZ];
			t=time(NULL);
 		 	tm1=localtime(&t);
			strftime(buf,sizeof(buf),"%c\n",tm1);
			system("sleep 5");
			system("date");
			if ((tm2.tm_hour==tm1->tm_hour)&&(tm2.tm_min==tm1->tm_min)) {
				if(((!strstr(NaN,idel_day)))&&(strstr(buf,idel_day))){
					system("echo idel");
					continue;
				}	
				else if(strstr(NaN,idel_day)){
					system("echo no idel. The command will be exectued in 60s.");
					system("sleep 60");
					break;
				}
			}	
		}
		printf("now begin working in \'%s\'...\n\n",cmdstr);
		system(cmdstr);
		printf("\nnow end work.\n");
		if(loop_time == 1)
			break;
	}
    return 0;
}