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


/*
*    Find Freedom Internet maintenance date and time on their web page.
*
*    Copyright (c) 2023 R.J. van der Putten, Leiden, Holland, 
*    rob at sput dot nl.
* 
*    This program is free software; you can redistribute it and/or modify
*    it under the terms of the GNU General Public License version 3 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.
*/


char *months[12] = { \
	"januari",
	"februari",
	"maart",
	"april",
	"mei",
	"juni",
	"juli",
	"augustus",
	"september",
	"oktober",
	"november",
	"december"
};


/*  Find month  */
int fndmon(char *s)
{
    int i;

    i = 0;
    while (i < 12) {
	if(strcasecmp(s, months[i]) == 0)
	    break;
	i++;
    }

    return(i);
}

/*  Guess year  */
int fndyear(int mon)
{
    int year;
    time_t t;
    struct tm *curr;

    t = 0;
    year = 0;
    curr = NULL;

    t = time(NULL);
    curr = localtime(&t);
    year = curr->tm_year;
    if (mon < 4 && curr->tm_mon > 9) {
	/*  Curr: Oct - Dec and Ann: Jan - Mar; Probably next year  */
	year++;
    } else if (curr->tm_mon < 4 && mon > 9) {
	/*  Curr: Jan - Mar and Ann: Oct - Dec; Probably last year  */
	year--;
    }

    return(year);
}

/*  Process date  */
int procdate(char *s, struct tm *loc)
{
    int mon, year;
    char month[16];

    mon = 0;
    year = 0;
    memset(month, 0, 16);

    /*
    *  Begintijd: Vrijdag 10 november 2023 01.00
    *  Begintijd: Vrijdag 10 november 01.00
    */
    if(strncasecmp(s, "Begintijd: ", 11) != 0)
	return(-1);

    if (sscanf(s, "%*s %*s %d %15s %d %d.%d", \
      &(loc->tm_mday), month, &year, &(loc->tm_hour), &(loc->tm_min)) != 5) {
	/*  Missing year?  */
	if (sscanf(s, "%*s %*s %d %15s %d.%d", \
	  &(loc->tm_mday), month, &(loc->tm_hour), &(loc->tm_min)) != 4) {
	    /*  Garbled date!  */
	    return(-1);
	}
	year = 0;
    }
    mon = fndmon(month);
    if(mon > 11)
	return(-1);
    if (year == 0) {
	/*  No year  */
	year = fndyear(mon);
	loc->tm_year = year;
    } else {
	loc->tm_year = year - 1900;
    }
    loc->tm_mon   = mon;
    loc->tm_isdst = -1;

    return(0);
}


int main(int argc, char **argv)
{
    int i, len, lf, loclen;
    char date[256], line[4096];
    time_t t;
    struct tm loc, *prev;

    if (argc != 2 || argv[1][0] == '-') {
	fprintf(stderr, "Usage: proc-storing Location\n");
	exit(1);
    }

    i = 0;
    len = 0;
    lf = 0;				/*  Location when not zero  */
    loclen = 0;				/*  Length of location  */
    t = 0;				/*  Epoch  */
    prev = NULL;			/*  The previous day  */
    memset(date, 0, 256);		/*  Date  */
    memset(line, 0, 4096);
    memset(&loc, 0, sizeof(loc));	/*  Local time  */

    loclen = strlen(argv[1]);
    if (loclen < 2 || loclen > 255) {
	fprintf(stderr, "Wrong Location length: %d\n", loclen);
	exit(1);
    }

    while (fgets(line, 4096, stdin)) {
	i = 0;
	while (line[i] != 0 && i < 4096) {
	    if (line[i] == 10 || line[i] == 13) {
		line[i] = 0;
		break;
	    }
	    i++;
	}
	len = i + 1;
	if (len > 4088) {
	    fprintf(stderr, "Line too long %d\n", len);
	    exit(1);
	}
	i = 0;
	while (i < len) {
	    if (strncasecmp(line + i, "Begintijd", 9) == 0) {
		strncpy(date, line + i, 255);
		date[255] = 0;
		lf = 0;
		break;
	    } else if (strncasecmp(line + i, "* ", 2) == 0 && \
	      strncasecmp(line + i + 2, argv[1], loclen) == 0) {
		lf = 1;
		printf("%s\n", date);
		break;
	    } else if (lf != 0) {
		if (strncasecmp(line + i, \
		  "Het onderhoud start om", 22) == 0) {
		    printf("\t%s\n", line + i);
		} else if (strncasecmp(line + i, \
		  "De verwachte duur van het onderhoud is", 38) == 0) {
		    /*  All info is available  */
		    if (sscanf(line + i + 39, "%d %*s", &len) == 1 && \
		      procdate(date, &loc) == 0 && \
		      (t = mktime(&loc)) != -1) {
			/*  Date looks OK  */
			t = t - 86400;	/*  Previous day  */
		 	prev = localtime(&t);
		 	printf("\t%04d-%02d-%02d\t", prev->tm_year + 1900, \
			  prev->tm_mon + 1, prev->tm_mday);
			printf("%04d-%02d-%02d %02d:%02d - %02d:%02d\n", \
			  loc.tm_year + 1900, loc.tm_mon + 1, loc.tm_mday, \
			  loc.tm_hour, loc.tm_min, \
			  loc.tm_hour + len, loc.tm_min);
		    }
		    lf = 0;	/*  End of this location  */
		    break;
		}
	    }
	    i++;
	}	/*  End of while i < len  */
    }		/*  End of while fgets line stdin  */

    return(0);
}