#!/usr/bin/perl -w
# NAME: shwevents.pl
# AIM: Read and list events in Rainlendar event file
# 04/10/2015 geoff mclane http://geoffair.net/mperl
use strict;
use warnings;
use File::Basename;  # split path ($name,$dir,$ext) = fileparse($file [, qr/\.[^.]*/] )
use Time::Local;
use Cwd;
my $os = $^O;
my $perl_dir = '/home/geoff/bin';
my $PATH_SEP = '/';
my $temp_dir = '/tmp';
if ($os =~ /win/i) {
    $perl_dir = 'C:\GTools\perl';
    $temp_dir = $perl_dir;
    $PATH_SEP = "\\";
}
unshift(@INC, $perl_dir);
require 'lib_utils.pl' or die "Unable to load 'lib_utils.pl' Check paths in \@INC...\n";
# log file stuff
our ($LF);
my $pgmname = $0;
if ($pgmname =~ /(\\|\/)/) {
    my @tmpsp = split(/(\\|\/)/,$pgmname);
    $pgmname = $tmpsp[-1];
}
my $outfile = $temp_dir.$PATH_SEP."temp.$pgmname.txt";
open_log($outfile);

# user variables
my $VERS = "0.0.5 2015-10-04";
my $load_log = 1;
my $in_file = '';
my $verbosity = 0;
my $out_file = '';
my $show_all_events = 0;
my $min_lenght = length("EVENT: Pauline's Birthday RPT:FREQ=YEARLY;BYMONTHDAY=14;BYMONTH=6 2015/06/14 11:00:00 ");

# ### DEBUG ###
my $debug_on = 1;
my $def_file = 'C:\Users\user\.rainlendar2\Default.ics';

### program variables
my @warnings = ();
my $cwd = cwd();

sub VERB1() { return $verbosity >= 1; }
sub VERB2() { return $verbosity >= 2; }
sub VERB5() { return $verbosity >= 5; }
sub VERB9() { return $verbosity >= 9; }

sub show_warnings($) {
    my ($val) = @_;
    if (@warnings) {
        prt( "\nGot ".scalar @warnings." WARNINGS...\n" );
        foreach my $itm (@warnings) {
           prt("$itm\n");
        }
        prt("\n");
    } else {
        prt( "\nNo warnings issued.\n\n" ) if (VERB9());
    }
}

sub pgm_exit($$) {
    my ($val,$msg) = @_;
    if (length($msg)) {
        $msg .= "\n" if (!($msg =~ /\n$/));
        prt($msg);
    }
    show_warnings($val);
    close_log($outfile,$load_log);
    exit($val);
}


sub prtw($) {
   my ($tx) = shift;
   $tx =~ s/\n$//;
   prt("$tx\n");
   push(@warnings,$tx);
}

my %bgnend = (
    'VCALENDAR' => 1,
    'VEVENT' => 1,
    'VALARM' => 1
    );

my %freqs = (
    'WEEKLY' => 1,
    'MONTHLY' => 1,
    'YEARLY' => 1
    );

my %raindays = (
    'MO' => 1,
    'TU' => 2,
    'WE' => 3,
    'TH' => 4,
    'FR' => 5,
    'SA' => 6,
    'SU' => 7
    );


sub get_next_month_dt($$) {
    my ($bgn,$now) = @_;
    my ($year,$mth,$day,$hour,$min,$sec);
    my ($nyear,$nmth,$nday,$nhour,$nmin,$nsec);
    my ($ep1,$ep2);
    $ep1 = -1;
    if ($bgn =~ /^\s*(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})Z\s*$/) {
        $year = $1;
        $mth  = $2;
        $day  = $3;
        $hour = $4;
        $min  = $5;
        $sec  = $6;
        $ep1  = timelocal($sec,$min,$hour,$day,$mth-1,$year); 
        if ($now =~ /^\s*(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})Z\s*$/) {
            $nyear = $1;
            $nmth  = $2;
            $nday  = $3;
            $nhour = $4;
            $nmin  = $5;
            $nsec  = $6;
            $ep2  = timelocal($nsec,$nmin,$nhour,$nday,$nmth-1,$nyear); 

            while ($ep1 < $ep2) {
                $mth += 1;
                if ($mth > 12) {
                    $mth = 1;
                    $year += 1;
                }
                $ep1  = timelocal($sec,$min,$hour,$day,$mth-1,$year); 
            }
        } else {
            prtw("WARNING: $now did not parse correctly\n");
        }
    } else {
        prtw("WARNING: $bgn did not parse correctly\n");
    }
    return $ep1;
}

sub get_next_year_dt($$) {
    my ($bgn,$now) = @_;
    my ($year,$mth,$day,$hour,$min,$sec);
    my ($nyear,$nmth,$nday,$nhour,$nmin,$nsec);
    my ($ep1,$ep2);
    $ep1 = -1;
    if ($bgn =~ /^\s*(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})Z\s*$/) {
        $year = $1;
        $mth  = $2;
        $day  = $3;
        $hour = $4;
        $min  = $5;
        $sec  = $6;
        $ep1  = timelocal($sec,$min,$hour,$day,$mth-1,$year); 
        if ($now =~ /^\s*(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})Z\s*$/) {
            $nyear = $1;
            $nmth  = $2;
            $nday  = $3;
            $nhour = $4;
            $nmin  = $5;
            $nsec  = $6;
            $ep2  = timelocal($nsec,$nmin,$nhour,$nday,$nmth-1,$nyear); 

            while ($ep1 < $ep2) {
                $year += 1;
                $ep1  = timelocal($sec,$min,$hour,$day,$mth-1,$year); 
            }
        } else {
            prtw("WARNING: $now did not parse correctly\n");
        }
    } else {
        prtw("WARNING: $bgn did not parse correctly\n");
    }
    return $ep1;
}


# DTSTART:20150707T133000Z
sub parse_datetime($) {
    my $dt = shift;
    my ($year,$mth,$day,$hour,$min,$sec);
    if ($dt =~ /^\s*(\d{4})(\d{2})(\d{2})T(\d{2})(\d{2})(\d{2})Z\s*$/) {
        $year = $1;
        $mth  = $2;
        $day  = $3;
        $hour = $4;
        $min  = $5;
        $sec  = $6;
        return timelocal($sec,$min,$hour,$day,$mth-1,$year); 
    }
    prtw("WARNING: $dt failed parsing...\n");
    return -1;
}

sub process_in_file($) {
    my ($inf) = @_;
    if (! open INF, "<$inf") {
        pgm_exit(1,"ERROR: Unable to open file [$inf]\n"); 
    }
    my @lines = <INF>;
    close INF;
    my $lncnt = scalar @lines;
    prt("Processing $lncnt lines, from [$inf]...\n");
    my ($line,$inc,$lnn,$len,$tline,@arr,$cnt,$act,$val,$ok,$last,$prev,$epoch,$date);
    my (@arr2,$act2,$val2,$epoch2,$date2,$freq2,$bgndate,$tmp,$nxtdate,$msg);
    my $day_of_week = 0;
    $lnn = 0;
    my %acts = ();
    my @stack = ();
    my $event = '';
    my $gotrpt = 0;
    my $gotdat = 0;
    my $expired = 0;
    my $rptstg = '';
    my %repeats = ();
    my $now = time();
    my $nowdate = lu_get_YYYYMMDD_hhmmss($now);
    $nowdate =~ s/\///g;
    $nowdate =~ s/://g;
    $nowdate =~ s/\s/T/g;
    $nowdate .= 'Z';
    $epoch = parse_datetime($nowdate);
    prt("Now date $nowdate ($epoch) $now\n");
    ###pgm_exit(1,"TEMP EXIT\n");

    foreach $line (@lines) {
        chomp $line;
        $lnn++;
        $tline = trim_all($line);
        $len = length($tline);
        next if ($len == 0);
        @arr = split(":",$line);
        $cnt = scalar @arr;
        if ($cnt == 2) {
            $act = $arr[0];
            $val = $arr[1];
            $ok = defined $bgnend{$val};
            $acts{$act} = 1;
            if ($act eq 'BEGIN') {
                push(@stack,$val);
                prt("$lnn: BGN $val\n") if (!$ok);
            } elsif ($act eq 'END') {
                if (@stack) {
                    $inc = pop @stack;
                    if ($val ne $inc) {
                        prt("$lnn: got END $val but last in stack is $inc\n");
                    }
                    if ($val eq 'VEVENT') {
                        if (length($event)) {
                            $msg = "EVENT: $event ";
                            $freq2 = '';
                            $expired = 0;
                            $day_of_week = 0;
                            if ($gotrpt) {
                                @arr = split(";",$rptstg);
                                $cnt = scalar @arr;
                                foreach $inc (@arr) {
                                    @arr2 = split("=",$inc);
                                    $cnt = scalar @arr2;
                                    if ($cnt == 2) {
                                        $act2 = $arr2[0];
                                        $val2 = $arr2[1];
                                        if ($act2 eq 'UNTIL') {
                                            $date2 = $val2."T230000Z";
                                            $epoch2 =  parse_datetime($date2);
                                            if ($epoch2 < $now) {
                                                $msg .= "EXPIRED ";
                                                $expired = 1;
                                            }
                                        } elsif ($act2 eq 'FREQ') {
                                            if (defined $freqs{$val2}) {
                                                $freq2 = $val2;
                                            } else {
                                                pgm_exit(1,"Error: add new FREQ $val2 ($inc) ** FIX ME ***\n");
                                            }
                                        } elsif ($act2 eq 'INTERVAL') {
                                            # TODO: What is this???
                                        } elsif ($act2 eq 'BYDAY') {
                                            if (defined $raindays{$val2}) {
                                                $day_of_week = $raindays{$val2};
                                            } else {
                                                prtw("WARNING: value $val2 not in raindays! ** FIX ME **\n");
                                            }
                                        } elsif ($act2 eq 'BYMONTHDAY') {
                                            # seems this is the same as begin date day
                                        } elsif ($act2 eq 'BYMONTH') {
                                            # seems this is the same as begin date month
                                        } else {
                                            prtw("WARNING: act2 $act2 NOT handled! $event\n");
                                        }
                                    } else {
                                        prtw("WARNING:$lnn: item $inc did not split in 2!\n");
                                    }
                                }
                                if (!$expired) {
                                    if ($freq2 eq 'WEEKLY') {
                                        # FREQ=WEEKLY;UNTIL=20150622;BYDAY=MO
                                    } elsif ($freq2 eq 'MONTHLY') {
                                        $tmp = get_next_month_dt($bgndate,$nowdate);
                                        $nxtdate = lu_get_YYYYMMDD_hhmmss($tmp);
                                        $msg .= ' ' while(length($msg) < $min_lenght);
                                        $msg .= "NEXT: $nxtdate ";
                                        #prt("NEXT: $nxtdate ");
                                        #pgm_exit(1,"\nTEMP EXIT\n");
                                    } elsif ($freq2 eq 'YEARLY') {
                                        $tmp = get_next_year_dt($bgndate,$nowdate);
                                        $nxtdate = lu_get_YYYYMMDD_hhmmss($tmp);
                                        $msg .= ' ' while(length($msg) < $min_lenght);
                                        $msg .= "NEXT: $nxtdate ";
                                    } else {
                                        ptrw("WARNING: Unhandled FREQ $freq2 $event\n");
                                    }
                                }
                            } elsif ($gotdat) {
                                if ($epoch < $now) {
                                    $msg .= "CLOSED ";
                                    $expired = 1;
                                }
                            }
                            prt("$msg\n") if (!$expired || $show_all_events);
                        }
                        $event = '';
                        $gotrpt = 0;
                        $gotdat = 0;
                    }
                } else {
                    prt("$lnn: got END $val with no stack\n");
                }
                prt("$lnn: END $val\n") if (!$ok);
            } elsif ($act eq 'SUMMARY') {
                prt("$lnn: SUM $val\n") if (VERB9());
                $event .= " " if (length($event));
                $event .= "$val";
            } elsif ($act eq 'RRULE') {
                prt("$lnn: RPT $val\n") if (VERB9());
                $event .= " " if (length($event));
                $event .= "RPT:$val";
                $gotrpt = 1;
                $rptstg = $val;
                $repeats{$val} = 1;
            } elsif ($act eq 'DTSTART') {
                $bgndate = $val;
                $epoch = parse_datetime($val);
                #$date = lu_get_YYYYMMDD_hhmmss_UTC($epoch);
                $date = lu_get_YYYYMMDD_hhmmss($epoch);
                prt("$lnn: DAT $val ($epoch) $date\n") if (VERB9());
                $event .= " " if (length($event));
                $event .= "$date";
                $gotdat = 1;
            }
        } else {
            prtw("WARNING: $lnn: $line did not split in 2! got $cnt!\n");
        }
    }
    @arr = sort keys %repeats;
    $cnt = scalar @arr;
    prt("Got $cnt different repeats...\n");
    ##prt( join("\n",@arr)."\n");

    @arr = sort keys %acts;
    $cnt = scalar @arr;
    prt("Got $cnt different actions...\n");
    ##prt( join(" ",@arr)."\n");
}

#########################################
### MAIN ###
parse_args(@ARGV);
process_in_file($in_file);
pgm_exit(0,"");
########################################

sub need_arg {
    my ($arg,@av) = @_;
    pgm_exit(1,"ERROR: [$arg] must have a following argument!\n") if (!@av);
}

sub parse_args {
    my (@av) = @_;
    my ($arg,$sarg);
    my $verb = VERB2();
    while (@av) {
        $arg = $av[0];
        if ($arg =~ /^-/) {
            $sarg = substr($arg,1);
            $sarg = substr($sarg,1) while ($sarg =~ /^-/);
            if (($sarg =~ /^h/i)||($sarg eq '?')) {
                give_help();
                pgm_exit(0,"Help exit(0)");
            } elsif ($sarg =~ /^v/) {
                if ($sarg =~ /^v.*(\d+)$/) {
                    $verbosity = $1;
                } else {
                    while ($sarg =~ /^v/) {
                        $verbosity++;
                        $sarg = substr($sarg,1);
                    }
                }
                $verb = VERB2();
                prt("Verbosity = $verbosity\n") if ($verb);
            } elsif ($sarg =~ /^l/) {
                if ($sarg =~ /^ll/) {
                    $load_log = 2;
                } else {
                    $load_log = 1;
                }
                prt("Set to load log at end. ($load_log)\n") if ($verb);
            } elsif ($sarg =~ /^o/) {
                need_arg(@av);
                shift @av;
                $sarg = $av[0];
                $out_file = $sarg;
                prt("Set out file to [$out_file].\n") if ($verb);
            } else {
                pgm_exit(1,"ERROR: Invalid argument [$arg]! Try -?\n");
            }
        } else {
            $in_file = $arg;
            prt("Set input to [$in_file]\n") if ($verb);
        }
        shift @av;
    }

    if ($debug_on) {
        prtw("WARNING: DEBUG is ON!\n");
        if (length($in_file) ==  0) {
            $in_file = $def_file;
            prt("Set DEFAULT input to [$in_file]\n");
        }
    }
    if (length($in_file) ==  0) {
        pgm_exit(1,"ERROR: No input files found in command!\n");
    }
    if (! -f $in_file) {
        pgm_exit(1,"ERROR: Unable to find in file [$in_file]! Check name, location...\n");
    }
}

sub give_help {
    prt("$pgmname: version $VERS\n");
    prt("Usage: $pgmname [options] in-file\n");
    prt("Options:\n");
    prt(" --help  (-h or -?) = This help, and exit 0.\n");
    prt(" --verb[n]     (-v) = Bump [or set] verbosity. def=$verbosity\n");
    prt(" --load        (-l) = Load LOG at end. ($outfile)\n");
    prt(" --out <file>  (-o) = Write output to this file.\n");
}

# eof - template.pl