use strict;
use warnings;

#convert DDHHMM into int of m
sub d2i {
	my( $d, $h, $m ) = unpack '(A2)*', $_[0];
	return ( ( $d - 1 ) * 24 + $h ) * 60 + $m;
}

#convert int of m into DDHHMM
sub i2d {
	sprintf "%02d%02d%02d", int($_[0]/1440)+1, int($_[0]/60)%24, $_[0]%60;
}

#find and open files ... only ever 1 of each file type
my ($d,$t);
foreach (<*>) {
	$d = $_ if (/\.dat$/);
	$t = $_ if (/\.mrg$/);
}
open(D, $d) or die "Unable to open DAT file.  Exiting.\n"; my @dl = <D>; close(D);
open(T, $t) or die "Unable to open MRG file.  Exiting.\n"; my @tl = <T>; close(T);

#create big array of data points with added d2i
my @big;
foreach (@dl,@tl) {
	chomp($_);
	if (/^\/\d\d\d\d\d\d\//) {
		my @n = split(/\//);
		push @big,[$n[1],$n[2],$n[5],d2i($n[1]),d2i$n[2]];
	}
}

#break by day if needed
my @ex = map {
	my $s = $_->[3];
	my $e = $_->[4];
	my @out;
	while (int($s/1440) != int($e/1440)) { 
		my $newe = ( int($s/1440) + 1) * 1440 - 1;
		push @out, [i2d($s),i2d($newe),$_->[2],$s,$newe]; 
		$s = $newe + 1;
	}
	(@out, [i2d($s),$_->[1],$_->[2],$s,$e]); 
} @big;

#build parallel arrays of minute and values ... total minimized for overlaps
my (@tally, @id);
for my $e (0 .. $#ex) {
	my $r = $ex[$e];
	for my $i ($r->[3] .. $r->[4] ) {
		if( !defined($tally[$i]) or $tally[$i] > $r->[2] ) {
			$tally[$i] = $r->[2];
			$id[$i] = $e;
		}
	}
}

#recreate [DDHHMM,DDHHMM,V] with overarching tally and ids
my @res;
my $i = 0;
while ($i < $#id) {
	++$i until defined $id[$i];
	my $id = $id[$i];
	my $start = $i;
	++$i while defined ($id[$i]) and $id[$i] == $id;
	my $end = $i - 1;
	push @res, [i2d($start),i2d($end),$tally[$start]];
}

#output organized final to file
open (C,'>CDA.txt');
my @last = ("","","");
print C "To do later: ... this still needs specific formatting work(easy)\n";
foreach (@res) {
	if (substr($last[0],0,2) ne substr(@$_[0],0,2)) { print C "\n"; }
	print C "@$_[0]  @$_[1]  @$_[2]\n";
	$last[0] = @$_[0];
}
close(C);

#[temporary] report comparison for manual check
@big = sort {$a->[0] <=> $b->[0]} (@big);
foreach (@big) {
	print "@$_[0] @$_[1] @$_[2]\n";
}
print "\n";
foreach (@res) {
	print "@$_[0] @$_[1] @$_[2]\n";
}