srtmerge

#!/usr/bin/perl
use strict;
use warnings;

# Processes $ARGV[0].
my %tshash;
my $tskey;
my @tsvs;

open(my $tsh, '<', $ARGV[0]) or die "Could not open file '$ARGV[0]' $!";
my @tslines = <$tsh>;
close($tsh);

@tslines = grep { $_ !~ /^ *$/ } @tslines;

for (my $i = 0; $i < @tslines; $i++) {
    if ($tslines[$i] =~ /^(\d+)$/) {
        if ($i + 1 < @tslines && $tslines[$i + 1] =~ /^\d{2}:\d{2}:\d{2},\d{3} --> \d{2}:\d{2}:\d{2},\d{3}$/) {
            # Appends '%-' for easy parsing.
            $tslines[$i] =~ s/^(\d+)$/$1%-/;
        }
    }
}

# Constructs hashmap of number to (timestamp, text).
foreach my $line (@tslines) {
    chomp $line;
    if ($line =~ /^(\d+)%-/) {
        if (defined $tskey) {
            $tshash{$tskey} = [shift @tsvs, join("\n", @tsvs)];
        }
        $tskey = $1;
        @tsvs = ();
    } else {
        push @tsvs, $line;
    }
}

if (defined $tskey) {
    $tshash{$tskey} = [shift @tsvs, join("\n", @tsvs)];
}

# Processes $ARGV[1].
my %hash;
my $key;
my $value = '';

open(my $fh, '<', $ARGV[1]) or die "Could not open file '$ARGV[1]' $!";
my @lines = <$fh>;
close $fh;

# Appends `%-` to each number, and removes timestamp.
for (my $i = 0; $i < @lines; $i++) {
    if ($lines[$i] =~ /^(\d+)$/) {
        if ($i + 1 < @lines && $lines[$i + 1] =~ /^\d{2}:\d{2}:\d{2},\d{3} --> \d{2}:\d{2}:\d{2},\d{3}$/) {
            $lines[$i] =~ s/^(\d+)$/$1%-/;
        }
    }
}

@lines = grep { $_ !~ /^[0-9][0-9]:[0-9][0-9]:[0-9][0-9],[0-9][0-9][0-9]/ } @lines;
@lines = grep { $_ !~ /^ *$/ } @lines;

# Constructs hashmap of number to text
foreach my $line (@lines) {
    chomp $line;
    if ($line =~ /^(\d+) *% *-/) {
        if (defined $key) {
            $hash{$key} = $value;
        }
        $key = $1;
        $value = '';
    } else {
        $value .= "$line\n";
    }
}

if (defined $key) {
    $hash{$key} = $value;
}

# Merges argv1 text to argv2 text
foreach my $tskey (sort { $a <=> $b } keys %tshash) {
    print "$tskey\n";
    print "$tshash{$tskey}->[0]\n";

    if (exists $hash{$tskey} && $hash{$tskey} ne "") {
        my $value = $hash{$tskey};
        chomp $value;
        print "$value\n\n";
    } else {
        my $value = $tshash{$tskey}->[1];
        chomp $value;
        print "$value\n\n";
    }
}