#! /usr/local/bin/perl

# split stanzas with multiple entries into more stanzas with unique entries

# read input file

if (read (STDIN, $text, 400000) == 400000) {
  die "input file too long (>= 400000 bytes)";
};

close (STDIN);

@text = split (/\s*\n\s*\n\s*/, $text);

undef $text;

foreach $stanza (@text) {
  @lines = split (/\s*\n\s*/, $stanza);
  for ($i=0; $i<=$#lines; $i++) {
    if ($lines[$i] =~ /([^:]*):/) {
      $hdr = $1;
      $bdy = $';
      $hdr = &strip ($hdr);
      $bdy = &strip ($bdy);
      $lines[$i] = "$hdr:$bdy";
    } elsif (! /^\s*(\#.*)?$/) {
      die "illegal line: $lines[$i]";
    };
  };
  @lines = sort @lines;
  undef @ix;
  undef @iz;
  for ($i=0; $i<=$#lines; $i++) {
    $lines[$i] =~ /([^:]*):/;
    $hdr[$i] = $1;
    $bdy[$i] = $';
    if (! $i || ($hdr[$i] ne $hdr[$i-1])) {
      push (@iz, $i);
    };
  };
  push (@iz, $#lines+1);
  undef @lines;
  @ix = @iz;
  pop (@ix);
  LOOP: for (;;) {
    foreach $i (@ix) {
      print "$hdr[$i]: $bdy[$i]\n";
    };
    print "\n";
    for ($i=$#ix; $i>=0; $i--) {
      $ix[$i]++;
      if ($ix[$i] >= $iz[$i+1]) {
        last LOOP if $i==0;
        $ix[$i] = $iz[$i];
      } else {
        last;
      };
    };
  };
};

sub strip {
  local ($_) = $_[0];
  local ($x, $y);
  if (/^\s*$/) {
    return '';
  } else {
    /^\s*(\S)/;
    $x = $1;
    $y = $';
    if ($y =~ /(\S)\s*$/) {
      return $x . $` . $1;
    } else {
      return $x;
    };
  };
}