#!/usr/bin/perl -w
#
# $Revision: 1.1.1.1 $
#
# $Date: 2003-07-27 11:07:11 $

package Elinfo;

sub new {
    bless {
        COUNT  => 0,
        MINLEV => undef,
        SEEN   => 0,
        CHARS  => 0,
        EMPTY  => 1,
        PTAB   => {},
        KTAB   => {},
        ATAB   => {}
      },
      shift;
}

package main;

use English;
use XML::Parser;

my %elements;
my $seen = 0;
my $root;

my $file = shift;

my $subform = '      @<<<<<<<<<<<<<<<      @>>>>';
die "Can't find file \"$file\""
  unless -f $file;

my $parser = new XML::Parser( ErrorContext => 2 );
$parser->setHandlers(
    Start => \&start_handler,
    Char  => \&char_handler
);

$parser->parsefile($file);

set_minlev( $root, 0 );

my $el;

foreach $el ( sort bystruct keys %elements ) {
    my $ref = $elements{$el};
    print "\n================\n$el: ", $ref->{COUNT}, "\n";
    print "Had ",                      $ref->{CHARS}, " bytes of character data\n"
      if $ref->{CHARS};
    print "Always empty\n"
      if $ref->{EMPTY};

    showtab( 'Parents',    $ref->{PTAB}, 0 );
    showtab( 'Children',   $ref->{KTAB}, 1 );
    showtab( 'Attributes', $ref->{ATAB}, 0 );
}

################
## End of main
################

sub start_handler {
    my $p  = shift;
    my $el = shift;

    my $elinf = $elements{$el};

    if ( not defined($elinf) ) {
        $elements{$el} = $elinf = new Elinfo;
        $elinf->{SEEN} = $seen++;
    }

    $elinf->{COUNT}++;

    my $partab = $elinf->{PTAB};

    my $parent = $p->current_element;
    if ( defined($parent) ) {
        $partab->{$parent}++;
        my $pinf = $elements{$parent};

        # Increment our slot in parent's child table
        $pinf->{KTAB}->{$el}++;
        $pinf->{EMPTY} = 0;
    }
    else {
        $root = $el;
    }

    # Deal with attributes

    my $atab = $elinf->{ATAB};

    while (@_) {
        my $att = shift;

        $atab->{$att}++;
        shift;    # Throw away value
    }

}    # End start_handler

sub char_handler {
    my ( $p, $data ) = @_;
    my $inf = $elements{ $p->current_element };

    $inf->{EMPTY} = 0;
    if ( $data =~ /\S/ ) {
        $inf->{CHARS} += length($data);
    }
}    # End char_handler

sub set_minlev {
    my ( $el, $lev ) = @_;

    my $elinfo = $elements{$el};
    if ( !defined( $elinfo->{MINLEV} ) or $elinfo->{MINLEV} > $lev ) {
        my $newlev = $lev + 1;

        $elinfo->{MINLEV} = $lev;
        foreach ( keys %{ $elinfo->{KTAB} } ) {
            set_minlev( $_, $newlev );
        }
    }
}    # End set_minlev

sub bystruct {
    my $refa = $elements{$a};
    my $refb = $elements{$b};

    $refa->{MINLEV} <=> $refb->{MINLEV}
      or $refa->{SEEN} <=> $refb->{SEEN};
}    # End bystruct

sub showtab {
    my ( $title, $table, $dosum ) = @_;

    my @list = sort keys %{$table};

    if (@list) {
        print "\n   $title:\n";

        my $item;
        my $sum = 0;
        foreach $item (@list) {
            my $cnt = $table->{$item};
            $sum += $cnt;
            formline( $subform, $item, $cnt );
            print $ACCUMULATOR, "\n";
            $ACCUMULATOR = '';
        }

        if ( $dosum and @list > 1 ) {
            print "                            =====\n";
            formline( $subform, '', $sum );
            print $ACCUMULATOR, "\n";
            $ACCUMULATOR = '';
        }
    }

}    # End showtab

# Tell Emacs that this is really a perl script
# Local Variables:
# mode:perl
# End: