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

my $usage = "$0 path/to/index\n";

die $usage unless @ARGV;

for my $invindex (@ARGV) {
    my $reader      = Lucy::Index::IndexReader->open( index => $invindex );
    my $schema      = $reader->get_schema();
    my $fields      = $schema->all_fields();
    my $seg_readers = $reader->seg_readers;
    for my $seg_reader (@$seg_readers) {
        my $seg_name = $seg_reader->get_seg_name;
        my $seg_num  = $seg_reader->get_seg_num;
        my $num_docs = $seg_reader->doc_max;
        printf( "Segment %s [%d] has %s docs\n",
            $seg_name, $seg_num, $num_docs );

        my $lex_reader = $seg_reader->obtain('Lucy::Index::LexiconReader');
        my $plist_reader
            = $seg_reader->obtain('Lucy::Index::PostingListReader');
        for my $field (@$fields) {
            my $lexicon = $lex_reader->lexicon( field => $field );
            while ( $lexicon && $lexicon->next ) {
                my $seg_freq = 0;
                my $plist    = $plist_reader->posting_list(
                    field => $field,
                    term  => $lexicon->get_term
                );
                while ( $plist->next ) {
                    $seg_freq++;
                }
                printf( " %24s: %s [%d]\n",
                    $field, $lexicon->get_term, $seg_freq );
            }
        }
    }

}