#!/usr/bin/perl
package App::Music::ChordPro::Output::Common;
use strict;
use warnings;
# Substitute %X sequences in title formats.
sub fmt_subst {
    my ( $s, $t, $strict ) = @_;
    my $res = "";
    my $m = $s->{meta};
    while ( $t =~ /^(.*?)\%(.)(.*)/ ) {
        $res .= $1;
        $t = $3;
        my $f = $2;
        if ( $f eq '{' && $t =~ /^(.*?)\}(.*)/ ) {
            my ( $key, $rest ) = ( lc($1), $2 );
            ( $key, my $inx ) = ( $1, $2 ) if $key =~ /^(.*)\.(\d+)$/;
            if ( defined $m->{$key} ) {
                if ( $inx ) {
                    if ( $inx > 0 && $inx <= @{ $m->{$key} } ) {
                        $res .= $m->{$key}->[$inx-1];
                    }
                }
                else {
                    $res .= join( $::config->{metadata}->{separator}, @{ $m->{$key} } );
                }
            }
            $t = $rest;
            next;
        }
        next if $strict;
        if ( $f eq '%' ) {
            $res .= '%';
        }
        elsif ( $f eq 't' ) {
            $res .= $m->{title}->[0] if $m->{title}->[0];
        }
        elsif ( $f eq 's' ) {
            $res .= $m->{subtitle}->[0] if $m->{subtitle}->[0];
        }
        elsif ( $f eq 'p' ) {
            $res .= $s->{page} if $s->{page};
        }
        elsif ( $f eq 'P' ) {
            $res .= $s->{page};      ####FIXME
        }
        else {
            warn("Ignoring unknown %$f sequence in title.");
        }
    }
    $res . $t;
}
1;