#!/usr/bin/perl
# vim: sts=4 sw=4 ts=4 expandtab:
# gl - List files from .git/gitids.txt

use strict;
use warnings;
use File::Spec;
use Cwd qw/getcwd abs_path/;

=pod

=head1 NAME

git-list

=head1 SYNOPSIS

    git-list [-h] [number pattern]

=head1 DESCRIPTION

git-list lists the corresponding filenames given their numbers that was
previously assigned by git-id. It lists one filename per line of output. Any
other argument or numbers that has no filenames associated with it will be
printed as is.

[number pattern] can either be a single number or a range:

    git-list 1 5-6

=head1 OPTIONS

    -h         Show this help message

=head1 SEE ALSO

    git-number(1), git-id(1)

=cut

if (defined $ARGV[0] && $ARGV[0] eq '-h') {
    system(qq[perldoc $0]);
    exit 0;
}

my $wanted_ids = explode_args(@ARGV);

if (ref $wanted_ids eq 'ARRAY') {
    my $file_for = get_file_ids();
    foreach my $id (@$wanted_ids) {
        if (defined $file_for->{$id}) {
            print $file_for->{$id};
        } else {
            print $id;
        }
        print "\n";
    }
} elsif ($wanted_ids eq 'all') {
    my @file_list = get_file_list();
    foreach my $entry (@file_list) {
        print  $entry->{filename} . "\n";
    }
}
exit 0;
# Add subs below this line

sub get_file_list {
    my $git_dir = `git rev-parse --git-dir`;
    chomp $git_dir;

    my $gitids = "$git_dir/gitids.txt";
    if (! -f $gitids) {
        print "Please run git-number first\n";
        exit 1;
    }

    open my $cache, "<$gitids" or die "Error: $!";

    my $headers = read_headers($cache);
    my $cwd = getcwd();
    my $needfixdir = 0;
    if ($headers->{cwd} ne $cwd) {
        $needfixdir = 1;
        $cwd = abs_path($cwd);
    }
    my @file_list;
    my $status_processor_for = {
        '' => sub {
            while (my $line = <$cache>) {
                next if $line !~ /^#?[0-9]+\t/;
                chomp $line;
                if (my ($number, $status, $filename)
                        = $line =~ /^#?([0-9]+)\t([^:]+:\s+)?(.*)/) {



                    if ($filename =~ / \(.*\)$/ && ! -e $filename) {
                        # Looks like a submodule status, see if it really is a submodule
                        my ($dir) = $filename =~ /(.*) \(.*\)$/;
                        if (-d $dir && -e "$dir/.git") {
                                $filename = $dir;
                        }
                    }

                    if ($needfixdir) {
                        $filename = fixdir($filename, $headers->{cwd}, $cwd);
                    }
                    push @file_list, {
                            number => $number,
                            status => $status,
                            filename => $filename,
                        };
                }
            }
        },
        '--short' => sub {
            while (my $line = <$cache>) {
                next if $line !~ /^[0-9]+\s/;
                chomp $line;
                if (my ($number, $status, $filename)
                        = $line =~ /^([0-9]+)\s+([^ ]+)\s+(.*)/) {

                    if ($needfixdir) {
                        $filename = fixdir($filename, $headers->{cwd}, $cwd);
                    }
                    push @file_list, {
                            number => $number,
                            status => $status,
                            filename => $filename,
                        };
                }
            }
        },
    };

    my $status_format = $headers->{'status-format'};
    $status_processor_for->{$status_format}->();
    close $cache;
    return @file_list;
}

sub read_headers {
    my ($cache) = @_;
    my %headers;
    while (my $line = <$cache>) {
        chomp $line;
        last if length $line == 0;
        my ($field, $value) = split(/:\s*/, $line, 2);
        $headers{$field} = $value;
    }
    return \%headers;
}

sub get_file_ids {
    my @file_list = get_file_list();

    my %file_for;
    foreach my $entry (@file_list) {
        my $filename = $entry->{filename};
        # First we escape characters that need escaping
        if ($filename =~ /[`\$"]/) {
            $filename =~ s/([`\$"])/\\$1/g;
        }
        # Then we double-quote the name if necessary
        if ($filename =~ /[ '\[\]()&]/) {
            $filename = '"' . $filename . '"';
        }
        $file_for{$entry->{number}} = $filename;
    }
    return \%file_for;
}

sub explode_args {
    my (@ARGV) = @_;
    if (scalar @ARGV == 0) {
        return 'all';
    }
    my @wanted_ids;
    foreach my $arg (@ARGV) {
        if ($arg =~ m/^[0-9]+$/) {
            push @wanted_ids, $arg;
        } elsif ($arg =~ m/^([0-9]+)-([0-9]+)/) {
            my $a = $1;
            my $b = $2;
            if ($a > $b) {
                $a = $b;
                $b = $1;
            }
            push @wanted_ids, $a..$b;
        } else {
            push @wanted_ids, $arg;
        }
    }
    return \@wanted_ids;
}

sub fixdir {
    my ($filename, $orig_cwd, $cwd) = @_;
    my $abspath = File::Spec->catfile($orig_cwd, $filename);
    $abspath = abs_path($abspath);
    return File::Spec->abs2rel($abspath, $cwd);
}