#!/usr/bin/perl
# vim: sts=4 sw=4 ts=4 expandtab:
=pod

=head1 NAME

git-id

=head1 SYNOPSIS

    git-id

=head1 DESCRIPTION

Runs git-status and prepends numeric ids to filenames.

=head1 OPTIONS

=over 4

=item -h

Show this help message

=item -s

=item --column

=item -u(no|normal|all)

=item --color=(always|auto|never)

These options are similar to git-status'.

=back

=head1 SEE ALSO

    git-number(1), git-list(1)

=cut

use strict;
use warnings;
use Cwd;

my $red = "\e[31m";
my $normal = "\e[0m";
my $git_dir = `git rev-parse --git-dir`;
chomp $git_dir;

my $gitids = "$git_dir/gitids.txt";

my $color = 'always';
my $STATUS_DEFAULT = 0;
my $STATUS_SHORT = 1;
my $status_style = $STATUS_DEFAULT;
my $status_opt = '';

my $untracked_in_columns = 0;
while (scalar @ARGV && $ARGV[0] =~ /^-/) {
    my $option = shift @ARGV;
    last if $option eq '--';
    if ($option =~ /--color=(always|auto|never)/) {
        $color = $1;
        if ($color =~ /never/) {
            $red = $normal = '';
        }
    } elsif ($option eq '--short') {
        $status_style = $STATUS_SHORT;
    } elsif ($option =~ m{^-u(no|normal|all)$}) {
        $status_opt .= " $option";
    } elsif ($option =~ /^--column/) {
        if ($option eq '--column=never' || ($option =~ /--column(=auto)?$/ && ! -t STDOUT)) {
            $untracked_in_columns = 0;
        } else {
            $untracked_in_columns = 1;
        }
        $status_opt .= " $option";
    } else {
        print "Unknown option: $option\n";
        exit 1;
    }
}

if (! $untracked_in_columns) {
    $status_opt .= " --column=never";
}

my @status_option_for = ( '', '--short' );
my $status_format = $status_option_for[$status_style];
my $git_cmd = "git -c color.status=$color status $status_opt $status_format "
              . join(' ', @ARGV);
open my $git_status, "$git_cmd|"
    or die "Error: $!";

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

# Headers
print $cache "cwd: " . getcwd . "\n";
print $cache "status-format: $status_format\n";
print $cache "\n";

my $seen_untracked = 0;
my @untracked;
my $c = 1;
while (my $line = <$git_status>) {
    if ($line =~ /Untracked files:/) {
        $seen_untracked = 1;
    }

    if ($status_style == $STATUS_DEFAULT) {
        if ($seen_untracked && $line =~ /\t/ && $untracked_in_columns) {
            push @untracked, $line;
            last;
        }

        if ($line =~ /#\t/) {
            $line =~ s/#\t/#$c\t/;
            $c += 1;
        } elsif ($line =~ /\t/) {
            $line =~ s/\t/$c\t/;
            $c += 1;
        }
    } elsif ($status_style == $STATUS_SHORT) {
        if ($line !~ /^#/) {
            $line =~ s/^/$c /;
            $c += 1;
        }
    }
    show_and_cache($line);
}

if ($untracked_in_columns) {
    my $seen_files = 0;
    my @the_rest;
    while (my $line = <$git_status>) {
        if ($line =~ /\t/) {
            $seen_files = 1;
            push @untracked, $line;
        } else {
            push @the_rest, $line;
        }
    }

    my $rows = @untracked;
    foreach my $line (@untracked) {
        my $id = $c;
        $line =~ s/([\t ])(\S)/add_number(\$id, $1, $2, $rows)/ge;
        $line =~ s/^ +//;
        show_and_cache($line);
        $c += 1;
    }
    print join "", @the_rest;
}

close $git_status;
close $cache;
exit 0;

sub show_and_cache {
    my ($line) = @_;
    my $tocache = $line;
    $tocache =~ s/{(\d+)}[\t ]{1,2}/\n$1\t/g;
    $line =~ s/{(\d+)}/$1/g;
    print $line;
    $tocache =~ s/\e\[(\d*(;\d*)*)m//g;
    if ($untracked_in_columns) {
        $tocache =~ s/\s*\n/\n/gms; # Trailing spaces from columnar formatting
    }
    print $cache $tocache;
}

sub add_number {
    my ($nref, $space, $first_char, $incr) = @_;

    my $num = $$nref;
    if ($num < 10 && $space eq ' ') {
        $num = "{$num} ";
    } else {
        $num = "{$num}";
    }
    my $str = "$normal$num$space$red$first_char";
    $$nref += $incr;
    return $str;
}