#!/usr/bin/perl -w
# vim: set sw=4 ts=4 tw=78 et si:
#
# mkdir_heute - choose or make a dir for 'heute' (today)
#
# This script scans a basedir (~/A) for directories named YYYY/MM/DD
# where YYYY, MM and DD are numbers corresponding to a year, month, day of
# month and prints them on STDERR. You may choose a directory from the list
# or a new directory which will be created and named after the current day.
#
# The script returns the choosen directory on STDOUT and may be used in a
# shell alias like this:
#
# alias cdheute='cd `mkdir_heute`'
#
# so that you may say 'cdheute' on the command line and your working directory
# will be changed to the choosen directory.
#
use strict;
use warnings;

use Directory::Organize;
use Getopt::Long;
use Term::ReadKey;

use version; our $VERSION = qv('v1.0.0');

$|++;

my %params;

init_params(\%params);

print choosedir(\%params);

#----- only subs from now on -----

sub init_params {
    my ($params) = @_;

    my $clo = { termreadkey => 1, };

    GetOptions($clo, 'basedir=s', 'columns=i', 'listlines=i', 'termreadkey!');

    if ($clo->{basedir}) {
        $params->{basedir} = $clo->{basedir};
    }
    else {
        $params->{basedir} = "$ENV{HOME}/A";
    }

    if ($clo->{termreadkey}) {
        my ($wchar, $hchar, $wpixels, $hpixels) = GetTerminalSize("STDOUT");
        $params->{columns} = defined $wchar ? $wchar  : 80;
        $params->{listlines} = defined $hchar ? $hchar - 4 : 21;
    }
    else {
        $params->{columns} = 80;
        $params->{listlines} = 21;
    }

    if ($clo->{columns}) {
        $params->{columns} = $clo->{columns}
    }

    if ($clo->{listlines}) {
        $params->{listlines} = $clo->{listlines};
    }

    return $params;
} # init_params()

sub makedir {
    my $path = shift;
    my $dir  = '';
    $path =~ s{^(.*[^/])$}{$1/}; # provide a sentinel
    while ($path =~ s{^([^/]*)/}{}) {
        if ($1) {
            $dir .= $1;
            (-d $dir) || mkdir($dir,0777) || return 0;
            $dir .= '/';
        }
        else {
            $dir = '/' unless ($dir);
        }
    }
    return 1;
} # makedir()

sub choosedir {
    my ($params)  = @_;

    my $basedir   = $params->{basedir};
    my $listlines = $params->{listlines};
    my $firstline = 0;

    my $do = Directory::Organize->new($basedir);

    NEW_DESCRIPTIONS:
    while (1) {
        my @directories = $do->get_descriptions();
        my $lastline  = scalar(@directories) - $listlines - 1;

        SHOW_DESCRIPTIONS:
        while (1) {
            show_dirs(\@directories,$params,$firstline);

        # let the user choose a directory
            my $input = '';
            while (1) {
                return '.' if eof(STDIN);
                my $project_text = '';
                $input = <STDIN>;
                chomp $input;
                if ($input =~ /^\d+$/) {
                    if ($input < scalar @directories) {
                        printf STDERR "=== %s ===\n", $directories[$input]->[1];
                        return $basedir . '/' . $directories[$input]->[0];
                    }
                }
                elsif ($input =~ /^f(irst)?$/i) {
                    $firstline = 0;
                    next SHOW_DESCRIPTIONS;
                }
                elsif ($input =~ /^l(ast)?$/i) {
                    $firstline = $lastline;
                    next SHOW_DESCRIPTIONS;
                }
                elsif ($input =~ /^n(ext)?$/i) {
                    $firstline += $listlines;
                    $firstline = $lastline if ($firstline > $lastline);
                    next SHOW_DESCRIPTIONS;
                }
                elsif ($input =~ /^p(revious)?$/i) {
                    $firstline -= $listlines;
                    $firstline = 0 if ($firstline < 0);
                    next SHOW_DESCRIPTIONS;
                }
                elsif ($input =~ /^\/(.*)$/i) {
                    $do->set_pattern($1);
                    $firstline = 0;
                    next NEW_DESCRIPTIONS;
                }
                elsif ($input =~ m{^d
                                     \s*
                                     (?:
                                       ([=<>])      # operator
                                       \s*
                                       (\d{4})      # year
                                       -?
                                       (\d\d)?      # month
                                       -?
                                       (\d\d)?      # day
                                     )?
                                   }ix) {
                    $do->set_time_constraint($1,$2,$3,$4);
                    $firstline = 0;
                    next NEW_DESCRIPTIONS;
                }
                elsif ($input =~ /^(\.|q(uit)?)$/i) {
                    return '.';
                }
                elsif ($input =~ /^\+(.*)$/) {
                    if ($1) {
                        $project_text = $1;
                        $project_text =~ s/^\s+//;
                        $project_text =~ s/\s+$//;
                        return $do->new_dir($project_text);
                    }
                    next SHOW_DESCRIPTIONS;
                }
            }
        } # SHOW_DESCRIPTIONS
    } # NEW_DESCRIPTIONS
} # choosedir()

sub show_dirs {
    my ($dirs,$params,$firstline) = @_;
    my $listlines = $params->{listlines};
    my $columns   = $params->{columns} - 23;
    my $i = 0;
    foreach my $dir (@$dirs) {
        printf STDERR "%-7s: %-12s: %.*s\n", $i, $dir->[0], $columns, $dir->[1]
            if ($i >= $firstline);
        last if ($i - $firstline >= $listlines);
        $i++;
    }
    print STDERR "+(plus): new directory (add description after '+')\n";
    print STDERR "q      : current directory\n";
} # show_dirs()

__END__

=head1 NAME

mkdir_heute - create and find directories interactive

=head SYNOPSIS

  mkdir_heute

  mkdir_heute --basedir=~/archive

  mkdir_heute --listlines=15 --columns=80

=head1 VERSION

This documentation refers to version v1.0.0.

=head1 USAGE

This script scans a basedir (~/A) for directories named YYYY/MM/DD
where YYYY, MM and DD are numbers corresponding to a year, month, day of
month and prints them on STDERR.

The script returns the choosen directory on STDOUT and may be used in a
shell alias like this:

  alias cdheute='cd `mkdir_heute`'

so that you may say 'cdheute' on the command line and your working directory
will be changed to the choosen directory.

When invoked you may

=over 4

=item *

choose a directory from the list with it's number

=item *

choose the current directory with 'q' or '.'

=item *

advance to the next or last page with 'n' or 'l'

=item *

return to the previous or first page with 'p' or 'f'

=item *

constrain the shown directories with '/' and a pattern

=item *

constrain the creation date of the directories with 'd' followed by '=', '<'
or '>' and a date (eg. 2009, 2009-04 or 2009-04-24)

=item *

create a new directory with '+' followed by a description for it

=back

=head1 DESCRIPTION

=head2 Command Line Arguments

=over 4

=item --basedir

With this argument it is possible to redirect the script to another base
directory under which it scans for project descriptions to display. A new
directory would be created below this directory.

  mkdir_heute --basedir=~/archive

  mkdir_heute -b ~/archive

=item --columns

Limit the displaywidth to the given number of columns.

  mkdir_heute --columns=80

  mkdir_heute -c 80

=back

=item --listlines

Limit the number of listed lines.
This should be 4 lines less than your screen provides.

  mkdir_heute --listlines=21

  mkdir_heute -l 15

=back

=item --termreadkey / --notermreadkey

The size of the screen is determined by C<Term::ReadKey::GetTerminalSize()>.
If your system has no functioning module I<Term::ReadKey>, you can switch
this off and the programs defaults to 80 columns and 21 listlines.
Off course you set other limits with C<-c> or C<-l> instead.

=back

Usually 

=head1 DIAGNOSTICS

=head2 Unable to get Terminal Size. The TIOCGWINSZ ioctl didn't work. The
 COLUMNS and LINES environment variables didn't work. The resize program
 didn't work. at /usr/lib/perl5/Term/ReadKey.pm line 343.

This happened to me especially on elder systems when invoked via backtics
such as

  cd `mkdir_heute`

although the program works fine when invoked directly.

One workaround is to install the program I<resize> which comes on
Debian GNU Linux within the package I<xutils>.

If you can't install the program I<resize>, you could disable I<Term::ReadKey>
at program startup like this

  cd `mkdir_heute --notermreadkey`

=head1 AUTHOR

Mathias Weidner

=head1 LICENCE AND COPYRIGHT

Copyright (c) 2009-2018 Mathias Weidner (mamawe@cpan.org).
All rights reserved.

This module is free software; you can redistribute and/or modify it
under the same terms as Perl itself. See L<perlartistic>.

This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.