#!/usr/bin/perl -w

=head1 NAME

chronicle-spooler - Automatically post pre-written entries.

=cut

=head1 SYNOPSIS


  Path Options:

   --config         Specify a configuration file to read.
   --spool-dir      Specify where pending entries are located.
   --live-dir       Specify where the entries should be moved to.


  Post-Spool Commands:

   --post-move   Specify a command to execute once entries have been moved.

  Optional Features:

   --test        Only report on what would be executed.

  Help Options:

   --help        Show the help information for this script.
   --manual      Read the manual for this script.

=cut


=head1 ABOUT

  chronicle-spooler is a companion scrip to the chronicle blog compiler.

  It is designed to facilitate posting new entries automatically upon
 particular dates.  (ie. If you have ten written blog entries in a spool
 directory it will move them into place upon the date you've specified.)

=cut


=head1 DATE SPECIFICATION

  To specify the date a particular entry should be made live you
 must add another pseudo-header to your blog entry files, as follows:

=for example begin

    Title:  This is the title of the blog post
    Date:  2nd March 2007
    Publish: 15th April 2008
    Tags: one, two, three, long tag

    The text of your entry goes here.

=for example end

  In this example we know that this entry will be made live upon the
 15th April 2008, and not before.

=cut

=head1 AUTHOR

 Steve
 --
 http://www.steve.org.uk/

=cut

=head1 LICENSE

Copyright (c) 2008 by Steve Kemp.  All rights reserved.

This module is free software;
you can redistribute it and/or modify it under
the same terms as Perl itself.
The LICENSE file contains the full text of the license.

=cut


use strict;
use warnings;


use Date::Parse;
use File::Copy;
use Getopt::Long;
use Pod::Usage;


#
#  Release number
#
#  NOTE:  Set by 'make release'.
#
my $RELEASE = 'UNRELEASED';


#
#  Our configuration options.
#
my %CONFIG;


#
#  Read the global and per-user configuration files, if they exist.
#
readConfigurationFile("/etc/chroniclerc");
readConfigurationFile( $ENV{ 'HOME' } . "/.chroniclerc" );


#
#  Parse the command line arguments.
#
parseCommandLineArguments();


#
#  Another configuration file?
#
readConfigurationFile( $CONFIG{ 'config' } ) if ( defined $CONFIG{ 'config' } );


#
#  Make sure we have arguments which are sane.
#
#  Specifically we need an input directory and an output directory.
#
#
sanityCheckArguments();


#
#  Find the potentially pending entries.
#
my @files = findPendingPosts( $CONFIG{ 'spool-dir' } );


#
#  Process each entry
#
my $live = 0;
foreach my $entry ( sort(@files) )
{
    if ( shouldBeLive($entry) )
    {
        if ( $CONFIG{ 'test' } )
        {
            print "test: make entry live: $entry\n";
        }
        else
        {
            makeEntryLive($entry);
            $live += 1;
        }
    }
}


#
#  If we should run our command do so.
#
if ( ( $CONFIG{ 'post-move' } ) && $live )
{
    if ( $CONFIG{ 'test' } )
    {
        print "test: should run: $CONFIG{'post-move'}\n";
    }
    else
    {
        system( $CONFIG{ 'post-move' } );
    }
}



#
#  All done.
#
exit;



=begin doc

  Parse the command line arguments this script was given.

=end doc

=cut

sub parseCommandLineArguments
{
    my $HELP    = 0;
    my $MANUAL  = 0;
    my $VERSION = 0;

    #
    #  Parse options.
    #
    if (
        !GetOptions(

            # input / output
            "spool-dir=s", \$CONFIG{ 'spool-dir' },
            "live-dir=s",  \$CONFIG{ 'live-dir' },

            # testing?
            "test", \$CONFIG{ 'test' },

            # command?
            "post-move=s", \$CONFIG{ 'post-move' },

            # Help options
            "help",    \$HELP,
            "manual",  \$MANUAL,
            "verbose", \$CONFIG{ 'verbose' },
            "version", \$VERSION,

        )
      )
    {
        exit;
    }

    pod2usage(1) if $HELP;
    pod2usage( -verbose => 2 ) if $MANUAL;

    if ($VERSION)
    {
        print("chronicle release $RELEASE\n");
        exit;
    }
}



=begin doc

  Read the specified configuration file if it exists.

=end doc

=cut

sub readConfigurationFile
{
    my ($file) = (@_);

    #
    #  If it doesn't exist ignore it.
    #
    return if ( !-e $file );


    my $line = "";

    open( FILE, "<", $file ) or die "Cannot read file '$file' - $!";
    while ( defined( $line = <FILE> ) )
    {
        chomp $line;
        if ( $line =~ s/\\$// )
        {
            $line .= <FILE>;
            redo unless eof(FILE);
        }

        # Skip lines beginning with comments
        next if ( $line =~ /^([ \t]*)\#/ );

        # Skip blank lines
        next if ( length($line) < 1 );

        # Strip trailing comments.
        if ( $line =~ /(.*)\#(.*)/ )
        {
            $line = $1;
        }

        # Find variable settings
        if ( $line =~ /([^=]+)=([^\n]+)/ )
        {
            my $key = $1;
            my $val = $2;

            # Strip leading and trailing whitespace.
            $key =~ s/^\s+//;
            $key =~ s/\s+$//;
            $val =~ s/^\s+//;
            $val =~ s/\s+$//;

            # command expansion?
            if ( $val =~ /(.*)`([^`]+)`(.*)/ )
            {

                # store
                my $pre  = $1;
                my $cmd  = $2;
                my $post = $3;

                # get output
                my $output = `$cmd`;
                chomp($output);

                # build up replacement.
                $val = $pre . $output . $post;
            }

            # Store value.
            $CONFIG{ $key } = $val;
        }
    }

    close(FILE);
}



=begin doc

  Sanity check our arguments, and setup to make sure there is nothing
 obviously broken.

=end doc

=cut

sub sanityCheckArguments
{
    if (    ( !$CONFIG{ 'spool-dir' } )
         || ( !-d $CONFIG{ 'spool-dir' } ) )
    {
        print <<EOF;

  Please specify the spool directory, which contains the entries which
 are to be moved into the live directory in the future.

EOF
        exit;
    }

    if (    ( !$CONFIG{ 'live-dir' } )
         || ( !-d $CONFIG{ 'live-dir' } ) )
    {
        print <<EOF;

  Please specify the output directory into which entries should be
 moved to make them live.

EOF
        exit;
    }
}



=begin doc

  Find any files that might be in the pending directory.

=end doc

=cut

sub findPendingPosts
{
    my ($dir) = (@_);

    my $pattern = "*";
    my @files;

    foreach my $file ( sort( glob("$dir/$pattern") ) )
    {
        push( @files, $file ) unless ( -d $file );
    }

    return (@files);
}


=begin doc

  Read the given file and see if it should be published now.
  That means that the file contained a "Publish:" pseudo-header
 which is either in the past, or equal to todays date.

=end doc

=cut

sub shouldBeLive
{
    my ($file) = (@_);

    #
    #  If the file doesn't exist we don't publish it.  Huh?
    #
    return 0 if ( !-e $file );

    #
    #  Look for a header
    #
    my $header = "";

    open( FILE, "<", $file )
      or die "Failed to read file $file - $!";

    foreach my $line (<FILE>)
    {
        if (    ( $line =~ /^Publish:(.*)/i )
             && ( !length($header) ) )
        {
            $header = $1;

            # Strip leading and trailing whitespace.
            $header =~ s/^\s+//;
            $header =~ s/\s+$//;
        }
    }
    close(FILE);

    #
    #  No header?  Not to be published
    #
    return 0 if ( length($header) < 1 );

    #
    #  OK we got a header - is it current / past?
    #
    my $today = time;
    if ( !defined($today) )
    {
        print "FAILED TO FIND TODAY\n";
        return 0;
    }

    #
    #  Date of entry
    #
    my $ent = str2time($header);
    if ( !defined($ent) )
    {
        print "FAILED TO PARSE: '$header'\n";
        return 0;
    }


    #
    #  Do the date test.
    #
    if ( $ent < $today )
    {
        return 1;
    }
    else
    {
        return 0;
    }
}



=begin doc

  Move the specified file into our "live" directory.

=end doc

=cut

sub makeEntryLive
{
    my ($file) = (@_);


    if ( -d $CONFIG{ 'live-dir' } )
    {

        #
        #  Is there already a file there with that name?
        #
        #  If so don't truncate it.
        #
        my $dir  = $file;
        my $base = $file;
        if ( $base =~ /^(.*)[\\\/](.*)$/ )
        {
            $dir  = $1;
            $base = $2;
        }

        while ( -e "$CONFIG{'live-dir'}/$base" )
        {
            $base = "x$base";
        }

        #
        #  Moving
        #
        File::Copy::move( $file, $CONFIG{ 'live-dir' } . "/" . $base );
    }
    else
    {
        print "Weirdness  $CONFIG{'live-dir'} is not a directory!\n";
        exit;
    }
}