# POPFILE LOADABLE MODULE
package POPFile::Configuration;

use POPFile::Module;
@ISA = ( "POPFile::Module" );

#----------------------------------------------------------------------------
#
# This module handles POPFile's configuration parameters.  It is used to
# load and save from the popfile.cfg file and individual POPFile modules
# register specific parameters with this module.  This module also handles
# POPFile's command line parsing
#
# Copyright (c) 2001-2004 John Graham-Cumming
#
#   This file is part of POPFile
#
#   POPFile is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   POPFile 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.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with POPFile; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
#----------------------------------------------------------------------------

use strict;
use warnings;
use locale;

use Getopt::Long;

#----------------------------------------------------------------------------
# new
#
#   Class new() function
#----------------------------------------------------------------------------
sub new
{
    my $type = shift;
    my $self = POPFile::Module->new();

    # This hash has indexed by parameter name and has two fields:
    #
    # value         The current value
    # default       The default value

    $self->{configuration_parameters__} = {};

    # Name of the PID file that we created

    $self->{pid_file__} = '';

    # The time to delay checking of the PID file

    $self->{pid_delay__} = 5;

    # The last time the PID was checked

    $self->{pid_check__} = time;

    # Used to tell whether we need to save the configuration

    $self->{save_needed__} = 0;

    # We track when out start() is called so that we know when the modules
    # are done setting the default values so that we know which have default
    # and which do not

    $self->{started__} = 0;

    # Local copies of POPFILE_ROOT and POPFILE_USER

    $self->{popfile_root__} = $ENV{POPFILE_ROOT} || './';
    $self->{popfile_user__} = $ENV{POPFILE_USER} || './';

    bless $self, $type;

    $self->name( 'config' );

    return $self;
}

# ----------------------------------------------------------------------------
#
# initialize
#
# Called to initialize the interface
#
# ----------------------------------------------------------------------------
sub initialize
{
    my ( $self ) = @_;

    # This is the location where we store the PID of POPFile in a file
    # called popfile.pid

    $self->config_( 'piddir', './' );

    # The default timeout in seconds for POP3 commands

    $self->global_config_( 'timeout', 60 );

    # The default location for the message files

    $self->global_config_( 'msgdir', 'messages/' );

    # The maximum number of characters to consider in a message during
    # classification, display or reclassification

    $self->global_config_( 'message_cutoff', 100000 );

    # Register for the TICKD message which is sent hourly by the
    # Logger module.   We use this to hourly save the configuration file
    # so that POPFile's configuration is saved in case of a hard crash.
    #
    # This is particularly needed by the IMAP module which stores some
    # state related information in the configuration parameters.  Note that
    # because of the save_needed__ bool there wont be any write to the
    # disk unless a configuration parameter has been changed since the
    # last save.  (see parameter())

    $self->mq_register_( 'TICKD', $self );

    return 1;
}

# ----------------------------------------------------------------------------
#
# start
#
# Called to start this module
#
# ----------------------------------------------------------------------------
sub start
{
    my ( $self ) = @_;

    $self->{started__} = 1;

    # Check to see if the PID file is present, if it is then another POPFile
    # may be running, warn the user and terminate, note the 0 at the end
    # means that we allow the piddir to be absolute and outside the user
    # sandbox

    $self->{pid_file__} = $self->get_user_path( $self->config_( 'piddir' ) . 'popfile.pid', 0 );

    if (defined($self->live_check_())) {
        return 0;
    }

    $self->write_pid_();

    return 1;
}

# ----------------------------------------------------------------------------
#
# service
#
# service() is a called periodically to give the module a chance to do housekeeping work.
#
# If any problem occurs that requires POPFile to shutdown service() should return 0 and
# the top level process will gracefully terminate POPFile including calling all stop()
# methods.  In normal operation return 1.#
# ----------------------------------------------------------------------------
sub service
{
    my ( $self ) = @_;

    my $time = time;

    if ( $self->{pid_check__} <= ( $time - $self->{pid_delay__})) {

        $self->{pid_check__} = $time;

        if ( !$self->check_pid_() ) {
            $self->write_pid_();
            $self->log_( 0, "New POPFile instance detected and signalled" );
        }
    }

    return 1;
}

# ----------------------------------------------------------------------------
#
# stop
#
# Called to shutdown this module
#
# ----------------------------------------------------------------------------
sub stop
{
    my ( $self ) = @_;

    $self->save_configuration();

    $self->delete_pid_();
}

# ----------------------------------------------------------------------------
#
# deliver
#
# Called by the message queue to deliver a message
#
# ----------------------------------------------------------------------------
sub deliver
{
    my ( $self, $type, @message ) = @_;

    if ( $type eq 'TICKD' ) {
        $self->save_configuration();
    }
}

# ----------------------------------------------------------------------------
#
# live_check_
#
# Checks if an instance of POPFile is currently running. Takes 10 seconds.
# Returns the process-ID of the currently running POPFile, undef if none.
#
# ----------------------------------------------------------------------------
sub live_check_
{
    my ( $self ) = @_;

    if ( $self->check_pid_() ) {

        my $oldpid = $self->get_pid_();

        my $error = "\n\nA copy of POPFile appears to be running.\n Attempting to signal the previous copy.\n Waiting " . ($self->{pid_delay__} * 2) . " seconds for a reply.\n";

        $self->delete_pid_();

        print STDERR $error;

        select(undef, undef, undef, ($self->{pid_delay__} * 2));

        my $pid = $self->get_pid_();

        if (defined($pid)) {
            $error = "\n A copy of POPFile is running.\n It has signaled that it is alive with process ID: $pid\n";
            print STDERR $error;
            return $pid;
        } else {
            print STDERR "\nThe other POPFile ($oldpid) failed to signal back, starting new copy ($$)\n";
	}
    }
    return undef;
}

# ----------------------------------------------------------------------------
#
# check_pid_
#
# returns 1 if the pid file exists, 0 otherwise
#
# ----------------------------------------------------------------------------

sub check_pid_
{
    my ( $self ) = @_;
    return (-e $self->{pid_file__});
}

# ----------------------------------------------------------------------------
#
# get_pid_
#
# returns the pidfile proccess ID if a pid file is present, undef otherwise (0 might be a valid PID)
#
# ----------------------------------------------------------------------------
sub get_pid_
{
    my ( $self ) = @_;

    if (open PID, $self->{pid_file__}) {
        my $pid = <PID>;
        $pid =~ s/[\r\n]//g;
        close PID;
        return $pid;
    }

    return undef;
}

# ----------------------------------------------------------------------------
#
# write_pid_
#
# writes the current process-ID into the pid file
#
# ----------------------------------------------------------------------------
sub write_pid_
{
    my ( $self ) = @_;

    if ( open PID, ">$self->{pid_file__}" ) {
        print PID "$$\n";
        close PID;
    }
}

# ----------------------------------------------------------------------------
#
# delete_pid_
#
# deletes the pid file
#
# ----------------------------------------------------------------------------
sub delete_pid_
{
    my ( $self ) = @_;

    unlink( $self->{pid_file__} );
}

# ----------------------------------------------------------------------------
#
# parse_command_line - Parse ARGV
#
# The arguments are the keys of the configuration hash.  Any argument that is not already
# defined in the hash generates an error, there must be an even number of ARGV elements because
# each command argument has to have a value.
#
# ----------------------------------------------------------------------------
sub parse_command_line
{
    my ( $self ) = @_;

    # Options from the command line specified with the --set parameter

    my @set_options;

    # The following command line options are supported:
    #
    # --set          Permanently sets a configuration item for the current user
    # --             Everything after this point is an old style POPFile option
    #
    # So its possible to do
    #
    # --set bayes_param=value --set=-bayes_param=value --set -bayes_param=value -- -bayes_param value

    if ( !GetOptions( "set=s" => \@set_options ) ) {
        return 0;
    }

    # Join together the options specified with --set and those after the --, the
    # options in @set_options are going to be of the form foo=bar and hence need to
    # be split into foo bar

    my @options;

    for my $i (0..$#set_options) {
        $set_options[$i] =~ /-?(.+)=(.+)/;

	if ( !defined( $1 ) ) {
            print STDERR "\nBad option: $set_options[$i]\n";
            return 0;
	}

        push @options, ("-$1");
        if ( defined( $2 ) ) {
            push @options, ($2);
	}
    }

    push @options, @ARGV;

    if ( $#options >= 0 )  {
        my $i = 0;

        while ( $i <= $#options )  {
            # A command line argument must start with a -

            if ( $options[$i] =~ /^-(.+)$/ ) {
                my $parameter = $self->upgrade_parameter__($1);

                if ( defined($self->{configuration_parameters__}{$parameter}) ) {
                    if ( $i < $#options ) {
                        $self->parameter( $parameter, $options[$i+1] );
                        $i += 2;
                    } else {
                        print STDERR "\nMissing argument for $options[$i]\n";
                        return 0;
                    }
                } else {
                    print STDERR "\nUnknown option $options[$i]\n";
                    return 0;
                }
            } else {
                print STDERR "\nExpected a command line option and got $options[$i]\n";
                return 0;
            }
        }
    }

    return 1;
}

# ----------------------------------------------------------------------------
#
# upgrade_parameter__
#
# Given a parameter from either command line or from the configuration file return the
# upgraded version (e.g. the old port parameter becomes pop3_port
#
# ----------------------------------------------------------------------------

sub upgrade_parameter__
{
    my ( $self, $parameter ) = @_;

    # This table maps from the old parameter to the new one, for
    # example the old xpl parameter which controls insertion of the
    # X-POPFile-Link header in email is now called GLOBAL_xpl and is
    # accessed through POPFile::Module::global_config_ The old piddir
    # parameter is now config_piddir and is accessed through either
    # config_ if accessed from the config module or through
    # module_config_ from outside

    my %upgrades = ( # PROFILE BLOCK START

                     # Parameters that are now handled by Classifier::Bayes

                     'corpus',                   'bayes_corpus',
                     'unclassified_probability', 'bayes_unclassified_probability',

                     # Parameters that are now handled by POPFile::Configuration

                     'piddir',                   'config_piddir',

                     # Parameters that are now global to POPFile

                     'debug',                    'GLOBAL_debug',
                     'msgdir',                   'GLOBAL_msgdir',
                     'timeout',                  'GLOBAL_timeout',

                     # Parameters that are now handled by POPFile::Logger

                     'logdir',                   'logger_logdir',

                     # Parameters that are now handled by Proxy::POP3

                     'localpop',                 'pop3_local',
                     'port',                     'pop3_port',
                     'sport',                    'pop3_secure_port',
                     'server',                   'pop3_secure_server',
                     'separator',                'pop3_separator',
                     'toptoo',                   'pop3_toptoo',

                     # Parameters that are now handled by UI::HTML

                     'language',                 'html_language',
                     'last_reset',               'html_last_reset',
                     'last_update_check',        'html_last_update_check',
                     'localui',                  'html_local',
                     'page_size',                'html_page_size',
                     'password',                 'html_password',
                     'send_stats',               'html_send_stats',
                     'skin',                     'html_skin',
                     'test_language',            'html_test_language',
                     'update_check',             'html_update_check',
                     'ui_port',                  'html_port',

                     # Parameters the have moved from the UI::HTML to
                     # POPFile::History

                     'archive',                  'history_archive',
                     'archive_classes',          'history_archive_classes',
                     'archive_dir',              'history_archive_dir',
                     'history_days',             'history_history_days',
                     'html_archive',             'history_archive',
                     'html_archive_classes',     'history_archive_classes',
                     'html_archive_dir',         'history_archive_dir',
                     'html_history_days',        'history_history_days',

    ); # PROFILE BLOCK STOP

    if ( defined( $upgrades{$parameter} ) ) {
        return $upgrades{$parameter};
    } else {
        return $parameter;
    }
}

# ----------------------------------------------------------------------------
#
# load_configuration
#
# Loads the current configuration of popfile into the configuration hash from a local file.
# The format is a very simple set of lines containing a space separated name and value pair
#
# ----------------------------------------------------------------------------
sub load_configuration
{
    my ( $self ) = @_;

    $self->{started__} = 1;

    if ( open CONFIG, '<' . $self->get_user_path( 'popfile.cfg' ) ) {
        while ( <CONFIG> ) {
            s/(\015|\012)//g;
            if ( /(\S+) (.+)?/ ) {
                my $parameter = $1;
                my $value     = $2;
                $value = '' if !defined( $value );

                $parameter = $self->upgrade_parameter__($parameter);

                if ( defined( $self->{configuration_parameters__}{$parameter} ) ) {
                    $self->{configuration_parameters__}{$parameter}{value} = $value;
                } else {
                    $self->{deprecated_parameters__}{$parameter} = $value;
                }
            }
        }

        close CONFIG;
    }

    $self->{save_needed__} = 0;
}

# ----------------------------------------------------------------------------
#
# save_configuration
#
# Saves the current configuration of popfile from the configuration hash to a local file.
#
# ----------------------------------------------------------------------------
sub save_configuration
{
    my ( $self ) = @_;

    if ( $self->{save_needed__} == 0 ) {
        return;
    }

    if ( open CONFIG, '>' . $self->get_user_path( 'popfile.cfg' ) ) {
        $self->{save_needed__} = 0;

        foreach my $key (sort keys %{$self->{configuration_parameters__}}) {
            print CONFIG "$key $self->{configuration_parameters__}{$key}{value}\n";
        }

        close CONFIG;
    }
}

# ----------------------------------------------------------------------------
#
# get_user_path, get_root_path
#
# Resolve a path relative to POPFILE_USER or POPFILE_ROOT
#
# $path              The path to resolve
# $sandbox           Set to 1 if this path must be sandboxed (i.e. absolute
#                    paths and paths containing .. are not accepted).
#
# ----------------------------------------------------------------------------
sub get_user_path
{
    my ( $self, $path, $sandbox ) = @_;

    return $self->path_join__( $self->{popfile_user__}, $path, $sandbox );
}

sub get_root_path
{
    my ( $self, $path, $sandbox ) = @_;

    return $self->path_join__( $self->{popfile_root__}, $path, $sandbox );
}

# ----------------------------------------------------------------------------
#
# path_join__
#
# Join two paths togther
#
# $left              The LHS
# $right             The RHS
# $sandbox           Set to 1 if this path must be sandboxed (i.e. absolute
#                    paths and paths containing .. are not accepted).
#
# ----------------------------------------------------------------------------
sub path_join__
{
    my ( $self, $left, $right, $sandbox ) = @_;

    $sandbox = 1 if ( !defined( $sandbox ) );

    if ( ( $right =~ /^\// ) ||
         ( $right =~ /^[A-Za-z]:[\/\\]/ ) ||
         ( $right =~ /\\\\/ ) ) {
        if ( $sandbox ) {
            $self->log_( 0, "Attempt to access path $right outside sandbox" );
            return undef;
        } else {
            return $right;
        }
    }

    if ( $sandbox && ( $right =~ /\.\./ ) ) {
        $self->log_( 0, "Attempt to access path $right outside sandbox" );
        return undef;
    }

    $left  =~ s/\/$//;
    $right =~ s/^\///;

    return "$left/$right";
}

# ----------------------------------------------------------------------------
#
# parameter
#
# Gets or sets a parameter
#
# $name          Name of the parameter to get or set
# $value         Optional value to set the parameter to
#
# Always returns the current value of the parameter
#
# ----------------------------------------------------------------------------
sub parameter
{
    my ( $self, $name, $value ) = @_;

    if ( defined( $value ) ) {
        $self->{save_needed__} = 1;
        $self->{configuration_parameters__}{$name}{value} = $value;
        if ( $self->{started__} == 0 ) {
            $self->{configuration_parameters__}{$name}{default} = $value;
        }
    }

    return $self->{configuration_parameters__}{$name}{value};
}

# ----------------------------------------------------------------------------
#
# is_default
#
# Returns whether the parameter has the default value or not
#
# $name          Name of the parameter
#
# Returns 1 if the parameter still has its default value
#
# ----------------------------------------------------------------------------
sub is_default
{
    my ( $self, $name ) = @_;

    return ( $self->{configuration_parameters__}{$name}{value} eq
             $self->{configuration_parameters__}{$name}{default} );
}

# GETTERS

sub configuration_parameters
{
    my ( $self ) = @_;

    return sort keys %{$self->{configuration_parameters__}};
}

sub deprecated_parameter
{
    my ( $self, $name ) = @_;

    return $self->{deprecated_parameters__}{$name};
}

1;