#!/usr/bin/env perl
#
# This file is part of Config-Model
#
# This software is Copyright (c) 2013 by Dominique Dumont.
#
# This is free software, licensed under:
#
#   The GNU Lesser General Public License, Version 2.1, February 1999
#

use strict;
use warnings;
use 5.10.1;

use Config::Model;
use Config::Model::Lister;
use Config::Model::ObjTreeScanner;
use Getopt::Long;
use Pod::Usage;
use Log::Log4perl qw(get_logger :levels);
use File::Slurp qw/slurp/;
use Path::Class ;
use POSIX qw/setsid/;
use AnyEvent ; # why AnyEvent ? See comment below around Tk UI

my $log4perl_syst_conf_file = '/etc/log4config-model.conf';
my $log4perl_user_conf_file = $ENV{HOME} . '/.log4config-model';
my $fallback_conf           = << 'EOC';
log4perl.logger=WARN, Screen
log4perl.appender.Screen        = Log::Log4perl::Appender::Screen
log4perl.appender.Screen.stderr = 0
log4perl.appender.Screen.layout = Log::Log4perl::Layout::PatternLayout
log4perl.appender.Screen.layout.ConversionPattern = %d %m %n
EOC

my $log4perl_conf =
    -e $log4perl_user_conf_file ? $log4perl_user_conf_file
  : -e $log4perl_syst_conf_file ? $log4perl_syst_conf_file
  :                               \$fallback_conf;

Log::Log4perl::init($log4perl_conf);

my $ui_type;

my $model_dir;
my $trace = 0;
my $root_dir;

my $man        = 0;
my $help       = 0;
my $force_load = 0;
my $dev        = 0;
my $backend;
my $experience = 'beginner';
my $dumptype;
my $load;
my @fix_from;
my $fix_filter ;
my $request_save  = 0;
my $open_item   = '';
my $fuse_dir;
my $fuse_debug  = 0;
my $apply_fixes = 0;
my $search;
my $search_type = 'all';
my $dir_char_mockup ;
my $try_application_as_model = 0; # means search a model instead of an application name
my $backup ;


my %command_option = (
    list    => [],
    check   => [],
    migrate => [],
    fix     => [
        "from=s" => \@fix_from ,
        "filter=s" => \$fix_filter ,
    ],
    modify  => [],
    search  => [ 
        "search=s"                      => \$search,
        "narrow-search=s"               => \$search_type, 
    ],
    edit    => [
        "ui|if=s"               => \$ui_type,
        "open_item|open-item=s" => \$open_item,
    ],
    dump   => [ "dumptype:s" => \$dumptype, ],
    fusefs => [
        "fuse_dir|fuse-dir=s" => \$fuse_dir,
        "dfuse!"              => \$fuse_debug,
        "dir-char=s"          => \$dir_char_mockup ,
    ],
);

my @global_options = (
    "model_dir|model-dir=s"         => \$model_dir,
    "try-app-as-model!"             => \$try_application_as_model,
    "experience=s"                  => \$experience,
    "dev!"                          => \$dev,
    "force_load|force-load!"        => \$force_load,
    "root_dir|root-dir=s"           => \$root_dir,
    "backend=s"                     => \$backend,
    "stack-trace|trace!"            => \$trace,
    "backup:s"                      => \$backup,
    );

# retrieve the main command, i.e. the first arg without leading dash
my ($command) = grep { ! /^-/ } @ARGV ;

pod2usage(-message => 'no command specified', -verbose => 0) 
    unless defined $command ;

pod2usage( -verbose => 1 ) if $command =~ /help/;
pod2usage( -verbose => 2 ) if $command =~ /man/;

# scan lib/Config/Model/extensions dir to find cme-* subcommands 
my @dir_to_scan = @INC ;
my %extension_path;
foreach my $inc ( @dir_to_scan ) {
    my $dir = dir("$inc/Config/Model/extensions/") ;
    next unless -d $dir ;
    foreach my $ext ($dir ->children ) {
        my $cmd = substr $ext->basename, 4 ;

        # don't clobber commands found before in @INC
        next if $extension_path{$cmd} ; 

        $command_option{$cmd} = [] ;
        $extension_path{$cmd} = $ext ;
    }
}

# run extention if the command matches one extension
if (my $path = $extension_path{$command}){
    say "doing $path";
    do $path; # thus @INC and @ARGV  are still valid
    exit ;
}

my $cmd_options =  $command_option{$command} 
    || pod2usage(-message => "unknown command: $command", -verbose => 0) ;

my $result = GetOptions( @global_options, @$cmd_options);

pod2usage(-verbose => 0) if not $result;

# now @ARGV should be $command, $application, [ $config_file ]
shift @ARGV;
my $application = shift @ARGV ;

# ignore $dev if run as root
if ( $> and $dev ) {
    unshift @INC, 'lib';
    $model_dir = 'lib/Config/Model/models/';
    warn "-dev option is ignored when run as root\n";
}

Config::Model::Exception::Any->Trace(1) if $trace;

if ( defined $root_dir && !-e $root_dir ) {
    mkdir $root_dir, 0755 || die "can't create $root_dir:$!";
}

my $model = Config::Model->new( model_dir => $model_dir );

my ( $categories, $appli_info, $appli_map ) =
  Config::Model::Lister::available_models;

if (not $application or $command eq 'list') {
    print "You forgot to specify an application to run cme on. Like 'cme $command stuff'.\n"
        unless $application ;
    print "The following applications are available:\n";
    foreach my $cat ( keys %$categories ) {
        my $names = $categories->{$cat} || [];
        next unless @$names;
        print "$cat:\n  ", join( "\n  ", @$names ), "\n";
    }
    exit 1;
}

my $root_model = $appli_map->{$application};
$root_model ||= $application if $try_application_as_model ;

if (not defined $root_model) {
    die "Unknown application: $application. Run 'cme list' to list available applications\n";
}

my $config_file ;
$config_file = shift @ARGV if $appli_info->{$application}{require_config_file} ;

my $inst = $model->instance(
    root_class_name => $root_model,
    instance_name   => $application,
    root_dir        => $root_dir,
    check           => $force_load ? 'no' : 'yes',
    skip_read       => $load ? 1 : 0,
    backend         => $backend,
    backup          => $backup ,
    config_file     => $config_file,
);

my $root = $inst->config_root;

if ( $command eq  'dump' ) {
    my $dump_string = $root->dump_tree( mode => $dumptype || 'custom' );
    print $dump_string ;
}
elsif ( $command eq 'check' ) {
    say "loading data";
    Config::Model::ObjTreeScanner->new(leaf_cb => sub{})->scan_node(undef, $root) ;
    say "checking data";
    $root->dump_tree( mode => 'full' );
    say "check done";
}
elsif ( $command eq 'search' ) {
    pod2usage(-message => "missing -search option with search command" )
        unless defined $search;
    my @res = $root->tree_searcher( type => $search_type )->search($search);
    foreach my $path ( @res ) {
        print "$path";
        my $obj = $root->grab($path);
        if ( $obj->get_type =~ /leaf|check_list/ ) {
            my $v = $obj->fetch;
            $v = defined $v ? $v : '<undef>';
            print " -> '$v'";
        }
        print "\n";
    }
}
elsif ($command eq 'migrate') {
    $request_save = 1;
    $root->migrate;
}
elsif ($command eq 'fix') {
    @fix_from = ('') unless @fix_from ;
    foreach my $path (@fix_from) {
        my $node_to_fix = $inst->config_root->grab($path) ;
        say "Fixing from ",$node_to_fix->name,"..." ;
        $node_to_fix->apply_fixes($fix_filter);
    }
    $request_save = 1;
}
elsif ( $command eq 'modify' ) {
    $root->load("@ARGV");
    $request_save = 1;
}
elsif ( $command =~ /^fuse/ ) {
    eval { require Config::Model::FuseUI; };
    my $has_fuse = $@ ? 0 : 1;

    die "could not load Config::Model::FuseUI. Is Fuse installed ?\n"
      unless $has_fuse;
    die "Missing -fuse_dir option\n" unless defined $fuse_dir;
    die "Directory $fuse_dir does not exists\n" unless -d $fuse_dir;

    my @extra ;
    push @extra, dir_char_mockup => $dir_char_mockup if  $dir_char_mockup ;
    my $ui = Config::Model::FuseUI->new(
        root       => $root,
        mountpoint => "$fuse_dir",
        @extra ,
    );

    print "Mounting config on $fuse_dir in background.\n",
        "Use command 'fusermount -u $fuse_dir' to unmount\n";

    # now fork
    my $pid = fork;

    if ( defined $pid and $pid == 0 ) {

        # child process, just run fuse and wait for exit
        $ui->run_loop( debug => $fuse_debug );
        $request_save = 1;
    }
    else {
        exit;    # don't save data in parent process
    }
}
elsif ( $command eq 'edit' ) {
    eval { require Config::Model::TkUI; };
    my $has_tk = $@ ? 0 : 1;

    eval { require Config::Model::CursesUI; };
    my $has_curses = $@ ? 0 : 1;

    if (not defined $ui_type ) {
        if ($has_tk) {
            $ui_type = 'tk';
        }
        elsif ($has_curses) {
            warn "You should install Config::Model::TkUI for a ",
                "more friendly user interface\n";
            $ui_type = 'curses';
        }
        else {
            warn "You should install Config::Model::TkUI or ",
                "Config::Model::CursesUI ",
                "for a more friendly user interface\n";
            $ui_type = 'shell';
        }
    }

    if ( $ui_type eq 'simple' ) {

        # experience not yet implemented
        require Config::Model::SimpleUI;
        my $shell_ui = Config::Model::SimpleUI->new(
            root   => $root,
            title  => $root_model . ' configuration',
            prompt => ' >',
        );

        # engage in user interaction
        $shell_ui->run_loop;
    }
    elsif ( $ui_type eq 'shell' ) {

        # experience not yet implemented
        require Config::Model::TermUI;
        my $shell_ui = Config::Model::TermUI->new(
            root   => $root,
            title  => $root_model . ' configuration',
            prompt => ' >',
        );

        # engage in user interaction
        $shell_ui->run_loop;
    }
    elsif ( $ui_type eq 'curses' ) {
        die "cannot run curses interface: ",
            "Config::Model::CursesUI is not installed\n"
          unless $has_curses;
        my $err_file = '/tmp/cme-error.log';

        print "In case of error, check $err_file\n";

        open( FH, "> $err_file" ) || die "Can't open $err_file: $!";
        open STDERR, ">&FH";

        my $dialog = Config::Model::CursesUI->new( experience => $experience, );

        # engage in user interaction
        $dialog->start($model);

        close FH;
    }
    elsif ( $ui_type eq 'tk' ) {
        die "cannot run Tk interface: Config::Model::CursesUI is not installed\n"
          unless $has_tk;

        require Tk;
        require Tk::ErrorDialog;
        Tk->import;
        
        # BLEEUAARGHHH. 
        # Currently AnyEvent is loaded and called only within Debian::Dpkg backend
        # and C::M::Debian::Dependency. When called in a Tk environment
        # AnyEvent creates its own TK mw which may be along the one created below
        # this require make sure that AnyEvent Tk mw is created and used for Tk application 
        require AnyEvent::Impl::Tk ;
        # without that, C::M::TkUI::quit (which just destroys one $mw, not 2) is not enough
        # to end the program :-( 

        no warnings 'once' ;
        my $mw = $AnyEvent::Impl::Tk::mw ;#|| MainWindow->new;
        # $mw->withdraw;

        # Thanks to Jerome Quelin for the tip
        $mw->optionAdd( '*BorderWidth' => 1 );

        my $cmu = $mw->ConfigModelUI( 
            -root => $root, 
            -experience => $experience 
        );

        if ($open_item) {
            my $obj = $root->grab($open_item);
            $cmu->force_element_display($obj);
        }

        &MainLoop;    # Tk's
    }
    elsif ( $ui_type =~ /^no/i ) {

        # trigger a dump to load all sub-models
        my $dump = $root->dump_tree;
        $request_save = 1 if $apply_fixes or $load or @ARGV;
    }
    else {
        die "Unsupported user interface: $ui_type";
    }
}
else {
    die "Looks like the author forgot to implement $command. Bad author, bad.";
}

if ($request_save) {
    my @changes = $inst->list_changes ;
    say "\n",join( "\n- ","Changes:", @changes ) if @changes;
    # if load was forced, must write back to clean up errors (even if they are not changes
    # at semantic level, i.e. removed unnecessary stuff)
    $inst->write_back(force => $force_load)  ;
}
exit 0;

__END__

=pod

=head1 NAME

cme - Edit data of configuration managed by Config::Model

=head1 SYNOPSIS

  # general synopsis
  cme [ global_options ] command application [ options ] arguments

  # edit dpkg config with GUI
  cme edit dpkg 

  # edit /etc/sshd_config (requires Config::Model::OpenSsh)
  sudo cme edit sshd
  
  # edit ~/.ssh/config (requires Config::Model::OpenSsh)
  cme edit ssh
  
  # just check the validity of a file 
  cme check multistrap file.conf 
  
  # check dpkg files, update deprecated parameters and save
  cme migrate dpkg 
  
  # like migrate, but also apply all suggested fixes
  cme fix dpkg 
  
  # modify configuration with command line
  cme modify dpkg source 'format="quilt (3.0)"'

  # edit a file (file name specification is mandatory here)
  cme edit multistrap my.conf 

  # map conf data to a fuse file system
  cme fusefs multistrap my.conf -d fuse_dir
  
  # likewise for dpkg data
  cme fusefs dpkg -d fuse_dir
  
  # list all available applications (depends on your installation)
  cme list 
  

=head1 DESCRIPTION

C<cme> program will use Config::Model configuration
descriptions to check or modify or fix configuration files.

=head1 Commands

=head2 list

Show a list all applications where a model is available. This list depends on 
installed Config::Model modules.

=head2 edit

Edit a configuration. By default, a Tk GUI will be opened If L<Config::Model::TkUI> is
installed. You can choose another user interface with the C<-ui> option:

=over

=item *

C<tk>: provides a Tk graphical interface (If L<Config::Model::TkUI> is
installed).

=item *

C<curses>: provides a curses user interface (If
L<Config::Model::CursesUI> is installed).

=item *

C<shell>: provides a shell like interface.  See L<Config::Model::TermUI>
for details.

=back

=head2 check

Checks the content of the configuration file of an application. Prints warnings
and errors on STDOUT.

Example:

 cme check fstab

=head2 migrate

Checks the content of the configuration file of an application (and show
warnings if needed), update deprecated parameters (old value are saved
to new parameters) and save the new configuration.

For more details, see L<Config::Model::Value/Upgrade>

=head2 fix

A bit like C<migrate> command, except that warnings are fixed. The configuration
is saved if anything was changed. Options are:

=over 

=item from

Use option C<-from> to fix only a subset of a configuration tree. Example:

 cme fix dpkg -from 'control binary:foo Depends'

This option can be repeated:

 cme fix dpkg -from 'control binary:foo Depends' -from 'control source Build-Depends'

=item filter

Filter the leaf according to a pattern. The pattern is applied to the element name to be fixed
Example:

 cme fix dpkg -from control -filter Build # will fix all Build-Depends and Build-Depend-Indep

or 

 cme fix dpkg -filter Depend 

=back

=head2 modify

Modify a configuration file with the values passed on the command line.
These command must follow the syntax defined in L<Config::Model::Loader>.

Example:

   cme modify dpkg source format="quilt (3.0)"
   cme modify multistrap my_mstrap.conf sections:base source="http://ftp.fr.debian.org"

=head2 search

You can search the configuration with the following options

=over 

=item -search

Specifies a string or pattern to search. C<cme> will a list of path pointing 
to the matching tree element and their value. 
See L<Config::Model::AnyThing/grab(...)> for details
on the path syntax.

=item -narrow-search

Narrows down the search to:

=over 

=item element 

=item value 

=item key 

=item summary 

Summary text

=item description

description text 

=item help

value help text

=back 

=back 

Example:

 $ cme search multistrap my_mstrap.conf -search http -narrow value
 sections:base source -> 'http://ftp.fr.debian.org'
 sections:debian source -> 'http://ftp.uk.debian.org/debian'
 sections:toolchains source -> 'http://www.emdebian.org/debian'

=head2 dump

Dump configuration content on STDOUT with Config::Model syntax.

By default, dump only custom values, i.e. different from application
built-in values or model default values. You can use the C<-dumptype> option for
other types of dump:

 -dumptype [ full | preset | custom ]

Choose to dump every values (full), only preset values or only
customized values (default)

=head2 fusefs 

Map the configuration file content to a FUSE virtual file system on a
directory specified with option C<-fuse-dir>. To stop (and write the
configuration data back to the configuration file), run C<< fusermount
-u <mounted_fuse_dir> >>.

Options:

=over

=item -fuse-dir

Mandatory. Directory where the virtual file system will be mounted.

=item -dfuse

Use this option to debug fuse problems.

=item -dir-char

Fuse will fail if an element name or key name contains '/'. You can specify a 
subsitution string to replace '/' in the fused dir. Default is C<< <slash> >>.

=back

=head1 Global options

The following options are available for all commands:

=over

=item -experience

Change the experience level. By default only parameters with "beginner" experience
are shown or modifiable. You can choose C<advanced> or C<master> level to get 
access to more parameters. Note that experience level can be changed in the GUI with the 
I<options> menu.

=item -force-load

Load file even if error are found in data. Bad data are discarded

=item -backup

Create a backup of configuration files before saving. By default, C<old> will
be appended to the backup file. I.e. C<foo.conf> will be backed up as C<foo.conf.old>.
You can specify an alternate suffix. For instance C<-backup dpkg-old>.

=back

=head1 Advanced options

=over

=item -dev

Use this option if you want to test a model under development. This
option will add C<lib> in C<@INC> and use C<lib/Config/Model/models>
as model directory. This option is ignored when run as root.

=item -model-dir

Specify an alternate directory to find model files. Mostly useful for
tests.

=item -root-dir

Specify a pseudo root directory to read and write the configuration
files. (Actual default directory and file names depends on the model
(See C<-model> option). For instance, if you specify C<~/mytest>, the
C</etc/ssh/sshd_config> files will be written in C<~/mytest/etc/ssh/>
directory.

=item -stack-trace

Provides a full stack trace when exiting on error.

=item -backend

Specify a read/write backend. The actual backend name depends on the model
passed to C<-model> option. See L<Config::Model::BackendMgr> for details.

=item -try-app-as-model

When set, try to load a model using directly the application name specified as 3rd parameter
on the command line. Experimental.

=back

=head1 Embedding cme

You can use cme from another program by using C<-ui simple>
option. This way you will be able to send command on the standard input
of C<cme> and get the results from the standard output.

=head1 cme extensions

New C<cme> subcommands can be placed in extensions directory (i.e. in
C<Config/Model/extensions>. When a cme command matched one of this extension,
the extension will be run. For instance, if you have:

 .../Config/Model/extensions/cme-foo
 
Running C<cme foo> will run this program (who must be written in Perl) with 
the same arguments as C<cme>.

=head1 Logging

All Config::Model logging is now based on L<Log::Log4perl>. 
Logging can be configured in the following files:

=over

=item *

 ~/.log4config-model

=item * 

 /etc/log4config-model.conf

=back

A sample of a C<.log4config-model> is provided in contrib directory in C<Config::Model>
distribution of on L<github|https://github.com/dod38fr/config-model/blob/master/contrib/log4config-model>

Without these files, the following Log4perl config is used:

 log4perl.logger=WARN, Screen
 log4perl.appender.Screen        = Log::Log4perl::Appender::Screen
 log4perl.appender.Screen.stderr = 0
 log4perl.appender.Screen.layout = Log::Log4perl::Layout::PatternLayout
 log4perl.appender.Screen.layout.ConversionPattern = %d %m %n

Log4perl uses the following categories:

=over

=item Anything

=item Anything::Change

Trace change notification through configuration tree and instance.

=item Backend

=item Backend::Debian::Dpkg

=item Backend::Debian::Dpkg::Control

=item Backend::Debian::Dpkg::Copyright

=item Backend::Fstab

=item Backend::IniFile

=item Backend::PlainFile

=item Backend::ShellVar

=item Backend::Yaml

=item FuseUI

=item Instance

=item Loader

=item Model::Searcher

=item Tree::Element::CheckList

=item Tree::Element::Id

=item Tree::Element::Id::Hash

=item Tree::Element::Id::List

=item Tree::Element::Value

=item Tree::Element::Value::Dependency

=item Tree::Node

=item Tree::Node::Warped

=item ValueComputer

=item Warper

=item Wizard::Helper

=item Model


=back

More categories will come.

=head1 BUGS

=head2 Configuration models can lag behind the target application

If a configuration model is not up-to-date, you will get errors complaining about
unknown parameters. In such a case, please file a bug on 
L<request tracked|http://rt.cpan.org/> or fix the model and send a pull request. 
You can see this 
L<example from OpenSsh|https://github.com/dod38fr/config-model/wiki/New-parameter-for-openssh-example>
to learn how to fix a model.

=head1 SUPPORT

For support, please check the following resources:

=over

=item *

The config-model users mailing list:

 config-model-users at lists.sourceforge.net

=item *

The config-model wiki: L<http://github.com/dod38fr/config-model/wiki>

=back

=head1 FEEDBACKS

Feedback from users are highly desired. If you find this module useful, please
share your use cases, success stories with the author or with the config-model-
users mailing list. 

=head1 AUTHOR

Dominique Dumont, ddumont at cpan dot org

=head1 SEE ALSO

L<Config::Model::Model>, 
L<Config::Model::Instance>, 
L<Config::Model::Node>, 
L<Config::Model::HashId>,
L<Config::Model::ListId>,
L<Config::Model::WarpedNode>,
L<Config::Model::Value>

=cut
