#!/usr/bin/env perl
#
# This file is part of App-Cme
#
# This software is Copyright (c) 2014-2020 by Dominique Dumont.
#
# This is free software, licensed under:
#
#   The GNU Lesser General Public License, Version 2.1, February 1999
#
# PODNAME: cme
# ABSTRACT: Check or edit configuration data with Config::Model

# see perlunicook
use utf8;      # so literals and identifiers can be in UTF-8
use v5.12;     # or later to get "unicode_strings" feature
use strict;    # quote strings, declare variables
use warnings;  # on by default
use warnings  qw(FATAL utf8);    # fatalize encoding glitches
use open      qw(:std :utf8);    # undeclared streams in UTF-8
use charnames qw(:full :short);  # unneeded in v5.16

use App::Cme;
App::Cme->run;

__END__

=pod

=encoding UTF-8

=head1 NAME

cme - Check or edit configuration data with Config::Model

=head1 VERSION

version 1.032

=head1 SYNOPSIS

  # general synopsis
  cme [ global_options ] command application [ options ] [ file ] [ modification_instructions ]

  # edit dpkg config with GUI (and Config::Model::Dpkg)
  cme edit dpkg

  # read data from arbitrary file (for model read from alternate file)
  cme check dpkg-copyright -file path/to/file

  # edit /etc/sshd_config (with Config::Model::OpenSsh)
  sudo cme edit sshd

  # edit ~/.ssh/config (with Config::Model::OpenSsh)
  cme edit ssh

  # just check the validity of a file. Both commands are equivalent
  cme check multistrap file.conf
  cme check multistrap -file 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="(3.0) quilt"'

  # likewise with an application that accepts file override
  cme modify dpkg-copyright 'Comment="Modified with cme"'

  # 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

Depending on the command described below, C<cme> program will use
Config::Model configuration descriptions to check or modify or fix
configuration files.

The 3rd parameter specify the application you want to work on. Most of
the time, the relevant configuration file(s) will be found by cme. This
is the most simple case. For instance:

  sudo cme check popcon

Some application like C<multistrap> have no constraint on the
configuration file name and will require you to specify your
configuration file name:

  cme check multistrap raspbian.conf

or

  cme check multistrap -file raspbian.conf

=head1 Configuration file specification

The configuration of an application can take different forms. Either
several files (like debian packages), a single file with a predefined
file (popcon), or a single file with an arbitrary file name
(multistrap).

When needed the configuration file name is specified as the 3rd command
argument, i.e. C<cme command application file_name>. This applies if the
application requires a configuration file name (like multistrap), or if
the application allows configuration file override.

=head1 Main commands

This section describes the main commands shipped with cme. Other
Config::Model extensions can bring more command. Run C<cme help> to
get the list of available commands on your system.

=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. See L<App::Cme::Command::edit>.

=head2 shell

Edit the configuration with a shell like interface. See L<App::Cme::Command::shell>.

=head2 check

Checks the content of the configuration file of an application. See L<App::Cme::Command::check>.

=head2 migrate

Update deprecated parameters (old value are saved to new parameters)
and save the new configuration. See L<App::Cme::Command::migrate>.

=head2 fix

Migrate data and fix warnings.  See L<App::Cme::Command::fix>.

=head2 modify

Modify a configuration file with the values passed on the command
line.  See L<App::Cme::Command::modify>.

=head2 update

Update the content of the configuration file from external data.
Currently, only dpkg-copyright model support update sub command.
See L<App::Cme::Command::update>.

=head2 search

Search configuration data for a specific string. See L<App::Cme::Command::search>.

=head2 fusefs

Map the configuration file content to a FUSE virtual file system on a
directory specified with option C<-fuse-dir>. Modifications done in
the fuse file system are saved to the configuration file when the
C<fusermount -u> is run.

=head1 Global options

The following options are available for all commands:

=over

=item -create

Perform the operation even if the configuration file is missing. This
may be used to create a minimal configuration file. This option is
disabled by default as a missing configuration file often indicates an
error during the installation of the application.

=item -file

For model that support it, specify an alternate file to read and write the
configuration.

You can use this option for model that require the target file to be
specified (e.g. multitrap model), but file can in this case be also
specified with the 4th command argument. E.g. these 2 commands have
the same effect:

  cme check multistrap foo.conf
  cme check multistrap -file foo.conf

=item -force-load

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

=item -canonical

Write config data back using model order. By default, write items back
using the order found in the configuration file. This feature is
experimental and not supported by all backends.

=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>.

=item -save

Force a save even if no change was done. Useful to reformat the configuration file.

=item -strict

When set, cme will exit 1 if warnings are found during check (of left after fix)

=item -verbose

Show more information about what's going on.

=item -quiet

Suppress all output except error messages.

=back

=head1 Advanced options

=over

=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 -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 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.rootLogger=WARN, Screen
 log4perl.logger.Model.Legacy = INFO, SimpleScreen
 log4perl.additivity.Model.Legacy = 0

 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 = %M %m (line %L)%n

 log4perl.appender.SimpleScreen        = Log::Log4perl::Appender::Screen
 log4perl.appender.SimpleScreen.stderr = 0
 log4perl.appender.SimpleScreen.layout = Log::Log4perl::Layout::PatternLayout
 log4perl.appender.SimpleScreen.layout.ConversionPattern = %p: %m%n

 log4perl.oneMessagePerAppender = 1

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 Iterator

=item Model

=back

More categories will come.

=head1 EXIT CODE

cme exits 0 when no errors are found. Exit 1 otherwise.

=head1 BUGS

=head2 Files may be re-ordered

C<cme> imposes a specific ordering of the parameters of a configuration
file. This ordering is derived from the documentation of the configuration, like
L<ssh_confg>. C<cme> writes back files using this ordering.

Thus, the diff between the original configuration files and the new
version of the file may be more important than expected when C<cme> is
used the first time.

=head2 Comments may be dropped

Comments are not supported in some applidations (like the one that use
YAML in configuration files). Comments are dropped when using C<cme> to
edit or modify such files. For more details, see
L<Available
backend|https://github.com/dod38fr/config-model/wiki/Available-models-and-backends#Available_backend>
page.

=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<github|https://github.com/dod38fr/cme-perl/issues> 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 FOR MORE INFORMATION

For more information, please check:

=over

=item *

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

=item *

Blogs about this project: L<https://ddumont.wordpress.com/category/perl/configmodel/>

=back

=head1 CONTRIBUTORS

In alphabetical order:

 Ross Vandegrift

=head1 FEEDBACKS

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

=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>

=head1 AUTHOR

Dominique Dumont

=head1 COPYRIGHT AND LICENSE

This software is Copyright (c) 2014-2020 by Dominique Dumont.

This is free software, licensed under:

  The GNU Lesser General Public License, Version 2.1, February 1999

=cut