#
# (c) Jan Gehring <jan.gehring@gmail.com>
#

=head1 NAME

Rex::Commands::File - Transparent File Manipulation

=head1 DESCRIPTION

With this module you can manipulate files.

=head1 SYNOPSIS

 task "read_passwd", "server01", sub {
   my $fh = file_read "/etc/passwd";
   for my $line ($fh->read_all) {
     print $line;
   }
   $fh->close;
 };
 
 task "read_passwd2", "server01", sub {
   say cat "/etc/passwd";
 };


 task "write_passwd", "server01", sub {
   my $fh = file_write "/etc/passwd";
   $fh->write("root:*:0:0:root user:/root:/bin/sh\n");
   $fh->close;
 };
 
 delete_lines_matching "/var/log/auth.log", matching => "root";
 delete_lines_matching "/var/log/auth.log", matching => qr{Failed};
 delete_lines_matching "/var/log/auth.log",
                matching => "root", qr{Failed}, "nobody";
 
 file "/path/on/the/remote/machine",
   source => "/path/on/local/machine";
 
 file "/path/on/the/remote/machine",
   content => "foo bar";
 
 file "/path/on/the/remote/machine",
   source => "/path/on/local/machine",
   owner  => "root",
   group  => "root",
   mode  => 400,
   on_change => sub { say shift, " was changed."; },
   on_no_change => sub { say shift, " wasn't changed."; };


=head1 EXPORTED FUNCTIONS

=cut

package Rex::Commands::File;

use v5.12.5;
use warnings;
use Fcntl;

our $VERSION = '1.14.1'; # VERSION

require Rex::Exporter;
use Data::Dumper;
use Rex::Config;
use Rex::FS::File;
use Rex::Commands::Upload;
use Rex::Commands::MD5;
use Rex::File::Parser::Data;
use Rex::Helper::File::Spec;
use Rex::Helper::System;
use Rex::Helper::Path;
use Rex::Hook;
use Carp;

use Rex::Interface::Exec;
use Rex::Interface::File;
use Rex::Interface::Fs;
require Rex::CMDB;

use File::Basename qw(dirname basename);

use vars qw(@EXPORT);
use base qw(Rex::Exporter);

@EXPORT = qw(file_write file_read file_append
  cat sed
  delete_lines_matching append_if_no_such_line delete_lines_according_to
  file template append_or_amend_line
  extract);

use vars qw(%file_handles);

=head2 template($file [, %params])

Parse a template and return the content.

By default, it uses L<Rex::Template>. If any of the L<template_ng|Rex#template_ng> or L<1.3|Rex#1.3> (or newer) feature flag is enabled, then L<Rex::Template::NG> is used instead of this module (recommended).

For more advanced functionality, you may use your favorite template engine via the L<set_template_function|Rex::Config#set_template_function> configuration option.

Template variables may be passed either as hash or a hash reference. The following calls are equivalent:

 template( $template, variable => value );
 
 template( $template, { variable => value } );

=head3 List of exposed template variables

The following template variables are passed to the underlying templating engine, in order of precedence from low to high (variables of the same name are overridden by the next level aka "last one wins"):

=over 4

=item task parameters

All task parameters coming from the command line via C<S<rex taskname --param=value>>, or from calling a task as a function, like C<S<taskname( { param =E<gt> value } )>>.

=item resource parameters

All resource parameters as returned by C<Rex::Resource-E<gt>get_current_resource()-E<gt>get_all_parameters>, when called inside a resource.

=item explicit template variables

All manually specified, explicit template variables passed to C<template()>.

=item system information

The results from all available L<Rex::Hardware> modules as returned by C<Rex::Hardware-E<gt>get('All')>.

Pass C<__no_sys_info__ =E<gt> TRUE> as a template variable to disable including system information:

 my $content = template( $template, __no_sys_info__ => TRUE );

=back

=head3 Embedded templates

Use C<__DATA__> to embed templates at the end of the file. Prefix embedded template names with C<@>. If embedding multiple templates, mark their end with C<@end>.

=head4 Single template

 my $content = template( '@hello', name => 'world' ); # Hello, world!
 __DATA__
 @hello
 Hello, <%= $name -%>!

=head4 Multiple templates

Use C<@end> to separate multiple templates inside C<__DATA__>.

 my $content     = template( '@hello', name => 'world' ); # Hello, world!
 my $alternative = template( '@hi',    name => 'world' ); # Hi, world!

 __DATA__
 @hello
 Hello, <%= $name -%>!
 @end

 @hi
 Hi, <%= $name -%>!
 @end

=head3 File templates

 my $content = template("/files/templates/vhosts.tpl",
               name      => "test.lan",
               webmaster => 'webmaster@test.lan');

The file name specified is subject to "path_map" processing as documented
under the file() function to resolve to a physical file name.

In addition to the "path_map" processing, if the B<-E> command line switch
is used to specify an environment name, existence of a file ending with
'.<env>' is checked and has precedence over the file without one, if it
exists. E.g. if rex is started as:

 $ rex -E prod task1

then in task1 defined as:

 task "task1", sub {
    say template("files/etc/ntpd.conf");
 };

will print the content of 'files/etc/ntpd.conf.prod' if it exists.

Note: the appended environment mechanism is always applied, after
the 'path_map' mechanism, if that is configured.

=cut

sub template {
  my ( $file, @params ) = @_;
  my $param;

  if ( ref $params[0] eq "HASH" ) {
    $param = $params[0];
  }
  else {
    $param = {@params};
  }

  if ( !exists $param->{server} ) {
    $param->{server} = Rex::Commands::connection()->server;
  }

  my $content;
  if ( ref $file && ref $file eq 'SCALAR' ) {
    $content = ${$file};
  }
  else {
    $file = resolv_path($file);

    unless ( $file =~ m/^\// || $file =~ m/^\@/ ) {

      # path is relative and no template
      Rex::Logger::debug("Relativ path $file");

      $file = Rex::Helper::Path::get_file_path( $file, caller() );

      Rex::Logger::debug("New filename: $file");
    }

    # if there is a file called filename.environment then use this file
    # ex:
    # $content = template("files/hosts.tpl");
    #
    # rex -E live ...
    # will first look if files/hosts.tpl.live is available, if not it will
    # use files/hosts.tpl
    if ( -f "$file." . Rex::Config->get_environment ) {
      $file = "$file." . Rex::Config->get_environment;
    }

    if ( -f $file ) {
      $content = eval { local ( @ARGV, $/ ) = ($file); <>; };
    }
    elsif ( $file =~ m/^\@/ ) {
      my @caller = caller(0);

      my $file_path = Rex::get_module_path( $caller[0] );

      if ( !-f $file_path ) {
        my ($mod_name) = ( $caller[0] =~ m/^.*::(.*?)$/ );
        if ( $mod_name && -f "$file_path/$mod_name.pm" ) {
          $file_path = "$file_path/$mod_name.pm";
        }
        elsif ( -f "$file_path/__module__.pm" ) {
          $file_path = "$file_path/__module__.pm";
        }
        elsif ( -f "$file_path/Module.pm" ) {
          $file_path = "$file_path/Module.pm";
        }
        elsif ( -f $caller[1] ) {
          $file_path = $caller[1];
        }
        elsif ( $caller[1] =~ m|^/loader/[^/]+/__Rexfile__.pm$| ) {
          $file_path = $INC{"__Rexfile__.pm"};
        }
      }

      my $file_content = eval { local ( @ARGV, $/ ) = ($file_path); <>; };
      my ($data)       = ( $file_content =~ m/.*__DATA__(.*)/ms );
      my $fp = Rex::File::Parser::Data->new( data => [ split( /\n/, $data ) ] );
      my $snippet_to_read = substr( $file, 1 );
      $content = $fp->read($snippet_to_read);
    }
    else {
      die("$file not found");
    }
  }

  my %template_vars;
  if ( !exists $param->{__no_sys_info__} ) {
    %template_vars = _get_std_template_vars($param);
  }
  else {
    delete $param->{__no_sys_info__};
    %template_vars = %{$param};
  }

  # configuration variables
  my $config_values = Rex::Config->get_all;
  for my $key ( keys %{$config_values} ) {
    if ( !exists $template_vars{$key} ) {
      $template_vars{$key} = $config_values->{$key};
    }
  }

  if ( Rex::CMDB::cmdb_active() && Rex::Config->get_register_cmdb_template ) {
    my $data = Rex::CMDB::cmdb();
    for my $key ( keys %{ $data->{value} } ) {
      if ( !exists $template_vars{$key} ) {
        $template_vars{$key} = $data->{value}->{$key};
      }
    }
  }

  return Rex::Config->get_template_function()->( $content, \%template_vars );
}

sub _get_std_template_vars {
  my ($param) = @_;

  my %merge1 = %{ $param || {} };
  my %merge2;

  if ( Rex::get_cache()->valid("system_information_info") ) {
    %merge2 = %{ Rex::get_cache()->get("system_information_info") };
  }
  else {
    %merge2 = Rex::Helper::System::info();
    Rex::get_cache()->set( "system_information_info", \%merge2 );
  }

  my %template_vars = ( %merge1, %merge2 );

  return %template_vars;
}

=head2 file($file_name [, %options])

This function is the successor of I<install file>. Please use this function to upload files to your server.

 task "prepare", "server1", "server2", sub {
   file "/file/on/remote/machine",
     source => "/file/on/local/machine";
 
   file "/etc/hosts",
     content => template("templates/etc/hosts.tpl"),
     owner  => "user",
     group  => "group",
     mode   => 700,
     on_change => sub { say "Something was changed." },
     on_no_change => sub { say "Nothing has changed." };
 
   file "/etc/motd",
     content => `fortune`;
 
   file "/etc/named.conf",
     content    => template("templates/etc/named.conf.tpl"),
     no_overwrite => TRUE;  # this file will not be overwritten if already exists.
 
   file "/etc/httpd/conf/httpd.conf",
     source => "/files/etc/httpd/conf/httpd.conf",
     on_change => sub { service httpd => "restart"; };
 
   file "/etc/named.d",
     ensure => "directory",  # this will create a directory
     owner  => "root",
     group  => "root";
 
   file "/etc/motd",
     ensure => "absent";   # this will remove the file or directory
 
 };

The first parameter is either a string or an array reference. In the latter case the
function is called for all strings in the array. Therefore, the following constructs 
are equivalent:

  file '/tmp/test1', ensure => 'directory';
  file '/tmp/test2', ensure => 'directory';

  file [ qw( /tmp/test1 /tmp/test2 ) ], ensure => 'directory'; # use array ref

  file [ glob('/tmp/test{1,2}') ], ensure => 'directory'; # explicit glob call for array contents

Use the glob carefully as B<it can leak local filesystem information> (e.g. when using wildcards).

The I<source> is subject to a path resolution algorithm. This algorithm
can be configured using the I<set> function to set the value of the
I<path_map> variable to a hash containing path prefixes as its keys.
The associated values are arrays listing the prefix replacements in order
of (decreasing) priority.

  set "path_map", {
    "files/" => [ "files/{environment}/{hostname}/_root_/",
                  "files/{environment}/_root_/" ]
  };

With this configuration, the file "files/etc/ntpd.conf" will be probed for
in the following locations:

 - files/{environment}/{hostname}/_root_/etc/ntpd.conf
 - files/{environment}/_root_/etc/ntpd.conf
 - files/etc/ntpd.conf

Furthermore, if a path prefix matches multiple prefix entries in 'path_map',
e.g. "files/etc/ntpd.conf" matching both "files/" and "files/etc/", the
longer matching prefix(es) have precedence over shorter ones. Note that
keys without a trailing slash (i.e. "files/etc") will be treated as having
a trailing slash when matching the prefix ("files/etc/"). 

If no file is found using the above procedure and I<source> is relative,
it will search from the location of your I<Rexfile> or the I<.pm> file if
you use Perl packages.

All the possible variables ('{environment}', '{hostname}', ...) are documented
in the CMDB YAML documentation.

=head3 Hooks

This function supports the following L<hooks|Rex::Hook>:

=over 4

=item before

This gets executed before anything is done. All original parameters are passed to it, including the applied defaults (C<ensure =E<gt> 'present'>, resolved path for C<source>).

The return value of this hook overwrites the original parameters of the function call.

=item before_change

This gets executed right before the new file is written. All original parameters are passed to it, including the applied defaults (C<ensure =E<gt> 'present'>, resolved path for C<source>).

=item after_change

This gets executed right after the file is written. All original parameters, including the applied defaults (C<ensure =E<gt> 'present'>, resolved path for C<source>), and any returned results are passed to it.

=item after

This gets executed right before the C<file()> function returns. All original parameters, including the applied defaults (C<ensure =E<gt> 'present'>, resolved path for C<source>), and any returned results are passed to it.

=back

=cut

sub file {
  my ( $file, @options ) = @_;

  if ( ref $file eq "ARRAY" ) {
    my @ret;

    # $file is an array, so iterate over these files
    for my $f ( @{$file} ) {
      push( @ret, file( $f, @options ) );
    }

    return \@ret;
  }

  my $option = {@options};

  $file = resolv_path($file);

  my ($is_directory);
  if ( exists $option->{ensure} && $option->{ensure} eq "directory" ) {
    $is_directory = 1;
  }

  if ( exists $option->{source} && !$is_directory ) {
    $option->{source} = resolv_path( $option->{source} );
  }

  # default: ensure = present
  $option->{ensure} ||= "present";

  my $fs = Rex::Interface::Fs->create;

  if ( $option->{ensure} ne 'absent' && $fs->is_symlink($file) ) {
    my $original_file = $file;
    $file = resolve_symlink($file);
    Rex::Logger::info(
      "$original_file is a symlink, operating on $file instead", 'warn' );
  }

  #### check and run before hook
  eval {
    my @new_args = Rex::Hook::run_hook( file => "before", $file, %{$option} );
    if (@new_args) {
      ( $file, @options ) = @new_args;
      $option = {@options};
    }
    1;
  } or do {
    die("Before hook failed. Cancelling file() action: $@");
  };
  ##############################

  Rex::get_current_connection()->{reporter}
    ->report_resource_start( type => "file", name => $file );

  my $need_md5     = ( $option->{"on_change"} && !$is_directory ? 1 : 0 );
  my $on_change    = $option->{"on_change"}    || sub { };
  my $on_no_change = $option->{"on_no_change"} || sub { };

  my $__ret = { changed => 0 };

  my ( $new_md5, $old_md5 );

  if ( exists $option->{no_overwrite}
    && $option->{no_overwrite}
    && $fs->is_file($file) )
  {
    Rex::Logger::debug(
      "File already exists and no_overwrite option given. Doing nothing.");
    $__ret = { changed => 0 };

    Rex::get_current_connection()->{reporter}->report(
      changed => 0,
      message =>
        "File already exists and no_overwrite option given. Doing nothing."
    );
  }

  elsif ( ( exists $option->{content} || exists $option->{source} )
    && !$is_directory )
  {

    # first upload file to tmp location, to get md5 sum.
    # than we can decide if we need to replace the current (old) file.

    my $tmp_file_name = get_tmp_file_name($file);

    if ( exists $option->{content} ) {
      my $fh    = file_write($tmp_file_name);
      my @lines = split( qr{$/}, $option->{"content"} );
      for my $line (@lines) {
        $fh->write( $line . $/ );
      }
      $fh->close;
    }
    elsif ( exists $option->{source} ) {
      $option->{source} =
        Rex::Helper::Path::get_file_path( $option->{source}, caller );

      upload $option->{source}, $tmp_file_name;
    }

    # now get md5 sums
    eval { $old_md5 = md5($file); };
    $new_md5 = md5($tmp_file_name);

    if ( $new_md5 && $old_md5 && $new_md5 eq $old_md5 ) {
      Rex::Logger::debug(
        "No need to overwrite existing file. Old and new files are the same. $old_md5 eq $new_md5."
      );

      # md5 sums are the same, delete tmp.
      $fs->unlink($tmp_file_name);
      $need_md5 = 0; # we don't need to execute on_change hook

      Rex::get_current_connection()->{reporter}->report(
        changed => 0,
        message =>
          "No need to overwrite existing file. Old and new files are the same. $old_md5 eq $new_md5."
      );
    }
    else {
      $old_md5 ||= "";
      Rex::Logger::debug(
        "Need to use the new file. md5 sums are different. <<$old_md5>> = <<$new_md5>>"
      );

      #### check and run before_change hook
      Rex::Hook::run_hook( file => "before_change", $file, %{$option} );
      ##############################

      if (Rex::is_sudo) {
        my $current_options =
          Rex::get_current_connection_object()->get_current_sudo_options;
        Rex::get_current_connection_object()->push_sudo_options( {} );

        if ( exists $current_options->{user} ) {
          $fs->chown( "$current_options->{user}:", $tmp_file_name );
        }
      }

      $fs->rename( $tmp_file_name, $file );
      Rex::get_current_connection_object()->pop_sudo_options()
        if (Rex::is_sudo);

      $__ret = { changed => 1 };

      Rex::get_current_connection()->{reporter}->report(
        changed => 1,
        message => "File updated. old md5: $old_md5, new md5: $new_md5"
      );

      #### check and run after_change hook
      Rex::Hook::run_hook( file => "after_change", $file, %{$option}, $__ret );
      ##############################

    }

  }

  if ( exists $option->{"ensure"} ) {
    if ( $option->{ensure} eq "present" ) {
      if ( !$fs->is_file($file) ) {

        #### check and run before_change hook
        Rex::Hook::run_hook( file => "before_change", $file, %{$option} );
        ##############################

        my $fh = file_write($file);
        $fh->write("");
        $fh->close;
        $__ret = { changed => 1 };

        Rex::get_current_connection()->{reporter}->report(
          changed => 1,
          message => "file is now present, with no content",
        );

        #### check and run after_change hook
        Rex::Hook::run_hook(
          file => "after_change",
          $file, %{$option}, $__ret
        );
        ##############################

      }
      elsif ( !$__ret->{changed} ) {
        $__ret = { changed => 0 };
        Rex::get_current_connection()->{reporter}->report( changed => 0, );
      }
    }
    elsif ( $option->{ensure} eq "absent" ) {
      $need_md5 = 0;

      #### check and run before_change hook
      Rex::Hook::run_hook( file => "before_change", $file, %{$option} );
      ##############################

      if ( $fs->is_file($file) ) {
        $fs->unlink($file);
        $__ret = { changed => 1 };
        Rex::get_current_connection()->{reporter}->report(
          changed => 1,
          message => "File removed."
        );
      }
      elsif ( $fs->is_dir($file) ) {
        $fs->rmdir($file);
        $__ret = { changed => 1 };
        Rex::get_current_connection()->{reporter}->report(
          changed => 1,
          message => "Directory removed.",
        );
      }
      else {
        $__ret = { changed => 0 };
        Rex::get_current_connection()->{reporter}->report( changed => 0, );
      }

      #### check and run after_change hook
      Rex::Hook::run_hook( file => "after_change", $file, %{$option}, $__ret );
      ##############################

    }
    elsif ( $option->{ensure} eq "directory" ) {
      Rex::Logger::debug("file() should be a directory");
      my %dir_option;
      if ( exists $option->{owner} ) {
        $dir_option{owner} = $option->{owner};
      }
      if ( exists $option->{group} ) {
        $dir_option{group} = $option->{group};
      }
      if ( exists $option->{mode} ) {
        $dir_option{mode} = $option->{mode};
      }

      Rex::Commands::Fs::mkdir( $file, %dir_option, on_change => $on_change );
    }
  }

  if ( !exists $option->{content}
    && !exists $option->{source}
    && $option->{ensure} ne "absent" )
  {

    # no content and no source, so just verify that the file is present
    if ( !$fs->is_file($file) && !$is_directory ) {

      #### check and run before_change hook
      Rex::Hook::run_hook( file => "before_change", $file, %{$option} );
      ##############################

      my $fh = file_write($file);
      $fh->write("");
      $fh->close;

      my $f_type = "file is now present, with no content";
      if ( exists $option->{ensure} && $option->{ensure} eq "directory" ) {
        $f_type = "directory is now present";
      }

      Rex::get_current_connection()->{reporter}->report(
        changed => 1,
        message => $f_type,
      );

      #### check and run after_change hook
      Rex::Hook::run_hook( file => "after_change", $file, %{$option}, $__ret );
      ##############################

    }
  }

  if ( $option->{ensure} ne "absent" ) {

    if ($need_md5) {
      eval { $new_md5 = md5($file); };
    }
    my %stat_old = $fs->stat($file);

    if ( exists $option->{"mode"} ) {
      $fs->chmod( $option->{"mode"}, $file );
    }

    if ( exists $option->{"group"} ) {
      $fs->chgrp( $option->{"group"}, $file );
    }

    if ( exists $option->{"owner"} ) {
      $fs->chown( $option->{"owner"}, $file );
    }

    my %stat_new = $fs->stat($file);

    if ( %stat_old && %stat_new && $stat_old{mode} ne $stat_new{mode} ) {
      Rex::get_current_connection()->{reporter}->report(
        changed => 1,
        message =>
          "File-System permissions changed from $stat_old{mode} to $stat_new{mode}.",
      );
    }

    if ( %stat_old && %stat_new && $stat_old{uid} ne $stat_new{uid} ) {
      Rex::get_current_connection()->{reporter}->report(
        changed => 1,
        message => "Owner changed from $stat_old{uid} to $stat_new{uid}.",
      );
    }

    if ( %stat_old && %stat_new && $stat_old{gid} ne $stat_new{gid} ) {
      Rex::get_current_connection()->{reporter}->report(
        changed => 1,
        message => "Group changed from $stat_old{gid} to $stat_new{gid}.",
      );
    }

  }

  my $on_change_done = 0;

  if ($need_md5) {
    unless ( $old_md5 && $new_md5 && $old_md5 eq $new_md5 ) {
      $old_md5 ||= "";
      $new_md5 ||= "";

      Rex::Logger::debug("File $file has been changed... Running on_change");
      Rex::Logger::debug("old: $old_md5");
      Rex::Logger::debug("new: $new_md5");

      &$on_change($file);

      $on_change_done = 1;

      Rex::get_current_connection()->{reporter}->report(
        changed => 1,
        message => "Content changed.",
      );

      $__ret = { changed => 1 };
    }
  }

  if ( $__ret->{changed} == 1 && $on_change_done == 0 ) {
    &$on_change($file);
  }
  elsif ( $__ret->{changed} == 0 ) {
    Rex::Logger::debug(
      "File $file has not been changed... Running on_no_change");
    &$on_no_change($file);
  }

  #### check and run after hook
  Rex::Hook::run_hook( file => "after", $file, %{$option}, $__ret );
  ##############################

  Rex::get_current_connection()->{reporter}
    ->report_resource_end( type => "file", name => $file );

  return $__ret->{changed};
}

sub get_tmp_file_name {
  my $file = shift;

  my $dirname  = dirname($file);
  my $filename = ".rex.tmp." . basename($file);

  my $tmp_file_name =
      $dirname eq '.'
    ? $filename
    : Rex::Helper::File::Spec->catfile( $dirname, $filename );

  return $tmp_file_name;
}

=head2 file_write($file_name)

This function opens a file for writing (it will truncate the file if it already exists). It returns a Rex::FS::File object on success.

On failure it will die.

 my $fh;
 eval {
   $fh = file_write("/etc/groups");
 };
 
 # catch an error
 if($@) {
   print "An error occurred. $@.\n";
 }
 
 # work with the filehandle
 $fh->write("...");
 $fh->close;

=cut

sub file_write {
  my ($file) = @_;
  $file = resolv_path($file);

  Rex::Logger::debug("Opening file: $file for writing.");

  my $fh = Rex::Interface::File->create;
  if ( !$fh->open( ">", $file ) ) {
    Rex::Logger::debug("Can't open $file for writing.");
    die("Can't open $file for writing.");
  }

  return Rex::FS::File->new( fh => $fh );
}

=head2 file_append($file_name)

=cut

sub file_append {
  my ($file) = @_;
  $file = resolv_path($file);

  Rex::Logger::debug("Opening file: $file for appending.");

  my $fh = Rex::Interface::File->create;

  if ( !$fh->open( ">>", $file ) ) {
    Rex::Logger::debug("Can't open $file for appending.");
    die("Can't open $file for appending.");
  }

  return Rex::FS::File->new( fh => $fh );
}

=head2 file_read($file_name)

This function opens a file for reading. It returns a Rex::FS::File object on success.

On failure it will die.

 my $fh;
 eval {
   $fh = file_read("/etc/groups");
 };
 
 # catch an error
 if($@) {
   print "An error occurred. $@.\n";
 }
 
 # work with the filehandle
 my $content = $fh->read_all;
 $fh->close;

=cut

sub file_read {
  my ($file) = @_;
  $file = resolv_path($file);

  Rex::Logger::debug("Opening file: $file for reading.");

  my $fh = Rex::Interface::File->create;

  if ( !$fh->open( "<", $file ) ) {
    Rex::Logger::debug("Can't open $file for reading.");
    die("Can't open $file for reading.");
  }

  return Rex::FS::File->new( fh => $fh );
}

=head2 cat($file_name)

This function returns the complete content of $file_name as a string.

 print cat "/etc/passwd";

=cut

sub cat {
  my ($file) = @_;
  $file = resolv_path($file);

  my $fh = file_read($file);
  unless ($fh) {
    die("Can't open $file for reading");
  }
  my $content = $fh->read_all;
  $fh->close;

  return $content;
}

=head2 delete_lines_matching($file, $regexp)

Delete lines that match $regexp in $file.

 task "clean-logs", sub {
    delete_lines_matching "/var/log/auth.log" => "root";
 };

=cut

sub delete_lines_matching {
  my ( $file, @m ) = @_;
  $file = resolv_path($file);

  Rex::get_current_connection()->{reporter}
    ->report_resource_start( type => "delete_lines_matching", name => $file );

  for (@m) {
    if ( ref($_) ne "Regexp" ) {
      $_ = qr{\Q$_\E};
    }
  }

  my $fs = Rex::Interface::Fs->create;

  my %stat = $fs->stat($file);

  if ( !$fs->is_file($file) ) {
    Rex::Logger::info("File: $file not found.");
    die("$file not found");
  }

  if ( !$fs->is_writable($file) ) {
    Rex::Logger::info("File: $file not writable.");
    die("$file not writable");
  }

  my $nl      = $/;
  my @content = split( /$nl/, cat($file) );

  my $old_md5 = "";
  eval { $old_md5 = md5($file); };

  my @new_content;

OUT:
  for my $line (@content) {
  IN:
    for my $match (@m) {
      if ( $line =~ $match ) {
        next OUT;
      }
    }

    push @new_content, $line;
  }

  file $file,
    content => join( $nl, @new_content ),
    owner   => $stat{uid},
    group   => $stat{gid},
    mode    => $stat{mode};

  my $new_md5 = "";
  eval { $new_md5 = md5($file); };

  if ( $new_md5 ne $old_md5 ) {
    Rex::get_current_connection()->{reporter}->report(
      changed => 1,
      message => "Content changed.",
    );
  }
  else {
    Rex::get_current_connection()->{reporter}->report( changed => 0, );
  }

  Rex::get_current_connection()->{reporter}
    ->report_resource_end( type => "delete_lines_matching", name => $file );
}

=head2 delete_lines_according_to($search, $file [, @options])

This is the successor of the delete_lines_matching() function. This function also allows the usage of on_change and on_no_change hooks.

It will search for $search in $file and remove the found lines. If on_change hook is present it will execute this if the file was changed.

 task "cleanup", "server1", sub {
   delete_lines_according_to qr{^foo:}, "/etc/passwd",
    on_change => sub {
      say "removed user foo.";
    };
 };

=cut

sub delete_lines_according_to {
  my ( $search, $file, @options ) = @_;
  $file = resolv_path($file);

  my $option       = {@options};
  my $on_change    = $option->{on_change}    || undef;
  my $on_no_change = $option->{on_no_change} || undef;

  my ( $old_md5, $new_md5 );

  if ($on_change) {
    $old_md5 = md5($file);
  }

  delete_lines_matching( $file, $search );

  if ( $on_change || $on_no_change ) {
    $new_md5 = md5($file);

    if ( $old_md5 ne $new_md5 ) {
      &$on_change($file) if $on_change;
    }
    else {
      &$on_no_change($file) if $on_no_change;
    }
  }

}

=head2 append_if_no_such_line($file, $new_line [, @regexp])

Append $new_line to $file if none in @regexp is found. If no regexp is
supplied, the line is appended unless there is already an identical line
in $file.

 task "add-group", sub {
   append_if_no_such_line "/etc/groups", "mygroup:*:100:myuser1,myuser2", on_change => sub { service sshd => "restart"; };
 };

Since 0.42 you can use named parameters as well

 task "add-group", sub {
   append_if_no_such_line "/etc/groups",
     line  => "mygroup:*:100:myuser1,myuser2",
     regexp => qr{^mygroup},
     on_change => sub {
                say "file was changed, do something.";
              };
 
   append_if_no_such_line "/etc/groups",
     line  => "mygroup:*:100:myuser1,myuser2",
     regexp => [qr{^mygroup:}, qr{^ourgroup:}]; # this is an OR
 };

=cut

sub append_if_no_such_line {
  _append_or_update( 'append_if_no_such_line', @_ );
}

=head2 append_or_amend_line($file, $line [, @regexp])

Similar to L<append_if_no_such_line>, but if the line in the regexp is
found, it will be updated. Otherwise, it will be appended.

 task "update-group", sub {
   append_or_amend_line "/etc/groups",
     line  => "mygroup:*:100:myuser3,myuser4",
     regexp => qr{^mygroup},
     on_change => sub {
       say "file was changed, do something.";
     },
     on_no_change => sub {
       say "file was not changed, do something.";
     };
 };

=cut

sub append_or_amend_line {
  _append_or_update( 'append_or_amend_line', @_ );
}

sub _append_or_update {
  my $action = shift;
  my $file   = shift;

  $file = resolv_path($file);
  my ( $new_line, @m );

  # check if parameters are in key => value format
  my ( $option, $on_change, $on_no_change );

  Rex::get_current_connection()->{reporter}
    ->report_resource_start( type => $action, name => $file );

  eval {
    no warnings;
    $option = {@_};

    # if there is no line parameter, it is the old parameter format
    # so go dieing
    if ( !exists $option->{line} ) {
      die;
    }
    $new_line = $option->{line};
    if ( exists $option->{regexp} && ref $option->{regexp} eq "Regexp" ) {
      @m = ( $option->{regexp} );
    }
    elsif ( ref $option->{regexp} eq "ARRAY" ) {
      @m = @{ $option->{regexp} };
    }
    $on_change    = $option->{on_change}    || undef;
    $on_no_change = $option->{on_no_change} || undef;
    1;
  } or do {
    ( $new_line, @m ) = @_;

    # check if something in @m (the regexpes) is named on_change or on_no_change
    for my $option ( [ on_change => \$on_change ],
      [ on_no_change => \$on_no_change ] )
    {
      for ( my $i = 0 ; $i < $#m ; $i++ ) {
        if ( $m[$i] eq $option->[0] && ref( $m[ $i + 1 ] ) eq "CODE" ) {
          ${ $option->[1] } = $m[ $i + 1 ];
          splice( @m, $i, 2 );
          last;
        }
      }
    }
  };

  unless ( defined $new_line ) {
    my ( undef, undef, undef, $subroutine ) = caller(1);
    $subroutine =~ s/^.*:://;
    die "Undefined new line while trying to run $subroutine on $file";
  }

  my $fs = Rex::Interface::Fs->create;

  my %stat = $fs->stat($file);

  my ( $old_md5, $ret );
  $old_md5 = md5($file);

  # slow but secure way
  my $content;
  eval {
    $content = [ split( /\n/, cat($file) ) ];
    1;
  } or do {
    $ret = 1;
  };

  if ( !@m ) {
    push @m, qr{\Q$new_line\E};
  }

  my $found;
  for my $line ( 0 .. $#{$content} ) {
    for my $match (@m) {
      if ( ref($match) ne "Regexp" ) {
        $match = qr{$match};
      }
      if ( $content->[$line] =~ $match ) {
        $found = 1;
        last if $action eq 'append_if_no_such_line';
        $content->[$line] = "$new_line";
      }
    }
  }

  my $new_md5;
  if ( $action eq 'append_if_no_such_line' && $found ) {
    $new_md5 = $old_md5;
  }
  else {
    push @$content, "$new_line" unless $found;

    file $file,
      content => join( "\n", @$content ),
      owner   => $stat{uid},
      group   => $stat{gid},
      mode    => $stat{mode};
    $new_md5 = md5($file);
  }

  if ( $on_change || $on_no_change ) {
    if ( $old_md5 && $new_md5 && $old_md5 ne $new_md5 ) {
      if ($on_change) {
        $old_md5 ||= "";
        $new_md5 ||= "";

        Rex::Logger::debug("File $file has been changed... Running on_change");
        Rex::Logger::debug("old: $old_md5");
        Rex::Logger::debug("new: $new_md5");
        &$on_change($file);
      }
    }
    elsif ($on_no_change) {
      $new_md5 ||= "";

      Rex::Logger::debug(
        "File $file has not been changed (md5 $new_md5)... Running on_no_change"
      );
      &$on_no_change($file);
    }
  }

  if ( $old_md5 && $new_md5 && $old_md5 ne $new_md5 ) {
    Rex::get_current_connection()->{reporter}->report(
      changed => 1,
      message => "Content changed.",
    );
  }
  else {
    Rex::get_current_connection()->{reporter}->report( changed => 0, );
  }

  Rex::get_current_connection()->{reporter}
    ->report_resource_end( type => $action, name => $file );
}

=head2 extract($file [, %options])

This function extracts a file. The target directory optionally specified with the `to` option will be created automatically.

Supported formats are .box, .tar, .tar.gz, .tgz, .tar.Z, .tar.bz2, .tbz2, .zip, .gz, .bz2, .war, .jar.

 task prepare => sub {
   extract "/tmp/myfile.tar.gz",
    owner => "root",
    group => "root",
    to   => "/etc";
 
   extract "/tmp/foo.tgz",
    type => "tgz",
    mode => "g+rwX";
 };

Can use the type=> option if the file suffix has been changed. (types are tar, tgz, tbz, zip, gz, bz2)

=cut

sub extract {
  my ( $file, %option ) = @_;
  $file = resolv_path($file);

  my $pre_cmd = "";
  my $to      = ".";
  my $type    = "";

  if ( $option{chdir} ) {
    $to = $option{chdir};
  }

  if ( $option{to} ) {
    $to = $option{to};
  }
  $to = resolv_path($to);

  if ( $option{type} ) {
    $type = $option{type};
  }

  Rex::Commands::Fs::mkdir($to);
  $pre_cmd = "cd $to; ";

  my $exec = Rex::Interface::Exec->create;
  my $cmd  = "";

  if ( $type eq 'tgz'
    || $file =~ m/\.tar\.gz$/
    || $file =~ m/\.tgz$/
    || $file =~ m/\.tar\.Z$/ )
  {
    $cmd = "${pre_cmd}gunzip -c $file | tar -xf -";
  }
  elsif ( $type eq 'tbz' || $file =~ m/\.tar\.bz2/ || $file =~ m/\.tbz2/ ) {
    $cmd = "${pre_cmd}bunzip2 -c $file | tar -xf -";
  }
  elsif ( $type eq 'tar' || $file =~ m/\.(tar|box)/ ) {
    $cmd = "${pre_cmd}tar -xf $file";
  }
  elsif ( $type eq 'zip' || $file =~ m/\.(zip|war|jar)$/ ) {
    $cmd = "${pre_cmd}unzip -o $file";
  }
  elsif ( $type eq 'gz' || $file =~ m/\.gz$/ ) {
    $cmd = "${pre_cmd}gunzip -f $file";
  }
  elsif ( $type eq 'bz2' || $file =~ m/\.bz2$/ ) {
    $cmd = "${pre_cmd}bunzip2 -f $file";
  }
  else {
    Rex::Logger::info("File not supported.");
    die("File ($file) not supported.");
  }

  $exec->exec($cmd);

  my $fs = Rex::Interface::Fs->create;
  if ( $option{owner} ) {
    $fs->chown( $option{owner}, $to, recursive => 1 );
  }

  if ( $option{group} ) {
    $fs->chgrp( $option{group}, $to, recursive => 1 );
  }

  if ( $option{mode} ) {
    $fs->chmod( $option{mode}, $to, recursive => 1 );
  }

}

=head2 sed($search, $replace, $file [, %options])

Search some string in a file and replace it.

 task sar => sub {
   # this will work line by line
   sed qr{search}, "replace", "/var/log/auth.log";
 
   # to use it in a multiline way
   sed qr{search}, "replace", "/var/log/auth.log",
    multiline => TRUE;
 };

Like similar file management commands, it also supports C<on_change> and C<on_no_change> hooks.

=cut

sub sed {
  my ( $search, $replace, $file, @option ) = @_;
  $file = resolv_path($file);
  my $options = {};

  Rex::get_current_connection()->{reporter}
    ->report_resource_start( type => "sed", name => $file );

  if ( ref( $option[0] ) ) {
    $options = $option[0];
  }
  else {
    $options = {@option};
  }

  my $on_change    = $options->{"on_change"}    || undef;
  my $on_no_change = $options->{"on_no_change"} || undef;

  my @content;

  if ( exists $options->{multiline} ) {
    $content[0] = cat($file);
    $content[0] =~ s/$search/$replace/gms;
  }
  else {
    @content = split( /\n/, cat($file) );
    for (@content) {
      s/$search/$replace/;
    }
  }

  my $fs   = Rex::Interface::Fs->create;
  my %stat = $fs->stat($file);

  my $ret = file(
    $file,
    content      => join( "\n", @content ),
    on_change    => $on_change,
    on_no_change => $on_no_change,
    owner        => $stat{uid},
    group        => $stat{gid},
    mode         => $stat{mode}
  );

  Rex::get_current_connection()->{reporter}
    ->report_resource_end( type => "sed", name => $file );

  return $ret;
}

1;