use strict;
use warnings;
package Mixin::Linewise::Writers 0.111;
# ABSTRACT: get linewise writers for strings and filenames

use 5.008001; # PerlIO
use Carp ();
use IO::File;

use Sub::Exporter -setup => {
  exports => { map {; "write_$_" => \"_mk_write_$_" } qw(file string) },
  groups  => {
    default => [ qw(write_file write_string) ],
    writers => [ qw(write_file write_string) ],
  },
};

#pod =head1 SYNOPSIS
#pod
#pod   package Your::Pkg;
#pod   use Mixin::Linewise::Writers -writers;
#pod
#pod   sub write_handle {
#pod     my ($self, $data, $handle) = @_;
#pod
#pod     $handle->print("datum: $_\n") for @$data;
#pod   }
#pod
#pod Then:
#pod
#pod   use Your::Pkg;
#pod
#pod   Your::Pkg->write_file($data, $filename);
#pod
#pod   Your::Pkg->write_string($data, $string);
#pod
#pod   Your::Pkg->write_handle($data, $fh);
#pod
#pod =head1 EXPORTS
#pod
#pod C<write_file> and C<write_string> are exported by default.  Either can be
#pod requested individually, or renamed.  They are generated by
#pod L<Sub::Exporter|Sub::Exporter>, so consult its documentation for more
#pod information.
#pod
#pod Both can be generated with the option "method" which requests that a method
#pod other than "write_handle" is called with the created IO::Handle.
#pod
#pod If given a "binmode" option, any C<write_file> type functions will use
#pod that as an IO layer, otherwise, the default is C<encoding(UTF-8)>.
#pod
#pod   use Mixin::Linewise::Writers -writers => { binmode => "raw" };
#pod   use Mixin::Linewise::Writers -writers => { binmode => "encoding(iso-8859-1)" };
#pod
#pod =head2 write_file
#pod
#pod   Your::Pkg->write_file($data, $filename);
#pod   Your::Pkg->write_file($data, $options, $filename);
#pod
#pod This method will try to open a new file with the given name.  It will then call
#pod C<write_handle> with that handle.
#pod
#pod An optional hash reference may be passed before C<$filename> with options.
#pod The only valid option currently is C<binmode>, which overrides any
#pod default set from C<use> or the built-in C<encoding(UTF-8)>.
#pod
#pod Any arguments after C<$filename> are passed along after to C<write_handle>.
#pod
#pod =cut

sub _mk_write_file {
  my ($self, $name, $arg) = @_;
  my $method = defined $arg->{method} ? $arg->{method} : 'write_handle';
  my $dflt_enc = defined $arg->{binmode} ? $arg->{binmode} : 'encoding(UTF-8)';

  sub {
    my ($invocant, $data, $options, $filename);
    if ( ref $_[2] eq 'HASH' ) {
      # got options before filename
      ($invocant, $data, $options, $filename) = splice @_, 0, 4;
    }
    else {
      ($invocant, $data, $filename) = splice @_, 0, 3;
    }

    my $binmode = defined $options->{binmode} ? $options->{binmode} : $dflt_enc;
    $binmode =~ s/^://; # we add it later

    # Check the file
    Carp::croak "no filename specified"           unless $filename;
    Carp::croak "'$filename' is not a plain file" if -e $filename && ! -f _;

    # Write out the file
    my $handle = IO::File->new($filename, ">:$binmode")
      or Carp::croak "couldn't write to file '$filename': $!";

    $invocant->write_handle($data, $handle, @_);
  }
}

#pod =head2 write_string
#pod
#pod   my $string = Your::Pkg->write_string($data);
#pod   my $string = Your::Pkg->write_string(\%option, $data);
#pod
#pod C<write_string> will create a new handle on the given string, then call
#pod C<write_handle> to write to that handle, and return the resulting string.
#pod Because handles on strings must be octet-oriented, the string B<will contain
#pod octets>.  It will be opened in the default binmode established by importing.
#pod (See L</EXPORTS>, above, and the options, below.)
#pod
#pod Any arguments after C<$data> are passed along after to C<write_handle>.
#pod
#pod Like C<write_file>, this method can take a leading hashref with one valid
#pod argument: C<binmode>.
#pod
#pod =cut

sub _mk_write_string {
  my ($self, $name, $arg) = @_;
  my $method = defined $arg->{method} ? $arg->{method} : 'write_handle';
  my $dflt_enc = defined $arg->{binmode} ? $arg->{binmode} : 'encoding(UTF-8)';

  sub {
    my ($opt) = @_ > 2 && ref $_[1] ? splice(@_, 1, 1) : undef;
    my ($invocant, $data) = splice @_, 0, 2;

    my $binmode = ($opt && $opt->{binmode}) ? $opt->{binmode} : $dflt_enc;
    $binmode =~ s/^://; # we add it later

    my $string = '';
    open my $handle, ">:$binmode", \$string
      or die "error opening string for output: $!";

    $invocant->write_handle($data, $handle, @_);
    close $handle or die "error closing string after output: $!";

    return $string;
  }
}

1;

__END__

=pod

=encoding UTF-8

=head1 NAME

Mixin::Linewise::Writers - get linewise writers for strings and filenames

=head1 VERSION

version 0.111

=head1 SYNOPSIS

  package Your::Pkg;
  use Mixin::Linewise::Writers -writers;

  sub write_handle {
    my ($self, $data, $handle) = @_;

    $handle->print("datum: $_\n") for @$data;
  }

Then:

  use Your::Pkg;

  Your::Pkg->write_file($data, $filename);

  Your::Pkg->write_string($data, $string);

  Your::Pkg->write_handle($data, $fh);

=head1 PERL VERSION

This module should work on any version of perl still receiving updates from
the Perl 5 Porters.  This means it should work on any version of perl released
in the last two to three years.  (That is, if the most recently released
version is v5.40, then this module should work on both v5.40 and v5.38.)

Although it may work on older versions of perl, no guarantee is made that the
minimum required version will not be increased.  The version may be increased
for any reason, and there is no promise that patches will be accepted to lower
the minimum required perl.

=head1 EXPORTS

C<write_file> and C<write_string> are exported by default.  Either can be
requested individually, or renamed.  They are generated by
L<Sub::Exporter|Sub::Exporter>, so consult its documentation for more
information.

Both can be generated with the option "method" which requests that a method
other than "write_handle" is called with the created IO::Handle.

If given a "binmode" option, any C<write_file> type functions will use
that as an IO layer, otherwise, the default is C<encoding(UTF-8)>.

  use Mixin::Linewise::Writers -writers => { binmode => "raw" };
  use Mixin::Linewise::Writers -writers => { binmode => "encoding(iso-8859-1)" };

=head2 write_file

  Your::Pkg->write_file($data, $filename);
  Your::Pkg->write_file($data, $options, $filename);

This method will try to open a new file with the given name.  It will then call
C<write_handle> with that handle.

An optional hash reference may be passed before C<$filename> with options.
The only valid option currently is C<binmode>, which overrides any
default set from C<use> or the built-in C<encoding(UTF-8)>.

Any arguments after C<$filename> are passed along after to C<write_handle>.

=head2 write_string

  my $string = Your::Pkg->write_string($data);
  my $string = Your::Pkg->write_string(\%option, $data);

C<write_string> will create a new handle on the given string, then call
C<write_handle> to write to that handle, and return the resulting string.
Because handles on strings must be octet-oriented, the string B<will contain
octets>.  It will be opened in the default binmode established by importing.
(See L</EXPORTS>, above, and the options, below.)

Any arguments after C<$data> are passed along after to C<write_handle>.

Like C<write_file>, this method can take a leading hashref with one valid
argument: C<binmode>.

=head1 AUTHOR

Ricardo SIGNES <cpan@semiotic.systems>

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2008 by Ricardo SIGNES.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut