package Panotools::Makefile;

=head1 NAME

Panotools::Makefile - Makefile creation

=head1 SYNOPSIS

Simple object interface for generating Makefiles

=head1 DESCRIPTION

Writing Makefiles directly from perl scripts with print and "\t" etc... is
prone to error, this library provides a simple perl interface for assembling
Makefiles.

=cut

use strict;
use warnings;

use Panotools::Script;
use Panotools::Makefile::Rule;
use Panotools::Makefile::Variable;
use Panotools::Makefile::Comment;
use File::Temp qw/tempdir/;
use File::Spec;

=head1 USAGE

  use Panotools::Makefile;

Create a new Makefile object:

  my $makefile = new Panotools::Makefile;

=cut

sub new
{
    my $class = shift;
    $class = ref $class || $class;
    my $self = bless {items => []}, $class;
    return $self;
}

=pod

Start adding items to the Makefile:

Rule() returns a new L<Panotools::Makefile::Rule> object, Variable() returns a
new L<Panotools::Makefile::Variable> object and Comment() returns a new
L<Panotools::Makefike::Variable> object:

  my $var_user = $makefile->Variable ('USER');
  $var_user->Values ("Dr. Largio d'Apalansius (MB)");

  my $rule_all = $makefile->Rule ('all');
  $rule_all->Command ('echo', '$(USER_SHELL)', '>', 'My File.txt');

  $makefile->Comment ('.PHONY target isn't strictly necessary in this case');
  my $rule_phony = $makefile->Rule;
  $rule_phony->Targets ('.PHONY');
  $rule_phony->Prerequisites ('all');

=cut

sub Rule
{
    my $self = shift;
    my $rule = new Panotools::Makefile::Rule (@_);
    push @{$self->{items}}, $rule;
    return $rule;
}

sub Variable
{
    my $self = shift;
    my $variable = new Panotools::Makefile::Variable (@_);
    push @{$self->{items}}, $variable;
    return $variable;
}

sub Comment
{
    my $self = shift;
    my $comment = new Panotools::Makefile::Comment (@_);
    push @{$self->{items}}, $comment;
    return $comment;
}

=pod

Write the Makefile:

  $makefile->Write ('/path/to/Makefile');

=cut

sub Write
{
    my $self = shift;
    my $path_makefile = shift;
    open MAKE, ">", $path_makefile or warn "cannot write-open $path_makefile";
    print MAKE "# Created by Panotools::Script $Panotools::Script::VERSION\n\n";
    print MAKE map {$_->Assemble} @{$self->{items}};
    close MAKE;
}

=pod

..or let the module execute rules with 'make' directly:

  $makefile->DoIt ('all') || warn "Didn't work :-(";

The following command will be executed, something that isn't possible with perl
system() or exec(), and would otherwise require careful assembly with backticks:

  echo Dr.\ Largio\ d\'Apalansius\ \(MB\) > My\ File.txt

On the Windows platform you get appropriate quoting:

  echo "Dr. Largio d'Apalansius (MB)" > "My File.txt"

=cut

sub DoIt
{
    my $self = shift;
    my $tempdir = tempdir (CLEANUP => 1);
    my $path_makefile = File::Spec->catfile ($tempdir, 'Makefile');
    $self->Write ($path_makefile);
    system ('make', '-f', $path_makefile, @_);
    return 1 if ($? == 0);
    return 0;
}

1;