package Debian::Debhelper::Buildsystem::dh_virtualenv;

use strict;
use base 'Debian::Debhelper::Buildsystem';
use Debian::Debhelper::Dh_Lib;
use File::Spec;

sub DESCRIPTION {
    'Python Virtualenv';
}

sub DEFAULT_BUILD_DIRECTORY {
        my $this=shift;
        return $this->canonpath($this->get_sourcepath("build"));
}

sub check_auto_buildable {
        my $this=shift;
        return -e $this->get_sourcepath("setup.py") ? 1 : 0;
}

sub new {
    my $class = shift;
    my $this = $class->SUPER::new(@_);
    $this->prefer_out_of_source_building();
    return $this;
}

sub get_install_root {
    my $prefix = "/usr/share/python";
    if (defined $ENV{DH_VIRTUALENV_INSTALL_ROOT}) {
        $prefix = $ENV{DH_VIRTUALENV_INSTALL_ROOT};
    }
    return $prefix;
}

sub get_venv_builddir {
    my $this = shift;
    my $builddir = $this->get_builddir();
    my $virtualenv_name = $ENV{DH_VIRTUALENV_INSTALL_SUFFIX} || $this->sourcepackage();
    my $prefix = $this->get_install_root();
    return "$builddir$prefix/$virtualenv_name";
}

sub get_exec {
    my $this = shift;
    my $executable = shift;
    my $builddir = $this->get_venv_builddir();
    return "$builddir/bin/$executable";
}

sub get_python {
    my $this = shift;
    return $this->get_exec("python");
}

sub get_pip {
    my $this = shift;
    return ($this->get_exec("python"), "-m", "pip");
}

sub configure {
    my $this = shift;
    doit('mkdir', '-p', $this->get_venv_builddir());
}

sub build {
    my $this = shift;
    my $sourcedir = $this->get_sourcedir();
    my $builddir = $this->get_venv_builddir();
    my @params = ();
    my $reqfile = ('requirements.txt');
    my @pipargs = ();

    if (defined $ENV{DH_VIRTUALENV_ARGUMENTS}) {
        @params = split(' ', $ENV{DH_VIRTUALENV_ARGUMENTS});
    }

    if (defined $ENV{DH_REQUIREMENTS_FILE}) {
        $reqfile = $ENV{DH_REQUIREMENTS_FILE};
    }

    if (defined $ENV{DH_PIP_EXTRA_ARGS}) {
        @pipargs = split(' ', $ENV{DH_PIP_EXTRA_ARGS});
    }

    $this->doit_in_builddir(
        'virtualenv', @params, Cwd::abs_path($builddir));

    my $python = $this->get_python();
    my @pip = $this->get_pip();

    if (defined $ENV{DH_UPGRADE_PIP}) {
        my $version = length $ENV{DH_UPGRADE_PIP} && '=='.$ENV{DH_UPGRADE_PIP} || '';
        $this->doit_in_sourcedir(
            @pip, 'install', '-U', 'pip' . $version, @pipargs);
    }
    if (defined $ENV{DH_UPGRADE_SETUPTOOLS}) {
        my $version = length $ENV{DH_UPGRADE_SETUPTOOLS} && '=='.$ENV{DH_UPGRADE_SETUPTOOLS} || '';
        $this->doit_in_sourcedir(
            @pip, 'install', '-U', 'setuptools' . $version, @pipargs);
    }
    if (defined $ENV{DH_UPGRADE_WHEEL}) {
        my $version = length $ENV{DH_UPGRADE_WHEEL} && '=='.$ENV{DH_UPGRADE_WHEEL} || '';
        $this->doit_in_sourcedir(
            @pip, 'install', '-U', 'wheel' . $version, @pipargs);
    }
    $this->doit_in_sourcedir(
        @pip, 'install', '-r', $reqfile, @pipargs);
}

sub test {
    my $this = shift;
    my $python = $this->get_python();
    $this->doit_in_sourcedir(
        $python, 'setup.py', 'test');
}

sub install {
    my $this = shift;
    my $destdir = shift;
    my @pip = $this->get_pip();
    my $python = $this->get_python();
    my $sourcepackage = $this->sourcepackage();
    my $venv = $this->get_venv_builddir();
    my $prefix = $this->get_install_root();

    $this->doit_in_sourcedir(
        @pip, 'install', '.');

    # Before we copy files, let's make the symlinks in the 'usr/local'
    # relative to the build path.
    my @files_in_local = <"$venv/local/*">;
    foreach (@files_in_local) {
        if ( -l $_ ) {
            my $target = readlink;
            my $relpath = File::Spec->abs2rel($target, "$venv/local");
            my $basename = Debian::Debhelper::Dh_Lib->basename($_);
            unlink;
            symlink($relpath, $_);
       }
    }

    $this->doit_in_builddir('mkdir', '-p', $destdir);
    $this->doit_in_builddir('cp', '-r', '-T', '.', $destdir);

    my $new_python = undef;
    my @binaries = undef;

    if (defined $ENV{DH_VIRTUALENV_INSTALL_SUFFIX}) {
        $new_python = "$prefix/" . $ENV{DH_VIRTUALENV_INSTALL_SUFFIX} . "/bin/python";
        my $curdir = "$destdir$prefix/" . $ENV{DH_VIRTUALENV_INSTALL_SUFFIX} . "/bin/*";
        @binaries = glob($curdir);
    } else {
        $new_python = "$prefix/$sourcepackage/bin/python";
        @binaries = <"$destdir$prefix/$sourcepackage/bin/*">;
    }

    # Fix shebangs so that we use the Python in the final location
    # instead of the Python in the build directory
    {
        local $^I = q{};
        local @ARGV = grep { -T } @binaries;
        while ( <> ) {
            s|^#!.*bin/(env )?python|#!$new_python|;
            print;
        }
    }
}

sub clean {
    my $this = shift;
    $this->rmdir_builddir();
}

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