#!/usr/bin/perl

use strict;
use warnings;
use autodie qw(:all);
use feature qw(:5.14);
use experimental 'switch';
use LWP::UserAgent;
use LWP::ConnCache;
use JSON;

our $packager = '';
my %pkgmap = ();
my %licenses = ();

my $template = <<'EOF';
# Automatically generated by apkbuild-pypi, template 3
[% authors %]
pkgname=[% pkgname %]
#_pkgreal is used by apkbuild-pypi to find modules at PyPI
_pkgreal=[% pkgreal %]
pkgver=[% pkgver %]
pkgrel=[% pkgrel %]
pkgdesc="[% pkgdesc %]"
provides="[% provides %]"
replaces="[% replaces %]"
url="http://packages.python.org/pypi/[% pkgreal %]"
arch="noarch"
license="[% license %]"
depends="python3"
checkdepends="python3-dev"
makedepends="py3-setuptools"
subpackages=""
source="[% source %]"
builddir="$srcdir/$_pkgreal-$pkgver"

build() {
	python3 setup.py build
}

check() {
	python3 setup.py test
}

package() {
	PYTHONPATH=$pkgdir`python3 -c "import site; print(site.getsitepackages()[0])"` \
	python3 setup.py install \
		--prefix=/usr \
		--root="$pkgdir" \
		--single-version-externally-managed
}

EOF

my $ua = LWP::UserAgent->new();
my $json = JSON->new;
$ua->env_proxy;
$ua->conn_cache(LWP::ConnCache->new);

sub read_file {
    my ($filename) = @_;
    open my $fh, '<:utf8', $filename;
    local $/;
    my $text = <$fh>;
    return $text;
}

sub read_assignments_from_file {
    my ($filename) = @_;
    return () if ( ! -e $filename );
    my $text = read_file($filename);
    my %sline = $text =~ /^(\w+)\s*=\s*([^\"\n]*)$/mg;
    my %mline = $text =~ /^(\w+)\s*=\s*\"([^\"]*)\".*$/mg;
    my %hash = ( %sline, %mline );

    my $authors = join("\n", $text =~ /^# Contributor: .*$/mg, $text =~ /^# Maintainer: .*$/mg);
    $hash{'authors'} = $authors if length($authors) > 1;

    my $provides = $text =~ m/provides=\"(.*)\"".*/mg;
    $hash{'provides'} = $1 if length($provides) >= 1;

    my $requires = $text =~ m/^requires=\"(.*)\"".*$/mg;
    $hash{'requires'} = $1 if length($requires) >= 1;

    return \%hash;
}

sub map_pypi_to_apk {
    my ($pypi) = @_;
    return $pkgmap{$pypi} unless !exists($pkgmap{$pypi});
    return 'py3-'.lc($pypi);
}

sub map_license {
    my ($license) = @_;

    $license =~ s/ or / /g;

    return $license;
}

sub get_source {
    my ($distdata) = @_;

    for my $url (@{$distdata->{urls}}) {
        return $url->{url} if $url->{python_version} eq 'source'
    }
    die "Unable to locate sources for $distdata->{name}.\n";
}

sub read_apkbuild {
    return read_assignments_from_file('APKBUILD');
}

sub write_apkbuild {
    my ($distdata, $apkbuild) = @_;

    my $replaces = undef;
    my $provides = undef;
    my $authors = undef;
    my $pkgrel = 0;

    if (defined $apkbuild) {
        $authors = $apkbuild->{authors};
        $provides = $apkbuild->{provides};
        $replaces = $apkbuild->{replaces};
        $pkgrel = $apkbuild->{pkgrel};

	if ($apkbuild->{pkgver} eq $distdata->{info}{version}) {
	    $pkgrel++;
	}
    }

    my %repl = (
	authors  => ($authors or "# Contributor: $packager\n# Maintainer: $packager"),
        pkgname  => map_pypi_to_apk($distdata->{info}{name}),
        pkgreal  => $distdata->{info}{name},
        pkgver   => $distdata->{info}{version},
        pkgrel	 => $pkgrel,
        source   => get_source($distdata),
        license  => map_license($distdata->{info}{license}),
        pkgdesc  => $distdata->{info}{summary},
        provides => ($provides or ''),
        replaces => ($replaces or ''),
    );
    $template =~ s/\[% (.*?) %\]/$repl{$1}/g;

    open my $fh, '>:utf8', 'APKBUILD';
    print {$fh} $template;
    close $fh;

    say "Wrote $repl{pkgname}/APKBUILD";

    return \%repl;
}

sub prepare_tree {
    system('abuild checksum unpack prepare');
}

sub find_package_name {
    my ($apkbuild) = @_;

    my $pkgreal = '';

    if (exists $apkbuild->{_realname}) {
        $pkgreal = $apkbuild->{_realname};
    } elsif (exists $apkbuild->{_pkgreal}) {
        $pkgreal = $apkbuild->{_pkgreal};
    } elsif (exists $apkbuild->{_pkgname}) {
        $pkgreal = $apkbuild->{_pkgname};
    } elsif (exists $apkbuild->{_name}) {
        $pkgreal = $apkbuild->{_name};
    } elsif (exists $apkbuild->{_realpkgname}) {
        $pkgreal = $apkbuild->{_realpkgname};
    } elsif (exists $apkbuild->{_pkg_real}) {
        $pkgreal = $apkbuild->{_pkg_real};
    } elsif (exists $apkbuild->{source}) {
        $pkgreal = $apkbuild->{source};
        $pkgreal =~ m/(\w+)-/;
        $pkgreal = $1;
    } else {
        print "No pkg real found\n";
        die;
    }
    return $pkgreal;
}

sub get_data {
    my ($package) = @_;
    my $response = $ua->get("https://pypi.python.org/pypi/$package/json");
    $response->is_success or die $response->status_line;
    my $distdata = $json->decode($response->decoded_content);

    return $distdata;
}

sub get_deps {
    my ($data) = @_;

    chdir "src/$data->{pkgreal}-$data->{pkgver}";
    my $reqs = `python3 ./setup.py --requires`;

    my @reqs = split /\n/, $reqs;

    foreach my $i (0 .. $#reqs) {
        $reqs[$i] =~ s/(\(|\s+).*$//;
        $reqs[$i] = map_pypi_to_apk($reqs[$i]);
    }

    chdir '../..';

    my $apk = read_file('APKBUILD');

    $reqs = join ' ', @reqs;

    $apk =~ s/pymakedepends=""/pymakedepends="$reqs"/;

    # remove empty variables
    $apk =~ s/.*=""\n//g;

    open my $fh, '>:utf8', 'APKBUILD';

    print $fh $apk;

    say "Requires: $reqs";
}

my $abuild_conf = read_assignments_from_file('/etc/abuild.conf');
$packager = $abuild_conf->{PACKAGER} if $abuild_conf->{PACKAGER};

my $user_abuild_conf = read_assignments_from_file($ENV{"HOME"} . "/.abuild/abuild.conf");
$packager = $user_abuild_conf->{PACKAGER} if $user_abuild_conf->{PACKAGER};

sub usage {
    say <<'EOF';
Usage: apkbuild-pypi [create <package> | check | recreate | upgrade | update]

In the repository root:
    create <package>: Creates an APKBUILD for <package>

In the package root:
    check           : Reports current & latest version of the package
    recreate        : Recreates the APKBUILD
    upgrade         : Upgrades to the latest version of the package
    update          : Updates APKBUILD metadata
EOF
}

given ($ARGV[0]) {
    when ('create') {
        my $package = $ARGV[1];
        $package or die usage;

        my $distdata = get_data($package);
        my $apkname = map_pypi_to_apk($package);

        mkdir $apkname;
        chdir $apkname;

        my $data = write_apkbuild($distdata, undef);
        prepare_tree;

        get_deps($data);
    } when ('recreate') {
        my $apkbuild = read_apkbuild;
        if (! defined $apkbuild->{_pkgreal}) {
	     $apkbuild->{_pkgreal} = find_package_name($apkbuild);
        }
        my $distdata = get_data($apkbuild->{_pkgreal});
	my $pkgver = $distdata->{info}{version} =~ s/^[^0-9]+//r;
	if ($pkgver ne $apkbuild->{pkgver}) {
		#Reset pkgrel on upgrade on recreate
		say "Upgrading PyPI module from $apkbuild->{pkgver} to $pkgver";
		$apkbuild->{pkgrel}=0;
	}
	my $data = write_apkbuild($distdata, $apkbuild);

        prepare_tree;
        get_deps($data);
    } when ('upgrade') {
        my $apkbuild = read_apkbuild;

        if (! defined $apkbuild->{_pkgreal}) {
	     $apkbuild->{_pkgreal} = find_package_name($apkbuild);
        }

        my $distdata = get_data($apkbuild->{_pkgreal});

        my $pkgver = $distdata->{info}{version};

        if ($pkgver ne $apkbuild->{pkgver}) {
            say "Upgrading PyPI package from $apkbuild->{pkgver} to $pkgver";

            my $text = read_file('APKBUILD');

            $text =~ s/^(pkgver)=.*$/$1=$pkgver/mg or
                die "Can't find pkgver line in APKBUILD";
            $text =~ s/^(pkgrel)=.*$/$1=0/mg or
                die "Can't find pkgrel line in APKBUILD";

            open my $fh, '>:utf8', 'APKBUILD';
            print $fh $text;
            close $fh;
        } else {
            say "Already up to date with PyPI";
        }
    } when ('check') {
        my $apkbuild = read_apkbuild;

        if (! defined $apkbuild->{_pkgreal}) {
	     $apkbuild->{_pkgreal} = find_package_name($apkbuild);
        }
        my $distdata = get_data($apkbuild->{_pkgreal});

        my $pkgver = $distdata->{info}{version};


        say "$apkbuild->{pkgname}: Latest version: $pkgver Packaged version: $apkbuild->{pkgver}";
        if ($pkgver ne $apkbuild->{pkgver}) {
            exit(1);
        }
    } when ('update') {
        prepare_tree;
    } default {
        die usage;
    }
}