#!/usr/bin/perl

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

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

my $template = <<'EOF';
# Automatically generated by apkbuild-pypi, template 4
[% authors %]
pkgname=[% pkgname %]
#_pkgreal is used by apkbuild-pypi to find modules at PyPI
_pkgreal=[% pkgreal %]
pkgver=[% pkgver %]
pkgrel=[% pkgrel %]
pkgdesc="[% pkgdesc %]"
provides="[% provides %]"
replaces="[% replaces %]"
url="http://packages.python.org/pypi/[% pkgreal %]"
arch="noarch"
license="[% license %]"
depends=""
makedepends="py3-gpep517 py3-setuptools py3-wheel"
checkdepends="py3-pytest"
subpackages="$pkgname-pyc"
source="[% source %]"
builddir="$srcdir/$_pkgreal-$pkgver"

build() {
	gpep517 build-wheel \
		--wheel-dir .dist \
		--output-fd 3 3>&1 >&2
}

check() {
	python3 -m venv --clear --without-pip --system-site-packages .testenv
	.testenv/bin/python3 -m installer .dist/*.whl
	.testenv/bin/python3 -m pytest
}

package() {
	python3 -m installer -d "$pkgdir" \
		.dist/*.whl
}

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) = @_;
    my $pkgname = $distdata->{info}{name};

    my $source;
    for my $url (@{$distdata->{urls}}) {
        if ($url->{python_version} eq 'source') {
            $source = URI->new($url->{url});
            last;
        }
    }
    die "Unable to locate sources for $pkgname.\n" unless $source;

    my $filename = ($source->path_segments)[-1];
    my $pretty_path = substr($pkgname, 0, 1) . "/$pkgname";
    my $pretty_url = $source->clone;
    $pretty_url->path("/packages/source/$pretty_path/$filename");

    my $response = $ua->head($pretty_url);
    if ($response->is_success) {
        return $pretty_url->as_string;
    } else {
        return $source->as_string;
    }
}

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 ''),
    );
    $repl{source} =~ s/-$repl{pkgver}/-\$pkgver/g;
    $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 ($distdata, $data) = @_;

    my $reqs = $distdata->{info}{requires_dist};
    my %depends = ('py3-pytest' => 'py3-pytest');

    my @reqs =
        map {
            my $apkname = map_pypi_to_apk(s/(\(|\s+).*$//r);
            $depends{$apkname} = $apkname
        }
        grep { $_ !~ m/; extra ==/ }
        @$reqs;

    my @checkdeps =
        map {
            my $apkname = map_pypi_to_apk(s/(\(|\s+).*$//r);
            exists($depends{$apkname}) ? () : $apkname
        }
        grep { m/; extra == 'tests'/ }
        @$reqs;

    my $apk = read_file('APKBUILD');

    $reqs = join ' ', @reqs;

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

    unshift @checkdeps, 'py3-pytest';
    my $checkdeps = join ' ', @checkdeps;

    $apk =~ s/checkdepends="py3-pytest"/checkdepends="$checkdeps"/;

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

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

    print $fh $apk;

    say "Requires: @reqs\n\nCheckDepends: @checkdeps";
}

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
}

if (! defined $ARGV[0]) {
    die usage;
} elsif ($ARGV[0] eq '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($distdata, $data);
} elsif ($ARGV[0] eq '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($distdata, $data);
} elsif ($ARGV[0] eq '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 $fh;
    } else {
        say "Already up to date with PyPI";
    }
} elsif ($ARGV[0] eq '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 $apkbuild->{pkgver}) {
        exit(1);
    }
} elsif ($ARGV[0] eq 'update') {
    prepare_tree;
} else {
    die usage;
}