#------------------------------------------------------------------------------
# Copyright (C) 2014, Jasper Lievisse Adriaanse <jasper@openbsd.org>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
#------------------------------------------------------------------------------

package Portroach::SiteHandler::Hackage;

use HTML::TokeParser;
use LWP::UserAgent;

use Portroach::Const;
use Portroach::Config;

use strict;

require 5.006;


#------------------------------------------------------------------------------
# Globals
#------------------------------------------------------------------------------

push @Portroach::SiteHandler::sitehandlers, __PACKAGE__;

our %settings;


#------------------------------------------------------------------------------
# Func: new()
# Desc: Constructor.
#
# Args: n/a
#
# Retn: $self
#------------------------------------------------------------------------------

sub new
{
	my $self      = {};
	my $class     = shift;

	$self->{name} = 'Hackage';

	bless ($self, $class);
	return $self;
}


#------------------------------------------------------------------------------
# Func: CanHandle()
# Desc: Ask if this handler (package) can handle the given site.
#
# Args: $url - URL of site.
#
# Retn: $res - true/false.
#------------------------------------------------------------------------------

sub CanHandle
{
	my $self = shift;

	my ($url) = @_;

	return ($url =~ /http(s?):\/\/hackage\.haskell\.org\/package\//);
}


#------------------------------------------------------------------------------
# Func: GetFiles()
# Desc: Extract a list of files from the given URL. Parse the package's
#       HTML page and extract the latest version in a rather crude manner.
#       Ideally it should query the Hackage API for this.
#
# Args: $url     - URL we would normally fetch from.
#       \%port   - Port hash fetched from database.
#       \@files  - Array to put files into.
#
# Retn: $success - False if file list could not be constructed; else, true.
#------------------------------------------------------------------------------

sub GetFiles
{
	my $self = shift;

	my ($url, $port, $files) = @_;

	my ($hackage, $package, $query, $resp, $ua);
	$hackage = 'http://hackage.haskell.org/package/';

	# Strip all the digits at the end to keep the stem of the module.
	if ($port->{distname} =~ /(.*?)-(\d+)/) {
	    $package = $1;
	}

	$query = $hackage . $package;

	_debug("GET $query");
	$ua = LWP::UserAgent->new;
	$ua->agent(USER_AGENT);
	$resp = $ua->request(HTTP::Request->new(GET => $query));

	if ($resp->is_success) {
	    my $tp = HTML::TokeParser->new(\$resp->decoded_content);
	    # XXX: Bad heuristic to depend on the only <strong> tag, but
	    # it's the best we can get by with for the moment.
	    while (my $token = $tp->get_tag('strong')) {
		my ($url, $version);

		$version = $tp->get_trimmed_text('/strong');
		next unless $version;

		$url = 'package/' . $package . '-' . $version . '/' . $package . '-' . $version . '.tar.gz';
		push @$files, $url;
	    }
	} else {
	    _debug("GET failed: " . $resp->code);
	    return 0;
	}

	return 1;
}


#------------------------------------------------------------------------------
# Func: _debug()
# Desc: Print a debug message.
#
# Args: $msg - Message.
#
# Retn: n/a
#------------------------------------------------------------------------------

sub _debug
{
	my ($msg) = @_;

	$msg = '' if (!$msg);

	print STDERR "(" . __PACKAGE__ . ") $msg\n" if ($settings{debug});
}

1;
