#!/usr/bin/perl -w
#
# This file is part of the dgit test suite.
#
# Copyright (C)2004-2015 Best Practical Solutions, LLC
# Copyright (C)2019      Ian Jackson
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
#
# invocation protocol:
#
#   http-static-server >port-file tests/tmp/$thing/aq
#
# Will write the allocated port number to port-file.
# Then we fork and the parent exits 0.
# If port-file is unlinked, we exit.

use strict;
use IO::Handle;

our ($webroot) = @ARGV;
our $port = '';

# HTTP::Server::Simple handles requests in the main process so it
# must redirect and close STDOUT.  So transplant STDOUT to CHECK.
open CHECK, ">& STDOUT" or die $!;
open STDOUT, ">/dev/null" or die $!;

sub stat_type_check () {
    die "[$port, $webroot] stdout not ta plain file"
	unless -f _;
}

stat CHECK or die $!;
stat_type_check();

sub start_polling_fstat () {
    our $polling_pid = $$;
    $SIG{ALRM} = sub {
	return unless $$ = $polling_pid;
	stat CHECK or die $!;
	my $nlink = (stat _)[3];
	exit 0 unless $nlink;
	stat_type_check(); # doesn't seem possible to fail but check anyway
	alarm(1);
    };
    alarm(1);
}

package ServerClass;

use strict;
use Socket qw(AF_INET SOCK_STREAM);
use Socket qw(AF_INET SOCK_STREAM unpack_sockaddr_in);
use IO::Handle;

use base qw(HTTP::Server::Simple::CGI);
use HTTP::Server::Simple::Static;

sub handle_request {
    my ($self, $cgi) = @_;

    if (!$self->serve_static($cgi, $::webroot)) {
	print "HTTP/1.0 404 Not found\r\n";
	print $cgi->header,
	    $cgi->start_html('Not found'),
	    $cgi->h1('Not found'),
	    $cgi->end_html;
    }
}

sub port () { return 0; }

sub after_setup_listener () {
    my $sn = getsockname HTTP::Server::Simple::HTTPDaemon or die $!;
    ($main::port,) = unpack_sockaddr_in $sn;
    print main::CHECK $port, "\n" or die $!;
    flush main::CHECK or die $!;
    my $c = fork // die $!;
    exit 0 if $c;
    ::main::start_polling_fstat();
}

package main;

our $server = ServerClass->new();
$server->run();
