#!/usr/bin/perl
# ---------------------------------------------------------------
# Copyright (C) 2008  Georgia Public Library Service
# Bill Erickson <erickson@esilibrary.com>
#
# 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 2
# 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.
# ---------------------------------------------------------------
use strict; use warnings;
use Getopt::Long;
use Net::Domain qw/hostfqdn/;
use POSIX qw/setsid :sys_wait_h/;
use OpenSRF::Utils::Logger q/$logger/;
use OpenSRF::System;
use OpenSRF::Transport::PeerHandle;
use OpenSRF::Utils::SettingsClient;
use OpenSRF::Transport::Listener;
use OpenSRF::Utils;
use OpenSRF::Utils::Config;

my $opt_action = undef;
my $opt_service = undef;
my $opt_config = "@sysconfdir@/opensrf_core.xml";
my $opt_pid_dir = "@TMP@";
my $opt_no_daemon = 0;
my $opt_settings_pause = 0;
my $opt_help = 0;
my $verbose = 0;
my $sclient;
my $hostname = $ENV{OSRF_HOSTNAME} || hostfqdn();
my @hosted_services;

GetOptions(
    'action=s' => \$opt_action,
    'service=s' => \$opt_service,
    'config=s' => \$opt_config,
    'pid-dir=s' => \$opt_pid_dir,
    'no-daemon' => \$opt_no_daemon,
    'settings-startup-pause=i' => \$opt_settings_pause,
    'help' => \$opt_help,
    'verbose' => \$verbose,
);


sub haltme {
    kill('INT', -$$); #kill all in process group
    exit;
};
$SIG{INT} = \&haltme;
$SIG{TERM} = \&haltme;

sub get_pid_file {
    my $service = shift;
    return "$opt_pid_dir/$service.pid";
}

# stop a specific service
sub do_stop {
    my $service = shift;
    my $pid_file = get_pid_file($service);
    if(-e $pid_file) {
        my $pid = `cat $pid_file`;
        chomp $pid;
        msg("stopping service pid=$pid $service", 1);
        kill('INT', $pid);
        waitpid($pid, 0);
        unlink $pid_file;
    } else {
        msg("$service not running");
    }
    return 1;
}

sub do_init {
    OpenSRF::System->bootstrap_client(config_file => $opt_config);
    die "Unable to bootstrap client for requests\n"
        unless OpenSRF::Transport::PeerHandle->retrieve;

    load_settings(); # load the settings config if we can

    my $sclient = OpenSRF::Utils::SettingsClient->new;
    my $apps = $sclient->config_value("activeapps", "appname");

    # disconnect the top-level network handle
    OpenSRF::Transport::PeerHandle->retrieve->disconnect;

    if($apps) {
        $apps = [$apps] unless ref $apps;
        for my $app (@$apps) {
            push(@hosted_services, $app) 
                if $sclient->config_value('apps', $app, 'language') =~ /perl/i;
        }
    }
    return 1;
}

# start a specific service
sub do_start {
    my $service = shift;
    if(-e get_pid_file($service)) {
        msg("$service is already running");
        return;
    }

    load_settings() if $service eq 'opensrf.settings';

    my $sclient = OpenSRF::Utils::SettingsClient->new;
    my $apps = $sclient->config_value("activeapps", "appname");
    OpenSRF::Transport::PeerHandle->retrieve->disconnect;

    if(grep { $_ eq $service } @hosted_services) {
        return unless do_daemon($service);
        launch_net_server($service);
        launch_listener($service);
        $0 = "OpenSRF controller [$service]";
        while(my $pid = waitpid(-1, 0)) {
            $logger->debug("Cleaning up Perl $service process $pid");
        }
    }

    msg("$service is not configured to run on $hostname");
    return 1;
}

sub do_start_all {
    msg("starting all services for $hostname", 1);
    if(grep {$_ eq 'opensrf.settings'} @hosted_services) {
        do_start('opensrf.settings');
        # in batch mode, give opensrf.settings plenty of time to start 
        # before any non-Perl services try to connect
        sleep $opt_settings_pause if $opt_settings_pause;
    }
    for my $service (@hosted_services) {
        do_start($service) unless $service eq 'opensrf.settings';
    }
    return 1;
}

sub do_stop_all {
    msg("stopping all services for $hostname", 1);
    do_stop($_) for @hosted_services;
    return 1;
}

# daemonize us.  return true if we're the child, false if parent
sub do_daemon {
    return 1 if $opt_no_daemon;
    my $service = shift;
    my $pid_file = get_pid_file($service);
    #exit if OpenSRF::Utils::safe_fork();
    return 0 if OpenSRF::Utils::safe_fork();
    msg("starting service pid=$$ $service", 1);
    chdir('/');
    setsid();
    close STDIN;
    close STDOUT;
    close STDERR;
    `echo $$ > $pid_file`;
    return 1;
}

# parses the local settings file
sub load_settings {
    my $conf = OpenSRF::Utils::Config->current;
    my $cfile = $conf->bootstrap->settings_config;
    return unless $cfile;
    my $parser = OpenSRF::Utils::SettingsParser->new();
    $parser->initialize( $cfile );
    $OpenSRF::Utils::SettingsClient::host_config =
        $parser->get_server_config($conf->env->hostname);
}

# starts up the unix::server master process
sub launch_net_server {
    my $service = shift;
    push @OpenSRF::UnixServer::ISA, 'Net::Server::PreFork';
    unless(OpenSRF::Utils::safe_fork()) {
        $0 = "OpenSRF Drone [$service]";
        OpenSRF::UnixServer->new($service)->serve;
        exit;
    }
    return 1;
}

# starts up the inbound listener process
sub launch_listener {
    my $service = shift;
    unless(OpenSRF::Utils::safe_fork()) {
        $0 = "OpenSRF listener [$service]";
        OpenSRF::Transport::Listener->new($service)->initialize->listen;
        exit;
    }
    return 1;
}

sub msg {
    my $m = shift;
    my $v = shift;
    print "* $m\n" unless $v and not $verbose;
}

sub do_help {
    print <<HELP;

    Usage: perl $0 --pid_dir @TMP@ --config @sysconfdir@/opensrf_core.xml --service opensrf.settings --action start

    --action <action>
        Actions include start, stop, restart, and start_all, stop_all, and restart_all

    --service <service>
        Specifies which OpenSRF service to control

    --config <file>
        OpenSRF configuration file 
        
    --pid-dir <dir>
        Directory where process-specific PID files are kept
        
    --no-daemon
        Do not detach and run as a daemon process.  Useful for debugging.

    --settings-startup-pause
        How long to give the opensrf.settings server to start up when running 
        in batch mode (start_all).  The purpose is to give plenty of time for
        the settings server to be up and active before any non-Perl services
        attempt to connect.
        
    --help
        Print this help message
HELP
exit;
}


do_help() if $opt_help or not $opt_action;
do_init() and do_start($opt_service) if $opt_action eq 'start';
do_stop($opt_service) if $opt_action eq 'stop';
do_init() and do_stop($opt_service) and do_start($opt_service) if $opt_action eq 'restart';
do_init() and do_start_all() if $opt_action eq 'start_all';
do_init() and do_stop_all() if $opt_action eq 'stop_all';
do_init() and do_stop_all() and do_start_all() if $opt_action eq 'restart_all';