#!/usr/bin/perl -w

eval 'exec /usr/bin/perl -w -S $0 ${1+"$@"}'
    if 0; # not running under some shell
#  File: bin/run_stem

#  This file is part of Stem.
#  Copyright (C) 1999, 2000, 2001 Stem Systems, Inc.

#  Stem 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.

#  Stem 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.

#  You should have received a copy of the GNU General Public License
#  along with Stem; if not, write to the Free Software
#  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

#  For a license to use the Stem under conditions other than those
#  described here, to purchase support for this software, or to purchase a
#  commercial warranty contract, please contact Stem Systems at:

#       Stem Systems, Inc.		781-643-7504
#  	79 Everett St.			info@stemsystems.com
#  	Arlington, MA 02474
#  	USA


eval { use lib 'blib/lib' } if -d 'blib/lib';
eval { use lib '../blib/lib' } if -d '../blib/lib';

$Data::Dumper::Indent = 1 ;
$Data::Dumper::Purity = 1 ;
$Data::Dumper::Useqq = 1 ;

$| = 1 ;

#print "RUN STEM $0\n" ;

my @conf_args ;

# we set Stem's default environment before we load any Stem modules so
# they can use those values

use Stem::InstallConfig ;

BEGIN {
	my $env_text ;
	my $stem_lib_dir = $Stem::InstallConfig::Config{'conf_path'} ;

	my $is_win32 = $^O =~ /Win32/i ;

# get the site env and home env files

	my @env_files = "$stem_lib_dir/env" ;

	unless ( $is_win32 ) {

		push @env_files, ( $ENV{HOME} ||
				   $ENV{LOGDIR} ||
				   (getpwuid($>))[7] ) . '/.stem_env' ;
	}

	foreach my $env_file ( @env_files ) {

		next unless -r $env_file ;

# shut up a dumb warning
		use vars '*ARGVOUT' ;
		$env_text .= 
			do { local( @ARGV, $/ ) = $env_file ; <> } ;
	}


# set the starting %env from the files

	%Stem::Vars::Env = $env_text =~ /^([^=]+)=(.+)$/mg if $env_text ;


# set the %Stem::Vars::Env from %ENV any %ENV name starting with STEM_
# is used. the STEM_ is deleted and the rest of the lower case name is
# used with the %ENV value

	/^STEM_(\w+)/ and $Stem::Vars::Env{ lc $1 } = $ENV{ $_ } for keys %ENV ;

# set %Stem::Vars::Env from 'name=value' command line args
# all other args are assumed to be conf file names.
# we do this after we process %ENV so the command line args can override
# any shell environment values

	while( @ARGV ) {

		my $arg = shift ;

		if ( $arg =~ /([^=]+)=(.*)/ ) {

			$Stem::Vars::Env{ $1 } = $2 ;
			next ;
		}

		push @conf_args, $arg ;
	}

# set the default config search path. this will be changed by the install
# script.

	$Stem::Vars::Env{ 'conf_path' } ||= 'conf:.' ;

# set the trace levels

# 	$Stem::Vars::Env{ 'MainTraceStatus'    } ||= 1 ;
# 	$Stem::Vars::Env{ 'MainTraceError'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'ProcTraceStatus'    } ||= 1 ;
# 	$Stem::Vars::Env{ 'ProcTraceError'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'PortalTraceStatus'  } ||= 1 ;
# 	$Stem::Vars::Env{ 'PortalTraceError'   } ||= 1 ;
# 	$Stem::Vars::Env{ 'SockMsgTraceStatus' } ||= 1 ;
# 	$Stem::Vars::Env{ 'SockMsgTraceError'  } ||= 1 ;
# 	$Stem::Vars::Env{ 'ConfTraceStatus'    } ||= 1 ;
# 	$Stem::Vars::Env{ 'ConfTraceError'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'LogTraceStatus'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'LogTraceError'      } ||= 1 ;
# 	$Stem::Vars::Env{ 'CellTraceStatus'    } ||= 0 ;
# 	$Stem::Vars::Env{ 'CronTraceStatus'    } ||= 1 ;
# 	$Stem::Vars::Env{ 'CronTraceError'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'EventTraceStatus'   } ||= 0 ;
# 	$Stem::Vars::Env{ 'EventTraceError'    } ||= 0 ;
# 	$Stem::Vars::Env{ 'GatherTraceStatus'  } ||= 1 ;
# 	$Stem::Vars::Env{ 'GatherTraceError'   } ||= 1 ;
# 	$Stem::Vars::Env{ 'HubTraceStatus'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'HubTraceError'      } ||= 1 ;
# 	$Stem::Vars::Env{ 'TailTraceStatus'    } ||= 1 ;
# 	$Stem::Vars::Env{ 'TailTraceError'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'MsgTraceError'      } ||= 1 ;
# 	$Stem::Vars::Env{ 'MsgTraceStatus'     } ||= 1 ;
# 	$Stem::Vars::Env{ 'MsgTraceMsg'        } ||= 1 ;
# 	$Stem::Vars::Env{ 'SwitchTraceStatus'  } ||= 1 ;
# 	$Stem::Vars::Env{ 'SwitchTraceError'   } ||= 1 ;
# 	$Stem::Vars::Env{ 'AsynchIOTraceStatus'} ||= 1 ;
# 	$Stem::Vars::Env{ 'AsynchIOTraceError' } ||= 1 ;
# 	$Stem::Vars::Env{ 'TtyMsgTraceStatus'  } ||= 1 ;
# 	$Stem::Vars::Env{ 'TtyMsgTraceError'   } ||= 1 ;

}

# we load Stem after we process the command line args and %ENV so the
# modules can use those values

use Stem ;

use Stem::Trace 'log' => 'stem_status',
		'sub' => 'TraceStatus',
		'env' => 'MainTraceStatus' ;

my $prog_name = $0 ;

$prog_name =~ s|.+/|| ;

unless ( @conf_args ) {

	$prog_name eq 'run_stem' &&
			die "run_stem must be passed a stem config file" ;

	@conf_args = $prog_name ;
}

# always start with the site config file
# this defines site wide configuration settings that are internal
# to Stem

my $err = Stem::Conf::load_confs( 'site' ) ;

# ignore a missing site config

die $err if defined $err && $err !~ /Can't find config/ ;

$err = Stem::Conf::load_confs( @conf_args ) ;

TraceStatus "Stem startup" ;

TraceStatus $err if $err;

die $err if $err ;

###############
# this should use Stem::Event
###############
$SIG{ 'INT' } = sub {
	TraceStatus "INT signal received" ;
	Stem::Event::stop_loop()
} ;

Stem::Event::start_loop() ;

TraceStatus "Stem shutdown" ;

exit;

=head1 run_stem - Start up Stem and load configuration files

=head2 Synopsis

	run_stem foo=bar stem_conf_file

This script is the way most Stem applications are started. It does
several important things so you don't have to create your own top
level scripts. It is not required to execute run_stem to use Stem but
it makes it much easier to get it going in most cases. The following
are the steps that 'run_stem' does when bringing up Stem.

=head2 * Load Stem Environment

Many Stem modules and cells look at the Stem environment for default
configuration values or global flags. This allows you to control how
many of the cells and modules behave when loaded and instantiated.  If
a Stem attribute in a specification has its 'env' name description
set, it will use that name (optionally prefixed with the cell's
registration name) as a key to lookup in the Stem Environement. If
found there, that value becomes is used and overrides the default and
any value set in a configuration file. This allows the user to
override default setting from the outside without modifying Stem
configuration files. See Stem::Class for more on this.  The Stem
environment is set from these sources in the following order:

=over 4

=item Global Site Environment File

'run_stem' initially looks for a file named 'env' in the first
configuration directory (set at install time) and loads it if
found. These site and user files both have a simple key=value format
with one entry per line.

=item User Environment File

'run_stem' then will look in your home directory (not supported on
windows) for a file named .stem_env and loads it if found.

=item Shell Environment

Any shell environment variable with the form 'STEM_*' will
have the 'STEM_' part deleted and the rest of its name
converted to lower case. That will become the key in the Stem
environment with the value set to the shell variable's value.

=item Command Line

Any command line arguments of the form key=value will be
parsed out and used to set a Stem environment variable.

=back

=head2 * Load Stem Core Modules

	'run_stem' then loads all the core Stem modules with a use
	Stem line.

=head2 * Load Configuration Files

Any arguments left in @ARGV are assumed to be Stem configuration
files. Typically there is only one configuration file but you can have
pass in as many as you want.  The config file arguments can have a
.stem suffix or no suffix. The configuration directory list is
searched in order for the file and it is loaded and all of its entries
are constructed.

You can override the default configuration directory list (set at
install time) by setting the 'conf_path' Stem environment variable
from the shell environment or on the 'run_stem' command line. The
following are equivilent:

	export STEM_CONF_PATH=/etc/stem/conf:/home/foo/.stem
	run_stem bar

	run_stem conf_path=/etc/stem/conf:/home/foo/.stem bar

=head2 * Start Event Loop

The final operation 'run_stem' does is start the main event
loop. If no events were created by the loaded configuration
files, this will fail and 'run_stem will exit immediately. If
all the created events eventually get canceled, the event loop
will exit and 'run_stem' will exit too.

=cut