#!/usr/bin/env ruby

# $Id$
# $URL$


JOBSDIR = "jobs"
PARKDIR = "park"
PROCDIR = "processors"
RESULTDIR = "results"
FAILDIR = "failure"
MONITORDIR = "monitor"
CONFIG = "config"
@config = { "waittime" => 3, "maxproc" => 3 }

COUNTERFILE="jobscounter"
RUNNINGFILE="runningcounter"

def usage
	puts <<ENDTXT
Usage: pb <option>

add <command>>-->-------Add the given command as a job.
addfile|af <file>>------Add the given file as a job.
createconfing>-->-------Write a default configuration file.
run>---->------->-------Start the master scheduler process.
del <jobnr>>---->-------Delete the given job from the queue.
help|-h>>------->-------Show this help.
park>--->------->-------Place all queued jobs in the parkinglot.
unpark>->------->-------Place all jobs from the parkinglot back in the queue.
retry <jobnr>>-->-------Reschedule a failed job. Destroys all output.
prio <h|n|l> <jobnr>>---Change the priority of the given job.>--[unimplemented]
status|st>------>-------Show the status of the current jobs.
stop <jobnr>>--->-------Stop the given job.>----[unimplemented]
stopall>>------->-------Stop all running jobs.>-[unimplemented]
ENDTXT
	exit
end

def readconfig
	File.open("#{@basedir}/#{CONFIG}").each_line {|line|
		line.sub!(/#.*/, "")
		line.sub!(/^\s*/, "")
		line.sub!(/\s*$/, "")
		if line.match(/^$/)
			next
		end
		line.match(/([^=]*?)\s*=\s*(.*)/)
		case $1
			when "maxproc"		then @config["maxproc"] = $2
			when "waittime"		then @config["waittime"] = $2
			else			puts "unknown option #{$1}"
		end
	}
end

def status
	readconfig
	# show which jobs are running
	puts "Running jobs (#{Dir.entries("#{@basedir}/#{PROCDIR}").size - 2}/#{@config["maxproc"]}):"
	# just call 'ls' instead of trying to figure out how to format it nicely for the screen
	system("ls" ,"#{@basedir}/#{PROCDIR}/")
	# show queues
	puts "Jobs queued (#{Dir.entries("#{@basedir}/#{JOBSDIR}").size - 2}):"
	system("ls", "#{@basedir}/#{JOBSDIR}/")
	puts "Jobs parked (#{Dir.entries("#{@basedir}/#{PARKDIR}").size - 2}):"
	puts "Jobs finished: #{Dir.entries("#{@basedir}/#{RESULTDIR}").size - 2}"
	puts "Jobs failed (#{Dir.entries("#{@basedir}/#{FAILDIR}").size - 2}):"
	system("ls", "#{@basedir}/#{FAILDIR}/")
end

def createdirs
	[ JOBSDIR, PARKDIR, PROCDIR, RESULTDIR, FAILDIR, MONITORDIR ].each{|dir|
		if ! FileTest.directory?("#{@basedir}/#{dir}")
			Dir.mkdir("#{@basedir}/#{dir}")
		end
	}
end

def increasejobscounter
	jobscounter = 0
	if FileTest.exists?(COUNTERFILE)
		File.new(COUNTERFILE).flock(File::LOCK_EX)
		File.open(COUNTERFILE, "r+"){|file|
			jobscounter = file.read
			if jobscounter.empty?
				jobscounter = 0
			end
			jobscounter = jobscounter.to_i
			jobscounter += 1
			file.seek(0)
			file.puts jobscounter
		}
		File.new(COUNTERFILE, "r+").flock(File::LOCK_UN)
	else
		File.open(COUNTERFILE, "w"){|file|
			File.new(COUNTERFILE).flock(File::LOCK_EX)
			jobscounter = 1
			file.puts jobscounter
		}
		File.new(COUNTERFILE, "r+").flock(File::LOCK_UN)
	end
	return jobscounter
end

def addjob
	p ARGV.join(" ")
	jobnumber=sprintf("%06d", increasejobscounter)
	p jobnumber
end

def addjobfromfile
	# File.copy asdfasdf
end

def createconfig
	if ! FileTest.exists?("#{@basedir}/#{CONFIG}")
		File.new("#{@basedir}/#{CONFIG}", "w"){|file|
			file.puts <<EOT
# how many parallel processes?
maxproc=3
# take a break for how long between process end and starting a new one
waittime=3
EOT
		}
	end
end

def master
	# als ik threading ga gebruiken is deze dus niet nodig
	File.new(RUNNINGFILE, "w").flock(File::LOCK_EX){|file|
		file.puts "0"
	}


end

def deljob
end

def parkjobs
end

def unparkjobs
end

def unfail
end

def changeprio
end

def runprocessor
end

def stop
end

def stopall
end

pbcommand = $0

command = ARGV.shift
@basedir = Dir.pwd

createdirs

case command
	when "add"		then addjob
	when "addfile", "af"	then addjobfromfile ARGV
	when "createconfig"	then createconfig
	when "run"		then master
	when "del"		then deljob "$*"
	when "help"		then usage
	when "-h"		then usage
	when "park"		then parkjobs
	when "unpark"		then unparkjobs
	when "retry"		then unfail "$*"
	when "prio"		then changeprio "$*"
	when "process"		then runprocessor "$*"
	when "status", "st"	then status
	when "stop"		then stop "$*"
	when "stopall"		then stopall
	else			usage
end