#!/usr/bin/ruby

require 'getoptlong'
require 'ftools'
require 'tempfile'
#require 'rdoc/usage'

opts = GetoptLong.new(
	[ '--help', '-h', GetoptLong::NO_ARGUMENT ],
	[ '--directory', '-d', GetoptLong::REQUIRED_ARGUMENT ],
	[ '--translate', '-t', GetoptLong::REQUIRED_ARGUMENT ]
)

$logsPath = nil
$translations = Hash.new

opts.each do |opt, arg|
	case opt
		when '--translate'
			parts=arg.split '='
			if parts.length!=2
				STDERR.print "Only xxx=yyy translations accepted\n"
				exit 1
			end
			$translations[parts[0]] = parts[1]
			print "Translate #{parts[0]}=#{parts[1]}\n"
		when '--directory'
			if !File.directory? arg
				STDERR.print "Not a directory: #{arg.dump}\n"
				exit 1
			end
			if !(File.readable?(arg) && File.writable?(arg) && File.executable?(arg))
				STDERR.print "Can't access: #{arg.dump}\n"
				exit 1
			end
			$logsPath = arg+'/'
		when '--help'
			print <<EOF
Usage:

./PsiLogMerger.rb [-t a=b -t ...] -d dir

 -t a=b - translate host 'a' to 'b' - for example
          transport.host1.com=transport.host2.com
 -d dir - directory with Psi logs

EOF
			exit 0
	end
end

if $logsPath.nil?
	STDERR.print "No directory specified\n"
	exit 1
end

if $translations.length==0
	STDERR.print "No translations specified\n"
	exit 1
end

def merge(from, to)
	tmp = Tempfile.new('logmerger')
	f1 = File.new(from, "r")
	f2 = File.new(to, "r")

	l1=nil
	l2=nil
	while !f1.eof? || !f2.eof?
		l1=f1.gets if (l1.nil? && !f1.eof?)
		l2=f2.gets if (l2.nil? && !f2.eof?)

		if !l1.nil? && !l2.nil? && l1==l2
			tmp.write l1
			l1=nil
			l2=nil
			next
		end

		if l2.nil? || (!l1.nil? && l1<l2)
			tmp.write l1
			l1=nil
		else
			tmp.write l2
			l2=nil
		end
	end

	f1.close
	f2.close
	tmp.close

	File.copy tmp.path, to
end

def translate(from, to)
	print "Translating #{from} => #{to}\n"
	if !File.exist? to
		File.copy from, to
	else
		merge from, to
	end
end

def tryTranslate(filename)
	$translations.each do |transFrom,transTo|
		re = Regexp.new('^(.*)_at_'+Regexp.escape(transFrom)+'\.history$')
		m = re.match(filename);
		if m != nil
			translate($logsPath+filename, $logsPath+m[1]+'_at_'+transTo+'.history')
			return true
		end
	end
	return false
end

Dir.foreach($logsPath) do |filename|
	p = $logsPath+filename
	if File.directory?(p)
		next
	end
	if File.file?(p) && File.readable?(p)
		if tryTranslate filename
			next
		end
	else
		STDERR.print "Can't read #{filename.dump}\n"
	end
end