#!/usr/bin/env ruby

require 'find'

def diff(old, new)
	# a little safety for not embedding commands in system()
	return if old.include?(';') or
		new.include?(';') or
		old.include?('&&') or
		new.include?('&&') or
		old.include?('||') or
		new.include?('||')
	system("/usr/bin/diff -urN #{old} #{new} | /usr/bin/less -E")
end

LOCAL_MIRROR  = ENV['LOCAL_MIRROR'] || "#{ENV['HOME']}/slackware/slackware/slackware64-current"
WORKING_DIR   = ENV['WORKING_DIR'] || "#{ENV['HOME']}/slackware/pam/"
SOURCE_DIR   = "#{WORKING_DIR}/source"
SECTIONS      = %w{a ap f l k kde n tcl x xap}
PKGS          = %w{ Linux-PAM cups shadow hplip screen sudo kde
                    ConsoleKit cracklib polkit openssh openvpn popa3d proftpd
                    samba vsftpd xlockmore xscreensaver libcgroup  }
CWD           = Dir.pwd
RE_SECTION    = Regexp.new(/#{SOURCE_DIR}\/(#{SECTIONS.join("|")})\/(\w+-?\w*)\/?$/)

if not(File.directory?(WORKING_DIR))
    STDERR.write("ERROR: #{WORKING_DIR} is not a directory\n")
    STDERR.write("ERROR: try setting WORKING_DIR environment variable with your correct path to the pam/ working directory\n")
    exit 1
end
if not(File.directory?(LOCAL_MIRROR))
    STDERR.write("ERROR: #{LOCAL_MIRROR} is not a directory\n")
    STDERR.write("ERROR: try setting LOCAL_MIRROR environment variable with your correct path to a local slackware mirror\n")
    exit 1
end

@pkgs = Hash.new
Find.find("%s/source/" % [LOCAL_MIRROR]) do |spath|
    if File.directory?(spath)
        if PKGS.include?(File.basename(spath))
            Find.find(SOURCE_DIR) do |ppath|
                if File.directory?(ppath)
                    if File.basename(ppath) == File.basename(spath)
                      @pkgs[File.basename(spath)] = {:stock => spath, :pam => ppath}
                      Find.prune
                    end
                end
            end
            Find.prune
        end
    end
end

def show_all()
	@pkgs.each {|pkg|
		diff(pkg[1][:stock], pkg[1][:pam])
	}
end

def menu()
	printf("which package would you like a diff of?:\n")
	@pkgs.each {|pkg|
		num = @pkgs.to_a.index(pkg)
		next if num.nil?
		printf("\s[%d] %s\n",
		       num,
		       @pkgs.to_a[num][0]
		      )
	}
	printf(" [q] to quit\n")
	printf(" [a] to show all\n")

	response = gets.chomp
	if response =~ /^q$/i
		exit
	elsif response =~ /^a$/i
		show_all
		exit
	else
		diff(@pkgs.to_a[response.to_i][1][:stock], @pkgs.to_a[response.to_i][1][:pam])
	end

	menu
end

if __FILE__ == $PROGRAM_NAME
	if ARGV.include?("-a") || ARGV.include?("--all")
		show_all
	elsif ARGV.include?("-l") || ARGV.include?("--list")
	        puts @pkgs.keys
	elsif ARGV.include?("-h") || ARGV.include?("--help")
		puts "either add -a / --all to see all,\n -l / --list to see package names,\n #> #{__FILE__} <pkgname>,\n  or enter in to the menuu"
	elsif ARGV.count > 0
	        for arg in ARGV
	                if @pkgs.keys.include?(arg)
			        diff(@pkgs[arg][:stock], @pkgs[arg][:pam])
	                end
	        end
	else
		menu
	end
end