#!/usr/bin/ruby

# http://metasm.cr0.org/
require 'metasm'
include Metasm

if ARGV.length != 2
	abort 'usage: m_findcursoroffset <x> <y>, with the current value of the cursor coords (hint: use 1 1 and 2 2) - topleft = 0 0'
end

dfp = OS.current.find_process('Dwarf_Fortress') || OS.current.find_process('dwarfort')
abort 'no running df found' if not dfp
dbg = dfp.debugger

file = 'caret_offset.tmp'

x, y = ARGV.shift.to_i, ARGV.shift.to_i
bin = [x, y].pack('l*')

if not File.exist? file
	puts "full memory scan, could take a while..."
	offs = dbg.pattern_scan(bin)
else
	offs = File.read(file).split.map { |o| o.to_i(16) }
	offs.delete_if { |o| dbg[o, bin.length] != bin }
end

File.open(file, 'w') { |fd| fd.puts offs.map { |o| o.to_s(16) } }

case offs.length
when 0
	File.unlink(file)
	puts "no offset found :(", "I removed the cache file, try again"
when 1
	base = ((offs.first > 0x8000000) ? 0x8048000 : 0x400000)
	puts "found cursor offset: #{'%x' % offs.first}  (=#{'%x' % base}+#{'%x' % (offs.first - base)})"
	puts "cursor value: #{dbg[offs.first, 4*3].unpack('l*').inspect}"
else
	puts "found #{offs.length} candidates, try again after moving the cursor"
end