source_rom = "iic_rom4.bin"
dest_rom = "iic_rom4x.bin"
rom_base = 0xc000

source_files = Rake::FileList.new('*.s')

desc "Default: clean and build it"
task :default => [:clean, :assemble, :build_rom] do
  sh "ls -l #{dest_rom}"
end

desc "Clean object files"
task :clean do
  sh "rm -f #{dest_rom}"
  sh "rm -f sf512_#{dest_rom}"
  sh "rm -f *.o"
  sh "rm -f *.lst"
  sh "rm -f *.b"
end

desc "Assemble all source files"
task :assemble => source_files.ext('.b')

rule ".o" => ".s" do |t|
  sh "ca65 -l #{t.name}.lst #{t.source}"
end

rule ".b" => ".o" do |t|
  sh "ld65 -t none -o #{t.name} #{t.source}"
end

desc "Build ROM"
task :build_rom => [:assemble] do
  puts "Building ROM image..."
  obj_files = Rake::FileList.new('*.b')
  rom = File.read(source_rom)
  obj_files.each do |t|
    if t =~ /B(\h)_(\h{4})/
      bnum = $1.to_i(16)
      badd = $2.to_i(16)
      addr = bnum * 16384 + badd - rom_base
      fc = File.read(t)
      fl = fc.bytes.count
      puts "Loading #{t} into bank #{bnum} @ #{badd.to_s(16)}, file addr $#{addr.to_s(16)}, len $#{fl.to_s(16)} (#{fl})"
      nzc = 0
      fc.each_byte do |b|
        nzc += 1 if rom.getbyte(addr) != 0 && rom.getbyte(addr) != b
        rom.setbyte(addr, b)
        addr += 1
      end
      puts "\tNote: patched pver #{nzc} nonzero bytes!" if nzc > 0
    else
      puts "I dont know where to load #{t}"
    end 
  end
  File.write(dest_rom, rom)
  puts "ROM image done: #{dest_rom}"
end

desc "Build SST27SF512 Image"
task :sf512 => [:build_rom] do
  sh "cat #{dest_rom} #{dest_rom} > sf512_#{dest_rom}"
end