project_name "HOS"
path_prepend "x86_64-elf-gcc/bin"

configure do
  rscons "x86_64-elf-gcc.rb", "-b", "#{build_dir}/x86_64-elf-gcc"
  check_program "ldc2"
  check_program "x86_64-w64-mingw32-gcc"
  check_program "x86_64-elf-gcc"
  check_c_compiler
  check_program "mformat", on_fail: "Install the mtools package"
  check_cfg package: "freetype2", on_fail: "Install libfreetype-dev", use: "freetype"
  sh %w[git submodule update --init]
end

# Kernel default font size.
KFONT_SIZE = 15

class Image < Builder
  def run(options)
    unless @cache.up_to_date?(@target, nil, @sources, @env)
      print_run_message("Creating disk image <target>#{@target}<reset>", nil)
      File.binwrite(@target, "\0" * (1440 * 1024))
      system(*%W[mformat -i #{@target} -f 1440 ::])
      system(*%W[mmd -i #{@target} ::/EFI])
      system(*%W[mmd -i #{@target} ::/EFI/BOOT])
      system(*%W[mcopy -i #{@target} #{@sources.first} ::/EFI/BOOT])
      @cache.register_build(@target, nil, @sources, @env)
    end
    true
  end
end

class FontGen < Builder
  def run(options)
    if @command
      finalize_command
    else
      fontgen = @vars["fontgen"]
      @sources += [fontgen]
      command = %W[#{fontgen} #{@sources.first} #{KFONT_SIZE} #{@target}]
      standard_command("FontGen <target>#{@target}<reset>", command, {})
    end
  end
end

# FontGen Environment
fontgen_env = env "fontgen", use: "freetype" do |env|
  env.Program("^/fontgen", glob("src/fontgen/**/*.c"))
end

## Kernel Environment
#kernel_env = env "kernel" do |env|
#  env.add_builder(Image)
#  env.add_builder(FontGen)
#  env["OBJDUMP"] = "x86_64-elf-objdump"
#  env["SIZE"] = "x86_64-elf-size"
#  env["CCFLAGS"] += %w[-ffreestanding -Wall -O2]
#  env["LDFLAGS"] += %w[-ffreestanding -nostdlib -T src/link.ld]
#  env["LDFLAGS"] += %W[-Wl,-Map,${_TARGET}.map]
#  env["LIBS"] += %w[gcc]
#  env.FontGen("^/kfont/kfont.c", "font/Hack-Regular.ttf",
#             "fontgen" => fontgen_env.expand("^/fontgen"))
#  env.barrier
#  env["CPPPATH"] += ["#{env.build_root}/kfont"]
#  env.Program("^/hos.elf", glob("src/**/*.{S,c}") + ["^/kfont/kfont.c"])
#  env.depends("#{env.build_root}/hos.elf", "src/link.ld")
#  env.Disassemble("^/hos.elf.txt", "^/hos.elf")
#  env.Size("^/hos.elf.size", "^/hos.elf")
#  env.Image("^/hos.img", %w[^/hos.elf])
#end

task "run", desc: "Run HOS in QEMU" do
  img = kernel_env.expand("^/hos.img")
  sh %W[qemu-system-x86_64 -bios OVMF.fd -hda #{img}]
end