# This Source Code Form is subject to the terms of the Mozilla Public License,
# v. 2.0. If a copy of the MPL was not distributed with this file, You can
# obtain one at https://mozilla.org/MPL/2.0/.
# frozen_string_literal: true

require 'open3'
require 'rake/clean'

STAGES = Dir.glob('boot/stage*')
  .collect { |stage| File.basename stage }
  .sort { |a, b| a.delete_prefix('stage').to_i <=> b.delete_prefix('stage').to_i }
  .drop(1) # First assembly stage does not count.

CLOBBER.include 'build'

def run(exe)
  ENV.fetch('QEMU', '').split << exe
end

directory 'build'

task default: :boot

desc 'Final stage'
task boot: "build/valid/#{STAGES.last}/cl"
task boot: "boot/#{STAGES.last}/cl.elna" do |t|
  groupped = t.prerequisites.group_by { |stage| File.extname stage }.transform_values(&:first)
  exe = groupped['']
  expected = groupped[''] + '.s'
  source = groupped['.elna']

  cat_arguments = ['cat', source]
  diff_arguments = ['diff', '-Nur', '--text', expected, '-']
  Open3.pipeline(cat_arguments, run(exe), diff_arguments)
end

desc 'Convert previous stage language into the current stage language'
task :convert do
  File.open('boot/stage23/cl.elna', 'w') do |current_stage|
    seen_proc = false

    File.readlines('boot/stage22/cl.elna').each do |line|
      if line.start_with? 'proc'
        seen_proc = true 
        current_stage << line
      elsif seen_proc && line.start_with?('begin')
        seen_proc = false
        current_stage << line
      elsif !seen_proc && line.start_with?('begin')
        current_stage << <<~CODE
          proc g(location: ElnaLocation)
          begin
          \tprintf("# %i %i\\n\\0", location.line, location.column)
          end

          proc f()
          var
          \tlocation: ElnaLocation
          begin
          \tlocation.line := 2;
          \tlocation.column := 3;
          \tg(location)
          end

        CODE
        current_stage << line
        current_stage << <<~CODE
          \tf();
        CODE
      else
        current_stage << line
      end
    end
  end
end