require 'pathname'
require 'rake/clean'
require 'open3'

DFLAGS = ['--warn-no-deprecated', '-L/usr/lib64/gcc-12']
BINARY = 'build/bin/elna'
TESTS = FileList['tests/*.eln'].flat_map do |test|
  build = Pathname.new 'build'
  test_basename = Pathname.new(test).basename('')

  [build + 'riscv' + test_basename].map { |path| path.sub_ext('').to_path }
end

SOURCES = FileList['source/**/*.d']

directory 'build'

CLEAN.include 'build'
CLEAN.include '.dub'

rule(/build\/riscv\/[^\/\.]+$/ => ->(file) { test_for_out(file, '.o') }) do |t|
  sh '/opt/riscv/bin/riscv32-unknown-elf-ld',
    '-o', t.name,
    '-L/opt/riscv/lib/gcc/riscv32-unknown-elf/13.2.0/',
    '-L/opt/riscv/riscv32-unknown-elf/lib',
    '/opt/riscv/riscv32-unknown-elf/lib/crt0.o',
    '/opt/riscv/lib/gcc/riscv32-unknown-elf/13.2.0/crtbegin.o',
    t.source,
    '--start-group', '-lgcc', '-lc', '-lgloss', '--end-group',
    '/opt/riscv/lib/gcc/riscv32-unknown-elf/13.2.0/crtend.o'
end

rule(/build\/riscv\/.+\.o$/ => ->(file) { test_for_object(file, '.eln') }) do |t|
  Pathname.new(t.name).dirname.mkpath
  sh BINARY, '-o', t.name, t.source
end

file BINARY => SOURCES do |t|
  sh({ 'DFLAGS' => (DFLAGS * ' ') }, 'dub', 'build', '--compiler=gdc')
end

task default: BINARY

desc 'Run all tests and check the results'
task test: TESTS
task test: BINARY do
  TESTS.each do |test|
    expected = Pathname
      .new(test)
      .sub_ext('.txt')
      .sub(/^build\/[[:alpha:]]+\//, 'tests/expectations/')
      .to_path

    puts "Running #{test}"
    if test.include? '/riscv/'
      spike = [
        '/opt/riscv/bin/spike',
        '--isa=RV32IMAC',
        '/opt/riscv/riscv32-unknown-elf/bin/pk',
        test
      ]
      diff = ['diff', '-Nur', '--color', expected, '-']
      tail = ['tail', '-n', '1']

      last_stdout, wait_threads = Open3.pipeline_r spike, tail, diff
    else
      raise 'Unsupported test platform'
    end
    print last_stdout.read
    last_stdout.close

    fail unless wait_threads.last.value.exitstatus.zero?
  end
end

def test_for_object(out_file, extension)
  test_source = Pathname
    .new(out_file)
    .sub_ext(extension)
    .sub(/^build\/[[:alpha:]]+\//, 'tests/')
    .to_path
  [test_source, BINARY]
end

def test_for_out(out_file, extension)
  Pathname
    .new(out_file)
    .sub_ext(extension)
    .to_path
end