#! /usr/bin/env ruby
# coding: utf-8

require "test/unit"
require "vasputils.rb"
require "vasputils/incar.rb"
require "stringio"

# assert_equal( cor, data)
# assert_in_delta( cor, data, $tolerance )
# assert_raise( RuntimeError ){}

class TC_Incar < Test::Unit::TestCase
  #def setup
  # @k = Incar.new
  #end
  
  SAMPLE_PAIRS = {
    "SYSTEM"  => "Untitled",
    "PREC"    => "High",
    "IBRION"  => "2",
    "NSW"     => "100",
    "ISIF"    => "2",
    "ENCUT"   => "400",
    "NELM"    => "60",
    "NELMIN"  => "2",
    "EDIFF"   => "1.0e-05",
    "EDIFFG"  => "-0.02",
    "VOSKOWN" => "1",
    "NBLOCK"  => "1",
    "ISPIN"   => "1",
    "INIWAV"  => "1",
    "ISTART"  => "1",
    "ICHARG"  => "1",
    "LWAVE"   => ".TRUE.",
    "LCHARG"  => ".TRUE.",
    "ISMEAR"  => "0",
    "SIGMA"   => "0.1",
    "IALGO"   => "38",
    "LREAL"   => "Auto",
    "NGX"     => "36",
    "NGY"     => "36",
    "NGZ"     => "42",
  }

  def test_self_parse
    io = StringIO.new
    io.puts "# SCF input for VASP"
    io.puts "# Note that VASP uses the FIRST occurence of a keyword"
    io.puts "# if single point calc, IBRION = -1, NSW = 0, and comment out ISIF"
    io.puts ""
    io.puts "SYSTEM = Untitled (VASP)"
    io.puts "    PREC = High"
    io.puts "  IBRION = 2        #-1:atoms not moved, 1:quasi-Newton, 2:conjugate-gradient"
    io.puts "     NSW = 100      #maximum number of ionic steps"
    io.puts "    ISIF = 2"
    io.puts "   ENCUT = 400"
    io.puts "    NELM = 60       #maximum number of electronic steps"
    io.puts "  NELMIN = 2        #minimum number of electronic steps"
    io.puts "   EDIFF = 1.0e-05"
    io.puts "  EDIFFG = -0.02"
    io.puts " VOSKOWN = 1"
    io.puts "  NBLOCK = 1"
    io.puts "   ISPIN = 1        #1:non spin polarized, 2:spin polarized"
    io.puts "  INIWAV = 1"
    io.puts "  ISTART = 1"
    io.puts "  ICHARG = 1"
    io.puts "   LWAVE = .TRUE."
    io.puts "  LCHARG = .TRUE."
    io.puts "  ISMEAR = 0"
    io.puts "   SIGMA = 0.1"
    io.puts "   IALGO = 38       #38:KosugiAlgorithm, 48:RMM-DIIS"
    io.puts "   LREAL = Auto     #fast & not accurate"
    io.puts "     NGX = 36"
    io.puts "     NGY = 36"
    io.puts "     NGZ = 42"
    io.rewind
    pairs = VaspUtils::Incar.parse(io)
    assert_equal(SAMPLE_PAIRS, pairs)
  end

  def test_self_load_file
    pairs = VaspUtils::Incar.load_file "test/incar/INCAR.00"
    assert_equal(SAMPLE_PAIRS, pairs)

    corrects = {
      "SYSTEM"  => "Untitled",
      "PREC"    => "High",
      "IBRION"  => "2",
      "NSW"     => "0",
      "ISIF"    => "2",
      "ENCUT"   => "400",
      "NELM"    => "60",
      "NELMIN"  => "2",
      "EDIFF"   => "1.0e-05",
      "EDIFFG"  => "-0.02",
      "VOSKOWN" => "1",
      "NBLOCK"  => "1",
      "ISPIN"   => "1",
      "INIWAV"  => "1",
      "ISTART"  => "1",
      "ICHARG"  => "1",
      "LWAVE"   => ".TRUE.",
      "LCHARG"  => ".TRUE.",
      "ISMEAR"  => "0",
      "SIGMA"   => "0.1",
      "IALGO"   => "38",
      "LREAL"   => "Auto",
      "NGX"     => "36",
      "NGY"     => "36",
      "NGZ"     => "42",
    }
    pairs = VaspUtils::Incar.load_file "test/incar/INCAR.01"
    assert_equal(corrects, pairs)

    # not exist
    assert_raise(Errno::ENOENT){VaspUtils::Incar.load_file("")}
  end

  def test_dump
    pairs = {
      "SYSTEM" => "dummy",
      "PREC" => "High",
      "ENCUT" => "400",
      "EDIFF" => "1.0e-05",
      "LREAL" => ".TRUE.",
    }

    assert_equal(
      [
        "SYSTEM = dummy",
        "PREC = High",
        "ENCUT = 400",
        "EDIFF = 1.0e-05",
        "LREAL = .TRUE.",
      ].join("\n"),
      VaspUtils::Incar.dump(pairs)
    )

    assert_equal(
      [
        "SYSTEM = dummy",
        "PREC = High",
        "ENCUT = 400",
        "EDIFF = 1.0e-05",
        "LREAL = .TRUE.",
      ].join("\n"),
      VaspUtils::Incar.dump(pairs, nil)
    )

    outfile = "test/incar/tmp.incar"
    FileUtils.rm outfile if File.exist? outfile
    File.open(outfile, "w") { |io| VaspUtils::Incar.dump(pairs, io) }
    assert_equal(
      [
        "SYSTEM = dummy",
        "PREC = High",
        "ENCUT = 400",
        "EDIFF = 1.0e-05",
        "LREAL = .TRUE.",
      ].join("\n"),
      File.open(outfile).read
    )
    FileUtils.rm outfile if File.exist? outfile
  end
end