defmodule AssemblerTest do
  use ExUnit.Case
  doctest Assembler
  import Assembler

  test "assembles empty program" do
    assert assemble("") == []
  end

  test "assembles instructions correctly" do
    assert assemble("add 1, 2, 3") == [1101, 1, 2, 3]
    assert assemble("mul 1, 2, 3") == [1102, 1, 2, 3]
    assert assemble("in 7") == [3, 7]
    assert assemble("out 7") == [104, 7]
    assert assemble("out $7") == [4, 7]
    assert assemble("jnz 1, 2") == [1105, 1, 2]
    assert assemble("jnz $1, 2") == [1005, 1, 2]
    assert assemble("jez 1, 2") == [1106, 1, 2]
    assert assemble("jez $1, 2") == [1006, 1, 2]
    assert assemble("clt 1, 2, 3") == [1107, 1, 2, 3]
    assert assemble("clt $1, $2, $3") == [7, 1, 2, 3]
    assert assemble("ceq 1, 2, 3") == [1108, 1, 2, 3]
    assert assemble("ceq $1, $2, $3") == [8, 1, 2, 3]
    assert assemble("hlt") == [99]
  end

  test "assembles macros" do
    assert assemble("mov 1, 2") == [1101, 0, 1, 2]
    assert assemble("jmp 2") == [1105, 1, 2]
    assert assemble("sub 5, 3, res\nres: 0") == [1102, 3, -1, 8, 101, 5, 8, 8, 0]
  end

  test "assembles simple program" do
    program = """
    add 1, 2, 10
    mul 2, 3, 11
    add $10, $11, 12
    hlt
    """

    assert assemble(program) == [
             1101,
             1,
             2,
             10,
             1102,
             2,
             3,
             11,
             1,
             10,
             11,
             12,
             99
           ]
  end

  test "assembles simple program with a label" do
    program = """
      add 1, 2, 10
      jnz $10, nonZero
    nonZero:
      hlt
    """

    assert assemble(program) == [
             1101,
             1,
             2,
             10,
             1005,
             10,
             7,
             99
           ]
  end

  test "assembles a simple program with a data label" do
    program = """
      add 1, 2, var
      out $var
    var: 0
    """

    assert assemble(program) == [
             1101,
             1,
             2,
             6,
             4,
             6,
             0
           ]
  end

  test "assembles a program with a _self label" do
    program = """
      add 1, 2, _self
    """

    assert assemble(program) == [1101, 1, 2, 3]
  end

  test "assembles parameters with expressions" do
    assert assemble("add 1, _self + 1, 3") == [1101, 1, 3, 3]
    assert assemble("add 1, $(_self + 1), 3") == [101, 1, 3, 3]

    assert assemble("""
             add 1, label + 4 - 2, 3
           label: 42
           """) == [1101, 1, 6, 3, 42]

    assert assemble("""
             add 1, $(label + 4 - 2), 3
           label: 42
           """) == [101, 1, 6, 3, 42]
  end
end