#!/usr/bin/env ruby

require File.expand_path(File.join(File.dirname(__FILE__), "spec_common"))
require File.expand_path(File.join(File.dirname(__FILE__), "example"))
require 'bindata/base_primitive'
require 'bindata/io'

class ExampleSingle
  # reopen example to make @in_read public for testing
  def in_read?
    @in_read
  end
end

describe BinData::BasePrimitive, "when subclassing" do
  class SubClassOfBasePrimitive < BinData::BasePrimitive
    expose_methods_for_testing
  end

  before(:each) do
    @obj = SubClassOfBasePrimitive.new
  end

  it "should raise errors on unimplemented methods" do
    lambda { @obj.value_to_binary_string(nil) }.should raise_error(NotImplementedError)
    lambda { @obj.read_and_return_value(nil) }.should raise_error(NotImplementedError)
    lambda { @obj.sensible_default }.should raise_error(NotImplementedError)
  end
end

describe BinData::BasePrimitive do
  it "should conform to rule 1 for returning a value" do
    data = ExampleSingle.new(:value => 5)
    data.should_not be_in_read
    data.value.should == 5
  end

  it "should conform to rule 2 for returning a value" do
    io = StringIO.new([42].pack("V"))
    data = ExampleSingle.new(:value => 5)
    data.expose_methods_for_testing
    data.do_read(BinData::IO.new(io))
    data.should be_in_read
    data.value.should == 42
  end

  it "should conform to rule 3 for returning a value" do
    data = ExampleSingle.new(:initial_value => 5)
    data.should be_clear
    data.value.should == 5
  end

  it "should conform to rule 4 for returning a value" do
    data = ExampleSingle.new(:initial_value => 5)
    data.value = 17
    data.should_not be_clear
    data.value.should == 17
  end

  it "should conform to rule 5 for returning a value" do
    data = ExampleSingle.new
    data.should be_clear
    data.value.should == 0
  end

  it "should conform to rule 6 for returning a value" do
    data = ExampleSingle.new
    data.value = 8
    data.should_not be_clear
    data.value.should == 8
  end
end

describe ExampleSingle do
  before(:each) do
    @data = ExampleSingle.new
    @data.value = 5
  end

  it "should fail when assigning nil values" do
    lambda { @data.assign(nil) }.should raise_error(ArgumentError)
  end

  it "should allowing setting and retrieving value" do
    @data.value = 7
    @data.value.should == 7
  end

  it "should allowing setting and retrieving BinData::BasePrimitives" do
    obj = ExampleSingle.new
    obj.value = 7
    @data.value = obj
    @data.value.should == 7
  end

  it "should respond to known methods" do
    @data.should respond_to(:num_bytes)
  end

  it "should respond to known methods in #snapshot" do
    @data.should respond_to(:div)
  end

  it "should not respond to unknown methods in self or #snapshot" do
    @data.should_not respond_to(:does_not_exist)
  end

  it "should behave as #snapshot" do
    (@data + 1).should == 6
    (1 + @data).should == 6
  end

  it "should be equal to other ExampleSingle" do
    other = ExampleSingle.new
    other.value = 5
    @data.should == other
  end

  it "should be equal to raw values" do
    @data.should == 5
    5.should == @data
  end

  it "should work as hash keys" do
    hash = {5 => 17}

    obj = ExampleSingle.new
    obj.value = 5

    hash[obj].should == 17
  end
end

describe BinData::BasePrimitive, "after initialisation" do
  before(:each) do
    @data = ExampleSingle.new
  end

  it "should not allow both :initial_value and :value" do
    params = {:initial_value => 1, :value => 2}
    lambda { ExampleSingle.new(params) }.should raise_error(ArgumentError)
  end

  it "should have a sensible value" do
    @data.value.should == 0
  end

  it "should have symmetric IO" do
    @data.value = 42
    written = @data.to_binary_s

    ExampleSingle.read(written).should == 42
  end

  it "should allowing setting and retrieving value" do
    @data.value = 5
    @data.value.should == 5
  end

  it "should be clear" do
    @data.should be_clear
  end

  it "should not be clear after setting value" do
    @data.value = 5
    @data.should_not be_clear
  end

  it "should not be clear after reading" do
    @data.read("\x11\x22\x33\x44")
    @data.should_not be_clear
  end

  it "should return num_bytes" do
    @data.num_bytes.should == 4
  end

  it "should return a snapshot" do
    @data.value = 5
    @data.snapshot.should == 5
  end
end

describe BinData::BasePrimitive, "with :initial_value" do
  before(:each) do
    @data = ExampleSingle.new(:initial_value => 5)
  end

  it "should return that initial value before reading or being set" do
    @data.value.should == 5
  end

  it "should forget :initial_value after being set" do
    @data.value = 17
    @data.value.should_not == 5
  end

  it "should forget :initial_value after reading" do
    @data.read("\x11\x22\x33\x44")
    @data.value.should_not == 5
  end

  it "should remember :initial_value after being cleared" do
    @data.value = 17
    @data.clear
    @data.value.should == 5
  end
end

describe BinData::BasePrimitive, "with :value" do
  before(:each) do
    @data = ExampleSingle.new(:value => 5)
    @data.expose_methods_for_testing
  end

  it "should return that :value" do
    @data.value.should == 5
  end

  it "should change during reading" do
    io = StringIO.new([56].pack("V"))
    @data.do_read(BinData::IO.new(io))
    @data.value.should == 56
    @data.done_read
  end

  it "should not change after reading" do
    io = StringIO.new([56].pack("V"))
    @data.read(io)
    @data.value.should == 5
  end

  it "should not be able to change the value" do
    @data.value = 17
    @data.value.should == 5
  end
end

describe BinData::BasePrimitive, "with :check_value" do
  before(:each) do
    @io = StringIO.new([34].pack("V"))
  end

  it "should succeed when check_value is non boolean and correct" do
    data = ExampleSingle.new(:check_value => 34)
    lambda { data.read(@io) }.should_not raise_error
  end

  it "should fail when check_value is non boolean and incorrect" do
    data = ExampleSingle.new(:check_value => lambda { 123 * 5 })
    lambda { data.read(@io) }.should raise_error(BinData::ValidityError)
  end

  it "should succeed when check_value is boolean and true" do
    data = ExampleSingle.new(:check_value => lambda { (value % 2) == 0})
    lambda { data.read(@io) }.should_not raise_error
  end

  it "should fail when check_value is boolean and false" do
    data = ExampleSingle.new(:check_value => lambda { value > 100 })
    lambda { data.read(@io) }.should raise_error(BinData::ValidityError)
  end
end