require 'rspec'
require 'abstractivator/enum'

class Container
  module Traditional
    include Enum
    FOO = 'foo'
    BAR = 'bar'
  end

  define_enum(:Fruits, :apple, :orange)
  define_enum(:Vegetables, cucumber: 'Cucumis sativus', eggplant: 8)
end

define_enum(:Meats, :bacon, :more_bacon)

describe Enum do
  describe '::values' do
    it 'enumerates the values' do
      expect(Container::Traditional.values).to eql %w(foo bar)
    end
  end
  describe '::name_for' do
    it 'returns the symbol name of an enum value' do
      expect(Container::Traditional.name_for('foo')).to eql :FOO
    end
    it 'return nil if the value does not belong to the enumeration' do
      expect(Container::Traditional.name_for('baz')).to be_nil
    end
  end
  describe '::from_symbol' do
    it 'coerces a symbol to an enum value' do
      expect(Container::Traditional.from_symbol(:bar)).to eql 'bar'
    end
    it 'raises an error if no such value exists in the enumeration' do
      expect{Container::Traditional.from_symbol(:baz)}.to raise_error RuntimeError
    end
  end
  describe '::from' do
    it 'returns the typed version of the value' do
      result = Container::Fruits.from('apple')
      expect(result).to eql Container::Fruits::APPLE
    end
    it 'works if the value is already typed' do
      expect(Container::Fruits.from(Container::Fruits::APPLE)).to eql Container::Fruits::APPLE
    end
  end
  describe '::new' do
    it 'cannot be called' do
      expect{Container::Fruits.new('durian')}.to raise_error NoMethodError
    end
  end
  describe '#as_json' do
    it "as_json's the value" do
      hash = double
      expect(Meats::BACON.value).to receive(:as_json).and_return(hash)
      expect(Meats::BACON.as_json).to eql hash
    end
  end
  describe '#to_json' do
    it "to_json's the value" do
      json = double
      expect(Meats::BACON.value).to receive(:to_json).and_return(json)
      expect(Meats::BACON.to_json).to eql json
    end
  end
end

describe '#define_enum' do
  it 'defines an enum given an array of symbols' do
    expect(Container::Fruits::APPLE.value).to eql 'apple'
    expect(Container::Fruits::ORANGE.value).to eql 'orange'
  end
  it 'defines an enum given a hash' do
    expect(Container::Vegetables::CUCUMBER.value).to eql 'Cucumis sativus'
    expect(Container::Vegetables::EGGPLANT.value).to eql 8
  end
  it 'values know their parent' do
    expect(Container::Fruits::APPLE).to be_a Container::Fruits
    expect(Container::Fruits::ORANGE).to be_a Container::Fruits
    expect(Container::Vegetables::CUCUMBER).to be_a Container::Vegetables
    expect(Container::Vegetables::EGGPLANT).to be_a Container::Vegetables
  end
  it 'can define top level enumerations' do
    expect(Meats.values.map(&:value)).to eql %w(bacon more_bacon)
  end
  it 'raises an error when called with bad arguments' do
    expect{define_enum(:Stuff, 5)}.to raise_error /Arguments must be/
    expect{define_enum(:Stuff, '!@$' => '')}.to raise_error /Arguments must be/
  end
end