require('MiddleClass')
require('MindState')

context( 'StatefulObject', function()

  local Enemy = class('Enemy', StatefulObject)
  function Enemy:getStatus() return 'none' end

  local EnemyIddle = Enemy:addState('Iddle')
  function EnemyIddle:enterState() self.enteredIddle = true end
  function EnemyIddle:getStatus() return 'iddling' end


  local Goblin = class('Goblin', Enemy)
  local GoblinIddle = Goblin:addState('Iddle')
  function GoblinIddle:getStatus() return 'me bored boss' end
  function GoblinIddle:exitState() self.exitedIddle = true end
  function GoblinIddle:pausedState() self.pausedIddle = true end
  function GoblinIddle:poppedState() self.poppedIddle = true end
  function GoblinIddle:continuedState() self.continuedIddle = true end
  
  local GoblinAttacking = Goblin:addState('Attacking')
  function GoblinAttacking:pushedState() self.pushedAttacking = true end
  function GoblinAttacking:enterState() self.enteredAttacking = true end
  function GoblinAttacking:shout() return 'gnaaa!' end
  function GoblinAttacking:poppedState() self.poppedAttacking = true end

  context('An instance', function()

    context('When it goes from one state to another', function()
      local albert = Enemy:new()
      albert:gotoState('Iddle')

      local chester = Goblin:new()
      chester:gotoState('Iddle')
    
      test('it should not throw an error for a valid state name', function()
        assert_not_error(function() chester:gotoState('Attacking') end)
        assert_equal(chester:shout(), 'gnaaa!')
      end)
      test('it should throw an error for an invalid state name', function()
        assert_error(function() albert:gotoState('Sleeping') end)
      end)
      test('it should be able to go to the nil-state', function()
        assert_not_error(function() albert:gotoState(nil) end)
        assert_equal(albert:getStatus(), 'none')
      end)
      test('enterState callbacks should be called, if existing', function()
        assert_true(albert.enteredIddle)
        assert_true(chester.enteredIddle)
      end)
      test('exitState callbacks should be called, if existing', function()
        assert_nil(albert.exitedIddle)
        assert_true(chester.exitedIddle)
      end)
    end)
    
    context('When pushing states', function()
      local andrew = Enemy:new()
      local ian = Goblin:new()

      test('it should error if the statename is invalid', function()
        assert_error(function() andrew:pushState(nil) end)
        assert_error(function() andrew:pushState('Sleeping') end)
      end)
      test('it should correctly push valid states, without errors', function()
        assert_not_error(function() ian:pushState('Iddle') end)
        assert_not_error(function() ian:pushState('Attacking') end)
        assert_equal(ian:shout(), 'gnaaa!')
        assert_equal(ian:getStatus(), 'me bored boss')
      end)
      test('pushing the same state several times should not throw errors', function()
        assert_not_error(function() andrew:pushState('Iddle') end)
        assert_not_error(function() andrew:pushState('Iddle') end)
      end)
      test('enterState callbacks should be called, if existing', function()
        assert_true(andrew.enteredIddle)
        assert_true(ian.enteredIddle)
      end)
      test('pushedState callbacks should be called, if existing', function()
        assert_nil(andrew.pushedAttacking)
        assert_true(ian.pushedAttacking)
      end)
      test('pausedState callbacks should be called, if existing', function()
        assert_nil(andrew.pausedIddle)
        assert_true(ian.pausedIddle)
      end)
    end)

    context('When popping states', function()
      local renfield = Goblin:new()
      
      -- reset vlad and renfield before each test
      before(function()
        renfield = Goblin:new()
      end)

      test('it should be able to pop states by name, calling callbacks', function()
        renfield:pushState('Iddle')
        renfield:pushState('Attacking')

        assert_not_error(function() renfield:popState('Iddle') end)
        assert_equal(renfield:getStatus(), 'none')
        assert_equal(renfield:shout(), 'gnaaa!')
        assert_true(renfield.poppedIddle)
        assert_true(renfield.exitedIddle)
      end)

      test('it should be able to pop the top state, with appropiate callbacks', function()
        renfield:pushState('Iddle')
        renfield:pushState('Attacking')

        assert_not_error(function() renfield:popState() end)
        assert_equal(renfield:getStatus(), 'me bored boss')
        assert_error(function() renfield:shout() end)
        assert_true(renfield.poppedAttacking)
        assert_true(renfield.continuedIddle)
      end)
      
      test('popping the same state several times should not throw errors, and call no callbacks', function()
        renfield:pushState('Iddle')
        renfield:popState('Iddle')
        renfield.poppedIddle = nil
        assert_not_error(function() renfield:popState('Iddle') end)
        assert_nil(renfield.poppedIddle)
      end)
      
      test('popping inexistant states should not throw errors', function()
        assert_not_error(function() renfield:popState('Foo') end)
      end)
     
      test('popAllStates should work correctly and invoke all required callbacks', function()
        renfield:pushState('Iddle')
        renfield:pushState('Attacking')
      
        assert_not_error(function() renfield:popAllStates() end)
        assert_true(renfield.poppedAttacking)
        assert_true(renfield.continuedIddle)
        assert_true(renfield.poppedIddle)
        assert_true(renfield.exitedIddle)
      end)

    end)
    
    context('When testing whether it is on one state', function()
      local igor = Goblin:new()
      
      test('it should return true if the state is on the top of the stack', function() 
        igor:gotoState('Iddle')
        assert_true(igor:isInState('Iddle'))
      end)
      
      test('it should return true if the state is on the stack and "testStateStack" is true', function()
        igor:pushState('Attacking')
        assert_true(igor:isInState('Attacking'))
        assert_true(igor:isInState('Iddle', true))
      end)
      
      test('it should return false otherwise', function()
        assert_false(igor:isInState(nil))
        assert_false(igor:isInState('Foo', true))
      end)
    end)
    
    context('When getting the current state name', function()
      local peppy = Goblin:new()
      
      test('it should return nil when on nil-state', function()
        assert_nil(peppy:getCurrentStateName())
      end)
      
      test('it should return the top-of-the-stack statename otherwise', function()
        peppy:pushState('Iddle')
        assert_equal(peppy:getCurrentStateName(), 'Iddle')
        peppy:pushState('Attacking')
        assert_equal(peppy:getCurrentStateName(), 'Attacking')
      end)
    end)

  end) -- context 'An Instance'
  
  context('A mixin on a stateful object', function()
    -- pending
  end)
  
  context('A State', function()
    -- pending
  end)

end)