class Shoulda::Matchers::ActionController::AssignToMatcher

def assigned_value
  @controller.instance_variable_get("@#{@variable}")
end

def assigned_value?
  if @controller.instance_variables.map(&:to_s).include?("@#{@variable}")
    @failure_message_for_should_not =
      "Didn't expect action to assign a value for @#{@variable}, " <<
      "but it was assigned to #{assigned_value.inspect}"
    true
  else
    @failure_message_for_should =
      "Expected action to assign a value for @#{@variable}"
    false
  end
end

def description
  description = "assign @#{@variable}"
  if @options.key?(:expected_class)
    description << " with a kind of #{@options[:expected_class]}"
  end
  description
end

def equal_to_expected_value?
  if @options[:check_value]
    if @options[:expected_value] == assigned_value
      @failure_message_for_should_not =
        "Didn't expect action to assign #{@options[:expected_value].inspect} " <<
        "for #{@variable}, but got it anyway"
      true
    else
      @failure_message_for_should =
        "Expected action to assign #{@options[:expected_value].inspect} " <<
        "for #{@variable}, but got #{assigned_value.inspect}"
      false
    end
  else
    true
  end
end

def in_context(context)
  @context = context
  self
end

def initialize(variable)
  ActiveSupport::Deprecation.warn 'The assign_to matcher is deprecated and will be removed in 2.0'
  @variable    = variable.to_s
  @options = {}
  @options[:check_value] = false
end

def kind_of_expected_class?
  if @options.key?(:expected_class)
    if assigned_value.kind_of?(@options[:expected_class])
      @failure_message_for_should_not =
        "Didn't expect action to assign a kind of #{@options[:expected_class]} " <<
        "for #{@variable}, but got one anyway"
      true
    else
      @failure_message_for_should =
        "Expected action to assign a kind of #{@options[:expected_class]} " <<
        "for #{@variable}, but got #{assigned_value.inspect} " <<
        "(#{assigned_value.class.name})"
      false
    end
  else
    true
  end
end

def matches?(controller)
  @controller = controller
  normalize_expected_value!
  assigned_value? &&
    kind_of_expected_class? &&
    equal_to_expected_value?
end

def normalize_expected_value!
  if @options[:expectation_block]
    @options[:expected_value] = @context.instance_eval(&@options[:expectation_block])
  end
end

def with(expected_value = nil, &block)
  @options[:check_value] = true
  @options[:expected_value] = expected_value
  @options[:expectation_block] = block
  self
end

def with_kind_of(expected_class)
  @options[:expected_class] = expected_class
  self
end