module RSpec::Mocks::Syntax

def self.default_should_syntax_host
  # JRuby 1.7.4 introduces a regression whereby `defined?(::BasicObject) => nil`
  # yet `BasicObject` still exists and patching onto ::Object breaks things
  # e.g. SimpleDelegator expectations won't work
  #
  # See: https://github.com/jruby/jruby/issues/814
  if defined?(JRUBY_VERSION) && JRUBY_VERSION == '1.7.4' && RUBY_VERSION.to_f > 1.8
    return ::BasicObject
  end
  # On 1.8.7, Object.ancestors.last == Kernel but
  # things blow up if we include `RSpec::Mocks::Methods`
  # into Kernel...not sure why.
  return Object unless defined?(::BasicObject)
  # MacRuby has BasicObject but it's not the root class.
  return Object unless Object.ancestors.last == ::BasicObject
  ::BasicObject
end

def self.disable_expect(syntax_host=::RSpec::Mocks::ExampleMethods)
  return unless expect_enabled?(syntax_host)
  syntax_host.class_exec do
    undef receive
    undef receive_messages
    undef receive_message_chain
    undef allow
    undef expect_any_instance_of
    undef allow_any_instance_of
  end
  RSpec::Mocks::ExampleMethods::ExpectHost.class_exec do
    undef expect
  end
end

def self.disable_should(syntax_host=default_should_syntax_host)
  return unless should_enabled?(syntax_host)
  syntax_host.class_exec do
    undef should_receive
    undef should_not_receive
    undef stub
    undef unstub
    undef stub_chain
    undef as_null_object
    undef null_object?
    undef received_message?
  end
  Class.class_exec do
    undef any_instance
  end
end

def self.enable_expect(syntax_host=::RSpec::Mocks::ExampleMethods)
  return if expect_enabled?(syntax_host)
  syntax_host.class_exec do
    def receive(method_name, &block)
      Matchers::Receive.new(method_name, block)
    end
    def receive_messages(message_return_value_hash)
      matcher = Matchers::ReceiveMessages.new(message_return_value_hash)
      matcher.warn_about_block if block_given?
      matcher
    end
    def receive_message_chain(*messages, &block)
      Matchers::ReceiveMessageChain.new(messages, &block)
    end
    def allow(target)
      AllowanceTarget.new(target)
    end
    def expect_any_instance_of(klass)
      AnyInstanceExpectationTarget.new(klass)
    end
    def allow_any_instance_of(klass)
      AnyInstanceAllowanceTarget.new(klass)
    end
  end
  RSpec::Mocks::ExampleMethods::ExpectHost.class_exec do
    def expect(target)
      ExpectationTarget.new(target)
    end
  end
end

def self.enable_should(syntax_host=default_should_syntax_host)
  @warn_about_should = false if syntax_host == default_should_syntax_host
  return if should_enabled?(syntax_host)
  syntax_host.class_exec do
    def should_receive(message, opts={}, &block)
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      ::RSpec::Mocks.expect_message(self, message, opts, &block)
    end
    def should_not_receive(message, &block)
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      ::RSpec::Mocks.expect_message(self, message, {}, &block).never
    end
    def stub(message_or_hash, opts={}, &block)
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      if ::Hash === message_or_hash
        message_or_hash.each { |message, value| stub(message).and_return value }
      else
        ::RSpec::Mocks.allow_message(self, message_or_hash, opts, &block)
      end
    end
    def unstub(message)
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__, "`allow(...).to_receive(...).and_call_original` or explicitly enable `:should`")
      ::RSpec::Mocks.space.proxy_for(self).remove_stub(message)
    end
    def stub_chain(*chain, &blk)
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      ::RSpec::Mocks::StubChain.stub_chain_on(self, *chain, &blk)
    end
    def as_null_object
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      @_null_object = true
      ::RSpec::Mocks.space.proxy_for(self).as_null_object
    end
    def null_object?
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      defined?(@_null_object)
    end
    def received_message?(message, *args, &block)
      ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
      ::RSpec::Mocks.space.proxy_for(self).received_message?(message, *args, &block)
    end
    unless Class.respond_to? :any_instance
      Class.class_exec do
        def any_instance
          ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
          ::RSpec::Mocks.space.any_instance_proxy_for(self)
        end
      end
    end
  end
end

def self.expect_enabled?(syntax_host=::RSpec::Mocks::ExampleMethods)
  syntax_host.method_defined?(:allow)
end

def self.should_enabled?(syntax_host=default_should_syntax_host)
  syntax_host.method_defined?(:should_receive)
end

def self.warn_about_should!
  @warn_about_should = true
end

def self.warn_unless_should_configured(method_name , replacement="the new `:expect` syntax or explicitly enable `:should`")
  if @warn_about_should
    RSpec.deprecate(
      "Using `#{method_name}` from rspec-mocks' old `:should` syntax without explicitly enabling the syntax",
      :replacement => replacement
    )
    @warn_about_should = false
  end
end

def allow(target)
  AllowanceTarget.new(target)
end

def allow_any_instance_of(klass)
  AnyInstanceAllowanceTarget.new(klass)
end

def any_instance
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  ::RSpec::Mocks.space.any_instance_proxy_for(self)
end

def as_null_object
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  @_null_object = true
  ::RSpec::Mocks.space.proxy_for(self).as_null_object
end

def expect(target)
  ExpectationTarget.new(target)
end

def expect_any_instance_of(klass)
  AnyInstanceExpectationTarget.new(klass)
end

def null_object?
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  defined?(@_null_object)
end

def receive(method_name, &block)
  Matchers::Receive.new(method_name, block)
end

def receive_message_chain(*messages, &block)
  Matchers::ReceiveMessageChain.new(messages, &block)
end

def receive_messages(message_return_value_hash)
  matcher = Matchers::ReceiveMessages.new(message_return_value_hash)
  matcher.warn_about_block if block_given?
  matcher
end

def received_message?(message, *args, &block)
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  ::RSpec::Mocks.space.proxy_for(self).received_message?(message, *args, &block)
end

def should_not_receive(message, &block)
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  ::RSpec::Mocks.expect_message(self, message, {}, &block).never
end

def should_receive(message, opts={}, &block)
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  ::RSpec::Mocks.expect_message(self, message, opts, &block)
end

def stub(message_or_hash, opts={}, &block)
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  if ::Hash === message_or_hash
    message_or_hash.each { |message, value| stub(message).and_return value }
  else
    ::RSpec::Mocks.allow_message(self, message_or_hash, opts, &block)
  end
end

def stub_chain(*chain, &blk)
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__)
  ::RSpec::Mocks::StubChain.stub_chain_on(self, *chain, &blk)
end

def unstub(message)
  ::RSpec::Mocks::Syntax.warn_unless_should_configured(__method__, "`allow(...).to_receive(...).and_call_original` or explicitly enable `:should`")
  ::RSpec::Mocks.space.proxy_for(self).remove_stub(message)
end