class Minitest::Mock

def __call name, data # :nodoc:
  case data
  when Hash then
    args   = data[:args].inspect[1..-2]
    kwargs = data[:kwargs]
    if kwargs && !kwargs.empty? then
      args << ", " unless args.empty?
      args << kwargs.inspect[1..-2]
    end
    "#{name}(#{args}) => #{data[:retval].inspect}"
  else
    data.map { |d| __call name, d }.join ", "
  end
end

def expect name, retval, args = [], **kwargs, &blk
  name = name.to_sym
  if block_given?
    raise ArgumentError, "args ignored when block given" unless args.empty?
    raise ArgumentError, "kwargs ignored when block given" unless kwargs.empty?
    @expected_calls[name] << { :retval => retval, :block => blk }
  else
    raise ArgumentError, "args must be an array" unless Array === args
    if ENV["MT_KWARGS_HAC\K"] && (Hash === args.last ||
                                  Hash ==  args.last) then
      if kwargs.empty? then
        kwargs = args.pop
      else
        unless @@KW_WARNED then
          from = caller.first
          warn "Using MT_KWARGS_HAC\K yet passing kwargs. From #{from}"
          @@KW_WARNED = true
        end
      end
    end
    @expected_calls[name] <<
      { :retval => retval, :args => args, :kwargs => kwargs }
  end
  self
end

def initialize delegator = nil # :nodoc:
  @delegator = delegator
  @expected_calls = Hash.new { |calls, name| calls[name] = [] }
  @actual_calls   = Hash.new { |calls, name| calls[name] = [] }
end

def method_missing sym, *args, **kwargs, &block # :nodoc:
  unless @expected_calls.key?(sym) then
    if @delegator && @delegator.respond_to?(sym)
      return @delegator.public_send(sym, *args, **kwargs, &block)
    else
      raise NoMethodError, "unmocked method %p, expected one of %p" %
        [sym, @expected_calls.keys.sort_by(&:to_s)]
    end
  end
  index = @actual_calls[sym].length
  expected_call = @expected_calls[sym][index]
  unless expected_call then
    raise MockExpectationError, "No more expects available for %p: %p %p" %
      [sym, args, kwargs]
  end
  expected_args, expected_kwargs, retval, val_block =
    expected_call.values_at(:args, :kwargs, :retval, :block)
  expected_kwargs = kwargs.map { |ak, av| [ak, Object] }.to_h if
    Hash == expected_kwargs
  if val_block then
    # keep "verify" happy
    @actual_calls[sym] << expected_call
    raise MockExpectationError, "mocked method %p failed block w/ %p %p" %
      [sym, args, kwargs] unless val_block.call(*args, **kwargs, &block)
    return retval
  end
  if expected_args.size != args.size then
    raise ArgumentError, "mocked method %p expects %d arguments, got %p" %
      [sym, expected_args.size, args]
  end
  if expected_kwargs.size != kwargs.size then
    raise ArgumentError, "mocked method %p expects %d keyword arguments, got %p" %
      [sym, expected_kwargs.size, kwargs]
  end
  zipped_args = expected_args.zip(args)
  fully_matched = zipped_args.all? { |mod, a|
    mod === a or mod == a
  }
  unless fully_matched then
    fmt = "mocked method %p called with unexpected arguments %p"
    raise MockExpectationError, fmt % [sym, args]
  end
  unless expected_kwargs.keys.sort == kwargs.keys.sort then
    fmt = "mocked method %p called with unexpected keywords %p vs %p"
    raise MockExpectationError, fmt % [sym, expected_kwargs.keys, kwargs.keys]
  end
  zipped_kwargs = expected_kwargs.map { |ek, ev|
    av = kwargs[ek]
    [ek, [ev, av]]
  }.to_h
  fully_matched = zipped_kwargs.all? { |ek, (ev, av)|
    ev === av or ev == av
  }
  unless fully_matched then
    fmt = "mocked method %p called with unexpected keyword arguments %p vs %p"
    raise MockExpectationError, fmt % [sym, expected_kwargs, kwargs]
  end
  @actual_calls[sym] << {
    :retval => retval,
    :args => zipped_args.map { |e, a| e === a ? e : a },
    :kwargs => zipped_kwargs.map { |k, (e, a)| [k, e === a ? e : a] }.to_h,
  }
  retval
end

def respond_to? sym, include_private = false # :nodoc:
  return true if @expected_calls.key? sym.to_sym
  return true if @delegator && @delegator.respond_to?(sym, include_private)
  __respond_to?(sym, include_private)
end

def verify
  @expected_calls.each do |name, expected|
    actual = @actual_calls.fetch(name, nil)
    raise MockExpectationError, "expected #{__call name, expected[0]}" unless actual
    raise MockExpectationError, "expected #{__call name, expected[actual.size]}, got [#{__call name, actual}]" if
      actual.size < expected.size
  end
  true
end