require 'minitest/unit'
require 'pp'

module Test
  module Unit
    module Assertions
      include MiniTest::Assertions

      def mu_pp(obj)
        obj.pretty_inspect.chomp
      end

      UNASSIGNED = Object.new # :nodoc:

      def assert(test, msg = UNASSIGNED)
        case msg
        when UNASSIGNED
          msg = nil
        when String, Proc
        else
          bt = caller.reject { |s| s.rindex(MiniTest::MINI_DIR, 0) }
          raise ArgumentError, "assertion message must be String or Proc, but #{msg.class} was given.", bt
        end
        super
      end

      def assert_raise(*args, &b)
        assert_raises(*args, &b)
      end

      def assert_nothing_raised(*args)
        self._assertions += 1
        if Module === args.last
          msg = nil
        else
          msg = args.pop
        end
        begin
          line = __LINE__; yield
        rescue MiniTest::Skip
          raise
        rescue Exception => e
          bt = e.backtrace
          as = e.instance_of?(MiniTest::Assertion)
          if as
            ans = /\A#{Regexp.quote(__FILE__)}:#{line}:in /o
            bt.reject! {|ln| ans =~ ln}
          end
          if ((args.empty? && !as) ||
              args.any? {|a| a.instance_of?(Module) ? e.is_a?(a) : e.class == a })
            msg = message(msg) { "Exception raised:\n<#{mu_pp(e)}>" }
            raise MiniTest::Assertion, msg.call, bt
          else
            raise
          end
        end
        nil
      end

      def assert_nothing_thrown(msg=nil)
        begin
          yield
        rescue ArgumentError => error
          raise error if /\Auncaught throw (.+)\z/m !~ error.message
          msg = message(msg) { "<#{$1}> was thrown when nothing was expected" }
          flunk(msg)
        end
        assert(true, "Expected nothing to be thrown")
      end

      def assert_equal(exp, act, msg = nil)
        msg = message(msg) {
          exp_str = mu_pp(exp)
          act_str = mu_pp(act)
          exp_comment = ''
          act_comment = ''
          if exp_str == act_str
            if (exp.is_a?(String) && act.is_a?(String)) ||
               (exp.is_a?(Regexp) && act.is_a?(Regexp))
              exp_comment = " (#{exp.encoding})"
              act_comment = " (#{act.encoding})"
            elsif exp.is_a?(Float) && act.is_a?(Float)
              exp_str = "%\#.#{Float::DIG+2}g" % exp
              act_str = "%\#.#{Float::DIG+2}g" % act
            elsif exp.is_a?(Time) && act.is_a?(Time)
              if exp.subsec * 1000_000_000 == exp.nsec
                exp_comment = " (#{exp.nsec}[ns])"
              else
                exp_comment = " (subsec=#{exp.subsec})"
              end
              if act.subsec * 1000_000_000 == act.nsec
                act_comment = " (#{act.nsec}[ns])"
              else
                act_comment = " (subsec=#{act.subsec})"
              end
            elsif exp.class != act.class
              # a subclass of Range, for example.
              exp_comment = " (#{exp.class})"
              act_comment = " (#{act.class})"
            end
          elsif !Encoding.compatible?(exp_str, act_str)
            if exp.is_a?(String) && act.is_a?(String)
              exp_str = exp.dump
              act_str = act.dump
              exp_comment = " (#{exp.encoding})"
              act_comment = " (#{act.encoding})"
            else
              exp_str = exp_str.dump
              act_str = act_str.dump
            end
          end
          "<#{exp_str}>#{exp_comment} expected but was\n<#{act_str}>#{act_comment}"
        }
        assert(exp == act, msg)
      end

      def assert_not_nil(exp, msg=nil)
        msg = message(msg) { "<#{mu_pp(exp)}> expected to not be nil" }
        assert(!exp.nil?, msg)
      end

      def assert_not_equal(exp, act, msg=nil)
        msg = message(msg) { "<#{mu_pp(exp)}> expected to be != to\n<#{mu_pp(act)}>" }
        assert(exp != act, msg)
      end

      def assert_no_match(regexp, string, msg=nil)
        assert_instance_of(Regexp, regexp, "The first argument to assert_no_match should be a Regexp.")
        self._assertions -= 1
        msg = message(msg) { "<#{mu_pp(regexp)}> expected to not match\n<#{mu_pp(string)}>" }
        assert(regexp !~ string, msg)
      end

      def assert_not_same(expected, actual, message="")
        msg = message(msg) { build_message(message, <<EOT, expected, expected.__id__, actual, actual.__id__) }
<?>
with id <?> expected to not be equal\\? to
<?>
with id <?>.
EOT
        assert(!actual.equal?(expected), msg)
      end

      # get rid of overcounting
      def assert_respond_to obj, meth, msg = nil
        super if !caller[0].rindex(MiniTest::MINI_DIR, 0) || !obj.respond_to?(meth)
      end

      ms = instance_methods(true).map {|sym| sym.to_s }
      ms.grep(/\Arefute_/) do |m|
        mname = ('assert_not_' << m.to_s[/.*?_(.*)/, 1])
        alias_method(mname, m) unless ms.include? mname
      end

      def build_message(head, template=nil, *arguments)
        template &&= template.chomp
        template.gsub(/\?/) { mu_pp(arguments.shift) }
      end
    end
  end
end