# encoding: utf-8
# Define the common operation that both the `NullMetric` class and the Namespaced class should answer.
shared_examples "metrics commons operations" do
  let(:key) { "galaxy" }

  describe "#increment" do
    it "allows to increment a key with no amount" do
      expect { subject.increment(key, 100) }.not_to raise_error
    end

    it "allow to increment a key" do
      expect { subject.increment(key) }.not_to raise_error
    end

    it "raises an exception if the key is an empty string" do
      expect { subject.increment("", 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end

    it "raise an exception if the key is nil" do
      expect { subject.increment(nil, 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end
  end

  describe "#decrement" do
    it "allows to decrement a key with no amount" do
      expect { subject.decrement(key, 100) }.not_to raise_error
    end

    it "allow to decrement a key" do
      expect { subject.decrement(key) }.not_to raise_error
    end

    it "raises an exception if the key is an empty string" do
      expect { subject.decrement("", 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end

    it "raise an exception if the key is nil" do
      expect { subject.decrement(nil, 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end
  end

  describe "#gauge" do
    it "allows to set a value" do
      expect { subject.gauge(key, "pluto") }.not_to raise_error
    end


    it "raises an exception if the key is an empty string" do
      expect { subject.gauge("", 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end

    it "raise an exception if the key is nil" do
      expect { subject.gauge(nil, 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end
  end

  describe "#report_time" do
    it "allow to record time" do
      expect { subject.report_time(key, 1000) }.not_to raise_error
    end

    it "raises an exception if the key is an empty string" do
      expect { subject.report_time("", 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end

    it "raise an exception if the key is nil" do
      expect { subject.report_time(nil, 20) }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end
  end

  describe "#time" do
    it "allow to record time with a block given" do
      expect do
        subject.time(key) { 1+1 }
      end.not_to raise_error
    end

    it "returns the value of the block without recording any metrics" do
      expect(subject.time(:execution_time) { "hello" }).to eq("hello")
    end

    it "return a TimedExecution" do
      execution = subject.time(:do_something)
      expect { execution.stop }.not_to raise_error
    end


    it "raises an exception if the key is an empty string" do
      expect { subject.time("") {} }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end

    it "raise an exception if the key is nil" do
      expect { subject.time(nil) {} }.to raise_error(LogStash::Instrument::MetricNoKeyProvided)
    end
  end
end