# Copyright 2015 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

require 'grpc'

describe GRPC::Core::CompressionOptions do
  # Note these constants should be updated
  # according to what the core lib provides.

  # Names of supported compression algorithms
  ALGORITHMS = [:identity, :deflate, :gzip]

  # Names of valid supported compression levels
  COMPRESS_LEVELS = [:none, :low, :medium, :high]

  it 'implements to_s' do
    expect { GRPC::Core::CompressionOptions.new.to_s }.to_not raise_error
  end

  it '#to_channel_arg_hash gives the same result as #to_hash' do
    options = GRPC::Core::CompressionOptions.new
    expect(options.to_channel_arg_hash).to eq(options.to_hash)
  end

  # Test the normal call sequence of creating an instance
  # and then obtaining the resulting channel-arg hash that
  # corresponds to the compression settings of the instance
  describe 'creating, reading, and converting to channel args hash' do
    it 'works when no optional args were provided' do
      options = GRPC::Core::CompressionOptions.new

      ALGORITHMS.each do |algorithm|
        expect(options.algorithm_enabled?(algorithm)).to be true
      end

      expect(options.disabled_algorithms).to be_empty
      expect(options.default_algorithm).to be nil
      expect(options.default_level).to be nil
      expect(options.to_hash).to be_instance_of(Hash)
    end

    it 'works when disabling multiple algorithms' do
      options = GRPC::Core::CompressionOptions.new(
        default_algorithm: :identity,
        default_level: :none,
        disabled_algorithms: [:gzip, :deflate]
      )

      [:gzip, :deflate].each do |algorithm|
        expect(options.algorithm_enabled?(algorithm)).to be false
        expect(options.disabled_algorithms.include?(algorithm)).to be true
      end

      expect(options.default_algorithm).to be(:identity)
      expect(options.default_level).to be(:none)
      expect(options.to_hash).to be_instance_of(Hash)
    end

    it 'works when all optional args have been set' do
      options = GRPC::Core::CompressionOptions.new(
        default_algorithm: :gzip,
        default_level: :low,
        disabled_algorithms: [:deflate]
      )

      expect(options.algorithm_enabled?(:deflate)).to be false
      expect(options.algorithm_enabled?(:gzip)).to be true
      expect(options.disabled_algorithms).to eq([:deflate])

      expect(options.default_algorithm).to be(:gzip)
      expect(options.default_level).to be(:low)
      expect(options.to_hash).to be_instance_of(Hash)
    end

    it 'doesnt fail when no algorithms are disabled' do
      options = GRPC::Core::CompressionOptions.new(
        default_algorithm: :identity,
        default_level: :high
      )

      ALGORITHMS.each do |algorithm|
        expect(options.algorithm_enabled?(algorithm)).to be(true)
      end

      expect(options.disabled_algorithms).to be_empty
      expect(options.default_algorithm).to be(:identity)
      expect(options.default_level).to be(:high)
      expect(options.to_hash).to be_instance_of(Hash)
    end
  end

  describe '#new with bad parameters' do
    it 'should fail with more than one parameter' do
      blk = proc { GRPC::Core::CompressionOptions.new(:gzip, :none) }
      expect { blk.call }.to raise_error
    end

    it 'should fail with a non-hash parameter' do
      blk = proc { GRPC::Core::CompressionOptions.new(:gzip) }
      expect { blk.call }.to raise_error
    end
  end

  describe '#default_algorithm' do
    it 'returns nil if unset' do
      options = GRPC::Core::CompressionOptions.new
      expect(options.default_algorithm).to be(nil)
    end
  end

  describe '#default_level' do
    it 'returns nil if unset' do
      options = GRPC::Core::CompressionOptions.new
      expect(options.default_level).to be(nil)
    end
  end

  describe '#disabled_algorithms' do
    it 'returns an empty list if no algorithms were disabled' do
      options = GRPC::Core::CompressionOptions.new
      expect(options.disabled_algorithms).to be_empty
    end
  end

  describe '#algorithm_enabled?' do
    [:none, :any, 'gzip', Object.new, 1].each do |name|
      it "should fail for parameter ${name} of class #{name.class}" do
        options = GRPC::Core::CompressionOptions.new(
          disabled_algorithms: [:gzip])

        blk = proc do
          options.algorithm_enabled?(name)
        end
        expect { blk.call }.to raise_error
      end
    end
  end
end