# encoding: utf-8
require 'spec_helper'
require 'securerandom'

describe Ably::Rest::Channel, 'messages' do
  include Ably::Modules::Conversions

  vary_by_protocol do
    let(:default_client_options) { { api_key: api_key, environment: environment, protocol: protocol } }
    let(:client_options)         { default_client_options }
    let(:client)                 { Ably::Rest::Client.new(client_options) }
    let(:other_client)           { Ably::Rest::Client.new(client_options) }
    let(:channel)                { client.channel('test') }

    context 'publishing with an ASCII_8BIT message name' do
      let(:message_name) { random_str.encode(Encoding::ASCII_8BIT) }

      it 'is converted into UTF_8' do
        channel.publish message_name, 'example'
        message = channel.history.first
        expect(message.name.encoding).to eql(Encoding::UTF_8)
        expect(message.name.encode(Encoding::ASCII_8BIT)).to eql(message_name)
      end
    end

    describe 'encryption and encoding' do
      let(:channel_name)      { "persisted:#{random_str}" }
      let(:cipher_options)    { { key: random_str(32) } }
      let(:encrypted_channel) { client.channel(channel_name, encrypted: true, cipher_params: cipher_options) }

      context 'with #publish and #history' do
        shared_examples 'an Ably encrypter and decrypter' do |item, data|
          let(:algorithm)      { data['algorithm'].upcase }
          let(:mode)           { data['mode'].upcase }
          let(:key_length)     { data['keylength'] }
          let(:secret_key)     { Base64.decode64(data['key']) }
          let(:iv)             { Base64.decode64(data['iv']) }

          let(:cipher_options) { { key: secret_key, iv: iv, algorithm: algorithm, mode: mode, key_length: key_length } }

          let(:encoded)              { item['encoded'] }
          let(:encoded_data)         { encoded['data'] }
          let(:encoded_encoding)     { encoded['encoding'] }
          let(:encoded_data_decoded) do
            if encoded_encoding == 'json'
              JSON.parse(encoded_data)
            elsif encoded_encoding == 'base64'
              Base64.decode64(encoded_data)
            else
              encoded_data
            end
          end

          let(:encrypted)              { item['encrypted'] }
          let(:encrypted_data)         { encrypted['data'] }
          let(:encrypted_encoding)     { encrypted['encoding'] }
          let(:encrypted_data_decoded) do
            if encrypted_encoding.match(%r{/base64$})
              Base64.decode64(encrypted_data)
            else
              encrypted_data
            end
          end

          it 'encrypts message automatically when published' do
            expect(client).to receive(:post) do |path, message|
              if protocol == :json
                expect(message['encoding']).to eql(encrypted_encoding)
                expect(Base64.decode64(message['data'])).to eql(encrypted_data_decoded)
              else
                # Messages sent over binary protocol will not have Base64 encoded data
                expect(message['encoding']).to eql(encrypted_encoding.gsub(%r{/base64$}, ''))
                expect(message['data']).to eql(encrypted_data_decoded)
              end
            end.and_return(double('Response', status: 201))

            encrypted_channel.publish 'example', encoded_data_decoded
          end

          it 'sends and retrieves messages that are encrypted & decrypted by the Ably library' do
            encrypted_channel.publish 'example', encoded_data_decoded

            message = encrypted_channel.history.first
            expect(message.data).to eql(encoded_data_decoded)
            expect(message.encoding).to be_nil
          end
        end

        resources_root = File.expand_path('../../../resources', __FILE__)

        def self.add_tests_for_data(data)
          data['items'].each_with_index do |item, index|
            context "item #{index} with encrypted encoding #{item['encrypted']['encoding']}" do
              it_behaves_like 'an Ably encrypter and decrypter', item, data
            end
          end
        end

        context 'with AES-128-CBC using crypto-data-128.json fixtures' do
          data = JSON.parse(File.read(File.join(resources_root, 'crypto-data-128.json')))
          add_tests_for_data data
        end

        context 'with AES-256-CBC using crypto-data-256.json fixtures' do
          data = JSON.parse(File.read(File.join(resources_root, 'crypto-data-256.json')))
          add_tests_for_data data
        end

        context 'when publishing lots of messages' do
          let(:data) { MessagePack.pack({ 'key' => random_str }) }
          let(:message_count) { 20 }

          it 'encrypts on #publish and decrypts on #history' do
            message_count.times do |index|
              encrypted_channel.publish index.to_s, "#{index}-#{data}"
            end

            messages = encrypted_channel.history

            expect(messages.count).to eql(message_count)
            messages.each do |message|
              expect(message.data).to eql("#{message.name}-#{data}")
              expect(message.encoding).to be_nil
            end
          end
        end

        context 'when retrieving #history with a different protocol' do
          let(:other_protocol)       { protocol == :msgpack ? :json : :msgpack }
          let(:other_client)         { Ably::Rest::Client.new(default_client_options.merge(protocol: other_protocol)) }
          let(:other_client_channel) {  other_client.channel(channel_name, encrypted: true, cipher_params: cipher_options) }

          before do
            expect(other_client.protocol_binary?).to_not eql(client.protocol_binary?)
          end

          [MessagePack.pack({ 'key' => SecureRandom.hex }), 'ã unicode', { 'key' => SecureRandom.hex }].each do |payload|
            payload_description = "#{payload.class}#{" #{payload.encoding}" if payload.kind_of?(String)}"

            specify "delivers a #{payload_description} payload to the receiver" do
              encrypted_channel.publish 'example', payload

              message = other_client_channel.history.first
              expect(message.data).to eql(payload)
              expect(message.encoding).to be_nil
            end
          end
        end

        context 'when publishing on an unencrypted channel and retrieving with #history on an encrypted channel' do
          let(:unencrypted_channel)            { client.channel(channel_name) }
          let(:other_client_encrypted_channel) { other_client.channel(channel_name, encrypted: true, cipher_params: cipher_options) }

          let(:payload) { MessagePack.pack({ 'key' => random_str }) }

          it 'does not attempt to decrypt the message' do
            unencrypted_channel.publish 'example', payload

            message = other_client_encrypted_channel.history.first
            expect(message.data).to eql(payload)
            expect(message.encoding).to be_nil
          end
        end

        context 'when publishing on an encrypted channel and retrieving with #history on an unencrypted channel' do
          let(:client_options)                   { default_client_options.merge(log_level: :fatal) }
          let(:cipher_options)                   { { key: random_str(32), algorithm: 'aes', mode: 'cbc', key_length: 256 } }
          let(:encrypted_channel)                { client.channel(channel_name, encrypted: true, cipher_params: cipher_options) }
          let(:other_client_unencrypted_channel) { other_client.channel(channel_name) }

          let(:payload) { MessagePack.pack({ 'key' => random_str }) }

          before do
            encrypted_channel.publish 'example', payload
          end

          it 'retrieves the message that remains encrypted with an encrypted encoding attribute' do
            message = other_client_unencrypted_channel.history.first
            expect(message.data).to_not eql(payload)
            expect(message.encoding).to match(/^cipher\+aes-256-cbc/)
          end

          it 'logs a Cipher exception' do
            expect(other_client.logger).to receive(:error) do |message|
              expect(message).to match(/Message cannot be decrypted/)
            end
            other_client_unencrypted_channel.history
          end
        end

        context 'publishing on an encrypted channel and retrieving #history with a different algorithm on another client' do
          let(:client_options)            { default_client_options.merge(log_level: :fatal) }
          let(:cipher_options_client1)    { { key: random_str(32), algorithm: 'aes', mode: 'cbc', key_length: 256 } }
          let(:encrypted_channel_client1) { client.channel(channel_name, encrypted: true, cipher_params: cipher_options_client1) }
          let(:cipher_options_client2)    { { key: random_str(32), algorithm: 'aes', mode: 'cbc', key_length: 128 } }
          let(:encrypted_channel_client2) { other_client.channel(channel_name, encrypted: true, cipher_params: cipher_options_client2) }

          let(:payload) { MessagePack.pack({ 'key' => random_str }) }

          before do
            encrypted_channel_client1.publish 'example', payload
          end

          it 'retrieves the message that remains encrypted with an encrypted encoding attribute' do
            message = encrypted_channel_client2.history.first
            expect(message.data).to_not eql(payload)
            expect(message.encoding).to match(/^cipher\+aes-256-cbc/)
          end

          it 'logs a Cipher exception' do
            expect(other_client.logger).to receive(:error) do |message|
              expect(message).to match(/Cipher algorithm [\w-]+ does not match/)
            end
            encrypted_channel_client2.history
          end
        end

        context 'publishing on an encrypted channel and subscribing with a different key on another client' do
          let(:client_options)            { default_client_options.merge(log_level: :fatal) }
          let(:cipher_options_client1)    { { key: random_str(32), algorithm: 'aes', mode: 'cbc', key_length: 256 } }
          let(:encrypted_channel_client1) { client.channel(channel_name, encrypted: true, cipher_params: cipher_options_client1) }
          let(:cipher_options_client2)    { { key: random_str(32), algorithm: 'aes', mode: 'cbc', key_length: 256 } }
          let(:encrypted_channel_client2) { other_client.channel(channel_name, encrypted: true, cipher_params: cipher_options_client2) }

          let(:payload) { MessagePack.pack({ 'key' => random_str }) }

          before do
            encrypted_channel_client1.publish 'example', payload
          end

          it 'retrieves the message that remains encrypted with an encrypted encoding attribute' do
            message = encrypted_channel_client2.history.first
            expect(message.data).to_not eql(payload)
            expect(message.encoding).to match(/^cipher\+aes-256-cbc/)
          end

          it 'logs a Cipher exception' do
            expect(other_client.logger).to receive(:error) do |message|
              expect(message).to match(/CipherError decrypting data/)
            end
            encrypted_channel_client2.history
          end
        end
      end
    end
  end
end