feat: rack time format

Gemfile

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+source 'https://rubygems.org'
+
+gem 'pry'
+gem 'rack', '~> 1.6', '>= 1.6.4'

Gemfile.lock

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+GEM
+  remote: https://rubygems.org/
+  specs:
+    coderay (1.1.3)
+    method_source (1.0.0)
+    pry (0.14.2)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
+    rack (1.6.13)
+
+PLATFORMS
+  x86_64-darwin-22
+
+DEPENDENCIES
+  pry
+  rack (~> 1.6, >= 1.6.4)
+
+BUNDLED WITH
+   2.3.22

app.rb

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+# frozen_string_literal: true
+
+require_relative 'time_format'
+
+class App
+  def call(env)
+    request = Rack::Request.new(env)
+    return not_found unless request.get? && request.path == '/time'
+
+    time_format = TimeFormat.new(request.params['format']&.split(','))
+
+    if time_format.unknown_formats.empty?
+      response(body: time_format.formatted_time)
+    else
+      bad_request("Unknown time format [#{time_format.unknown_formats.join(',')}]")
+    end
+  end
+
+  private
+
+  def not_found
+    response(status: 404)
+  end
+
+  def bad_request(body)
+    response(status: 400, body: body)
+  end
+
+  def response(status: 200, headers: {}, body: [])
+    response = Rack::Response.new(body, status, headers)
+    response.finish
+  end
+end

config.ru

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+# frozen_string_literal: true
+
+require_relative 'app'
+require_relative 'middleware/logger'
+
+use AppLogger, logdev: File.expand_path('log/app.log', __dir__)
+run App.new

log/app.log

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+# Logfile created on 2023-07-13 05:54:24 +0300 by logger.rb/v1.4.2
+I, [2023-07-13T05:54:33.501996 #62736]  INFO -- : {"GATEWAY_INTERFACE"=>"CGI/1.1", "PATH_INFO"=>"/time", "QUERY_STRING"=>"format=year%2Cmonth%2Cdays%2Cdd", "REMOTE_ADDR"=>"127.0.0.1", "REMOTE_HOST"=>"127.0.0.1", "REQUEST_METHOD"=>"GET", "REQUEST_URI"=>"http://localhost:9292/time?format=year%2Cmonth%2Cdays%2Cdd", "SCRIPT_NAME"=>"", "SERVER_NAME"=>"localhost", "SERVER_PORT"=>"9292", "SERVER_PROTOCOL"=>"HTTP/1.1", "SERVER_SOFTWARE"=>"WEBrick/1.6.1 (Ruby/2.7.6/2022-04-12)", "HTTP_HOST"=>"localhost:9292", "HTTP_USER_AGENT"=>"curl/7.85.0", "HTTP_ACCEPT"=>"*/*", "rack.version"=>[1, 3], "rack.input"=>#<Rack::Lint::InputWrapper:0x00007f82ef8f3300 @input=#<StringIO:0x00007f82ef8f9a70>>, "rack.errors"=>#<Rack::Lint::ErrorWrapper:0x00007f82ef8f32d8 @error=#<IO:<STDERR>>>, "rack.multithread"=>true, "rack.multiprocess"=>false, "rack.run_once"=>false, "rack.url_scheme"=>"http", "rack.hijack?"=>true, "rack.hijack"=>#<Proc:0x00007f82ef8f35f8 /Users/vs/.rvm/gems/ruby-2.7.6/gems/rack-1.6.13/lib/rack/lint.rb:525>, "rack.hijack_io"=>nil, "HTTP_VERSION"=>"HTTP/1.1", "REQUEST_PATH"=>"/time", "rack.tempfiles"=>[]}

middleware/logger.rb

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+# frozen_string_literal: true
+
+require 'logger'
+
+class AppLogger
+  def initialize(app, **options)
+    @logger = Logger.new(options[:logdev] || $stdout)
+    @app = app
+  end
+
+  def call(env)
+    @logger.info(env)
+    @app.call(env)
+  end
+end

time_format.rb

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+# frozen_string_literal: true
+
+class TimeFormat
+  FORMATS = {
+    'year' => '%Y',
+    'month' => '%m',
+    'day' => '%d',
+    'hour' => '%H',
+    'minute' => '%M',
+    'second' => '%S'
+  }.freeze
+
+  def initialize(formats)
+    @formats = formats || []
+  end
+
+  def valid_formats
+    @formats.select { |format| FORMATS.include?(format) }
+  end
+
+  def unknown_formats
+    @formats - FORMATS.keys
+  end
+
+  def formatted_time
+    valid_formats.map { |format| Time.now.strftime(FORMATS[format]) }.join('-')
+  end
+end