diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index b72ff7b..d033c94 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,68 +1,46 @@
 # This configuration was generated by `rubocop --auto-gen-config`
-# on 2015-05-14 16:51:06 +0300 using RuboCop version 0.31.0.
+# on 2015-05-25 12:59:32 +0300 using RuboCop version 0.31.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 15
+# Offense count: 16
 Metrics/AbcSize:
-  Enabled: false
+  Max: 68
 
-# Offense count: 2
-Metrics/BlockNesting:
-  Max: 4
-
-# Offense count: 3
+# Offense count: 4
 # Configuration parameters: CountComments.
 Metrics/ClassLength:
-  Max: 337
+    Enabled: false
 
-# Offense count: 5
+# Offense count: 3
 Metrics/CyclomaticComplexity:
-  Max: 15
+  Max: 9
 
 # Offense count: 22
 # Configuration parameters: CountComments.
 Metrics/MethodLength:
-  Enabled: false
-
-# Offense count: 5
-Metrics/PerceivedComplexity:
-  Max: 18
+  Max: 117
 
 # Offense count: 4
+Metrics/PerceivedComplexity:
+  Max: 12
+
+# Offense count: 2
 Style/AccessorMethodName:
   Enabled: false
 
-# Offense count: 1
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles.
-Style/AndOr:
-  Enabled: false
-
-# Offense count: 19
-# Cop supports --auto-correct.
-# Configuration parameters: EnforcedStyle, SupportedStyles, ProceduralMethods, FunctionalMethods, IgnoredMethods.
-Style/BlockDelimiters:
-  Enabled: false
-
-# Offense count: 4
+# Offense count: 6
 Style/Documentation:
   Enabled: false
 
-# Offense count: 5
+# Offense count: 1
 # Configuration parameters: MinBodyLength.
 Style/GuardClause:
   Enabled: false
 
-# Offense count: 15
-# Cop supports --auto-correct.
-# Configuration parameters: MaxLineLength.
-Style/IfUnlessModifier:
-  Enabled: false
-
-# Offense count: 2
+# Offense count: 1
 # Configuration parameters: EnforcedStyle, MinBodyLength, SupportedStyles.
 Style/Next:
   Enabled: false
diff --git a/bin/github_changelog_generator b/bin/github_changelog_generator
index f0c5fd4..5d0d48a 100755
--- a/bin/github_changelog_generator
+++ b/bin/github_changelog_generator
@@ -1,4 +1,4 @@
 #! /usr/bin/env ruby
 
 require_relative "../lib/github_changelog_generator"
-GitHubChangelogGenerator::ChangelogGenerator.new.compound_changelog
+GitHubChangelogGenerator::ChangelogGenerator.new.run
diff --git a/lib/CHANGELOG.md b/lib/CHANGELOG.md
index a261d8f..3c6e8bd 100644
--- a/lib/CHANGELOG.md
+++ b/lib/CHANGELOG.md
@@ -1,8 +1,12 @@
 # Change Log
 
-## [Unreleased](https://github.com/skywinder/changelog_test/tree/HEAD)
+## [0.0.4](https://github.com/skywinder/changelog_test/tree/0.0.4) (2015-05-22)
 
-[Full Changelog](https://github.com/skywinder/changelog_test/compare/v0.0.3...HEAD)
+[Full Changelog](https://github.com/skywinder/changelog_test/compare/v0.0.3...0.0.4)
+
+**Closed issues:**
+
+- Test issue, that should appear in 0.0.4 [\#3](https://github.com/skywinder/changelog_test/issues/3)
 
 **Merged pull requests:**
 
diff --git a/lib/github_changelog_generator.rb b/lib/github_changelog_generator.rb
index 8a02b9a..c35db79 100755
--- a/lib/github_changelog_generator.rb
+++ b/lib/github_changelog_generator.rb
@@ -6,517 +6,34 @@ require "colorize"
 require "benchmark"
 
 require_relative "github_changelog_generator/parser"
-require_relative "github_changelog_generator/generator"
+require_relative "github_changelog_generator/generator/generator"
 require_relative "github_changelog_generator/version"
 require_relative "github_changelog_generator/reader"
-require_relative "github_changelog_generator/fetcher"
 
+# The main module, where placed all classes (now, at least)
 module GitHubChangelogGenerator
-  # Default error for ChangelogGenerator
-  class ChangelogGeneratorError < StandardError
-  end
-
   # Main class and entry point for this script.
   class ChangelogGenerator
-    attr_accessor :options, :all_tags, :github
-
     # Class, responsible for whole change log generation cycle
     # @return initialised instance of ChangelogGenerator
     def initialize
       @options = Parser.parse_options
-
-      @fetcher = GitHubChangelogGenerator::Fetcher.new @options
-
       @generator = Generator.new @options
-
-      # @all_tags = get_filtered_tags
-      @all_tags = @fetcher.get_all_tags
-
-      # TODO: refactor this double asssign of @issues and @pull_requests and move all logic in one method
-      @issues, @pull_requests = @fetcher.fetch_closed_issues_and_pr
-
-      @pull_requests = @options[:pulls] ? get_filtered_pull_requests : []
-
-      @issues = @options[:issues] ? get_filtered_issues : []
-
-      fetch_event_for_issues_and_pr
-      detect_actual_closed_dates
-    end
-
-    # Return tags after filtering tags in lists provided by option: --between-tags & --exclude-tags
-    #
-    # @return [Array]
-    def get_filtered_tags
-      all_tags = @fetcher.get_all_tags
-      filtered_tags = []
-      if @options[:between_tags]
-        @options[:between_tags].each do |tag|
-          unless all_tags.include? tag
-            puts "Warning: can't find tag #{tag}, specified with --between-tags option.".yellow
-          end
-        end
-        filtered_tags = all_tags.select { |tag| @options[:between_tags].include? tag }
-      end
-      filtered_tags
-    end
-
-    def detect_actual_closed_dates
-      if @options[:verbose]
-        print "Fetching closed dates for issues...\r"
-      end
-
-      threads = []
-
-      @issues.each { |issue|
-        threads << Thread.new {
-          find_closed_date_by_commit(issue)
-        }
-      }
-
-      @pull_requests.each { |pull_request|
-        threads << Thread.new {
-          find_closed_date_by_commit(pull_request)
-        }
-      }
-      threads.each(&:join)
-
-      if @options[:verbose]
-        puts "Fetching closed dates for issues: Done!"
-      end
-    end
-
-    # Fill :actual_date parameter of specified issue by closed date of the commit, it it was closed by commit.
-    # @param [Hash] issue
-    def find_closed_date_by_commit(issue)
-      unless issue["events"].nil?
-        # if it's PR -> then find "merged event", in case of usual issue -> fond closed date
-        compare_string = issue[:merged_at].nil? ? "closed" : "merged"
-        # reverse! - to find latest closed event. (event goes in date order)
-        issue["events"].reverse!.each { |event|
-          if event[:event].eql? compare_string
-            if event[:commit_id].nil?
-              issue[:actual_date] = issue[:closed_at]
-            else
-              begin
-                commit = @fetcher.fetch_commit(event)
-                issue[:actual_date] = commit[:author][:date]
-              rescue
-                puts "Warning: Can't fetch commit #{event[:commit_id]}. It is probably referenced from another repo.".yellow
-                issue[:actual_date] = issue[:closed_at]
-              end
-            end
-            break
-          end
-        }
-      end
-      # TODO: assert issues, that remain without 'actual_date' hash for some reason.
-    end
-
-    def print_json(json)
-      puts JSON.pretty_generate(json)
-    end
-
-    # This method fetches missing params for PR and filter them by specified options
-    # It include add all PR's with labels from @options[:include_labels] array
-    # And exclude all from :exclude_labels array.
-    # @return [Array] filtered PR's
-    def get_filtered_pull_requests
-      filter_merged_pull_requests
-
-      filtered_pull_requests = include_issues_by_labels(@pull_requests)
-
-      filtered_pull_requests = exclude_issues_by_labels(filtered_pull_requests)
-
-      if @options[:verbose]
-        puts "Filtered pull requests: #{filtered_pull_requests.count}"
-      end
-
-      filtered_pull_requests
-    end
-
-    # This method filter only merged PR and
-    # fetch missing required attributes for pull requests
-    # :merged_at - is a date, when issue PR was merged.
-    # More correct to use merged date, rather than closed date.
-    def filter_merged_pull_requests
-      if @options[:verbose]
-        print "Fetching merged dates...\r"
-      end
-      pull_requests = @fetcher.fetch_closed_pull_requests
-
-      @pull_requests.each { |pr|
-        fetched_pr = pull_requests.find { |fpr|
-          fpr.number == pr.number
-        }
-        pr[:merged_at] = fetched_pr[:merged_at]
-        pull_requests.delete(fetched_pr)
-      }
-
-      @pull_requests.select! do |pr|
-        !pr[:merged_at].nil?
-      end
-    end
-
-    # Include issues with labels, specified in :include_labels
-    # @param [Array] issues to filter
-    # @return [Array] filtered array of issues
-    def include_issues_by_labels(issues)
-      filtered_issues = @options[:include_labels].nil? ? issues : issues.select { |issue| (issue.labels.map(&:name) & @options[:include_labels]).any? }
-
-      if @options[:add_issues_wo_labels]
-        issues_wo_labels = issues.select { |issue|
-          !issue.labels.map(&:name).any?
-        }
-        filtered_issues |= issues_wo_labels
-      end
-      filtered_issues
-    end
-
-    # delete all labels with labels from @options[:exclude_labels] array
-    # @param [Array] issues
-    # @return [Array] filtered array
-    def exclude_issues_by_labels(issues)
-      unless @options[:exclude_labels].nil?
-        issues = issues.select { |issue|
-          !(issue.labels.map(&:name) & @options[:exclude_labels]).any?
-        }
-      end
-      issues
     end
 
     # The entry point of this script to generate change log
     # @raise (ChangelogGeneratorError) Is thrown when one of specified tags was not found in list of tags.
-    def compound_changelog
-      log = "# Change Log\n\n"
-
-      if @options[:unreleased_only]
-        log += generate_log_between_tags(all_tags[0], nil)
-      elsif @options[:tag1] and @options[:tag2]
-        tag1 = @options[:tag1]
-        tag2 = @options[:tag2]
-        tags_strings = []
-        all_tags.each { |x| tags_strings.push(x["name"]) }
-
-        if tags_strings.include?(tag1)
-          if tags_strings.include?(tag2)
-            to_a = tags_strings.map.with_index.to_a
-            hash = Hash[to_a]
-            index1 = hash[tag1]
-            index2 = hash[tag2]
-            log += generate_log_between_tags(all_tags[index1], all_tags[index2])
-          else
-            fail ChangelogGeneratorError, "Can't find tag #{tag2} -> exit".red
-          end
-        else
-          fail ChangelogGeneratorError, "Can't find tag #{tag1} -> exit".red
-        end
-      else
-        log += generate_log_for_all_tags
-      end
-
-      log += "\n\n\\* *This Change Log was automatically generated by [github_changelog_generator](https://github.com/skywinder/Github-Changelog-Generator)*"
+    def run
+      log = @generator.compound_changelog
 
       output_filename = "#{@options[:output]}"
       File.open(output_filename, "w") { |file| file.write(log) }
       puts "Done!"
       puts "Generated log placed in #{Dir.pwd}/#{output_filename}"
     end
-
-    # The full cycle of generation for whole project
-    # @return [String] The complete change log
-    def generate_log_for_all_tags
-      fetch_tags_dates
-
-      if @options[:verbose]
-        puts "Sorting tags..."
-      end
-
-      @all_tags.sort_by! { |x| @fetcher.get_time_of_tag(x) }.reverse!
-
-      if @options[:verbose]
-        puts "Generating log..."
-      end
-
-      log = ""
-
-      if @options[:unreleased] && @all_tags.count != 0
-        unreleased_log = generate_log_between_tags(all_tags[0], nil)
-        if unreleased_log
-          log += unreleased_log
-        end
-      end
-
-      (1...all_tags.size).each { |index|
-        log += generate_log_between_tags(all_tags[index], all_tags[index - 1])
-      }
-      if @all_tags.count != 0
-        log += generate_log_between_tags(nil, all_tags.last)
-      end
-
-      log
-    end
-
-    # Async fetching of all tags dates
-    def fetch_tags_dates
-      if @options[:verbose]
-        print "Fetching tag dates...\r"
-      end
-
-      # Async fetching tags:
-      threads = []
-      i = 0
-      all = @all_tags.count
-      @all_tags.each { |tag|
-        threads << Thread.new {
-          @fetcher.get_time_of_tag(tag)
-          if @options[:verbose]
-            print "Fetching tags dates: #{i + 1}/#{all}\r"
-            i += 1
-          end
-        }
-      }
-
-      print "                                 \r"
-
-      threads.each(&:join)
-
-      if @options[:verbose]
-        puts "Fetching tags dates: #{i}"
-      end
-    end
-
-    # Generate log only between 2 specified tags
-    # @param [String] older_tag all issues before this tag date will be excluded. May be nil, if it's first tag
-    # @param [String] newer_tag all issue after this tag will be excluded. May be nil for unreleased section
-    def generate_log_between_tags(older_tag, newer_tag)
-      filtered_pull_requests = delete_by_time(@pull_requests, :actual_date, older_tag, newer_tag)
-      filtered_issues = delete_by_time(@issues, :actual_date, older_tag, newer_tag)
-
-      newer_tag_name = newer_tag.nil? ? nil : newer_tag["name"]
-      older_tag_name = older_tag.nil? ? nil : older_tag["name"]
-
-      if @options[:filter_issues_by_milestone]
-        # delete excess irrelevant issues (according milestones)
-        filtered_issues = filter_by_milestone(filtered_issues, newer_tag_name, @issues)
-        filtered_pull_requests = filter_by_milestone(filtered_pull_requests, newer_tag_name, @pull_requests)
-      end
-
-      if filtered_issues.empty? && filtered_pull_requests.empty? && newer_tag.nil?
-        # do not generate empty unreleased section
-        return ""
-      end
-
-      create_log(filtered_pull_requests, filtered_issues, newer_tag, older_tag_name)
-    end
-
-    def filter_by_milestone(filtered_issues, newer_tag_name, src_array)
-      filtered_issues.select! { |issue|
-        # leave issues without milestones
-        if issue.milestone.nil?
-          true
-        else
-          # check, that this milestone in tag list:
-          @all_tags.find { |tag| tag.name == issue.milestone.title }.nil?
-        end
-      }
-      unless newer_tag_name.nil?
-
-        # add missed issues (according milestones)
-        issues_to_add = src_array.select { |issue|
-          if issue.milestone.nil?
-            false
-          else
-            # check, that this milestone in tag list:
-            milestone_is_tag = @all_tags.find { |tag|
-              tag.name == issue.milestone.title
-            }
-
-            if milestone_is_tag.nil?
-              false
-            else
-              issue.milestone.title == newer_tag_name
-            end
-          end
-        }
-
-        filtered_issues |= issues_to_add
-      end
-      filtered_issues
-    end
-
-    # Method filter issues, that belong only specified tag range
-    # @param [Array] array of issues to filter
-    # @param [Symbol] hash_key key of date value default is :actual_date
-    # @param [String] older_tag all issues before this tag date will be excluded. May be nil, if it's first tag
-    # @param [String] newer_tag all issue after this tag will be excluded. May be nil for unreleased section
-    # @return [Array] filtered issues
-    def delete_by_time(array, hash_key = :actual_date, older_tag = nil, newer_tag = nil)
-      fail ChangelogGeneratorError, "At least one of the tags should be not nil!".red if older_tag.nil? && newer_tag.nil?
-
-      newer_tag_time = newer_tag && @fetcher.get_time_of_tag(newer_tag)
-      older_tag_time = older_tag && @fetcher.get_time_of_tag(older_tag)
-
-      array.select { |req|
-        if req[hash_key]
-          t = Time.parse(req[hash_key]).utc
-
-          if older_tag_time.nil?
-            tag_in_range_old = true
-          else
-            tag_in_range_old = t > older_tag_time
-          end
-
-          if newer_tag_time.nil?
-            tag_in_range_new = true
-          else
-            tag_in_range_new = t <= newer_tag_time
-          end
-
-          tag_in_range = (tag_in_range_old) && (tag_in_range_new)
-
-          tag_in_range
-        else
-          false
-        end
-      }
-    end
-
-    # Generates log for section with header and body
-    #
-    # @param [Array] pull_requests List or PR's in new section
-    # @param [Array] issues List of issues in new section
-    # @param [String] newer_tag Name of the newer tag. Could be nil for `Unreleased` section
-    # @param [String] older_tag_name Older tag, used for the links. Could be nil for last tag.
-    # @return [String] Ready and parsed section
-    def create_log(pull_requests, issues, newer_tag, older_tag_name = nil)
-      newer_tag_time = newer_tag.nil? ? Time.new : @fetcher.get_time_of_tag(newer_tag)
-      if newer_tag.nil? && @options[:future_release]
-        newer_tag_name = @options[:future_release]
-        newer_tag_link = @options[:future_release]
-      else
-        newer_tag_name = newer_tag.nil? ? @options[:unreleased_label] : newer_tag["name"]
-        newer_tag_link = newer_tag.nil? ? "HEAD" : newer_tag_name
-      end
-
-      github_site = options[:github_site] || "https://github.com"
-      project_url = "#{github_site}/#{@options[:user]}/#{@options[:project]}"
-
-      log = generate_header(newer_tag_name, newer_tag_link, newer_tag_time, older_tag_name, project_url)
-
-      if @options[:issues]
-        # Generate issues:
-        issues_a = []
-        enhancement_a = []
-        bugs_a = []
-
-        issues.each { |dict|
-          added = false
-          dict.labels.each { |label|
-            if label.name == "bug"
-              bugs_a.push dict
-              added = true
-              next
-            end
-            if label.name == "enhancement"
-              enhancement_a.push dict
-              added = true
-              next
-            end
-          }
-          unless added
-            issues_a.push dict
-          end
-        }
-
-        log += generate_sub_section(enhancement_a, @options[:enhancement_prefix])
-        log += generate_sub_section(bugs_a, @options[:bug_prefix])
-        log += generate_sub_section(issues_a, @options[:issue_prefix])
-      end
-
-      if @options[:pulls]
-        # Generate pull requests:
-        log += generate_sub_section(pull_requests, @options[:merge_prefix])
-      end
-
-      log
-    end
-
-    # @param [Array] issues List of issues on sub-section
-    # @param [String] prefix Nae of sub-section
-    # @return [String] Generate ready-to-go sub-section
-    def generate_sub_section(issues, prefix)
-      log = ""
-
-      if options[:simple_list] != true && issues.any?
-        log += "#{prefix}\n\n"
-      end
-
-      if issues.any?
-        issues.each { |issue|
-          merge_string = @generator.get_string_for_issue(issue)
-          log += "- #{merge_string}\n\n"
-        }
-      end
-      log
-    end
-
-    # It generate one header for section with specific parameters.
-    #
-    # @param [String] newer_tag_name - name of newer tag
-    # @param [String] newer_tag_link - used for links. Could be same as #newer_tag_name or some specific value, like HEAD
-    # @param [Time] newer_tag_time - time, when newer tag created
-    # @param [String] older_tag_link - tag name, used for links.
-    # @param [String] project_url - url for current project.
-    # @return [String] - Generate one ready-to-add section.
-    def generate_header(newer_tag_name, newer_tag_link, newer_tag_time, older_tag_link, project_url)
-      log = ""
-
-      # Generate date string:
-      time_string = newer_tag_time.strftime @options[:dateformat]
-
-      # Generate tag name and link
-      if newer_tag_name.equal? @options[:unreleased_label]
-        log += "## [#{newer_tag_name}](#{project_url}/tree/#{newer_tag_link})\n\n"
-      else
-        log += "## [#{newer_tag_name}](#{project_url}/tree/#{newer_tag_link}) (#{time_string})\n\n"
-      end
-
-      if @options[:compare_link] && older_tag_link
-        # Generate compare link
-        log += "[Full Changelog](#{project_url}/compare/#{older_tag_link}...#{newer_tag_link})\n\n"
-      end
-
-      log
-    end
-
-    # Filter issues according labels
-    # @return [Array] Filtered issues
-    def get_filtered_issues
-      filtered_issues = include_issues_by_labels(@issues)
-
-      filtered_issues = exclude_issues_by_labels(filtered_issues)
-
-      if @options[:verbose]
-        puts "Filtered issues: #{filtered_issues.count}"
-      end
-
-      filtered_issues
-    end
-
-    # Fetch event for issues and pull requests
-    # @return [Array] array of fetched issues
-    def fetch_event_for_issues_and_pr
-      if @options[:verbose]
-        print "Fetching events for issues and PR: 0/#{@issues.count + @pull_requests.count}\r"
-      end
-
-      # Async fetching events:
-
-      @fetcher.fetch_events_async(@issues + @pull_requests)
-    end
   end
 
   if __FILE__ == $PROGRAM_NAME
-    GitHubChangelogGenerator::ChangelogGenerator.new.compound_changelog
+    GitHubChangelogGenerator::ChangelogGenerator.new.run
   end
 end
diff --git a/lib/github_changelog_generator/fetcher.rb b/lib/github_changelog_generator/fetcher.rb
index 863a422..5e08ff9 100644
--- a/lib/github_changelog_generator/fetcher.rb
+++ b/lib/github_changelog_generator/fetcher.rb
@@ -41,9 +41,7 @@ module GitHubChangelogGenerator
     def fetch_github_token
       env_var = @options[:token] ? @options[:token] : (ENV.fetch CHANGELOG_GITHUB_TOKEN, nil)
 
-      unless env_var
-        @logger.warn NO_TOKEN_PROVIDED.yellow
-      end
+      @logger.warn NO_TOKEN_PROVIDED.yellow unless env_var
 
       env_var
     end
@@ -51,9 +49,7 @@ module GitHubChangelogGenerator
     # Fetch all tags from repo
     # @return [Array] array of tags
     def get_all_tags
-      if @options[:verbose]
-        print "Fetching tags...\r"
-      end
+      print "Fetching tags...\r" if @options[:verbose]
 
       tags = []
 
@@ -98,9 +94,7 @@ Make sure, that you push tags to remote repo via 'git push --tags'".yellow
     # (pull request is kind of issue in term of GitHub)
     # @return [Tuple] with (issues, pull-requests)
     def fetch_closed_issues_and_pr
-      if @options[:verbose]
-        print "Fetching closed issues...\r"
-      end
+      print "Fetching closed issues...\r" if @options[:verbose]
       issues = []
 
       begin
diff --git a/lib/github_changelog_generator/generator.rb b/lib/github_changelog_generator/generator.rb
deleted file mode 100644
index f076f4b..0000000
--- a/lib/github_changelog_generator/generator.rb
+++ /dev/null
@@ -1,42 +0,0 @@
-module GitHubChangelogGenerator
-  class Generator
-    def initialize(options = nil)
-      @options = options
-    end
-
-    # Parse issue and generate single line formatted issue line.
-    #
-    # Example output:
-    # - Add coveralls integration [\#223](https://github.com/skywinder/github-changelog-generator/pull/223) ([skywinder](https://github.com/skywinder))
-    #
-    # @param [Hash] issue Fetched issue from GitHub
-    # @return [String] Markdown-formatted single issue
-    def get_string_for_issue(issue)
-      encapsulated_title = encapsulate_string issue[:title]
-
-      title_with_number = "#{encapsulated_title} [\\##{issue[:number]}](#{issue.html_url})"
-
-      unless issue.pull_request.nil?
-        if @options[:author]
-          if issue.user.nil?
-            title_with_number += " ({Null user})"
-          else
-            title_with_number += " ([#{issue.user.login}](#{issue.user.html_url}))"
-          end
-        end
-      end
-      title_with_number
-    end
-
-    def encapsulate_string(string)
-      string.gsub! '\\', '\\\\'
-
-      encpas_chars = %w(> * _ \( \) [ ] #)
-      encpas_chars.each do |char|
-        string.gsub! char, "\\#{char}"
-      end
-
-      string
-    end
-  end
-end
diff --git a/lib/github_changelog_generator/generator/generator.rb b/lib/github_changelog_generator/generator/generator.rb
new file mode 100644
index 0000000..5b4285f
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator.rb
@@ -0,0 +1,137 @@
+require "github_changelog_generator/fetcher"
+require_relative "generator_generation"
+require_relative "generator_fetcher"
+require_relative "generator_processor"
+
+module GitHubChangelogGenerator
+  # Default error for ChangelogGenerator
+  class ChangelogGeneratorError < StandardError
+  end
+
+  class Generator
+    attr_accessor :options, :all_tags, :github
+
+    # A Generator responsible for all logic, related with change log generation from ready-to-parse issues
+    #
+    # Example:
+    #   generator = GitHubChangelogGenerator::Generator.new
+    #   content = generator.compound_changelog
+    def initialize(options = nil)
+      @options = options
+
+      @fetcher = GitHubChangelogGenerator::Fetcher.new @options
+
+      fetch_tags
+
+      fetch_issues_and_pr
+    end
+
+    def fetch_issues_and_pr
+      issues, pull_requests = @fetcher.fetch_closed_issues_and_pr
+
+      @pull_requests = @options[:pulls] ? get_filtered_pull_requests(pull_requests) : []
+
+      @issues = @options[:issues] ? get_filtered_issues(issues) : []
+
+      fetch_events_for_issues_and_pr
+      detect_actual_closed_dates(@issues + @pull_requests)
+    end
+
+    def fetch_tags
+      # @all_tags = get_filtered_tags
+      @all_tags = @fetcher.get_all_tags
+
+      fetch_tags_dates
+      sort_tags_by_date
+    end
+
+    # Sort all tags by date
+    def sort_tags_by_date
+      puts "Sorting tags..." if @options[:verbose]
+      @all_tags.sort_by! { |x| @fetcher.get_time_of_tag(x) }.reverse!
+    end
+
+    # Encapsulate characters to make markdown look as expected.
+    #
+    # @param [String] string
+    # @return [String] encapsulated input string
+    def encapsulate_string(string)
+      string.gsub! '\\', '\\\\'
+
+      encpas_chars = %w(> * _ \( \) [ ] #)
+      encpas_chars.each do |char|
+        string.gsub! char, "\\#{char}"
+      end
+
+      string
+    end
+
+    # Generates log for section with header and body
+    #
+    # @param [Array] pull_requests List or PR's in new section
+    # @param [Array] issues List of issues in new section
+    # @param [String] newer_tag Name of the newer tag. Could be nil for `Unreleased` section
+    # @param [String] older_tag_name Older tag, used for the links. Could be nil for last tag.
+    # @return [String] Ready and parsed section
+    def create_log(pull_requests, issues, newer_tag, older_tag_name = nil)
+      newer_tag_time = newer_tag.nil? ? Time.new : @fetcher.get_time_of_tag(newer_tag)
+      if newer_tag.nil? && @options[:future_release]
+        newer_tag_name = @options[:future_release]
+        newer_tag_link = @options[:future_release]
+      else
+        newer_tag_name = newer_tag.nil? ? @options[:unreleased_label] : newer_tag["name"]
+        newer_tag_link = newer_tag.nil? ? "HEAD" : newer_tag_name
+      end
+
+      github_site = options[:github_site] || "https://github.com"
+      project_url = "#{github_site}/#{@options[:user]}/#{@options[:project]}"
+
+      log = generate_header(newer_tag_name, newer_tag_link, newer_tag_time, older_tag_name, project_url)
+
+      if @options[:issues]
+        # Generate issues:
+        bugs_a, enhancement_a, issues_a = parse_by_sections(issues)
+
+        log += generate_sub_section(enhancement_a, @options[:enhancement_prefix])
+        log += generate_sub_section(bugs_a, @options[:bug_prefix])
+        log += generate_sub_section(issues_a, @options[:issue_prefix])
+      end
+
+      if @options[:pulls]
+        # Generate pull requests:
+        log += generate_sub_section(pull_requests, @options[:merge_prefix])
+      end
+
+      log
+    end
+
+    # This method sort issues by types
+    # (bugs, features, or just closed issues) by labels
+    #
+    # @param [Array] issues
+    # @return [Array] tuple of filtered arrays: (Bugs, Enhancements Issues)
+    def parse_by_sections(issues)
+      issues_a = []
+      enhancement_a = []
+      bugs_a = []
+
+      issues.each do |dict|
+        added = false
+        dict.labels.each do |label|
+          if label.name == "bug"
+            bugs_a.push dict
+            added = true
+            next
+          end
+          if label.name == "enhancement"
+            enhancement_a.push dict
+            added = true
+            next
+          end
+        end
+        issues_a.push dict unless added
+      end
+      [bugs_a, enhancement_a, issues_a]
+    end
+  end
+end
diff --git a/lib/github_changelog_generator/generator/generator_fetcher.rb b/lib/github_changelog_generator/generator/generator_fetcher.rb
new file mode 100644
index 0000000..7cb3fd4
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator_fetcher.rb
@@ -0,0 +1,89 @@
+module GitHubChangelogGenerator
+  class Generator
+    # Fetch event for issues and pull requests
+    # @return [Array] array of fetched issues
+    def fetch_events_for_issues_and_pr
+      if @options[:verbose]
+        print "Fetching events for issues and PR: 0/#{@issues.count + @pull_requests.count}\r"
+      end
+
+      # Async fetching events:
+      @fetcher.fetch_events_async(@issues + @pull_requests)
+    end
+
+    # Async fetching of all tags dates
+    def fetch_tags_dates
+      print "Fetching tag dates...\r" if @options[:verbose]
+
+      # Async fetching tags:
+      threads = []
+      i = 0
+      all = @all_tags.count
+      @all_tags.each do |tag|
+        threads << Thread.new do
+          @fetcher.get_time_of_tag(tag)
+          if @options[:verbose]
+            print "Fetching tags dates: #{i + 1}/#{all}\r"
+            i += 1
+          end
+        end
+      end
+
+      print "                                 \r"
+
+      threads.each(&:join)
+
+      puts "Fetching tags dates: #{i}" if @options[:verbose]
+    end
+
+    # Find correct closed dates, if issues was closed by commits
+    def detect_actual_closed_dates(issues)
+      print "Fetching closed dates for issues...\r" if @options[:verbose]
+
+      max_thread_number = 50
+      issues.each_slice(max_thread_number) do |issues_slice|
+        threads = []
+        issues_slice.each do |issue|
+          threads << Thread.new { find_closed_date_by_commit(issue) }
+        end
+        threads.each(&:join)
+        puts "Fetching closed dates for issues: Done!" if @options[:verbose]
+      end
+    end
+
+    # Fill :actual_date parameter of specified issue by closed date of the commit, if it was closed by commit.
+    # @param [Hash] issue
+    def find_closed_date_by_commit(issue)
+      unless issue["events"].nil?
+        # if it's PR -> then find "merged event", in case of usual issue -> fond closed date
+        compare_string = issue[:merged_at].nil? ? "closed" : "merged"
+        # reverse! - to find latest closed event. (event goes in date order)
+        issue["events"].reverse!.each do |event|
+          if event[:event].eql? compare_string
+            set_date_from_event(event, issue)
+            break
+          end
+        end
+      end
+      # TODO: assert issues, that remain without 'actual_date' hash for some reason.
+    end
+
+    # Set closed date from this issue
+    #
+    # @param [Hash] event
+    # @param [Hash] issue
+    def set_date_from_event(event, issue)
+      if event[:commit_id].nil?
+        issue[:actual_date] = issue[:closed_at]
+      else
+        begin
+          commit = @fetcher.fetch_commit(event)
+          issue[:actual_date] = commit[:author][:date]
+        rescue
+          puts "Warning: Can't fetch commit #{event[:commit_id]}. It is probably referenced from another repo.".yellow
+          issue[:actual_date] = issue[:closed_at]
+        end
+      end
+    end
+  end
+end
diff --git a/lib/github_changelog_generator/generator/generator_generation.rb b/lib/github_changelog_generator/generator/generator_generation.rb
new file mode 100644
index 0000000..f5e6b8f
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator_generation.rb
@@ -0,0 +1,159 @@
+module GitHubChangelogGenerator
+  class Generator
+    # Main function to start change log generation
+    #
+    # @return [String] Generated change log file
+    def compound_changelog
+      log = "# Change Log\n\n"
+
+      if @options[:unreleased_only]
+        log += generate_log_between_tags(all_tags[0], nil)
+      elsif @options[:tag1] && @options[:tag2]
+        tag1 = @options[:tag1]
+        tag2 = @options[:tag2]
+        tags_strings = []
+        all_tags.each { |x| tags_strings.push(x["name"]) }
+
+        if tags_strings.include?(tag1)
+          if tags_strings.include?(tag2)
+            to_a = tags_strings.map.with_index.to_a
+            hash = Hash[to_a]
+            index1 = hash[tag1]
+            index2 = hash[tag2]
+            log += generate_log_between_tags(all_tags[index1], all_tags[index2])
+          else
+            fail ChangelogGeneratorError, "Can't find tag #{tag2} -> exit".red
+          end
+        else
+          fail ChangelogGeneratorError, "Can't find tag #{tag1} -> exit".red
+        end
+      else
+        log += generate_log_for_all_tags
+      end
+
+      log += "\n\n\\* *This Change Log was automatically generated by [github_changelog_generator](https://github.com/skywinder/Github-Changelog-Generator)*"
+      @log = log
+      @log = log
+    end
+
+    # @param [Array] issues List of issues on sub-section
+    # @param [String] prefix Nae of sub-section
+    # @return [String] Generate ready-to-go sub-section
+    def generate_sub_section(issues, prefix)
+      log = ""
+
+      log += "#{prefix}\n\n" if options[:simple_list] != true && issues.any?
+
+      if issues.any?
+        issues.each do |issue|
+          merge_string = get_string_for_issue(issue)
+          log += "- #{merge_string}\n\n"
+        end
+      end
+      log
+    end
+
+    # It generate one header for section with specific parameters.
+    #
+    # @param [String] newer_tag_name - name of newer tag
+    # @param [String] newer_tag_link - used for links. Could be same as #newer_tag_name or some specific value, like HEAD
+    # @param [Time] newer_tag_time - time, when newer tag created
+    # @param [String] older_tag_link - tag name, used for links.
+    # @param [String] project_url - url for current project.
+    # @return [String] - Generate one ready-to-add section.
+    def generate_header(newer_tag_name, newer_tag_link, newer_tag_time, older_tag_link, project_url)
+      log = ""
+
+      # Generate date string:
+      time_string = newer_tag_time.strftime @options[:date_format]
+
+      # Generate tag name and link
+      if newer_tag_name.equal? @options[:unreleased_label]
+        log += "## [#{newer_tag_name}](#{project_url}/tree/#{newer_tag_link})\n\n"
+      else
+        log += "## [#{newer_tag_name}](#{project_url}/tree/#{newer_tag_link}) (#{time_string})\n\n"
+      end
+
+      if @options[:compare_link] && older_tag_link
+        # Generate compare link
+        log += "[Full Changelog](#{project_url}/compare/#{older_tag_link}...#{newer_tag_link})\n\n"
+      end
+
+      log
+    end
+
+    # Generate log only between 2 specified tags
+    # @param [String] older_tag all issues before this tag date will be excluded. May be nil, if it's first tag
+    # @param [String] newer_tag all issue after this tag will be excluded. May be nil for unreleased section
+    def generate_log_between_tags(older_tag, newer_tag)
+      filtered_pull_requests = delete_by_time(@pull_requests, :actual_date, older_tag, newer_tag)
+      filtered_issues = delete_by_time(@issues, :actual_date, older_tag, newer_tag)
+
+      newer_tag_name = newer_tag.nil? ? nil : newer_tag["name"]
+      older_tag_name = older_tag.nil? ? nil : older_tag["name"]
+
+      if @options[:filter_issues_by_milestone]
+        # delete excess irrelevant issues (according milestones). Issue #22.
+        filtered_issues = filter_by_milestone(filtered_issues, newer_tag_name, @issues)
+        filtered_pull_requests = filter_by_milestone(filtered_pull_requests, newer_tag_name, @pull_requests)
+      end
+
+      if newer_tag.nil? && filtered_issues.empty? && filtered_pull_requests.empty?
+        # do not generate empty unreleased section
+        return ""
+      end
+
+      create_log(filtered_pull_requests, filtered_issues, newer_tag, older_tag_name)
+    end
+
+    # The full cycle of generation for whole project
+    # @return [String] The complete change log
+    def generate_log_for_all_tags
+      puts "Generating log..." if @options[:verbose]
+
+      log = generate_unreleased_section
+
+      (1...all_tags.size).each do |index|
+        log += generate_log_between_tags(all_tags[index], all_tags[index - 1])
+      end
+      if @all_tags.count != 0
+        log += generate_log_between_tags(nil, all_tags.last)
+      end
+
+      log
+    end
+
+    def generate_unreleased_section
+      log = ""
+      if @options[:unreleased] && @all_tags.count != 0
+        unreleased_log = generate_log_between_tags(all_tags[0], nil)
+        log += unreleased_log if unreleased_log
+      end
+      log
+    end
+
+    # Parse issue and generate single line formatted issue line.
+    #
+    # Example output:
+    # - Add coveralls integration [\#223](https://github.com/skywinder/github-changelog-generator/pull/223) ([skywinder](https://github.com/skywinder))
+    #
+    # @param [Hash] issue Fetched issue from GitHub
+    # @return [String] Markdown-formatted single issue
+    def get_string_for_issue(issue)
+      encapsulated_title = encapsulate_string issue[:title]
+
+      title_with_number = "#{encapsulated_title} [\\##{issue[:number]}](#{issue.html_url})"
+
+      unless issue.pull_request.nil?
+        if @options[:author]
+          if issue.user.nil?
+            title_with_number += " ({Null user})"
+          else
+            title_with_number += " ([#{issue.user.login}](#{issue.user.html_url}))"
+          end
+        end
+      end
+      title_with_number
+    end
+  end
+end
diff --git a/lib/github_changelog_generator/generator/generator_processor.rb b/lib/github_changelog_generator/generator/generator_processor.rb
new file mode 100644
index 0000000..cbbaa7f
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator_processor.rb
@@ -0,0 +1,174 @@
+module GitHubChangelogGenerator
+  class Generator
+    # delete all labels with labels from @options[:exclude_labels] array
+    # @param [Array] issues
+    # @return [Array] filtered array
+    def exclude_issues_by_labels(issues)
+      unless @options[:exclude_labels].nil?
+        issues = issues.select do |issue|
+          var = issue.labels.map(&:name) & @options[:exclude_labels]
+          !(var).any?
+        end
+      end
+      issues
+    end
+
+    def filter_by_milestone(filtered_issues, newer_tag_name, src_array)
+      filtered_issues.select! do |issue|
+        # leave issues without milestones
+        if issue.milestone.nil?
+          true
+        else
+          # check, that this milestone in tag list:
+          @all_tags.find { |tag| tag.name == issue.milestone.title }.nil?
+        end
+      end
+      unless newer_tag_name.nil?
+
+        # add missed issues (according milestones)
+        issues_to_add = src_array.select do |issue|
+          if issue.milestone.nil?
+            false
+          else
+            # check, that this milestone in tag list:
+            milestone_is_tag = @all_tags.find do |tag|
+              tag.name == issue.milestone.title
+            end
+
+            if milestone_is_tag.nil?
+              false
+            else
+              issue.milestone.title == newer_tag_name
+            end
+          end
+        end
+
+        filtered_issues |= issues_to_add
+      end
+      filtered_issues
+    end
+
+    # Method filter issues, that belong only specified tag range
+    # @param [Array] array of issues to filter
+    # @param [Symbol] hash_key key of date value default is :actual_date
+    # @param [String] older_tag all issues before this tag date will be excluded. May be nil, if it's first tag
+    # @param [String] newer_tag all issue after this tag will be excluded. May be nil for unreleased section
+    # @return [Array] filtered issues
+    def delete_by_time(array, hash_key = :actual_date, older_tag = nil, newer_tag = nil)
+      fail ChangelogGeneratorError, "At least one of the tags should be not nil!".red if older_tag.nil? && newer_tag.nil?
+
+      newer_tag_time = newer_tag && @fetcher.get_time_of_tag(newer_tag)
+      older_tag_time = older_tag && @fetcher.get_time_of_tag(older_tag)
+
+      array.select do |req|
+        if req[hash_key]
+          t = Time.parse(req[hash_key]).utc
+
+          if older_tag_time.nil?
+            tag_in_range_old = true
+          else
+            tag_in_range_old = t > older_tag_time
+          end
+
+          if newer_tag_time.nil?
+            tag_in_range_new = true
+          else
+            tag_in_range_new = t <= newer_tag_time
+          end
+
+          tag_in_range = (tag_in_range_old) && (tag_in_range_new)
+
+          tag_in_range
+        else
+          false
+        end
+      end
+    end
+
+    # Include issues with labels, specified in :include_labels
+    # @param [Array] issues to filter
+    # @return [Array] filtered array of issues
+    def include_issues_by_labels(issues)
+      filtered_issues = @options[:include_labels].nil? ? issues : issues.select do |issue|
+        labels = issue.labels.map(&:name) & @options[:include_labels]
+        (labels).any?
+      end
+
+      if @options[:add_issues_wo_labels]
+        issues_wo_labels = issues.select do |issue|
+          !issue.labels.map(&:name).any?
+        end
+        filtered_issues |= issues_wo_labels
+      end
+      filtered_issues
+    end
+
+    # Return tags after filtering tags in lists provided by option: --between-tags & --exclude-tags
+    #
+    # @return [Array]
+    def get_filtered_tags
+      all_tags = @fetcher.get_all_tags
+      filtered_tags = []
+      if @options[:between_tags]
+        @options[:between_tags].each do |tag|
+          unless all_tags.include? tag
+            puts "Warning: can't find tag #{tag}, specified with --between-tags option.".yellow
+          end
+        end
+        filtered_tags = all_tags.select { |tag| @options[:between_tags].include? tag }
+      end
+      filtered_tags
+    end
+
+    # General filtered function
+    #
+    # @param [Array] all_issues
+    # @return [Array] filtered issues
+    def filter_array_by_labels(all_issues)
+      filtered_issues = include_issues_by_labels(all_issues)
+      exclude_issues_by_labels(filtered_issues)
+    end
+
+    # Filter issues according labels
+    # @return [Array] Filtered issues
+    def get_filtered_issues(issues)
+      issues = filter_array_by_labels(issues)
+      puts "Filtered issues: #{issues.count}" if @options[:verbose]
+      issues
+    end
+
+    # This method fetches missing params for PR and filter them by specified options
+    # It include add all PR's with labels from @options[:include_labels] array
+    # And exclude all from :exclude_labels array.
+    # @return [Array] filtered PR's
+    def get_filtered_pull_requests(pull_requests)
+      pull_requests = filter_array_by_labels(pull_requests)
+      pull_requests = filter_merged_pull_requests(pull_requests)
+      puts "Filtered pull requests: #{pull_requests.count}" if @options[:verbose]
+      pull_requests
+    end
+
+    # This method filter only merged PR and
+    # fetch missing required attributes for pull requests
+    # :merged_at - is a date, when issue PR was merged.
+    # More correct to use merged date, rather than closed date.
+    def filter_merged_pull_requests(pull_requests)
+      print "Fetching merged dates...\r" if @options[:verbose]
+      closed_pull_requests = @fetcher.fetch_closed_pull_requests
+
+      pull_requests.each do |pr|
+        fetched_pr = closed_pull_requests.find do |fpr|
+          fpr.number == pr.number
+        end
+        pr[:merged_at] = fetched_pr[:merged_at]
+        closed_pull_requests.delete(fetched_pr)
+      end
+
+      pull_requests.select! do |pr|
+        !pr[:merged_at].nil?
+      end
+
+      pull_requests
+    end
+  end
+end
diff --git a/lib/github_changelog_generator/parser.rb b/lib/github_changelog_generator/parser.rb
index 891fb9f..6e87f7d 100644
--- a/lib/github_changelog_generator/parser.rb
+++ b/lib/github_changelog_generator/parser.rb
@@ -9,7 +9,7 @@ module GitHubChangelogGenerator
       options = {
         tag1: nil,
         tag2: nil,
-        dateformat: "%Y-%m-%d",
+        date_format: "%Y-%m-%d",
         output: "CHANGELOG.md",
         issues: true,
         add_issues_wo_labels: true,
@@ -30,7 +30,7 @@ module GitHubChangelogGenerator
         issue_prefix: "**Closed issues:**",
         bug_prefix: "**Fixed bugs:**",
         enhancement_prefix: "**Implemented enhancements:**",
-        branch: "origin"
+        git_remote: "origin"
       }
 
       parser = OptionParser.new do |opts|
@@ -45,7 +45,7 @@ module GitHubChangelogGenerator
           options[:token] = last
         end
         opts.on("-f", "--date-format [FORMAT]", "Date format. Default is %Y-%m-%d") do |last|
-          options[:dateformat] = last
+          options[:date_format] = last
         end
         opts.on("-o", "--output [NAME]", "Output file. Default is CHANGELOG.md") do |last|
           options[:output] = last
@@ -123,11 +123,6 @@ module GitHubChangelogGenerator
         exit
       end
 
-      if ARGV[1]
-        options[:tag1] = ARGV[0]
-        options[:tag2] = ARGV[1]
-      end
-
       if options[:verbose]
         puts "Performing task with options:"
         pp options
@@ -138,54 +133,83 @@ module GitHubChangelogGenerator
     end
 
     def self.detect_user_and_project(options)
-      if ARGV[0] && !ARGV[1]
-        github_site = options[:github_site] ? options[:github_site] : "github.com"
+      options[:user], options[:project] = user_project_from_option(ARGV[0], ARGV[1], options[:github_site])
+      if !options[:user] || !options[:project]
+        if ENV["RUBYLIB"] =~ /ruby-debug-ide/
+          options[:user] = "skywinder"
+          options[:project] = "changelog_test"
+        else
+          remote = `git config --get remote.#{options[:git_remote]}.url`
+          options[:user], options[:project] = user_project_from_remote(remote)
+        end
+      end
+    end
+
+    # Try to find user and project name from git remote output
+    #
+    # @param [String] output of git remote command
+    # @return [Array] user and project
+    def self.user_project_from_option(arg0, arg2, github_site = "github.com")
+      user = nil
+      project = nil
+
+      if arg0 && !arg2
         # this match should parse  strings such "https://github.com/skywinder/Github-Changelog-Generator" or "skywinder/Github-Changelog-Generator" to user and name
-        match = /(?:.+#{Regexp.escape(github_site)}\/)?(.+)\/(.+)/.match(ARGV[0])
+        match = /(?:.+#{Regexp.escape(github_site)}\/)?(.+)\/(.+)/.match(arg0)
 
         begin
           param = match[2].nil?
         rescue
-          puts "Can't detect user and name from first parameter: '#{ARGV[0]}' -> exit'"
+          puts "Can't detect user and name from first parameter: '#{arg0}' -> exit'"
           exit
         end
         if param
           exit
         else
-          options[:user] = match[1]
-          options[:project] = match[2]
-        end
-
-      end
-
-      if !options[:user] && !options[:project]
-        if ENV["RUBYLIB"] =~ /ruby-debug-ide/
-          options[:user] = "skywinder"
-          options[:project] = "changelog_test"
-        else
-          remote = `git config --get remote.#{options[:branch]}.url`
-          # try to find repo in format:
-          # origin	git@github.com:skywinder/Github-Changelog-Generator.git (fetch)
-          # git@github.com:skywinder/Github-Changelog-Generator.git
-          match = /.*(?:[:\/])((?:-|\w|\.)*)\/((?:-|\w|\.)*)(?:\.git).*/.match(remote)
-
-          if match && match[1] && match[2]
-            puts "Detected user:#{match[1]}, project:#{match[2]}"
-            options[:user] = match[1]
-            options[:project] = match[2]
-          else
-            # try to find repo in format:
-            # origin	https://github.com/skywinder/ChangelogMerger (fetch)
-            # https://github.com/skywinder/ChangelogMerger
-            match = /.*\/((?:-|\w|\.)*)\/((?:-|\w|\.)*).*/.match(remote)
-            if match && match[1] && match[2]
-              puts "Detected user:#{match[1]}, project:#{match[2]}"
-              options[:user] = match[1]
-              options[:project] = match[2]
-            end
-          end
+          user = match[1]
+          project = match[2]
         end
       end
+      [user, project]
+    end
+
+    # Try to find user and project name from git remote output
+    #
+    # @param [String] output of git remote command
+    # @return [Array] user and project
+    def self.user_project_from_remote(remote)
+      # try to find repo in format:
+      # origin	git@github.com:skywinder/Github-Changelog-Generator.git (fetch)
+      # git@github.com:skywinder/Github-Changelog-Generator.git
+      regex1 = /.*(?:[:\/])((?:-|\w|\.)*)\/((?:-|\w|\.)*)(?:\.git).*/
+
+      # try to find repo in format:
+      # origin	https://github.com/skywinder/ChangelogMerger (fetch)
+      # https://github.com/skywinder/ChangelogMerger
+      regex2 = /.*\/((?:-|\w|\.)*)\/((?:-|\w|\.)*).*/
+
+      remote_structures = [regex1, regex2]
+
+      user = nil
+      project = nil
+      remote_structures.each do |regex|
+        matches = Regexp.new(regex).match(remote)
+
+        if matches && matches[1] && matches[2]
+          puts "Detected user:#{matches[1]}, project:#{matches[2]}"
+          user = matches[1]
+          project = matches[2]
+        end
+
+        break unless matches.nil?
+      end
+
+      [user, project]
     end
   end
+
+  if __FILE__ == $PROGRAM_NAME
+    remote = "invalid reference to project"
+    p user_project_from_option(ARGV[0], ARGV[1], remote)
+  end
 end
diff --git a/spec/unit/parser_spec.rb b/spec/unit/parser_spec.rb
new file mode 100644
index 0000000..6f80a6e
--- /dev/null
+++ b/spec/unit/parser_spec.rb
@@ -0,0 +1,45 @@
+describe GitHubChangelogGenerator::Parser do
+  describe "#self.user_project_from_remote" do
+    context "when remote is 1" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_remote("origin  https://github.com/skywinder/ActionSheetPicker-3.0 (fetch)") }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array(["skywinder", "ActionSheetPicker-3.0"]) }
+    end
+    context "when remote is 2" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_remote("https://github.com/skywinder/ActionSheetPicker-3.0") }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array(["skywinder", "ActionSheetPicker-3.0"]) }
+    end
+    context "when remote is 3" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_remote("https://github.com/skywinder/ActionSheetPicker-3.0") }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array(["skywinder", "ActionSheetPicker-3.0"]) }
+    end
+    context "when remote is 4" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_remote("origin git@github.com:skywinder/ActionSheetPicker-3.0.git (fetch)") }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array(["skywinder", "ActionSheetPicker-3.0"]) }
+    end
+    context "when remote is invalid" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_remote("some invalid text") }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array([nil, nil]) }
+    end
+  end
+  describe "#self.user_project_from_option" do
+    # context "when option is invalid" do
+    #   it("should exit") { expect { GitHubChangelogGenerator::Parser.user_project_from_option("blah", nil) }.to raise_error(SystemExit) }
+    # end
+
+    context "when option is valid" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_option("skywinder/ActionSheetPicker-3.0", nil) }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array(["skywinder", "ActionSheetPicker-3.0"]) }
+    end
+    context "when option nil" do
+      subject { GitHubChangelogGenerator::Parser.user_project_from_option(nil, nil) }
+      it { is_expected.to be_a(Array) }
+      it { is_expected.to match_array([nil, nil]) }
+    end
+  end
+end