diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 3986315..3a25a49 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,5 +1,5 @@
 # This configuration was generated by `rubocop --auto-gen-config`
-# on 2015-05-22 14:05:01 +0300 using RuboCop version 0.31.0.
+# on 2015-05-22 15:54:38 +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
@@ -16,7 +16,7 @@ Metrics/BlockNesting:
 # Offense count: 3
 # Configuration parameters: CountComments.
 Metrics/ClassLength:
-  Max: 321
+  Max: 294
 
 # Offense count: 5
 Metrics/CyclomaticComplexity:
@@ -47,16 +47,11 @@ Style/AndOr:
 Style/BlockDelimiters:
   Enabled: false
 
-# Offense count: 4
+# Offense count: 6
 Style/Documentation:
   Enabled: false
 
-# Offense count: 2
-# Cop supports --auto-correct.
-Style/EmptyLines:
-  Enabled: false
-
-# Offense count: 1
+# Offense count: 4
 # Cop supports --auto-correct.
 # Configuration parameters: EnforcedStyle, SupportedStyles.
 Style/EmptyLinesAroundClassBody:
diff --git a/lib/github_changelog_generator.rb b/lib/github_changelog_generator.rb
index 06d89bc..a4fed13 100755
--- a/lib/github_changelog_generator.rb
+++ b/lib/github_changelog_generator.rb
@@ -6,44 +6,21 @@ 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"
 
 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
 
-
     # 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 run
@@ -55,422 +32,6 @@ module GitHubChangelogGenerator
       puts "Generated log placed in #{Dir.pwd}/#{output_filename}"
     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
-
-
-    # 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 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
-
-    # 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|
-          var = issue.labels.map(&:name) & @options[:exclude_labels]
-          !(var).any?
-        }
-      end
-      issues
-    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
-
-    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:
-        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 { |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
-      }
-      [bugs_a, enhancement_a, issues_a]
-    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
diff --git a/lib/github_changelog_generator/generator.rb b/lib/github_changelog_generator/generator.rb
deleted file mode 100644
index c7bf5a6..0000000
--- a/lib/github_changelog_generator/generator.rb
+++ /dev/null
@@ -1,125 +0,0 @@
-module GitHubChangelogGenerator
-  class Generator
-    # 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
-    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
-
-    # 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
-
-    # 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] 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)*"
-      @log = log
-      @log = log
-    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
-
-
-  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..30c91e5
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator.rb
@@ -0,0 +1,442 @@
+require "github_changelog_generator/fetcher"
+require_relative "generator_processor"
+require_relative "generator_fetcher"
+
+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
+      # @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
+
+    # 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
+
+    # 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
+
+    # 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] 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)*"
+      @log = log
+      @log = 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
+
+    # 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 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
+
+    # 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|
+          var = issue.labels.map(&:name) & @options[:exclude_labels]
+          !(var).any?
+        }
+      end
+      issues
+    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:
+        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 { |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
+      }
+      [bugs_a, enhancement_a, issues_a]
+    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
+
+  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..45ec1a2
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator_fetcher.rb
@@ -0,0 +1,14 @@
+module GitHubChangelogGenerator
+  class Generator
+    # 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
+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..9ff3ea3
--- /dev/null
+++ b/lib/github_changelog_generator/generator/generator_processor.rb
@@ -0,0 +1,110 @@
+module GitHubChangelogGenerator
+  class Generator
+    # @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 = 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
+
+    # 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
+      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
+
+  end
+end