Implement HTML report generation and update report formats

Closes #50

- Allow Skunk to HTML output the results it generates
- Added support for generating HTML reports alongside existing JSON format.
- Introduced new classes for HTML report generation, including Overview, OverviewData, and FileData.
- Updated the Reporter module to include HTML in the report generator formats.
- Created a template for the HTML report with a responsive design.
- Refactored JSON report generation to improve code organization and clarity.

Author: JuanVqz

.reek.yml

@@ -7,6 +7,7 @@ detectors:
   FeatureEnvy:
     exclude:
     - Skunk::Command::StatusReporter#table
+    - Skunk::Generator::HtmlReport#create_directories_and_files
   InstanceVariableAssumption:
     exclude:
     - Skunk::Cli::Options::Argv
@@ -22,6 +23,10 @@ detectors:
     - initialize
     - Skunk::Cli::Application#execute
     - Skunk::Cli::Options::Argv#parse
+  TooManyInstanceVariables:
+    exclude:
+    - Skunk::Generator::Html::FileData
+    - Skunk::Generator::Html::OverviewData
   UtilityFunction:
     exclude:
     - capture_output_streams

.rubocop_todo.yml

@@ -1,14 +1,13 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2025-05-02 20:16:50 UTC using RuboCop version 1.75.4.
+# on 2025-10-08 01:52:15 UTC using RuboCop version 1.81.1.
 # 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: 1
-# Configuration parameters: Severity, Include.
-# Include: **/*.gemspec
+# Configuration parameters: Severity.
 Gemspec/RequiredRubyVersion:
   Exclude:
     - 'skunk.gemspec'
@@ -36,11 +35,11 @@ Lint/MissingSuper:
 Metrics/AbcSize:
   Max: 18
 
-# Offense count: 7
+# Offense count: 9
 # Configuration parameters: CountComments, CountAsOne, AllowedMethods, AllowedPatterns.
 # AllowedMethods: refine
 Metrics/BlockLength:
-  Max: 76
+  Max: 131
 
 # Offense count: 2
 # Configuration parameters: CountComments, CountAsOne, AllowedMethods, AllowedPatterns.

lib/skunk/generators/html/file_data.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+module Skunk
+  module Generator
+    module Html
+      # Data object for individual file information in the HTML overview report
+      class FileData
+        attr_reader :file, :skunk_score, :churn_times_cost, :churn, :cost, :coverage
+
+        def initialize(module_data)
+          @file = PathTruncator.truncate(module_data.pathname)
+          @skunk_score = module_data.skunk_score
+          @churn_times_cost = module_data.churn_times_cost
+          @churn = module_data.churn
+          @cost = module_data.cost.round(2)
+          @coverage = module_data.coverage.round(2)
+        end
+      end
+    end
+  end
+end

lib/skunk/generators/html/overview.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require "rubycritic/generators/html/base"
+
+require "skunk/generators/html/path_truncator"
+require "skunk/generators/html/overview_data"
+
+module Skunk
+  module Generator
+    module Html
+      # Generates an HTML overview report for the analysed modules.
+      class Overview < RubyCritic::Generator::Html::Base
+        def self.erb_template(template_path)
+          ERB.new(File.read(File.join(TEMPLATES_DIR, template_path)))
+        end
+
+        TEMPLATES_DIR = File.expand_path("templates", __dir__)
+        TEMPLATE = erb_template("skunk_overview.html.erb")
+
+        def initialize(analysed_modules)
+          super
+          @analysed_modules = analysed_modules
+          @data = OverviewData.new(analysed_modules)
+        end
+
+        def file_name
+          "skunk_overview.html"
+        end
+
+        def render
+          data = @data
+          TEMPLATE.result(binding)
+        end
+      end
+    end
+  end
+end

lib/skunk/generators/html/overview_data.rb

@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+require "skunk/generators/html/file_data"
+require "skunk/generators/html/path_truncator"
+
+module Skunk
+  module Generator
+    module Html
+      # Data object for the HTML overview report
+      class OverviewData
+        attr_reader :generated_at, :skunk_version,
+                    :analysed_modules_count, :skunk_score_total, :skunk_score_average,
+                    :worst_pathname, :worst_score, :files
+
+        def initialize(analysed_modules)
+          @analysed_modules = analysed_modules
+          @generated_at = Time.now.strftime("%Y-%m-%d %H:%M:%S")
+          @skunk_version = Skunk::VERSION
+
+          @analysed_modules_count = non_test_modules.count
+          @skunk_score_total = non_test_modules.sum(&:skunk_score)
+          @skunk_score_average = calculate_average
+          @worst_pathname = PathTruncator.truncate(find_worst_module&.pathname)
+          @worst_score = find_worst_module&.skunk_score
+          @files = build_files
+        end
+
+        private
+
+        def non_test_modules
+          @non_test_modules ||= @analysed_modules.reject do |a_module|
+            module_path = a_module.pathname.dirname.to_s
+            module_path.start_with?("test", "spec") || module_path.end_with?("test", "spec")
+          end
+        end
+
+        def calculate_average
+          return 0 if @analysed_modules_count.zero?
+
+          (@skunk_score_total.to_f / @analysed_modules_count).round(2)
+        end
+
+        def find_worst_module
+          @find_worst_module ||= sorted_modules.first
+        end
+
+        def sorted_modules
+          @sorted_modules ||= non_test_modules.sort_by(&:skunk_score).reverse!
+        end
+
+        def build_files
+          @build_files ||= sorted_modules.map do |module_data|
+            FileData.new(module_data)
+          end
+        end
+      end
+    end
+  end
+end

lib/skunk/generators/html/path_truncator.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+module Skunk
+  module Generator
+    module Html
+      # Utility class for truncating file paths to show only the relevant project structure
+      class PathTruncator
+        attr_reader :file_path
+
+        # Common project folder names to truncate from
+        PROJECT_FOLDERS = %w[app lib src test spec features db].freeze
+
+        # Truncates a file path to show only the relevant project structure
+        # starting from the first project folder found
+        #
+        # @param file_path [String] The full file path to truncate
+        # @return [String] The truncated path starting from the project folder
+        # :reek:NilCheck
+        def self.truncate(file_path)
+          return file_path if file_path.nil?
+
+          new(file_path).truncate
+        end
+
+        def initialize(file_path)
+          @file_path = file_path.to_s
+        end
+
+        # :reek:TooManyStatements
+        def truncate
+          return file_path if file_path.empty?
+
+          path_parts = file_path.split("/")
+          folder_index = path_parts.find_index do |part|
+            PROJECT_FOLDERS.include?(part)
+          end
+
+          if folder_index
+            # rubocop:disable Style/SlicingWithRange
+            path_parts[folder_index..-1].join("/")
+            # rubocop:enable Style/SlicingWithRange
+          else
+            file_path
+          end
+        end
+      end
+    end
+  end
+end