require 'active_support/inflector'
require 'forwardable'
require_relative 'which'
require_relative 'directory_of_classes'

module Quality
  current_dir = File.dirname(File.expand_path(__FILE__))
  TOOL_CLASSES = DirectoryOfClasses.new(dir: "#{current_dir}/tools",
                                        module_name: 'Quality::Tools')
  ALL_TOOLS = TOOL_CLASSES.basenames_without_extension
  TOOL_CLASSES.require_classes

  # Knows how to run different quality tools based on a configuration
  # already determined.
  class Runner
    TOOL_CLASSES.symbols_and_classes.each { |_symbol, clazz| include clazz }

    extend ::Forwardable

    def initialize(config,
                   gem_spec: Gem::Specification,
                   quality_checker_class: Quality::QualityChecker,
                   count_io: IO,
                   count_file: File,
                   globber: Dir,
                   which: Which.new)
      @config = config
      @gem_spec = gem_spec
      @quality_checker_class = quality_checker_class
      @count_io = count_io
      @count_file = count_file
      @globber = globber
      @which = which
    end

    def run_quality
      tools.each { |tool| run_quality_with_tool(tool) }
    end

    def run_quality_with_tool(tool)
      suppressed = @config.skip_tools.include? tool
      installed = @gem_spec.find_all_by_name(tool).any? ||
                  !@which.which(tool).nil?

      if installed && !suppressed
        method("quality_#{tool}".to_sym).call
      elsif !installed
        puts "#{tool} not installed"
      end
    end

    def run_ratchet
      @config.all_output_files.each { |filename| run_ratchet_on_file(filename) }
    end

    def run_ratchet_on_file(filename)
      puts "Processing #{filename}"
      existing_violations = count_existing_violations(filename)
      new_violations = [0, existing_violations - 1].max
      write_violations(filename, new_violations)
    end

    def write_violations(filename, new_violations)
      @count_file.open(filename, 'w') do |file|
        file.write(new_violations.to_s + "\n")
      end
    end

    def count_existing_violations(filename)
      existing_violations = @count_io.read(filename).to_i
      raise("Problem with file #{filename}") if existing_violations < 0
      existing_violations
    end

    def tools
      self.class.ancestors.map do |ancestor|
        ancestor_name = ancestor.to_s
        next unless ancestor_name.start_with?('Quality::Tools::')
        ancestor_name.split('::').last.underscore
      end.compact
    end

    def ratchet_quality_cmd(cmd,
                            command_options,
                            &count_violations_on_line)
      quality_checker = @quality_checker_class.new(cmd,
                                                   command_options,
                                                   @config.output_dir,
                                                   @config.verbose)
      quality_checker.execute(&count_violations_on_line)
    end

    def_delegators :@config, :ruby_files, :ruby_files_glob,
                   :python_files, :python_files_glob,
                   :source_files_glob, :punchlist_regexp,
                   :source_files_exclude_glob, :exclude_files,
                   :source_and_doc_files_glob, :js_files_arr
  end
end