require_relative 'context_builder'
require_relative 'source/source_code'
require_relative 'cli/warning_collector'
require_relative 'smells/smell_repository'

module Reek
  #
  # Applies all available smell detectors to a source.
  #
  # @public
  #
  # :reek:TooManyInstanceVariables: { max_instance_variables: 6 }
  class Examiner
    private_attr_reader :collector, :source, :smell_repository
    #
    # Creates an Examiner which scans the given +source+ for code smells.
    #
    # @param source [File, IO, String]
    #   If +source+ is a String it is assumed to be Ruby source code;
    #   if it is a File or IO, it is opened and Ruby source code is read from it;
    #
    # @param filter_by_smells [Array<String>]
    #   List of smell types to filter by, e.g. "DuplicateMethodCall".
    #
    # @param configuration [Configuration::AppConfiguration]
    #   The configuration for this Examiner.
    #
    # @public
    def initialize(source,
                   filter_by_smells = [],
                   configuration: Configuration::AppConfiguration.default)
      @source           = Source::SourceCode.from(source)
      @collector        = CLI::WarningCollector.new
      @smell_types      = Smells::SmellRepository.eligible_smell_types(filter_by_smells)
      @smell_repository = Smells::SmellRepository.new(smell_types: @smell_types,
                                                      configuration: configuration.directive_for(description))
      run
    end

    # FIXME: Should be named "origin"
    #
    # @return [String] description of the source being analysed
    #
    # @public
    def description
      @description ||= source.origin
    end

    #
    # @return [Array<SmellWarning>] the smells found in the source
    #
    # @public
    def smells
      @smells ||= collector.warnings
    end

    #
    # @return [Integer] the number of smells found in the source
    #
    # @public
    def smells_count
      smells.length
    end

    #
    # @return [Boolean] true if and only if there are code smells in the source.
    #
    # @public
    def smelly?
      !smells.empty?
    end

    private

    def run
      syntax_tree = source.syntax_tree
      return unless syntax_tree
      ContextBuilder.new(syntax_tree).context_tree.each do |element|
        smell_repository.examine(element)
      end

      smell_repository.report_on(collector)
    end
  end
end