module Aigu
  class Exporter
    def initialize(opts = {})
      @output_file = opts[:'output-file']
      @input_directory = opts[:'input-directory']
      @locale = opts[:locale]
      @ignore = opts[:ignore]
    end

    def process!
      puts "Generating Accent JSON file `#{@output_file}` based on YAML localization files in `#{@input_directory}` directory"

      if @ignore
        print 'Ignoring '
        puts @ignore.join(', ')
      end

      puts '---'

      build_output
      write_json_file

      puts '---'
      puts 'Done'
    end

  protected

    def build_output
      @output = {}

      pattern = File.join(@input_directory, '**', "*.#{@locale}.yml")
      Dir[pattern].each do |file|
        filepath = file.gsub(/\A#{@input_directory}\//, '')

        if ignored_filepath?(filepath)
          puts "Ignoring #{filepath}"
        else
          puts "Processing #{filepath}"
          content = YAML.load_file(file)
          base_key = file.gsub(@input_directory, '').gsub(/^\/*/, '').gsub(/\.yml$/, '|')

          content = flattenize_hash(content, base_key)
          content = flattenize_content_values(content)
          content = globalize_content_keys(content)
          @output.merge! content
        end
      end
    end

    def write_json_file
      file_path = @output_file
      puts "Generating #{file_path}"
      FileUtils.mkdir_p(File.dirname(file_path))

      File.open(file_path, 'w+') do |file|
        file << @output.to_json
      end
    end

    def globalize_content_keys(content)
      content.reduce({}) do |memo, (key, value)|
        globalized_key = key.gsub(/\.#{@locale}\|#{@locale}\./, '|')
        memo.merge globalized_key => value
      end
    end

    def flattenize_content_values(hash)
      result = {}

      hash.reduce({}) do |memo, (key, value)|
        if value.is_a?(Array)
          value.each_with_index do |array_value, index|
            tainted_key = "#{key}___KEY___#{index}"
            memo[tainted_key] = sanitize_value_to_string(array_value)
          end
        else
          memo[key] = sanitize_value_to_string(value)
        end

        memo
      end
    end

    def sanitize_value_to_string(value)
      case value
        when true
          '___TRUE___'
        when false
          '___FALSE___'
        when nil
          '___NULL___'
        else
          value
      end
    end

    def flattenize_hash(hash, base_key = '')
      if hash.is_a?(Hash)
        hash.reduce({}) do |memo, (key, value)|
          new_base_key = [base_key, key].join('.').gsub(/\|\.+/, '|')
          memo.merge! flattenize_hash(value, new_base_key)
        end
      else
        { base_key => hash }
      end
    end

    def ignored_filepath?(filepath)
      @ignore && @ignore.any? do |pattern|
        File.fnmatch(pattern, filepath, File::FNM_PATHNAME | File::FNM_DOTMATCH)
      end
    end
  end
end