module Aigu
  class Exporter
    def initialize(output_file: nil, input_directory: nil, locale: nil)
      @output_file = output_file
      @input_directory = input_directory
      @locale = locale
    end

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

      build_output
      write_json_file

      puts '---'
      puts 'Done'
    end

  protected

    def build_output
      @output = {}

      Dir[File.join(@input_directory, '**', "*.#{@locale}.yml")].each do |file|
        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

    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
  end
end