module Aigu
  class Importer
    ARRAY_REGEX = /___KEY___(?<index>\d+)$/

    def initialize(input_file: nil, output_directory: nil, locale: nil)
      @input_file = input_file
      @output_directory = output_directory
      @locale = locale
    end

    def process!
      puts "Generating YAML files in `#{@output_directory}` based on Accent-generated `#{@input_file}` file"
      puts '---'

      parse_json
      build_blob
      write_yaml_files

      puts '---'
      puts 'Done'
    end

  protected

    def parse_json
      json = File.read(@input_file)
      @object = JSON.parse(json)
      @object = expand_content_values(@object)
      @object = localize_content_keys(@object)
    end

    def write_yaml_files
      @blob.each_pair do |file_name, hash|
        file_path = File.join(@output_directory, "#{file_name}.yml")
        puts "Generating #{file_path}"
        FileUtils.mkdir_p(File.dirname(file_path))

        File.open(file_path, 'w+') do |file|
          file << hash.to_yaml(line_width: 100_000_000)
        end
      end
    end

    def build_blob
      @blob = Hash.recursive

      @object.each_pair do |key, value|
        filename, flat_key = key.split('|')

        parts = flat_key.split('.')
        hash = @blob[filename]

        parts.each_with_index do |part, index|
          if index + 1 < parts.length
            hash = hash[part]
          else
            hash[part] = value
          end
        end
      end
    end

    def localize_content_keys(content)
      content.reduce({}) do |memo, (key, value)|
        localized_key = key.gsub(/^([^|]+)\|/, "\\1.#{@locale}|#{@locale}.")
        memo.merge localized_key => value
      end
    end

    def expand_content_values(content)
      content.reduce({}) do |memo, (key, value)|
        match_data = key.match(ARRAY_REGEX)

        if match_data
          canonical_key = key.gsub(ARRAY_REGEX, '')
          value_index = match_data[:index].to_i
          memo[canonical_key] ||= []
          memo[canonical_key][value_index] = sanitize_string_to_value(value)
        else
          memo[key] = sanitize_string_to_value(value)
        end

        memo
      end
    end

    def sanitize_string_to_value(string)
      case string
        when '___TRUE___'
          true
        when '___FALSE___'
          false
        when '___NULL___'
          nil
        else
          string
      end
    end
  end
end