module Puppet::Util
  # This class can work with a list of subsettings inside
  # an ini file setting string to add, remove, extract and set their values.
  class SettingValue
    # The constructor method
    # @param setting_value [String] The initial setting value
    # @param subsetting_separator [String] The character is used to separate
    # subsettings in the setting_value string.
    # @param default_quote_char [String] Quote the setting string with this character.
    def initialize(setting_value, subsetting_separator = ' ', default_quote_char = '', key_val_separator = '')
      @setting_value = setting_value
      @subsetting_separator = subsetting_separator
      @quote_char = default_quote_char
      @key_val_separator = key_val_separator
      @subsetting_items = []

      return unless @setting_value
      unquoted, quote_char = unquote_setting_value(setting_value)
      @quote_char = quote_char unless quote_char.empty?
      # an item can contain escaped separator
      @subsetting_items = unquoted.scan(Regexp.new("(?:(?:[^\\#{@subsetting_separator}]|\\.)+)"))
      @subsetting_items.map! { |item| item.strip }
    end

    # If the setting value is quoted, the quotes are
    # removed and the unquoted string and the quoting
    # character are returned.
    # @param setting_value [String] The input value
    # @return [Array] The unquoted string and the quoting character
    def unquote_setting_value(setting_value)
      quote_char = ''
      if setting_value.start_with?('"') && setting_value.end_with?('"')
        quote_char = '"'
      elsif setting_value.start_with?("'") && setting_value.end_with?("'")
        quote_char = "'"
      end

      unquoted = if quote_char != ''
                   setting_value[1, setting_value.length - 2]
                 else
                   setting_value
                 end

      [unquoted, quote_char]
    end

    # Get the resulting setting value by joining all the
    # subsettings, separator and quote characters.
    # @return [String]
    def get_value # rubocop:disable Style/AccessorMethodName : Unable to alter without breaking code
      value = @subsetting_items.join @subsetting_separator
      @quote_char + value + @quote_char
    end

    # Get the value of the given subsetting item.
    # If the exact match is used the value will be true
    # if the item is found.
    # @param subsetting [String] The name of the subsetting to add.
    # @param use_exact_match [:true,:false] Should the full name match be used?
    # @return [nil,true,String]
    def get_subsetting_value(subsetting, use_exact_match = :false)
      index = find_subsetting(subsetting, use_exact_match)
      # the item is not found in the list
      return nil unless index
      # the exact match is set and the item is found, the value should be true
      return true if use_exact_match == :true
      item = @subsetting_items[index]
      item[(subsetting.length + @key_val_separator.length)..-1]
    end

    # Add a new subsetting item to the list of existing items
    # if such item is not already there.
    # @param subsetting [String] The name of the subsetting to add.
    # @param subsetting_value [String] The value of the subsetting.
    # It will be appended to the name.
    # @param use_exact_match [:true,:false] Should the full name match be used?
    # @param [Symbol] insert_type
    # @param [String,Integer] insert_value
    # @return [Array] The resulting subsettings list.
    def add_subsetting(subsetting, subsetting_value, use_exact_match = :false, insert_type = :end, insert_value = nil)
      index = find_subsetting(subsetting, use_exact_match)

      # update the existing values if the subsetting is found in the list
      return update_subsetting(subsetting, subsetting_value, use_exact_match) if index

      new_item = item_value(subsetting, subsetting_value)

      case insert_type
      when :start
        @subsetting_items.unshift(new_item)
      when :end
        @subsetting_items.push(new_item)
      when :before
        before_index = find_subsetting(insert_value, use_exact_match)
        if before_index
          @subsetting_items.insert(before_index, new_item)
        else
          @subsetting_items.push(new_item)
        end
      when :after
        after_index = find_subsetting(insert_value, use_exact_match)
        if after_index
          @subsetting_items.insert(after_index + 1, new_item)
        else
          @subsetting_items.push(new_item)
        end
      when :index
        before_index = insert_value.to_i
        before_index = @subsetting_items.length if before_index > @subsetting_items.length
        @subsetting_items.insert(before_index, new_item)
      else
        @subsetting_items.push(new_item)
      end

      @subsetting_items
    end

    # Update all matching items in the settings list to the new values.
    # @param subsetting [String] The name of the subsetting to add.
    # @param subsetting_value [String] The value of the subsetting.
    # @param use_exact_match [:true,:false] Should the full name match be used?
    # @return [Array] The resulting subsettings list.
    def update_subsetting(subsetting, subsetting_value, use_exact_match = :false)
      new_item = item_value(subsetting, subsetting_value)
      @subsetting_items.map! do |item|
        if match_subsetting?(item, subsetting, use_exact_match)
          new_item
        else
          item
        end
      end
    end

    # Find the first subsetting item matching the given name,
    # or, if the exact match is set, equal to the given name
    # and return its array index value. Returns nil if not found.
    # @param subsetting [String] The name of the subsetting to search.
    # @param use_exact_match [:true,:false] Look for the full string match?
    # @return [Integer, nil]
    def find_subsetting(subsetting, use_exact_match = :false)
      @subsetting_items.index do |item|
        match_subsetting?(item, subsetting, use_exact_match)
      end
    end

    # Check if the subsetting item matches the given name.
    # If the exact match is set the entire item is matched,
    # and only the item name and separator string if not.
    # @param item [String] The item value to check against the subsetting name.
    # @param subsetting [String] The subsetting name.
    # @param use_exact_match [:true,:false] Look for the full string match?
    # @return [true,false]
    def match_subsetting?(item, subsetting, use_exact_match = :false)
      if use_exact_match == :true
        item.eql?(subsetting)
      else
        item.start_with?(subsetting + @key_val_separator)
      end
    end

    # Remove all the subsetting items that match
    # the given subsetting name.
    # @param subsetting [String] The subsetting name to remove.
    # @param use_exact_match [:true,:false] Look for the full string match?
    # @return [Array] The resulting subsettings list.
    def remove_subsetting(subsetting, use_exact_match = :false)
      @subsetting_items.delete_if do |item|
        match_subsetting?(item, subsetting, use_exact_match)
      end
    end

    # The actual value of the subsetting item.
    # It's built from the subsetting name, its value and the separator
    # string if present.
    # @param subsetting [String] The subsetting name
    # @param subsetting_value [String] The value of the subsetting
    # @return [String]
    def item_value(subsetting, subsetting_value)
      (subsetting || '') + (@key_val_separator || '') + (subsetting_value || '')
    end
  end
end