# frozen_string_literal: true

module TanukiEmoji
  # Character represents an Emoji character or sequence which can be formed by one or more Unicode code points
  # respectively which combined form a unique pictographic representation (known as Emoji)
  #
  # @see https://www.unicode.org/reports/tr51/
  class Character
    attr_reader :name, :codepoints, :codepoints_alternates, :alpha_code, :aliases, :description

    # @param [String] name
    # @param [String] codepoints
    # @param [String] alpha_code
    def initialize(name, codepoints:, alpha_code:, description:)
      @name = name
      @codepoints = codepoints
      @codepoints_alternates = []
      @alpha_code = self.class.format_alpha_code(alpha_code)
      @aliases = []
      @description = description
    end

    # Add alternative codepoints to this character
    #
    # @param [String] codepoints
    def add_codepoints(codepoints)
      codepoints_alternates << codepoints
    end

    # Add alternative alpha_codes to this character
    #
    # @param [String] alpha_code
    def add_alias(alpha_code)
      aliases << self.class.format_alpha_code(alpha_code)
    end

    # Return a Hex formatted version of the Unicode code points
    #
    # @return [String] Hex formatted version of the unicode
    def hex
      unicode_to_hex(codepoints).join('-')
    end

    def to_s
      codepoints
    end

    def inspect
      "#<#{self.class.name}:#{name} #{codepoints}(#{hex})>"
    end

    # Convert Unicode code points to Hex format for inspection
    #
    # ensure alpha code is formatted with colons
    #
    # @param [String] alpha_code
    # @return [String] formatted alpha code
    def self.format_alpha_code(alpha_code)
      alpha_code.match?(/:([a-z_0-9]+):/) ? alpha_code : ":#{alpha_code}:"
    end

    private

    # Return each codepoint converted to its hex value as string
    #
    # @param [String] value
    # @return [Array<String>] hex value as string
    def unicode_to_hex(value)
      value.unpack('U*').map { |i| i.to_s(16).rjust(4, '0') }
    end
  end
end