# Represents a celestial body in the game that can be owned by a player.
# It tracks its position and can hold various buildings.

require 'securerandom'

# A planet object in the game that can be owned by a player and contains buildings.
#
# @example
#   planet = Planet.new(100, 100, 100)
#
class Planet
  # The owner of the planet, if any.
  attr_reader :owner

  # The unique identifier for the planet.
  attr_reader :planet_id

  # Creates a new planet with random position in the game space.
  #
  # @param width [Integer] The width of the game space.
  # @param height [Integer] The height of the game space.
  # @param depth [Integer] The depth of the game space.
  # @return [Planet] The new planet instance.
  #
  def initialize(width, height, depth)
    @owner = nil
    @buildings = []
    @position = [rand(width), rand(height), rand(depth)]
    @planet_id = SecureRandom.hex
  end

  # Determines if the planet can be claimed by a player.
  # A planet is claimable if it has no owner or no buildings.
  #
  # @return [Boolean] true if the planet can be claimed, false otherwise.
  #
  def claimable?
    if @owner.nil?
      return true
    elsif @buildings == []
      return true
    end
    return false
  end

  # Claims the planet and sets the player as the owner.
  #
  # @param player [Player] The player claiming the planet.
  #
  def claim(player)
    @owner = player
  end

  # Called to update the planet during the game tick.
  #
  # @param delta_time [Float] The time elapsed since the last update.
  #
  def update(delta_time)
  end

  # Returns information about the planet to be sent to the client.
  #
  # @return [Hash] A hash containing the planet's ID and position.
  #
  def info_update
    {
      'id' => @planet_id,
      'position' => @position
    }
  end

  # Saves the planet to a file for persistence.
  #
  # @return [String] The planet ID that was saved.
  #
  def save_to_file
    File.open("game_data/#{self.planet_id}_planet_.save", 'wb') do |fi|
      fi.write(Marshal.dump(self))
    end
    self.planet_id
  end

  # Loads a planet from a save file.
  #
  # @param fname [String] The filename of the save file.
  # @return [Planet] The loaded planet instance.
  #
  def self.load_from_save(fname)
    File.open("game_data/#{fname}_planet_.save", 'rb') do |fi|
      Marshal.load(fi.read)
    end
  end
end