class Message < ApplicationRecord
  belongs_to :user
  belongs_to :chat_channel

  validates :message_html, presence: true
  validates :message_markdown, presence: true, length: { maximum: 600 }

  before_validation :evaluate_markdown
  before_validation :evaluate_channel_permission
  after_create      :update_chat_channel_last_message_at

  def preferred_user_color
    color_options = [user.bg_color_hex || "#000000", user.text_color_hex || "#000000"]
    HexComparer.new(color_options).brightness(0.9)
  end

  private

  def update_chat_channel_last_message_at
    chat_channel.touch(:last_message_at)
  end

  def evaluate_markdown
    self.message_html = message_markdown
  end

  def evaluate_channel_permission
    channel = ChatChannel.find(chat_channel_id)
    return if channel.channel_type == "open"
    if channel.has_member?(user)
      # this is fine
    else
      errors.add(:base, "You are not a participant of this chat channel.")
    end
  end
end