class Message < ApplicationRecord
  belongs_to :user
  belongs_to :chat_channel

  validates :message_html, presence: true
  validates :message_markdown, presence: true, length: { maximum: 1024 }
  validate :channel_permission

  before_save       :determine_user_validity
  before_validation :evaluate_markdown
  after_create      :send_email_if_appropriate
  after_create      :update_chat_channel_last_message_at
  after_create      :update_all_has_unopened_messages_statuses

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

  def determine_user_validity
    raise unless chat_channel.status == "active" && (chat_channel.has_member?(user) || chat_channel.channel_type == "open")
  end

  def send_push
    reciever_ids = chat_channel.chat_channel_memberships.
      where.not(user_id: user.id).pluck(:user_id)
    PushNotificationSubscription.where(user_id: reciever_ids).each do |sub|
      return if no_push_necessary?(sub)

      Webpush.payload_send(
        endpoint: sub.endpoint,
        message: ActionView::Base.full_sanitizer.sanitize(message_html),
        p256dh: sub.p256dh_key,
        auth: sub.auth_key,
        ttl: 24 * 60 * 60,
        vapid: {
          subject: "https://dev.to",
          public_key: ApplicationConfig["VAPID_PUBLIC_KEY"],
          private_key: ApplicationConfig["VAPID_PRIVATE_KEY"]
        },
      )
    end
  end

  def direct_receiver
    return if chat_channel.channel_type != "direct"

    chat_channel.users.where.not(id: user.id).first
  end

  private

  def update_chat_channel_last_message_at
    chat_channel.touch(:last_message_at)
    chat_channel.index!
    chat_channel.delay.index!
  end

  def update_all_has_unopened_messages_statuses
    chat_channel.
      chat_channel_memberships.
      where("last_opened_at < ?", 10.seconds.ago).
      where.
      not(user_id: user_id).
      update_all(has_unopened_messages: true)
  end

  def evaluate_markdown
    html = MarkdownParser.new(message_markdown).evaluate_markdown
    html = append_rich_links(html)
    self.message_html = html
  end

  def append_rich_links(html)
    doc = Nokogiri::HTML(html)
    rich_style = "border: 1px solid #0a0a0a; border-radius: 3px; padding: 8px;"
    doc.css("a").each do |a|
      if article = rich_link_article(a)
        html = html + "<a style='color: #0a0a0a' href='#{article.path}'
          target='_blank' data-content='articles/#{article.id}'>
          <h1 style='#{rich_style}'  data-content='articles/#{article.id}'>
          #{article.title}</h1></a>".html_safe
      end
    end
    html
  end

  def channel_permission
    if chat_channel_id.blank?
      errors.add(:base, "Must be part of channel.")
    end

    channel = ChatChannel.find(chat_channel_id)
    return if channel.open?

    unless channel.has_member?(user)
      errors.add(:base, "You are not a participant of this chat channel.")
    end
  end

  def no_push_necessary?(sub)
    membership = sub.user.chat_channel_memberships.order("last_opened_at DESC").first
    membership.last_opened_at > 40.seconds.ago
  end

  def rich_link_article(link)
    if link["href"].include?("//#{ApplicationConfig['APP_DOMAIN']}/") && link["href"].split("/")[4]
      Article.find_by_slug(link["href"].split("/")[4].split("?")[0])
    end
  end

  def send_email_if_appropriate
    recipient = direct_receiver
    return if !chat_channel.direct? ||
      recipient.updated_at > 2.hours.ago ||
      recipient.chat_channel_memberships.order("last_opened_at DESC").
        first.last_opened_at > 18.hours.ago ||
      chat_channel.last_message_at > 45.minutes.ago ||
      recipient.email_connect_messages == false

    NotifyMailer.new_message_email(self).deliver
  end
end