# frozen_string_literal: true

class DiscourseChatIntegration::Rule < DiscourseChatIntegration::PluginModel
  # Setup ActiveRecord::Store to use the JSON field to read/write these values
  store :value, accessors: %i[channel_id type group_id category_id tags filter], coder: JSON

  scope :with_type, ->(type) { where("value::json->>'type'=?", type.to_s) }
  scope :with_channel, ->(channel) { with_channel_id(channel.id) }
  scope :with_channel_id, ->(channel_id) { where("value::json->>'channel_id'=?", channel_id.to_s) }

  scope :with_category_id,
        ->(category_id) do
          if category_id.nil?
            where(
              "(value::json->'category_id') IS NULL OR json_typeof(value::json->'category_id')='null'",
            )
          else
            where("value::json->>'category_id'=?", category_id.to_s)
          end
        end

  scope :with_group_ids,
        ->(group_id) { where("value::json->>'group_id' IN (?)", group_id.map!(&:to_s)) }

  scope :order_by_precedence,
        -> do
          order(
            "
      CASE
      WHEN value::json->>'type' = 'group_mention' THEN 1
      WHEN value::json->>'type' = 'group_message' THEN 2
      ELSE 3
      END
    ",
            "
      CASE
      WHEN value::json->>'filter' = 'mute' THEN 1
      WHEN value::json->>'filter' = 'thread' THEN 2
      WHEN value::json->>'filter' = 'watch' THEN 3
      WHEN value::json->>'filter' = 'tag_added' THEN 4
      WHEN value::json->>'filter' = 'follow' THEN 5
     END
    ",
          )
        end

  after_initialize :init_filter

  validates :filter,
            inclusion: {
              in: %w[thread watch follow tag_added mute],
              message: "%{value} is not a valid filter",
            }

  validates :type,
            inclusion: {
              in: %w[normal group_message group_mention],
              message: "%{value} is not a valid filter",
            }

  validate :channel_valid?, :category_valid?, :group_valid?, :tags_valid?

  def self.key_prefix
    "rule:".freeze
  end

  # We never want an empty array, set it to nil instead
  def tags=(array)
    if array.nil? || array.empty?
      super(nil)
    else
      super(array)
    end
  end

  # These are only allowed to be integers
  %w[channel_id category_id group_id].each do |name|
    define_method "#{name}=" do |val|
      if val.nil? || val.blank?
        super(nil)
      else
        super(val.to_i)
      end
    end
  end

  # Mock foreign key
  # Could return nil
  def channel
    DiscourseChatIntegration::Channel.find_by(id: channel_id)
  end

  def channel=(val)
    self.channel_id = val.id
  end

  private

  def channel_valid?
    if !(DiscourseChatIntegration::Channel.where(id: channel_id).exists?)
      errors.add(:channel_id, "#{channel_id} is not a valid channel id")
    end
  end

  def category_valid?
    if type != "normal" && !category_id.nil?
      errors.add(:category_id, "cannot be specified for that type of rule")
    end

    return unless type == "normal"

    if !(category_id.nil? || Category.where(id: category_id).exists?)
      errors.add(:category_id, "#{category_id} is not a valid category id")
    end
  end

  def group_valid?
    if type == "normal" && !group_id.nil?
      errors.add(:group_id, "cannot be specified for that type of rule")
    end

    return if type == "normal"

    if !Group.where(id: group_id).exists?
      errors.add(:group_id, "#{group_id} is not a valid group id")
    end
  end

  def tags_valid?
    return if tags.nil?

    tags.each do |tag|
      errors.add(:tags, "#{tag} is not a valid tag") if !Tag.where(name: tag).exists?
    end
  end

  def init_filter
    self.filter ||= "watch"
    self.type ||= "normal"
  end
end