discourse-chat-integration/lib/discourse_chat/rule.rb

  # Similar to an ActiveRecord class, but uses PluginStore for storage instead. Adapted from discourse-data-explorer
  # Using this means we can use a standard serializer for sending JSON to the client, and also have convenient save/update/delete methods
  # Since this is now being used in two plugins, maybe it should be built into core somehow
  class DiscourseChat::Rule
    attr_accessor :id, :provider, :channel, :category_id, :tags, :filter, :error_key

    def initialize(h={})
      @provider = ''
      @channel = ''
      @category_id = nil
      @tags = nil
      @filter = 'watch'
      @error_key = nil
      h.each {|k,v| public_send("#{k}=",v)}
    end

    def tags=(array)
      if array.nil? or array.empty?
        @tags = nil
      else
        @tags = array
      end
    end

    def category_id=(val)
      if val.nil? or val.blank?
        @category_id = nil
      else
        @category_id = val.to_i
      end
    end

    # saving/loading functions
    def self.alloc_id
      DistributedMutex.synchronize('discourse-chat_rule-id') do
        max_id = DiscourseChat.pstore_get("rule:_id")
        max_id = 1 unless max_id
        DiscourseChat.pstore_set("rule:_id", max_id + 1)
        max_id
      end
    end

    def self.from_hash(h)
      rule = DiscourseChat::Rule.new
      [:provider, :channel, :category_id, :tags, :filter, :error_key].each do |sym|
        rule.send("#{sym}=", h[sym]) if h[sym]
      end
      if h[:id]
        rule.id = h[:id].to_i
      end
      rule
    end

    def to_hash
      {
        id: @id,
        provider: @provider,
        channel: @channel,
        category_id: @category_id,
        tags: @tags,
        filter: @filter,
        error_key: @error_key,
      }
    end

    def self.find(id, opts={})
      hash = DiscourseChat.pstore_get("rule:#{id}")
      unless hash
        return DiscourseChat::Rule.new if opts[:ignore_deleted]
        raise Discourse::NotFound
      end
      from_hash hash
    end

    def update(h, validate=true)
      [:provider, :channel, :category_id, :tags, :filter, :error_key].each do |sym|
        public_send("#{sym}=", h[sym]) if h.key?(sym)
      end

      save(validate)
    end

    def save(validate=true)
      if validate
        return false if not valid?
      end

      unless @id && @id > 0
        @id = self.class.alloc_id
      end
      DiscourseChat.pstore_set "rule:#{id}", to_hash
      return self
    end

    def save!(validate=true)
      if not save(validate)
        raise 'Rule not valid'
      end
      return self
    end

    def valid?
      
      # Validate provider
      return false if not ::DiscourseChat::Provider.providers.map {|x| x::PROVIDER_NAME}.include? @provider
      
      # Validate channel
      return false if @channel.blank?

      provider = ::DiscourseChat::Provider.get_by_name(@provider)
      if defined? provider::PROVIDER_CHANNEL_REGEX
        channel_regex = Regexp.new provider::PROVIDER_CHANNEL_REGEX
        return false if not channel_regex.match?(@channel)
      end
      
      # Validate category
      return false if not (@category_id.nil? or Category.where(id: @category_id).exists?)

      # Validate tags
      if not @tags.nil?
        @tags.each do |tag|
          return false if not Tag.where(name: tag).exists?
        end
      end

      # Validate filter
      return false if not ['watch','follow','mute'].include? @filter

      return true
    end

    def destroy
      DiscourseChat.pstore_delete "rule:#{id}"
    end

    def read_attribute_for_serialization(attr)
      self.send(attr)
    end

    def self.all_for_provider(provider)
      self.where("value::json->>'provider'=?", provider)
    end

    def self.all_for_channel(provider, channel)
      self.where("value::json->>'provider'=? AND value::json->>'channel'=?", provider, channel)
    end

    def self.all_for_category(category_id)
      if category_id.nil?
        self.where("json_typeof(value::json->'category_id')='null'")
      else
        self.where("value::json->>'category_id'=?", category_id.to_s)
      end
    end

    # Use JSON selectors like this:
    #    Rule.where("value::json->>'provider'=?", "slack")
    def self.where(*args)
      rows = self._all_raw.where(*args)
      self._from_psr_rows(rows)
    end

    def self.all
      self._from_psr_rows(self._all_raw)
    end

    def self._all_raw
      PluginStoreRow.where(plugin_name: DiscourseChat.plugin_name)
        .where("key LIKE 'rule:%'")
        .where("key != 'rule:_id'")
    end

    def self._from_psr_rows(raw)
      rules = raw.map do |psr|
        from_hash PluginStore.cast_value(psr.type_name, psr.value)
      end

      filter_order = ["mute", "watch", "follow"]
      rules = rules.sort_by{ |r| [r.channel, r.category_id.nil? ? 0 : r.category_id, filter_order.index(r.filter)] } 
      return rules
    end

    def self.destroy_all
      self._all_raw().destroy_all
    end
  end