Removes intermediate alert queues - only leaves recipient queues

Implements #4366

scripts/lua/modules/pools/pools_alert_utils.lua

@@ -8,11 +8,13 @@ package.path = dirs.installdir .. "/scripts/lua/modules/pools/?.lua;" .. package
 
 local alert_consts = require "alert_consts"
 local pools = require "pools"
+local notification_recipients = require "notification_recipients"
 
 -- ################################################################################
 
 local pools_alert_utils = {}
 local alert_entity_pool_instances = {}
+local alert_entity_all_pools = {}
 
 -- ################################################################################
 
@@ -66,4 +68,45 @@ end
 
 -- ################################################################################
 
+-- @brief Returns an array of recipient ids responsible for a given an `entity_id` and a `pool_id`
+-- @param entity_id One of alert_consts.alert_entities
+-- @param pool_id The pool id of an existing entity pool
+-- @return An array of recipient ids
+function pools_alert_utils.get_entity_recipients_by_pool_id(entity_id, pool_id)
+   local res = {}
+
+   local entity = alert_consts.alertEntityById(entity_id)
+   -- Obtain the pools instance for the given entity
+   local pools_instance = pools_alert_utils.get_entity_pools_by_id(entity_id)
+
+   if pools_instance then
+      -- tprint("found pool instance for "..entity.label)
+      -- See if the pools for the current instance are in cache
+      if not alert_entity_all_pools[entity_id] then
+	 -- List of pools not yet cached, let's create it
+	 alert_entity_all_pools[entity_id] = {}
+	 local all_pools = pools_instance:get_all_pools()
+
+	 -- It's handy to have the cache as a lua table with pool ids as keys and pool details as values
+	 for _, pool in pairs(all_pools) do
+	    alert_entity_all_pools[entity_id][pool.pool_id] = pool
+	 end
+      end
+
+      -- Access the cache
+      local entity_pool = alert_entity_all_pools[entity_id][pool_id]
+      if entity_pool and entity_pool["recipients"] then
+	 for _, recipient in pairs(entity_pool["recipients"]) do
+	    -- Prepare the result with all the recipients
+	    res[#res + 1] = recipient
+	    -- tprint(string.format("Adding recipient [%s][%s][%i]", recipient, entity.label, pool_id))
+	 end
+      end
+   end
+
+   return res
+end
+
+-- ################################################################################
+
 return pools_alert_utils