===== Functions to work with alerts =====

==== GetCurrentAlerts() ====

The **GetCurrentAlerts** function returns a list of current alerts. Type of returned value is table. Its key is the alarm number, the value is the another table with the alert properties. 

Alert properties are:

^Key ^Description	                                                      ^Data type^                                          
|alertId|Alert id key in the project |Number |
|title	|Alert name	|String |
|startTime	|Alert trigger time |Number, UnixTime |
|alertLevel	|The flag indicates the alert can be confirmed.	|[1,2,3] Info, Warn, Alert |
|acknowledgedBy|	User name, who confirmed the alert. If the alert is not confirmed - empty string.|String |
|acknowledgedTime	|Time, when the alert was confiremed. If the alert is not confirmed - 0.|Number, UnixTime |
|canBeAcknowledged	|The flag indicates the alert can be confirmed.	|Boolean |
|groupId|The id key of the group the alert belongs to|Number |

Using this structure, it is possible to implement, for example, various notification scenarios about unconfirmed accidents.

An example of such program:
<code lua>
function main (userId)
  
  local ACK_DELAY_TOLERANCE = 30 
  local now = os.time()
  
  local alerts = GetCurrentAlerts()
  
  for a_num, a in ipairs(alerts) do 
      INFO("Processing alert #" .. a_num)
    --   tprint(a)
      INFO(tostring(a.canBeAcknowledged) .. ' ' .. a.startTime)
      local time_diff = (now - a.startTime)
        if (a.canBeAcknowledged and (time_diff > ACK_DELAY_TOLERANCE)) then 
            ERROR("The alert " .. a.title .. " exceeded ack time!")
        end 
   end 

end

function tprint(t, indent)
    if not indent then indent = 0 end 
    for k, v in pairs(t) do 
        local formatting = string.rep(' ', indent) .. k .. ': '
        if type(v) == "table" then 
            ERROR(formatting) 
            tprint(v, indent + 1) -- recursive call 
        else
            if type(v) == "boolean" then 
                v = v and "TRUE" or "FALSE"
            end 
            ERROR(formatting .. v) 
        end 
    end -- for 
end -- tprint 
</code>

=== Example of sending Telegram messages upon new alerts ===

Below is the example of how to send Telegram messages when the alert count has increased:
<code lua>
--[[
    Checks if number of alerts has increased and then sends message via 
    Telegram 
--]] 
TELEGRAM_BOT_ID = "229345xxxxx"                -- your telegram chat bot id 
active_alerts = 0                              -- global counter for current alerts

function main (userId)
  
  local alerts = GetCurrentAlerts()
  
  if (#alerts > active_alerts) then            -- number has increased, # - means count table elements
      local a_names = {}                       DEBUG("Alert count has increased!")

      for a_num, a in ipairs(alerts) do 
          INFO("Processing alert #" .. a_num)
          table.insert(a_names, a.title)
      end 
      SendTelegramMessage(TELEGRAM_BOT_ID, 
                          "Current alerts are: " .. table.concat(a_names, ', '))
  end 
  
  active_alerts = #alerts
  
end
</code>