--[[
  Submits a Rhai script to a distributed worker and returns the task ID.
  
  Since BLPOP cannot block inside Lua scripts (they execute atomically),
  this script only submits the task and returns the task ID. The client
  must then use BLPOP separately to wait for the result.

  ARGV[1] (string): The target circle name (e.g., "default").
  ARGV[2] (string): The Rhai script content to execute.

  Returns:
    - A JSON string containing the task ID and reply queue name.
]]

-- 1. Argument Validation
local circle_name = ARGV[1]
if not circle_name or circle_name == '' then
  return cjson.encode({error = "ARGV[1] 'circle_name' is required."})
end

local rhai_script = ARGV[2]
if not rhai_script or rhai_script == '' then
  return cjson.encode({error = "ARGV[2] 'rhai_script' is required."})
end

-- 2. Initialization
local task_details_prefix = "rhai_task_details:"
local tasks_queue_prefix = "rhai_tasks:"
local reply_queue_prefix = "rhai_reply:"

local task_id = redis.sha1hex(rhai_script .. redis.call('TIME')[1] .. redis.call('TIME')[2] .. math.random())
local reply_queue_key = reply_queue_prefix .. task_id
local task_details_key = task_details_prefix .. task_id
local task_queue_key = tasks_queue_prefix .. circle_name

-- 3. Task Creation & Queuing
redis.call('HSET', task_details_key,
  'script', rhai_script,
  'status', 'pending',
  'replyToQueue', reply_queue_key
)
redis.call('LPUSH', task_queue_key, task_id)

-- 4. Return task information for client to wait on
return cjson.encode({
  task_id = task_id,
  reply_queue = reply_queue_key
})