-- Complete a job: unlock group AND record metadata atomically in one call
-- argv: ns, jobId, groupId, status, timestamp, resultOrError, keepCompleted, keepFailed,
--       processedOn, finishedOn, attempts, maxAttempts
local ns = KEYS[1]
local jobId = ARGV[1]
local gid = ARGV[2]
local status = ARGV[3]
local timestamp = tonumber(ARGV[4])
local resultOrError = ARGV[5]
local keepCompleted = tonumber(ARGV[6])
local keepFailed = tonumber(ARGV[7])
local processedOn = ARGV[8]
local finishedOn = ARGV[9]
local attempts = ARGV[10]
local maxAttempts = ARGV[11]

-- Part 1: Atomically verify and mark completion (prevent duplicate processing)
local jobKey = ns .. ":job:" .. jobId
local processingKey = ns .. ":processing"

-- CRITICAL: Check both status AND processing set membership atomically
-- This prevents race with stalled job recovery
local jobStatus = redis.call("HGET", jobKey, "status")
local stillInProcessing = redis.call("ZSCORE", processingKey, jobId)

-- If job is not in "processing" state OR not in processing set, this is late/duplicate
if jobStatus ~= "processing" or not stillInProcessing then
  -- Job was already handled (recovered, failed, or completed by another worker)
  -- Return 0 to indicate this completion was ignored
  return 0
end

-- Atomically mark as completed and remove from processing
-- This prevents stalled checker from racing with us
redis.call("HSET", jobKey, "status", "completing") -- Temporary status to block stalled checker
redis.call("DEL", ns .. ":processing:" .. jobId)
redis.call("ZREM", processingKey, jobId)

-- Always remove this job from active list to prevent stale entries
local groupActiveKey = ns .. ":g:" .. gid .. ":active"
local activeJobId = redis.call("LINDEX", groupActiveKey, 0)
local wasActive = (activeJobId == jobId)

if wasActive then
  -- Normal case: remove from head of active list
  redis.call("LPOP", groupActiveKey)
else
  -- Race condition: not at head, but still remove to prevent stale entries
  redis.call("LREM", groupActiveKey, 1, jobId)
end

-- Check if there are more jobs in this group
local gZ = ns .. ":g:" .. gid
local jobCount = redis.call("ZCARD", gZ)
if jobCount == 0 then
  -- Remove empty group
  redis.call("DEL", gZ)
  redis.call("DEL", groupActiveKey)
  redis.call("SREM", ns .. ":groups", gid)
  redis.call("ZREM", ns .. ":ready", gid)
  redis.call("DEL", ns .. ":buffer:" .. gid)
  redis.call("ZREM", ns .. ":buffering", gid)
else
  -- Group has more jobs, re-add to ready if not buffering
  local groupBufferKey = ns .. ":buffer:" .. gid
  local isBuffering = redis.call("EXISTS", groupBufferKey)
  
  if isBuffering == 0 then
    local nextHead = redis.call("ZRANGE", gZ, 0, 0, "WITHSCORES")
    if nextHead and #nextHead >= 2 then
      local nextScore = tonumber(nextHead[2])
      local readyKey = ns .. ":ready"
      redis.call("ZADD", readyKey, nextScore, gid)
    end
  end
end

-- Part 2: Record job metadata (completed or failed)
local jobKey = ns .. ":job:" .. jobId

if status == "completed" then
  local completedKey = ns .. ":completed"
  
  -- CRITICAL: Always set final status first, even if job will be deleted
  -- This ensures any concurrent reads see "completed", not "completing"
  redis.call("HSET", jobKey, "status", "completed")
  
  if keepCompleted > 0 then
    -- Store full job metadata and add to completed set
    redis.call("HSET", jobKey, 
      "processedOn", processedOn,
      "finishedOn", finishedOn,
      "attempts", attempts,
      "maxAttempts", maxAttempts,
      "returnvalue", resultOrError
    )
    redis.call("ZADD", completedKey, timestamp, jobId)
    
    -- Trim old entries atomically
    local zcount = redis.call("ZCARD", completedKey)
    local toRemove = zcount - keepCompleted
    if toRemove > 0 then
      local oldIds = redis.call("ZRANGE", completedKey, 0, toRemove - 1)
      if #oldIds > 0 then
        redis.call("ZREMRANGEBYRANK", completedKey, 0, toRemove - 1)
        for i = 1, #oldIds do
          local oldId = oldIds[i]
          redis.call("DEL", ns .. ":job:" .. oldId)
          redis.call("DEL", ns .. ":unique:" .. oldId)
        end
      end
    end
  else
    -- keepCompleted == 0: Delete immediately (status already set above)
    redis.call("DEL", jobKey)
    redis.call("DEL", ns .. ":unique:" .. jobId)
  end
  
elseif status == "failed" then
  local failedKey = ns .. ":failed"
  local errorInfo = cjson.decode(resultOrError)
  
  -- CRITICAL: Always set final status first, even if job will be deleted
  redis.call("HSET", jobKey, "status", "failed")
  
  if keepFailed > 0 then
    redis.call("HSET", jobKey,
      "failedReason", errorInfo.message or "Error",
      "failedName", errorInfo.name or "Error",
      "stacktrace", errorInfo.stack or "",
      "processedOn", processedOn,
      "finishedOn", finishedOn,
      "attempts", attempts,
      "maxAttempts", maxAttempts
    )
    redis.call("ZADD", failedKey, timestamp, jobId)
  else
    -- Delete job (status already set above)
    redis.call("DEL", jobKey)
    redis.call("DEL", ns .. ":unique:" .. jobId)
  end
end

return 1