feat: complete phase one and two of task implementation

src/lua/purchase-ticket.lua

@@ -0,0 +1,46 @@
+-- Atomic ticket purchase script
+-- KEYS[1]: event tickets key (e.g., "event:1:tickets")
+-- KEYS[2]: event metadata key (e.g., "event:1:meta")
+-- KEYS[3]: global stats key ("global:stats")
+-- ARGV[1]: timestamp
+-- ARGV[2]: purchase ID (UUID)
+
+local ticketKey = KEYS[1]
+local metaKey = KEYS[2]
+local globalKey = KEYS[3]
+local timestamp = ARGV[1]
+local purchaseId = ARGV[2]
+
+-- Check if event exists
+if redis.call('EXISTS', metaKey) == 0 then
+    return {nil, "EVENT_NOT_FOUND"}
+end
+
+-- Atomically pop a ticket from the list
+local ticket = redis.call('LPOP', ticketKey)
+
+if not ticket then
+    return {nil, "NO_TICKETS_AVAILABLE"}
+end
+
+-- Update event metadata
+local soldCount = redis.call('HINCRBY', metaKey, 'soldTickets', 1)
+redis.call('HSET', metaKey, 'lastSoldAt', timestamp)
+
+-- Update global stats
+redis.call('HINCRBY', globalKey, 'totalSold', 1)
+
+-- Store purchase record
+local purchaseKey = 'purchase:' .. purchaseId
+redis.call('HSET', purchaseKey, {
+    'ticketId', ticket,
+    'eventId', string.match(ticketKey, 'event:(%d+):tickets'),
+    'purchaseId', purchaseId,
+    'timestamp', timestamp,
+    'status', 'completed'
+})
+
+-- Set expiration for purchase record (24 hours)
+redis.call('EXPIRE', purchaseKey, 86400)
+
+return {ticket, "SUCCESS", soldCount}