Adding the Initial WIP

app/storage.py

@@ -0,0 +1,76 @@
+from __future__ import annotations
+import asyncio
+import time
+from typing import Dict, Any, List
+import redis
+import json
+import os
+
+REDIS_URL = os.environ.get("REDIS_URL", "redis://redis:6379/0")
+RETENTION_SECONDS = 7 * 24 * 3600
+MAX_SAMPLES_PER_UPS = 7 * 24 * 60 * 2  # assume worst-case 30s interval -> ~20160 entries
+
+_redis: redis.Redis | None = None
+
+def get_redis() -> redis.Redis:
+    global _redis
+    if _redis:
+        return _redis
+    _redis = redis.Redis.from_url(REDIS_URL, decode_responses=True)
+    return _redis
+
+SNAP_KEY_PREFIX = "ups:snap:"  # latest hash per ups
+HIST_KEY_PREFIX = "ups:hist:"  # time-series list per ups (append JSON)
+
+async def store_snapshot(ups_name: str, data: Dict[str, Any]):
+    r = get_redis()
+    ts = int(time.time())
+    pipe = r.pipeline()
+    # store latest snapshot (hash)
+    pipe.hset(f"{SNAP_KEY_PREFIX}{ups_name}", mapping={**data, "_ts": ts})
+    # append to history list
+    hist_key = f"{HIST_KEY_PREFIX}{ups_name}"
+    pipe.rpush(hist_key, json.dumps({"ts": ts, "data": data}))
+    pipe.ltrim(hist_key, -MAX_SAMPLES_PER_UPS, -1)
+    # add pruning via async task (length-based + time-based)
+    pipe.execute()
+
+async def get_latest(ups_name: str) -> Dict[str, Any] | None:
+    r = get_redis()
+    h = r.hgetall(f"{SNAP_KEY_PREFIX}{ups_name}")
+    return h or None
+
+async def get_history(ups_name: str, since_seconds: int = RETENTION_SECONDS) -> List[Dict[str, Any]]:
+    r = get_redis()
+    key = f"{HIST_KEY_PREFIX}{ups_name}"
+    raw = r.lrange(key, 0, -1)
+    now = int(time.time())
+    out: List[Dict[str, Any]] = []
+    for item in raw:
+        try:
+            obj = json.loads(item)
+        except json.JSONDecodeError:
+            continue
+        if now - obj.get("ts", 0) <= since_seconds:
+            out.append(obj)
+    return out
+
+async def prune_old():
+    r = get_redis()
+    now = int(time.time())
+    cutoff = now - RETENTION_SECONDS
+    for key in r.scan_iter(f"{HIST_KEY_PREFIX}*"):
+        # prune from left while older than cutoff
+        while True:
+            item = r.lindex(key, 0)
+            if not item:
+                break
+            try:
+                obj = json.loads(item)
+            except json.JSONDecodeError:
+                r.lpop(key)
+                continue
+            if obj.get("ts", 0) < cutoff:
+                r.lpop(key)
+            else:
+                break