Refactor server state and add health checks

health.py

@@ -0,0 +1,73 @@
+import sqlite3
+from pathlib import Path
+from typing import Any, Dict
+
+from app_state import StateStore
+
+
+def health_payload(
+    data_dir: Path,
+    session_dir: Path,
+    state_store: StateStore,
+    continuous_snapshot: Dict[str, Any],
+    job_queue_size: int,
+) -> Dict[str, Any]:
+    checks = {
+        "data_dir": _dir_check(data_dir, writable=True),
+        "session_dir": _dir_check(session_dir, writable=True),
+        "state_file": _state_check(state_store),
+        "sqlite": _sqlite_check(),
+        "continuous": _continuous_check(continuous_snapshot),
+        "job_queue": {"ok": True, "size": job_queue_size},
+    }
+    ok = all(item.get("ok", False) for item in checks.values())
+    return {"ok": ok, "status": "ok" if ok else "degraded", "checks": checks}
+
+
+def _dir_check(path: Path, writable: bool = False) -> Dict[str, Any]:
+    path.mkdir(parents=True, exist_ok=True)
+    ok = path.exists() and path.is_dir()
+    payload: Dict[str, Any] = {"ok": ok, "path": str(path)}
+    if writable:
+        probe = path / ".healthcheck"
+        try:
+            probe.write_text("ok", encoding="utf-8")
+            probe.unlink(missing_ok=True)
+            payload["writable"] = True
+        except OSError as exc:
+            payload.update({"ok": False, "writable": False, "error": str(exc)})
+    return payload
+
+
+def _state_check(state_store: StateStore) -> Dict[str, Any]:
+    try:
+        state = state_store.load()
+        return {
+            "ok": True,
+            "path": str(state_store.path),
+            "has_api_credentials": bool(state.get("api_id") and state.get("api_hash")),
+            "tracked_channels": len(state.get("channels", {})),
+        }
+    except Exception as exc:
+        return {"ok": False, "path": str(state_store.path), "error": str(exc)}
+
+
+def _sqlite_check() -> Dict[str, Any]:
+    try:
+        conn = sqlite3.connect(":memory:")
+        conn.execute("SELECT 1")
+        conn.close()
+        return {"ok": True}
+    except sqlite3.Error as exc:
+        return {"ok": False, "error": str(exc)}
+
+
+def _continuous_check(snapshot: Dict[str, Any]) -> Dict[str, Any]:
+    status = snapshot.get("status", {})
+    config = snapshot.get("config", {})
+    return {
+        "ok": True,
+        "enabled": bool(config.get("enabled")),
+        "running": bool(status.get("running")),
+        "last_error": status.get("last_error"),
+    }