From 98b50dbbf48a9537e6bd53de020ed3f9ff09a142 Mon Sep 17 00:00:00 2001
From: Andreas Wrede <andreas@wrede.ca>
Date: Thu, 9 Jul 2026 16:42:00 -0400
Subject: [PATCH] feat: ownership visibility helpers for config entities

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NfPpSpccTWBfZg1FTveyaU
---
 hbd/server/config_access.py | 61 +++++++++++++++++++++++++++++++++++++
 tests/test_config_access.py | 58 +++++++++++++++++++++++++++++++++++
 2 files changed, 119 insertions(+)
 create mode 100644 hbd/server/config_access.py
 create mode 100644 tests/test_config_access.py

diff --git a/hbd/server/config_access.py b/hbd/server/config_access.py
new file mode 100644
index 0000000..936e207
--- /dev/null
+++ b/hbd/server/config_access.py
@@ -0,0 +1,61 @@
+"""Ownership rules for config-file entities (hosts, channels, threshold configs).
+
+Rule: an entry whose config dict has a non-empty ``owner`` is private to that
+owner — visible, usable, and editable only by the owner (and admins).  An
+entry with no ``owner`` is global: usable by everyone, editable by admins only.
+
+The scoped-merge helpers implement the non-admin save path for
+``POST /api/0/config``: the caller's visible subset of a section is replaced
+by the submitted payload; everything else is preserved untouched.
+"""
+
+from typing import Any, Dict
+
+
+class ScopedMergeError(Exception):
+    """A non-admin payload violated an ownership rule; message names the entry."""
+
+
+def is_global(cfg: Any) -> bool:
+    """True when *cfg* has no owner (usable by everyone)."""
+    return not (isinstance(cfg, dict) and cfg.get("owner"))
+
+
+def user_can_use(cfg: Any, username: str) -> bool:
+    """True when *username* may use/see this entry (global or own)."""
+    return is_global(cfg) or cfg.get("owner") == username
+
+
+def _as_list(value: Any) -> list:
+    if value is None:
+        return []
+    if isinstance(value, str):
+        return [value]
+    return list(value)
+
+
+def user_hosts(hosts_cfg: Any, username: str) -> Dict[str, Any]:
+    """Subset of *hosts_cfg* where *username* is owner or manager."""
+    result = {}
+    for name, cfg in (hosts_cfg or {}).items():
+        if not isinstance(cfg, dict):
+            continue
+        if cfg.get("owner") == username or username in _as_list(cfg.get("managers")):
+            result[name] = cfg
+    return result
+
+
+def user_channels(channels_cfg: Any, username: str) -> Dict[str, Any]:
+    """Subset of channels usable by *username*: global + own."""
+    return {
+        name: cfg for name, cfg in (channels_cfg or {}).items()
+        if isinstance(cfg, dict) and user_can_use(cfg, username)
+    }
+
+
+def user_threshold_configs(threshold_cfgs: Any, username: str) -> Dict[str, Any]:
+    """Subset of threshold configs usable by *username*: global + own."""
+    return {
+        name: cfg for name, cfg in (threshold_cfgs or {}).items()
+        if isinstance(cfg, dict) and user_can_use(cfg, username)
+    }
diff --git a/tests/test_config_access.py b/tests/test_config_access.py
new file mode 100644
index 0000000..7e4c968
--- /dev/null
+++ b/tests/test_config_access.py
@@ -0,0 +1,58 @@
+"""Tests for ownership rules and scoped config merges (hbd.server.config_access)."""
+import pytest
+from hbd.server import config_access as ca
+
+
+# ---------------------------------------------------------------------------
+# Visibility helpers
+# ---------------------------------------------------------------------------
+
+def test_is_global_when_no_owner():
+    assert ca.is_global({"type": "pushover"})
+    assert ca.is_global({"type": "email", "owner": ""})
+    assert ca.is_global(None)          # non-dict is treated as global
+    assert not ca.is_global({"type": "email", "owner": "alice"})
+
+
+def test_user_can_use_global_or_own():
+    assert ca.user_can_use({"type": "pushover"}, "alice")
+    assert ca.user_can_use({"owner": "alice"}, "alice")
+    assert not ca.user_can_use({"owner": "bob"}, "alice")
+
+
+HOSTS = {
+    "web1": {"owner": "alice", "watch": True},
+    "web2": {"owner": "bob", "managers": ["alice"]},
+    "web3": {"owner": "bob", "managers": "carol"},      # string manager form
+    "web4": {"watch": True},                            # unowned
+}
+
+
+def test_user_hosts_owner_and_manager():
+    assert set(ca.user_hosts(HOSTS, "alice")) == {"web1", "web2"}
+    assert set(ca.user_hosts(HOSTS, "carol")) == {"web3"}
+    assert ca.user_hosts(HOSTS, "dave") == {}
+    assert ca.user_hosts(None, "alice") == {}
+
+
+CHANNELS = {
+    "global_ch": {"type": "pushover"},
+    "alice_ch": {"type": "email", "owner": "alice"},
+    "bob_ch": {"type": "signal", "owner": "bob"},
+}
+
+
+def test_user_channels_global_plus_own():
+    assert set(ca.user_channels(CHANNELS, "alice")) == {"global_ch", "alice_ch"}
+    assert set(ca.user_channels(CHANNELS, "dave")) == {"global_ch"}
+
+
+TCS = {
+    "default": {"thresholds": {}},
+    "alice_tc": {"owner": "alice", "thresholds": {}},
+}
+
+
+def test_user_threshold_configs_global_plus_own():
+    assert set(ca.user_threshold_configs(TCS, "alice")) == {"default", "alice_tc"}
+    assert set(ca.user_threshold_configs(TCS, "bob")) == {"default"}