feat: extend operational investigation workflows

app/algorithms/valve_isolation/topology_search.py

@@ -1,10 +1,11 @@
 """Topology-only valve isolation search."""
 
 from collections import defaultdict, deque
-from typing import Any, Iterable
+from typing import Any, Iterable, Literal
 
 
 VALVE_LINK_TYPE = "valve"
+AccidentElementType = Literal["auto", "link", "node"]
 
 
 def _parse_link_entry(link_entry: str) -> tuple[str, str, str, str]:
@@ -14,12 +15,37 @@ def _parse_link_entry(link_entry: str) -> tuple[str, str, str, str]:
     return parts[0], parts[1], parts[2], parts[3]
 
 
+def _reachable_nodes(
+    adjacency: dict[str, list[tuple[str, str]]],
+    start_nodes: Iterable[str],
+    blocked_links: set[str],
+) -> set[str]:
+    visited = set(start_nodes)
+    queue = deque(visited)
+    while queue:
+        for neighbor, link_id in adjacency.get(queue.popleft(), ()):
+            if link_id not in blocked_links and neighbor not in visited:
+                visited.add(neighbor)
+                queue.append(neighbor)
+    return visited
+
+
 def valve_isolation_analysis(
     link_entries: Iterable[str],
     accident_elements: str | list[str],
     disabled_valves: list[str] | None = None,
+    *,
+    accident_element_type: AccidentElementType = "auto",
+    water_source_nodes: Iterable[str] | None = None,
+    closed_links: Iterable[str] = (),
 ) -> dict[str, Any]:
-    """Determine boundary valves and affected nodes from a topology snapshot."""
+    """Find nearest valve boundaries, then check source connectivity.
+
+    Legacy untyped IDs prefer links; explicit node mode handles cross-type ID
+    collisions. Supply impact is a before/after connectivity difference, not
+    a hydraulic pressure or demand calculation. Without source metadata only
+    the provisional boundary search is available.
+    """
 
     disabled_valves_set = set(disabled_valves or [])
     target_elements = (
@@ -27,8 +53,13 @@ def valve_isolation_analysis(
         if isinstance(accident_elements, str)
         else accident_elements
     )
+    if not target_elements:
+        raise ValueError("At least one accident element is required")
+    if accident_element_type not in {"auto", "link", "node"}:
+        raise ValueError(f"Invalid accident element type: {accident_element_type}")
+    closed_links_set = set(closed_links)
 
-    pipe_adj: dict[str, set[str]] = defaultdict(set)
+    adjacency: dict[str, list[tuple[str, str]]] = defaultdict(list)
     all_valves: dict[str, tuple[str, str]] = {}
     link_lookup: dict[str, tuple[str, str, str]] = {}
     node_set: set[str] = set()
@@ -39,46 +70,31 @@ def valve_isolation_analysis(
         node_set.update((node1, node2))
         if link_type_name == VALVE_LINK_TYPE:
             all_valves[link_id] = (node1, node2)
-        else:
-            pipe_adj[node1].add(node2)
-            pipe_adj[node2].add(node1)
+        if link_id not in closed_links_set:
+            adjacency[node1].append((node2, link_id))
+            adjacency[node2].append((node1, link_id))
+
+    unknown_disabled = disabled_valves_set - all_valves.keys()
+    if unknown_disabled:
+        raise ValueError(f"Disabled valve was not found in topology: {sorted(unknown_disabled)}")
 
     start_nodes: set[str] = set()
     for element in target_elements:
-        if element in node_set:
-            start_nodes.add(element)
-        elif element in link_lookup:
+        if accident_element_type != "node" and element in link_lookup:
             node1, node2, _ = link_lookup[element]
             start_nodes.update((node1, node2))
+        elif accident_element_type != "link" and element in node_set:
+            start_nodes.add(element)
         else:
             raise ValueError(f"Accident element {element} was not found in topology")
 
-    extra_adj: dict[str, list[str]] = defaultdict(list)
-    boundary_valves: dict[str, tuple[str, str]] = {}
-    for valve_id, (node1, node2) in all_valves.items():
-        if valve_id in disabled_valves_set:
-            extra_adj[node1].append(node2)
-            extra_adj[node2].append(node1)
-        else:
-            boundary_valves[valve_id] = (node1, node2)
-
-    affected_nodes: set[str] = set()
-    queue = deque(start_nodes)
-    while queue:
-        node = queue.popleft()
-        if node in affected_nodes:
-            continue
-        affected_nodes.add(node)
-        queue.extend(pipe_adj.get(node, set()) - affected_nodes)
-        queue.extend(
-            neighbor
-            for neighbor in extra_adj.get(node, ())
-            if neighbor not in affected_nodes
-        )
+    closable_valves = set(all_valves) - disabled_valves_set - closed_links_set
+    affected_nodes = _reachable_nodes(adjacency, start_nodes, closable_valves)
 
     must_close_valves: list[str] = []
     optional_valves: list[str] = []
-    for valve_id, (node1, node2) in boundary_valves.items():
+    for valve_id in closable_valves:
+        node1, node2 = all_valves[valve_id]
         node1_affected = node1 in affected_nodes
         node2_affected = node2 in affected_nodes
         if node1_affected and node2_affected:
@@ -89,14 +105,37 @@ def valve_isolation_analysis(
     must_close_valves.sort()
     optional_valves.sort()
     isolatable = bool(must_close_valves)
+    failure_reason = None if isolatable else "no_boundary_valves"
+    sources = set(water_source_nodes or ())
+    source_check_performed = bool(sources)
+    supply_affected_nodes = None
+    if water_source_nodes is not None:
+        if not sources:
+            isolatable = False
+            failure_reason = "water_sources_unavailable"
+        else:
+            after_closure = _reachable_nodes(adjacency, sources, set(must_close_valves))
+            if affected_nodes & after_closure:
+                isolatable = False
+                failure_reason = "connected_to_water_source"
+            if isolatable:
+                before_closure = _reachable_nodes(adjacency, sources, set())
+                supply_affected_nodes = sorted(before_closure - after_closure)
     result: dict[str, Any] = {
         "accident_elements": target_elements,
+        "accident_element_type": accident_element_type,
         "disabled_valves": disabled_valves,
         "affected_nodes": sorted(affected_nodes) if isolatable else [],
         "affected_node_count": len(affected_nodes),
         "must_close_valves": must_close_valves,
         "optional_valves": optional_valves,
         "isolatable": isolatable,
+        "source_check_performed": source_check_performed,
+        "isolation_failure_reason": failure_reason,
+        "supply_affected_nodes": supply_affected_nodes,
+        "supply_affected_node_count": (
+            len(supply_affected_nodes) if supply_affected_nodes is not None else None
+        ),
     }
     if len(target_elements) == 1:
         result["accident_element"] = target_elements[0]