feat(scada): add calibrated monitoring and incident recovery

app/domain/schemas/answer_ui.py

@@ -3,12 +3,28 @@ from __future__ import annotations
 
 import json
 import math
+import re
+from datetime import datetime
 from pathlib import Path
 from typing import Annotated, Any, Literal
 
 from jsonschema import Draft7Validator
 from pydantic import BaseModel, ConfigDict, Field, field_validator, model_serializer, model_validator
 
+CHART_SAMPLE_TIME_PATTERN = (
+    r"^(?:[1-9][0-9]{3}|0[1-9][0-9]{2}|00[1-9][0-9]|000[1-9])-[0-9]{2}-[0-9]{2}T(?:[01][0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]"
+    r"(?:\.[0-9]+)?(?:Z|[+-](?:[01][0-9]|2[0-3]):[0-5][0-9])$"
+)
+
+
+def validate_chart_sample_time(value: str) -> None:
+    """Match the bounded frontend RFC3339 spelling and an actual calendar date."""
+    if len(value) > 64 or re.fullmatch(CHART_SAMPLE_TIME_PATTERN, value) is None:
+        raise ValueError("Chart sample times require RFC3339 seconds and a timezone")
+    if datetime.fromisoformat(value).tzinfo is None:
+        raise ValueError("Chart sample times require a timezone")
+
+
 _catalog = json.loads(
     (Path(__file__).resolve().parents[3] / "contracts/answer-ui-catalog.json").read_text()
 )
@@ -71,8 +87,18 @@ class AnswerUiBlock(UiModel):
             if element.type == "Chart":
                 if any(len(series["data"]) != len(props["x_data"]) for series in props["series"]):
                     raise ValueError("Chart series must match the axis")
-                if any(not math.isfinite(value) for series in props["series"] for value in series["data"]):
+                if any(value is not None and not math.isfinite(value) for series in props["series"] for value in series["data"]):
                     raise ValueError("Chart values must be finite")
+                for series in props["series"]:
+                    times = series.get("sample_times")
+                    if times is not None:
+                        if len(times) != len(series["data"]):
+                            raise ValueError("Chart sample times must match the axis")
+                        for value, at in zip(series["data"], times, strict=True):
+                            if at is not None:
+                                if value is None:
+                                    raise ValueError("Chart sample times require an observed value")
+                                validate_chart_sample_time(at)
             if element.type == "Table" and any(len(row) != len(props["columns"]) for row in props["rows"]):
                 raise ValueError("Table row width must match its columns")
             if element.type == "FollowUpForm":