From 0835e3785bfaa004640284da25433e7dee4bbb64 Mon Sep 17 00:00:00 2001
From: Kai Chappell <git@kschappell.com>
Date: Sun, 17 Aug 2025 11:34:53 +0000
Subject: [PATCH] Add data persistence models

---
 src/py_dvt_ate/data/__init__.py | 14 ++++++
 src/py_dvt_ate/data/models.py   | 83 +++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 src/py_dvt_ate/data/__init__.py
 create mode 100644 src/py_dvt_ate/data/models.py

diff --git a/src/py_dvt_ate/data/__init__.py b/src/py_dvt_ate/data/__init__.py
new file mode 100644
index 0000000..ddab624
--- /dev/null
+++ b/src/py_dvt_ate/data/__init__.py
@@ -0,0 +1,14 @@
+"""Data persistence layer.
+
+Provides storage for test runs, results, and measurements using
+SQLite for metadata and Parquet for time-series data.
+"""
+
+from py_dvt_ate.data.models import Measurement, TestResult, TestRun, TestStatus
+
+__all__ = [
+    "Measurement",
+    "TestResult",
+    "TestRun",
+    "TestStatus",
+]
diff --git a/src/py_dvt_ate/data/models.py b/src/py_dvt_ate/data/models.py
new file mode 100644
index 0000000..907bf3d
--- /dev/null
+++ b/src/py_dvt_ate/data/models.py
@@ -0,0 +1,83 @@
+"""Data models for test persistence.
+
+This module defines dataclasses representing test runs, results, and measurements.
+These models map to SQLite tables (for metadata) and Parquet files (for time-series).
+"""
+
+from dataclasses import dataclass, field
+from datetime import datetime
+from enum import Enum
+
+
+class TestStatus(Enum):
+    """Test run status."""
+
+    PENDING = "pending"
+    RUNNING = "running"
+    PASSED = "passed"
+    FAILED = "failed"
+    ERROR = "error"
+    SKIPPED = "skipped"
+
+
+@dataclass
+class TestRun:
+    """Test run metadata.
+
+    Maps to the test_runs SQLite table.
+    """
+
+    id: str  # UUID
+    test_name: str
+    started_at: datetime
+    status: TestStatus
+    config_json: str  # JSON string of test configuration
+    description: str | None = None
+    completed_at: datetime | None = None
+    operator: str | None = None
+    notes: str | None = None
+    created_at: datetime = field(default_factory=datetime.now)
+
+
+@dataclass(frozen=True)
+class TestResult:
+    """Immutable test result with limits.
+
+    Maps to the test_results SQLite table.
+    Represents a single scalar measurement with pass/fail limits.
+    """
+
+    id: str  # UUID
+    test_run_id: str  # Foreign key to test_runs.id
+    parameter: str
+    value: float
+    unit: str
+    measured_at: datetime
+    lower_limit: float | None = None
+    upper_limit: float | None = None
+
+    @property
+    def passed(self) -> bool | None:
+        """Evaluate pass/fail. None if no limits defined."""
+        if self.lower_limit is None and self.upper_limit is None:
+            return None
+        lower_ok = self.lower_limit is None or self.value >= self.lower_limit
+        upper_ok = self.upper_limit is None or self.value <= self.upper_limit
+        return lower_ok and upper_ok
+
+
+@dataclass(frozen=True)
+class Measurement:
+    """Immutable measurement record for time-series data.
+
+    Maps to Parquet files for efficient storage and analysis.
+    Includes measurement conditions (temperature, voltage, current) at time of measurement.
+    """
+
+    timestamp: float  # Seconds since epoch (high precision)
+    parameter: str
+    value: float
+    unit: str
+    temperature: float = 0.0  # Chamber temperature at measurement
+    input_voltage: float = 0.0  # DUT input voltage at measurement
+    load_current: float = 0.0  # DUT load current at measurement