Add controlled coding agent automation

src/lai_automation/database.py

@@ -0,0 +1,107 @@
+from __future__ import annotations
+
+import json
+from collections.abc import Iterator
+from contextlib import contextmanager
+
+import pymysql
+from pymysql.cursors import DictCursor
+
+from .config import Settings
+from .models import FailureReport
+
+
+class FailureRepository:
+    def __init__(self, settings: Settings) -> None:
+        self.settings = settings
+
+    @contextmanager
+    def connection(self) -> Iterator[pymysql.Connection]:
+        connection = pymysql.connect(
+            host=self.settings.database_host,
+            port=self.settings.database_port,
+            user=self.settings.database_user,
+            password=self.settings.database_password,
+            database=self.settings.database_name,
+            cursorclass=DictCursor,
+            autocommit=False,
+            connect_timeout=10,
+            read_timeout=30,
+            write_timeout=30,
+        )
+        try:
+            yield connection
+        finally:
+            connection.close()
+
+    def claim_next(self) -> FailureReport | None:
+        with self.connection() as connection, connection.cursor() as cursor:
+            try:
+                cursor.execute(
+                    """
+                    UPDATE failure_reports
+                    SET status = 'open', updated_at = NOW()
+                    WHERE status = 'agent_running'
+                      AND updated_at < DATE_SUB(NOW(), INTERVAL %s MINUTE)
+                    """,
+                    (self.settings.stale_claim_minutes,),
+                )
+                connection.commit()
+                cursor.execute("SET TRANSACTION ISOLATION LEVEL READ COMMITTED")
+                cursor.execute("START TRANSACTION")
+            except Exception:
+                connection.rollback()
+                raise
+            cursor.execute(
+                """
+                SELECT * FROM failure_reports
+                WHERE status = 'open'
+                ORDER BY id
+                LIMIT 1
+                FOR UPDATE SKIP LOCKED
+                """
+            )
+            row = cursor.fetchone()
+            if not row:
+                connection.commit()
+                return None
+            cursor.execute(
+                "UPDATE failure_reports SET status = 'agent_running', updated_at = NOW() WHERE id = %s",
+                (row["id"],),
+            )
+            connection.commit()
+            return FailureReport.from_row(row)
+
+    def release(self, report_id: int, reason: str) -> None:
+        self._finish(report_id, "open", {"last_dry_run": reason})
+
+    def complete(self, report_id: int, metadata: dict) -> None:
+        self._finish(report_id, "resolved", metadata)
+
+    def fail(self, report_id: int, error: str, metadata: dict | None = None) -> None:
+        payload = {"agent_error": error, **(metadata or {})}
+        self._finish(report_id, "agent_failed", payload)
+
+    def _finish(self, report_id: int, status: str, additions: dict) -> None:
+        with self.connection() as connection, connection.cursor() as cursor:
+            try:
+                cursor.execute("SELECT context FROM failure_reports WHERE id = %s", (report_id,))
+                row = cursor.fetchone() or {}
+                context = row.get("context") or {}
+                if isinstance(context, str):
+                    context = json.loads(context)
+                context.update(additions)
+                cursor.execute(
+                    """
+                    UPDATE failure_reports
+                    SET status = %s, context = %s, updated_at = NOW()
+                    WHERE id = %s
+                    """,
+                    (status, json.dumps(context, ensure_ascii=True), report_id),
+                )
+                connection.commit()
+            except Exception as exception:
+                connection.rollback()
+                raise RuntimeError(
+                    f"Could not finalize failure report {report_id} as {status}"
+                ) from exception