Initialize repository snapshot

ledger/migrate.py

@@ -0,0 +1,52 @@
+from __future__ import annotations
+
+import sqlite3
+from pathlib import Path
+
+THIS_FILE = Path(__file__).resolve()
+PKG_DIR = THIS_FILE.parent
+SCHEMA_DIR = PKG_DIR / "schema"
+
+
+def _ensure_migrations_table(conn: sqlite3.Connection) -> None:
+    conn.execute(
+        """
+        CREATE TABLE IF NOT EXISTS migrations (
+          id INTEGER PRIMARY KEY,
+          name TEXT NOT NULL UNIQUE,
+          applied_at TEXT NOT NULL DEFAULT (datetime('now'))
+        );
+        """
+    )
+
+
+def _applied_migrations(conn: sqlite3.Connection) -> set[str]:
+    _ensure_migrations_table(conn)
+    rows = conn.execute("SELECT name FROM migrations;").fetchall()
+    names: set[str] = set()
+    for row in rows:
+        try:
+            names.add(row["name"])
+        except Exception:
+            names.add(row[0])
+    return names
+
+
+def _migration_files() -> list[Path]:
+    if not SCHEMA_DIR.exists():
+        return []
+    files = [p for p in SCHEMA_DIR.iterdir() if p.is_file() and p.suffix == ".sql"]
+    files.sort(key=lambda p: p.name)
+    return files
+
+
+def migrate(conn: sqlite3.Connection) -> None:
+    applied = _applied_migrations(conn)
+    for path in _migration_files():
+        name = path.name
+        if name in applied:
+            continue
+
+        sql = path.read_text(encoding="utf-8")
+        conn.executescript(sql)
+        conn.execute("INSERT INTO migrations (name) VALUES (?);", (name,))