initial commit after split

src/govoplan_core/db/migrations.py

@@ -0,0 +1,187 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+import os
+from pathlib import Path
+
+from alembic import command
+from alembic.config import Config
+from alembic.runtime.migration import MigrationContext
+from sqlalchemy import create_engine, inspect
+
+from govoplan_core.core.migrations import MigrationMetadataPlan, migration_metadata_plan
+from govoplan_core.server.default_config import get_server_config
+from govoplan_core.server.registry import build_platform_registry
+from govoplan_core.settings import settings
+
+# Historic development databases could be created partly through Alembic and
+# partly through Base.metadata.create_all(). In that state Alembic still says
+# "2c..." while the 3d/4e file-storage tables already exist, so a normal
+# upgrade attempts to create file_blobs again. This reconciliation is kept
+# deliberately narrow and only advances the marker when the complete expected
+# schema for the skipped revisions is already present.
+REVISION_AUTH_RBAC = "2c3d4e5f6a7b"
+REVISION_FILE_STORAGE = "3d4e5f6a7b8c"
+REVISION_FILE_FOLDERS = "4e5f6a7b8c9d"
+
+_FILE_STORAGE_TABLES = {
+    "file_blobs",
+    "file_assets",
+    "file_versions",
+    "file_shares",
+    "campaign_attachment_uses",
+}
+_FILE_FOLDER_TABLES = {"file_folders"}
+
+_FILE_STORAGE_COLUMNS = {
+    "file_blobs": {
+        "id",
+        "tenant_id",
+        "storage_backend",
+        "storage_key",
+        "checksum_sha256",
+        "size_bytes",
+    },
+    "file_assets": {
+        "id",
+        "tenant_id",
+        "owner_type",
+        "display_path",
+        "filename",
+        "current_version_id",
+    },
+    "file_versions": {
+        "id",
+        "file_asset_id",
+        "blob_id",
+        "version_number",
+        "checksum_sha256",
+    },
+    "file_shares": {"id", "file_asset_id", "target_type", "target_id", "permission"},
+    "campaign_attachment_uses": {
+        "id",
+        "campaign_id",
+        "campaign_version_id",
+        "file_asset_id",
+        "file_version_id",
+        "file_blob_id",
+    },
+    "file_folders": {"id", "tenant_id", "owner_type", "path"},
+}
+
+
+@dataclass(frozen=True, slots=True)
+class MigrationResult:
+    previous_revision: str | None
+    reconciled_revision: str | None
+    current_revision: str | None
+
+
+def registered_module_migration_plan() -> MigrationMetadataPlan:
+    server_config = get_server_config()
+    registry = build_platform_registry(
+        server_config.enabled_modules,
+        manifest_factories=server_config.manifest_factories,
+    )
+    return migration_metadata_plan(registry)
+
+
+def _repo_root() -> Path:
+    return Path(__file__).resolve().parents[3]
+
+
+def alembic_config(*, database_url: str | None = None) -> Config:
+    root = _repo_root()
+    config = Config(str(root / "alembic.ini"))
+    config.set_main_option("script_location", str(root / "alembic"))
+
+    plan = registered_module_migration_plan()
+    version_locations = [str(root / "alembic" / "versions")]
+    version_locations.extend(location for location in plan.script_locations if location)
+    config.set_main_option("version_locations", os.pathsep.join(dict.fromkeys(version_locations)))
+    config.set_main_option("version_path_separator", "os")
+
+    config.attributes["database_url"] = database_url or settings.database_url
+    return config
+
+
+def database_revision(database_url: str | None = None) -> str | None:
+    url = database_url or settings.database_url
+    engine = create_engine(url)
+    try:
+        with engine.connect() as connection:
+            return MigrationContext.configure(connection).get_current_revision()
+    finally:
+        engine.dispose()
+
+
+def _has_columns(inspector, table_name: str, required: set[str]) -> bool:
+    try:
+        actual = {column["name"] for column in inspector.get_columns(table_name)}
+    except Exception:
+        return False
+    return required.issubset(actual)
+
+
+def reconcile_legacy_create_all_schema(database_url: str | None = None) -> str | None:
+    """Repair the known Alembic/create_all drift without modifying table data.
+
+    Returns the revision stamped during reconciliation, or ``None`` when no
+    repair was necessary. A partial/unknown schema is intentionally left alone
+    so Alembic can fail visibly instead of guessing.
+    """
+
+    url = database_url or settings.database_url
+    engine = create_engine(url)
+    try:
+        with engine.connect() as connection:
+            current = MigrationContext.configure(connection).get_current_revision()
+            schema = inspect(connection)
+            tables = set(schema.get_table_names())
+
+            has_file_storage = _FILE_STORAGE_TABLES.issubset(tables) and all(
+                _has_columns(schema, table, _FILE_STORAGE_COLUMNS[table])
+                for table in _FILE_STORAGE_TABLES
+            )
+            has_file_folders = _FILE_FOLDER_TABLES.issubset(tables) and _has_columns(
+                schema,
+                "file_folders",
+                _FILE_STORAGE_COLUMNS["file_folders"],
+            )
+    finally:
+        engine.dispose()
+
+    target: str | None = None
+    if current == REVISION_AUTH_RBAC and has_file_storage and has_file_folders:
+        target = REVISION_FILE_FOLDERS
+    elif current == REVISION_AUTH_RBAC and has_file_storage:
+        target = REVISION_FILE_STORAGE
+    elif current == REVISION_FILE_STORAGE and has_file_folders:
+        target = REVISION_FILE_FOLDERS
+    elif current is None and has_file_storage and has_file_folders:
+        # This is the other create_all-only development shape. The strict
+        # column checks above ensure that we only stamp a complete known schema.
+        target = REVISION_FILE_FOLDERS
+
+    if target is None:
+        return None
+
+    command.stamp(alembic_config(database_url=url), target)
+    return target
+
+
+def migrate_database(
+    *,
+    database_url: str | None = None,
+    reconcile_legacy_schema: bool = True,
+) -> MigrationResult:
+    url = database_url or settings.database_url
+    previous = database_revision(url)
+    reconciled = reconcile_legacy_create_all_schema(url) if reconcile_legacy_schema else None
+    command.upgrade(alembic_config(database_url=url), "head")
+    current = database_revision(url)
+    return MigrationResult(
+        previous_revision=previous,
+        reconciled_revision=reconciled,
+        current_revision=current,
+    )