Add database migration script

.pg_format

@@ -5,4 +5,3 @@ type-case=1
 no-space-function=1
 keep-newline=1
 nogrouping=1
-placeholder=%(\(\w+\))?s

scanner/migrations/000001_request.up.sql

@@ -1,5 +1,3 @@
-begin;
-
 create type scanner.request_kind as enum(
 	'episode',
 	'movie'
@@ -17,12 +15,9 @@ create table scanner.requests(
 	kind scanner.request_kind not null,
 	title text not null,
 	year integer,
-	external_id jsonb not null default '{}' ::jsonb,
+	external_id jsonb not null default '{}'::jsonb,
 	status scanner.request_status not null,
-	started_at created_at timestamptz,
+	started_at timestamptz,
-	created_at created_at timestamptz not null default now() ::timestamptz,
+	created_at timestamptz not null default now()::timestamptz,
-	constraint unique_kty(kind, title, year)
+	constraint unique_kty unique(kind, title, year)
 );
-
-commit;
-

scanner/scanner/__init__.py

@@ -10,7 +10,7 @@ from scanner.providers.composite import CompositeProvider
 from scanner.providers.themoviedatabase import TheMovieDatabase
 from scanner.requests import RequestCreator, RequestProcessor
 
-from .database import get_db, init_pool
+from .database import get_db, init_pool, migrate
 from .routers.routes import router
 
 logging.basicConfig(level=logging.DEBUG)
@@ -26,6 +26,7 @@ async def lifespan(_):
 		KyooClient() as client,
 		TheMovieDatabase() as tmdb,
 	):
+		await migrate();
 		# creating the processor makes it listen to requests event in pg
 		async with (
 			RequestProcessor(db, client, CompositeProvider(tmdb)) as processor,

scanner/scanner/database.py

@@ -1,9 +1,12 @@
 import os
 from contextlib import asynccontextmanager
+from logging import getLogger
 from typing import Any, cast
 
 from asyncpg import Connection, Pool, create_pool
 
+logger = getLogger(__name__)
+
 pool: Pool
 
 
@@ -30,3 +33,53 @@ async def init_pool():
 async def get_db():
 	async with pool.acquire() as db:
 		yield cast(Connection, db)
+
+
+async def migrate(migrations_dir="./migrations"):
+	async with get_db() as db:
+		_ = await db.execute(
+			"""
+			create schema if not exists scanner;
+
+			create table if not exists scanner._migrations(
+				pk serial primary key,
+				name text not null,
+				applied_at timestamptz not null default now() ::timestamptz
+			);
+			""",
+		)
+
+		applied = await db.fetchval(
+			"""
+			select
+				count(*)
+			from
+				scanner._migrations
+			"""
+		)
+
+		if not os.path.exists(migrations_dir):
+			logger.warning(f"Migrations directory '{migrations_dir}' not found")
+			return
+
+		migrations = sorted(
+			f for f in os.listdir(migrations_dir) if f.endswith("up.sql")
+		)
+		for migration in migrations[applied:]:
+			file_path = os.path.join(migrations_dir, migration)
+			logger.info(f"Applying migration: {migration}")
+			try:
+				with open(file_path, "r") as f:
+					sql = f.read()
+					async with db.transaction():
+						_ = await db.execute(sql)
+						_ = await db.execute(
+							"""
+							insert into scanner._migrations(name)
+								values ($1)
+							""",
+							migration,
+						)
+			except Exception as e:
+				logger.error(f"Failed to apply migration {migration}", exc_info=e)
+				raise