Refactor code structure for improved readability and maintainability

migrations/env.py

@@ -0,0 +1,61 @@
+import asyncio
+from logging.config import fileConfig
+
+from alembic import context
+from sqlalchemy import Connection, pool
+from sqlalchemy.ext.asyncio import async_engine_from_config
+
+from app import models  # noqa: F401
+from app.config import settings
+from app.db import Base
+
+config = context.config
+config.set_main_option("sqlalchemy.url", settings.database_url)
+
+if config.config_file_name is not None:
+    fileConfig(config.config_file_name)
+
+target_metadata = Base.metadata
+
+
+def run_migrations_offline() -> None:
+    context.configure(
+        url=config.get_main_option("sqlalchemy.url"),
+        target_metadata=target_metadata,
+        literal_binds=True,
+        dialect_opts={"paramstyle": "named"},
+        compare_type=True,
+    )
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+def do_run_migrations(connection: Connection) -> None:
+    context.configure(connection=connection, target_metadata=target_metadata, compare_type=True)
+
+    with context.begin_transaction():
+        context.run_migrations()
+
+
+async def run_async_migrations() -> None:
+    connectable = async_engine_from_config(
+        config.get_section(config.config_ini_section, {}),
+        prefix="sqlalchemy.",
+        poolclass=pool.NullPool,
+    )
+
+    async with connectable.connect() as connection:
+        await connection.run_sync(do_run_migrations)
+
+    await connectable.dispose()
+
+
+def run_migrations_online() -> None:
+    asyncio.run(run_async_migrations())
+
+
+if context.is_offline_mode():
+    run_migrations_offline()
+else:
+    run_migrations_online()

migrations/script.py.mako

@@ -0,0 +1,24 @@
+"""${message}
+
+Revision ID: ${up_revision}
+Revises: ${down_revision | comma,n}
+Create Date: ${create_date}
+"""
+from collections.abc import Sequence
+
+from alembic import op
+import sqlalchemy as sa
+${imports if imports else ""}
+
+revision: str = ${repr(up_revision)}
+down_revision: str | None = ${repr(down_revision)}
+branch_labels: str | Sequence[str] | None = ${repr(branch_labels)}
+depends_on: str | Sequence[str] | None = ${repr(depends_on)}
+
+
+def upgrade() -> None:
+    ${upgrades if upgrades else "pass"}
+
+
+def downgrade() -> None:
+    ${downgrades if downgrades else "pass"}

migrations/versions/20260916_0001_create_payments_and_outbox.py

@@ -0,0 +1,76 @@
+"""Create payments and outbox tables.
+
+Revision ID: 20260916_0001
+Revises:
+Create Date: 2026-09-16 08:00:00
+"""
+
+from collections.abc import Sequence
+
+import sqlalchemy as sa
+from alembic import op
+from sqlalchemy.dialects import postgresql
+
+revision: str = "20260916_0001"
+down_revision: str | None = None
+branch_labels: str | Sequence[str] | None = None
+depends_on: str | Sequence[str] | None = None
+
+
+def upgrade() -> None:
+    currency = postgresql.ENUM("RUB", "USD", "EUR", name="currency", create_type=False)
+    payment_status = postgresql.ENUM(
+        "pending", "succeeded", "failed", name="payment_status", create_type=False
+    )
+    currency.create(op.get_bind(), checkfirst=True)
+    payment_status.create(op.get_bind(), checkfirst=True)
+
+    op.create_table(
+        "payments",
+        sa.Column("id", postgresql.UUID(as_uuid=True), nullable=False),
+        sa.Column("amount", sa.Numeric(precision=18, scale=2), nullable=False),
+        sa.Column("currency", currency, nullable=False),
+        sa.Column("description", sa.String(length=500), nullable=False),
+        sa.Column("metadata", postgresql.JSONB(astext_type=sa.Text()), nullable=False),
+        sa.Column("status", payment_status, nullable=False),
+        sa.Column("idempotency_key", sa.String(length=255), nullable=False),
+        sa.Column("webhook_url", sa.Text(), nullable=False),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.Column("processed_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("webhook_delivered_at", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+        sa.UniqueConstraint("idempotency_key"),
+    )
+    op.create_table(
+        "outbox",
+        sa.Column("id", postgresql.UUID(as_uuid=True), nullable=False),
+        sa.Column("aggregate_id", postgresql.UUID(as_uuid=True), nullable=False),
+        sa.Column("event_type", sa.String(length=100), nullable=False),
+        sa.Column("payload", postgresql.JSONB(astext_type=sa.Text()), nullable=False),
+        sa.Column("attempts", sa.Integer(), nullable=False),
+        sa.Column("last_error", sa.Text(), nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.text("now()"),
+            nullable=False,
+        ),
+        sa.Column("published_at", sa.DateTime(timezone=True), nullable=True),
+        sa.PrimaryKeyConstraint("id"),
+    )
+    op.create_index("ix_outbox_aggregate_id", "outbox", ["aggregate_id"])
+    op.create_index("ix_outbox_published_at", "outbox", ["published_at"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_outbox_published_at", table_name="outbox")
+    op.drop_index("ix_outbox_aggregate_id", table_name="outbox")
+    op.drop_table("outbox")
+    op.drop_table("payments")
+    postgresql.ENUM(name="payment_status").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="currency").drop(op.get_bind(), checkfirst=True)