"""补建所有 ORM 模型中存在但数据库缺失的列

0001 用 create_all 建表，对已有表不会 ALTER 追加列。
本迁移自动内省 ORM 元数据与实际数据库 schema 的差异，
为每张已有表补齐缺失列（不含 FK 约束，仅补列定义）。

Revision ID: 0020_backfill_all_missing_columns
Revises: 0019_backfill_missing_columns
"""

from __future__ import annotations

from typing import Sequence, Union

import sqlalchemy as sa

from alembic import op

revision: str = "0020_backfill_missing_schema"
down_revision: Union[str, None] = "0019_backfill_missing_columns"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None


def _import_all_models() -> None:
    from app.features.asset import models as _asset  # noqa: F401
    from app.features.auth import models as _auth  # noqa: F401
    from app.features.conversation import models as _conv  # noqa: F401
    from app.features.evaluation import models as _eval  # noqa: F401
    from app.features.memory import models as _memory  # noqa: F401
    from app.features.memoir import models as _memoir  # noqa: F401
    from app.features.payment import models as _payment  # noqa: F401
    from app.features.story import models as _story  # noqa: F401
    from app.features.user import models as _user  # noqa: F401


def upgrade() -> None:
    from app.core.db import Base

    _import_all_models()

    bind = op.get_bind()
    inspector = sa.inspect(bind)
    existing_tables = set(inspector.get_table_names())

    for table in Base.metadata.sorted_tables:
        if table.name not in existing_tables:
            continue

        db_cols = {c["name"] for c in inspector.get_columns(table.name)}

        for col in table.columns:
            if col.name in db_cols:
                continue

            kwargs: dict = {"nullable": True}

            if col.server_default is not None:
                kwargs["server_default"] = col.server_default.arg

            new_col = sa.Column(col.name, col.type, **kwargs)
            op.add_column(table.name, new_col)


def downgrade() -> None:
    pass