"""add asset image lifecycle fields

Revision ID: a41e8c7f4b20
Revises: 658b0503f71c
Create Date: 2026-08-30 09:00:00

"""
from __future__ import annotations

from alembic import op
import sqlalchemy as sa


revision = "a41e8c7f4b20"
down_revision = "658b0503f71c"
branch_labels = None
depends_on = None


def upgrade() -> None:
    op.add_column("product_assets", sa.Column("original_url", sa.Text(), nullable=True))
    op.add_column("product_assets", sa.Column("original_storage_key", sa.String(length=1024), nullable=True))
    op.add_column("product_assets", sa.Column("current_storage_key", sa.String(length=1024), nullable=True))
    op.add_column("product_assets", sa.Column("watermark_enabled", sa.Boolean(), nullable=False, server_default=sa.false()))
    op.add_column("product_assets", sa.Column("watermark_config", sa.JSON(), nullable=True))

    # 兼容旧数据：采集图优先以已转存文件为原图；生成图若此前已保存 source_url，则它是无水印原图。
    op.execute(
        """
        UPDATE product_assets
        SET original_url = CASE
            WHEN group_key = 'generated' AND source_url IS NOT NULL AND source_url <> '' THEN source_url
            ELSE COALESCE(stored_url, source_url)
        END
        """
    )


def downgrade() -> None:
    op.drop_column("product_assets", "watermark_config")
    op.drop_column("product_assets", "watermark_enabled")
    op.drop_column("product_assets", "current_storage_key")
    op.drop_column("product_assets", "original_storage_key")
    op.drop_column("product_assets", "original_url")