"""create product_images table

Revision ID: 020
Revises: 019
Create Date: 2026-06-18

R5 产品多图：一产品多张参考图，每张标 scene 场景类型（primary/scene/
texture/ingredient/model），生图按分镜 role 选用对应图，取不到回落主图。
product.image_path 仍保留当主图（向后兼容，零破坏）。
"""
from alembic import op
import sqlalchemy as sa

revision = "020"
down_revision = "019"
branch_labels = None
depends_on = None

_SCENES = ("primary", "scene", "texture", "ingredient", "model")


def upgrade():
    op.create_table(
        "product_images",
        sa.Column("id", sa.BigInteger, primary_key=True, autoincrement=True),
        sa.Column(
            "product_id", sa.BigInteger,
            sa.ForeignKey("products.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column("path", sa.String(512), nullable=False, comment="绝对路径，worker直接open"),
        sa.Column(
            "scene", sa.Enum(*_SCENES, name="productimagescene"),
            nullable=False, server_default="primary",
            comment="场景类型：白底主图/使用场景/质地/成分/上脸",
        ),
        sa.Column("is_primary", sa.Boolean, nullable=False, server_default=sa.false(),
                  comment="主图（同步 product.image_path）"),
        sa.Column("sort_order", sa.Integer, nullable=False, server_default="0"),
        sa.Column("created_at", sa.DateTime, server_default=sa.func.now(), nullable=False),
    )
    op.create_index("idx_product_images_product_id", "product_images", ["product_id"])


def downgrade():
    op.drop_index("idx_product_images_product_id", table_name="product_images")
    op.drop_table("product_images")