xiaoxia-saas/alembic/versions/054_confirm_gen_fields.py

"""确认生成 API 改造：为 generation_tasks 表添加 source_task_id、output_width、output_height、cover_url、custom_title 字段

Revision ID: 054_confirm_gen_fields
Revises: 053_generation_task_is_preview
Create Date: 2026-08-16

Changes:
1. generation_tasks 表新增 source_task_id（来源预览任务 ID，带索引）
2. generation_tasks 表新增 output_width / output_height（动态输出分辨率）
3. generation_tasks 表新增 cover_url / custom_title（自定义封面和标题）
"""

import sqlalchemy as sa

from alembic import op

revision = "054_confirm_gen_fields"
down_revision = "053_generation_task_is_preview"
branch_labels = None
depends_on = None


def upgrade() -> None:
    conn = op.get_bind()
    is_pg = conn.dialect.name == "postgresql"

    if is_pg:
        # 幂等检查：source_task_id 列是否已存在
        result = conn.execute(
            sa.text(
                "SELECT column_name FROM information_schema.columns "
                "WHERE table_name = 'generation_tasks' AND column_name = 'source_task_id'"
            )
        )
        if result.scalar() is not None:
            return

    # source_task_id
    op.add_column(
        "generation_tasks",
        sa.Column("source_task_id", sa.String(32), nullable=False, server_default=""),
    )

    # output_width
    op.add_column(
        "generation_tasks",
        sa.Column("output_width", sa.Integer, nullable=False, server_default=sa.text("1280")),
    )

    # output_height
    op.add_column(
        "generation_tasks",
        sa.Column("output_height", sa.Integer, nullable=False, server_default=sa.text("720")),
    )

    # cover_url
    op.add_column(
        "generation_tasks",
        sa.Column("cover_url", sa.String(1000), nullable=False, server_default=""),
    )

    # custom_title
    op.add_column(
        "generation_tasks",
        sa.Column("custom_title", sa.String(500), nullable=False, server_default=""),
    )

    # 索引
    op.create_index(
        "ix_generation_tasks_source_task_id",
        "generation_tasks",
        ["source_task_id"],
    )


def downgrade() -> None:
    op.drop_index("ix_generation_tasks_source_task_id", table_name="generation_tasks")
    op.drop_column("generation_tasks", "custom_title")
    op.drop_column("generation_tasks", "cover_url")
    op.drop_column("generation_tasks", "output_height")
    op.drop_column("generation_tasks", "output_width")
    op.drop_column("generation_tasks", "source_task_id")