life-echo/api/alembic/versions/0001_initial_schema.py

"""initial schema (squashed)

单一迁移：pgvector + 当前全部 ORM 表（含 conversations.deleted_at 软删除）；并补充 models 未声明的
story_image_intents.asset_id → assets 外键，以及每个 story 仅一条 primary intent 的唯一索引。
chapters 含 story 物化字段：markdown_compose_dirty、markdown_composed_at、reading_segments_json
（阅读片段快照，随 ORM 一并 create_all）。

已并入原 0002（stories-first：无 chapter_sections / memoir_images.section_id）与原 0003（segments.tts_audio_urls）
的语义：新库仅由当前 ORM 建表即可，无需后续 ALTER。
conversation_messages（会话轮次 durable log）由 app.features.conversation.models.ConversationMessage 一并 create_all。
segments.audio_duration_seconds（语音条时长秒数，历史 API / Redis 回填）由 ORM 一并 create_all，无独立迁移。
story_image_intents 无 source_span（主图回填在正文末尾，意图仅存 caption / prompt_brief 等）。

新库 / 删库重来：`alembic upgrade head`。

Revision ID: 0001_initial
Revises:
"""

from typing import Sequence, Union

from alembic import op
from sqlalchemy import text

revision: str = "0001_initial"
down_revision: Union[str, None] = None
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_models  # noqa: F401
    from app.features.auth import models as _auth_models  # noqa: F401
    from app.features.conversation import models as _conv_models  # noqa: F401
    from app.features.memory import models as _memory_models  # noqa: F401
    from app.features.memoir import models as _memoir_models  # noqa: F401
    from app.features.payment import models as _payment_models  # noqa: F401
    from app.features.story import models as _story_models  # noqa: F401
    from app.features.user import models as _user_models  # noqa: F401


def upgrade() -> None:
    conn = op.get_bind()
    conn.execute(text("CREATE EXTENSION IF NOT EXISTS vector"))

    from app.core.db import Base

    _import_all_models()
    Base.metadata.create_all(bind=conn)

    op.create_foreign_key(
        "fk_story_image_intents_asset_id_assets",
        "story_image_intents",
        "assets",
        ["asset_id"],
        ["id"],
        ondelete="SET NULL",
    )
    op.execute(
        """
        CREATE UNIQUE INDEX IF NOT EXISTS uq_story_primary_image_intent
        ON story_image_intents (story_id)
        WHERE intent_role = 'primary'
        """
    )


def downgrade() -> None:
    conn = op.get_bind()
    from app.core.db import Base

    op.execute("DROP INDEX IF EXISTS uq_story_primary_image_intent")
    op.drop_constraint(
        "fk_story_image_intents_asset_id_assets",
        "story_image_intents",
        type_="foreignkey",
    )

    _import_all_models()
    Base.metadata.drop_all(bind=conn)
    conn.execute(text("DROP EXTENSION IF EXISTS vector"))