"""幂等执行 memory_unit 表结构升级（对齐 model/memory_unit.py）。

用法：
    python scripts/apply_memory_unit_upgrade.py

对应 SQL 版本见 sql/memory_unit_upgrade_20260913.sql。
重复执行安全：ADD COLUMN 前检查 information_schema，MODIFY/UPDATE 本身幂等。
"""
from __future__ import annotations

import asyncio
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from sqlalchemy import text

from config.database import mysql as mysql_db
from config.database.mysql import get_session_factory
from config.settings import settings

TABLE = "memory_unit"

ADD_COLUMNS = {
    "session_id": "session_id VARCHAR(64) NULL COMMENT '产生记忆的会话ID'",
    "agent_run_id": "agent_run_id VARCHAR(64) NULL COMMENT '产生记忆的Agent运行ID'",
    "evidence_ref": "evidence_ref JSON NULL COMMENT '证据引用列表(会话/消息溯源)'",
    "historical_accuracy": "historical_accuracy DECIMAL(5,2) NOT NULL DEFAULT 0.50 COMMENT '历史准确率'",
    "confidence_version": "confidence_version VARCHAR(32) NULL COMMENT '置信度算法版本'",
    "confidence_reason": "confidence_reason VARCHAR(255) NULL COMMENT '置信度评分原因'",
    "confidence_update_time": "confidence_update_time DATETIME NULL COMMENT '置信度更新时间'",
    "memory_version": "memory_version INT NOT NULL DEFAULT 1 COMMENT '记忆版本号'",
    "last_verified_at": "last_verified_at DATETIME NULL COMMENT '最近验证时间'",
    "milvus_id": "milvus_id VARCHAR(128) NULL COMMENT 'Milvus向量主键'",
    "graph_node_id": "graph_node_id VARCHAR(128) NULL COMMENT 'Neo4j图谱节点ID'",
    "milvus_sync_status": "milvus_sync_status VARCHAR(16) NOT NULL DEFAULT 'pending' COMMENT '向量同步状态'",
    "neo4j_sync_status": "neo4j_sync_status VARCHAR(16) NOT NULL DEFAULT 'pending' COMMENT '图谱同步状态'",
    "sync_retry_count": "sync_retry_count INT NOT NULL DEFAULT 0 COMMENT '同步重试次数'",
    "last_sync_error": "last_sync_error VARCHAR(500) NULL COMMENT '最近同步错误'",
    "next_retry_at": "next_retry_at DATETIME NULL COMMENT '下次重试时间'",
    "last_synced_at": "last_synced_at DATETIME NULL COMMENT '最近成功同步时间'",
}


async def columns_of(session, database: str) -> dict[str, str]:
    rows = (
        await session.execute(
            text(
                "SELECT COLUMN_NAME, DATA_TYPE FROM information_schema.columns "
                "WHERE TABLE_SCHEMA = :d AND TABLE_NAME = :t"
            ),
            {"d": database, "t": TABLE},
        )
    ).mappings().all()
    return {str(r["COLUMN_NAME"]): str(r["DATA_TYPE"]).lower() for r in rows}


async def main() -> None:
    async with get_session_factory()() as session:
        db = settings.mysql.database
        cols = await columns_of(session, db)

        added = []
        for name, ddl in ADD_COLUMNS.items():
            if name in cols:
                print(f"[skip] 列已存在: {name}")
                continue
            await session.execute(text(f"ALTER TABLE {TABLE} ADD COLUMN {ddl}"))
            added.append(name)
            print(f"[ok]   新增列: {name}")
        await session.commit()

        cols = await columns_of(session, db)

        if cols.get("valid_from") == "date" or cols.get("valid_until") == "date":
            await session.execute(
                text(
                    f"ALTER TABLE {TABLE} "
                    "MODIFY COLUMN valid_from DATETIME NULL COMMENT '生效起始时间', "
                    "MODIFY COLUMN valid_until DATETIME NULL COMMENT '失效时间'"
                )
            )
            await session.commit()
            print("[ok]   valid_from/valid_until: DATE -> DATETIME")
        else:
            print("[skip] valid_from/valid_until 已是 DATETIME")

        result = await session.execute(
            text(f"UPDATE {TABLE} SET status = 'candidate' WHERE status = 'active'")
        )
        await session.commit()
        print(f"[ok]   status active->candidate: {result.rowcount} 行")

        await session.execute(
            text(
                f"ALTER TABLE {TABLE} MODIFY COLUMN status VARCHAR(16) NOT NULL "
                "DEFAULT 'candidate' COMMENT '记忆状态(candidate/confirmed/expired/rejected/archived)'"
            )
        )
        await session.commit()
        print("[ok]   status 默认值改为 candidate")

        result = await session.execute(
            text(
                f"UPDATE {TABLE} SET memory_type = 'SERVICE_FACT' "
                "WHERE memory_type IS NULL OR memory_type = 'FACT'"
            )
        )
        await session.commit()
        print(f"[ok]   memory_type NULL/FACT -> SERVICE_FACT: {result.rowcount} 行")

        await session.execute(
            text(
                f"ALTER TABLE {TABLE} MODIFY COLUMN memory_type VARCHAR(32) NOT NULL "
                "COMMENT '记忆业务类型'"
            )
        )
        await session.commit()
        print("[ok]   memory_type 收紧为 NOT NULL")

        final = await columns_of(session, db)
        missing = [name for name in ADD_COLUMNS if name not in final]
        if missing:
            print(f"[fail] 仍有缺失列: {missing}")
            raise SystemExit(1)
        null_types = (
            await session.execute(
                text(f"SELECT COUNT(*) AS n FROM {TABLE} WHERE memory_type IS NULL")
            )
        ).scalar()
        print(f"[done] 迁移完成，共新增 {len(added)} 列；memory_type NULL 残留: {null_types}")

    await mysql_db.dispose()


if __name__ == "__main__":
    asyncio.run(main())