"""chat_group 补 group_remark 列 + chat_group_member_stats 按天进出表

Revision ID: c9d0e1f2a3b4
Revises: b7c8d9e0f1a2
Create Date: 2026-09-09

内容
----
微信群列表对齐云客「微信群统计」页(2026-09-09 真机探明,数据源切
``getChatroomList``):

* ``chat_group.group_remark`` —— 群备注列(getChatroomList.remark /
  friend_list/es 的 friendWxRemark,此前只存 raw_json);
* ``chat_group_member_stats`` —— 群成员进出**按天**统计表。云客的新增/
  退出成员数是按任意时间窗实时算的,本地无成员进出事件流,改为每夜抓
  一次「当日窗」的 addMembers/lossMembers 落行,页面任意日窗=按天求和;
  上线日起积累,历史日期无数据。

幂等:列/表存在即跳过。SQLite/MySQL 通用。
"""
from collections.abc import Sequence

import sqlalchemy as sa
from alembic import op

# revision identifiers, used by Alembic.
revision: str = 'c9d0e1f2a3b4'
down_revision: str | Sequence[str] | None = 'b7c8d9e0f1a2'
branch_labels: str | Sequence[str] | None = None
depends_on: str | Sequence[str] | None = None

_TABLE = 'chat_group_member_stats'
_COL = 'group_remark'


def _has_table(table: str) -> bool:
    insp = sa.inspect(op.get_bind())
    return table in insp.get_table_names()


def _has_column(table: str, column: str) -> bool:
    insp = sa.inspect(op.get_bind())
    return column in {c["name"] for c in insp.get_columns(table)}


def upgrade() -> None:
    """Upgrade schema."""
    if not _has_column("chat_group", _COL):
        op.add_column("chat_group", sa.Column(_COL, sa.String(255), nullable=True))
    # 回填:群备注从存量 raw_json.friendWxRemark 提取(friend_list/es 来源;
    # getChatroomList 行无备注键)。幂等:只补 NULL 行。MySQL 方言
    # (JSON_UNQUOTE),SQLite(测试库,不走生产迁移)跳过。
    if op.get_bind().dialect.name == "mysql":
        op.execute(
            "UPDATE chat_group SET group_remark = JSON_UNQUOTE(JSON_EXTRACT(raw_json, '$.friendWxRemark')) "
            "WHERE group_remark IS NULL "
            "AND JSON_UNQUOTE(JSON_EXTRACT(raw_json, '$.friendWxRemark')) IS NOT NULL "
            "AND JSON_UNQUOTE(JSON_EXTRACT(raw_json, '$.friendWxRemark')) != ''"
        )
    if _has_table(_TABLE):
        return  # 已建过,幂等跳过
    op.create_table(
        _TABLE,
        sa.Column('channel', sa.String(16), primary_key=True),
        sa.Column('owner_account_id', sa.String(128), primary_key=True),
        sa.Column('room_id', sa.String(128), primary_key=True),
        sa.Column('day', sa.Integer(), primary_key=True),
        sa.Column('added', sa.Integer(), nullable=False, server_default='0'),
        sa.Column('lost', sa.Integer(), nullable=False, server_default='0'),
        sa.Column('fetched_at', sa.DateTime(), nullable=True),
        sa.Column('updated_at', sa.DateTime(), nullable=True),
    )


def downgrade() -> None:
    """Downgrade schema."""
    if _has_table(_TABLE):
        op.drop_table(_TABLE)
    if _has_column("chat_group", _COL):
        op.drop_column("chat_group", _COL)