"""微信（clawbot）接入通道

Revision ID: 0012
Revises: 0011
Create Date: 2026-11-05

两张表：

- `bot_channel`：一个工作区可以挂多个机器人通道，令牌只存 sha256。
- `bot_message`：进来的每条消息留痕，附带它变成了哪条任务/知识。

`bot_channel` 的 RLS 多放了一条口子：`token_hash = app_bot_token_hash()`。
原因很实在——**收到 webhook 时我们还不知道它是哪个工作区的**，而候选令牌
必须读过表才知道。没有这条口子，就只能要么关掉 RLS（不行），要么把令牌
放一张不挂租户的表里（等于把钥匙串放在门外）。现在的做法是：
请求先把 `app.bot_token_hash` 设成本次令牌的哈希，策略只允许命中那一行，
其余行照旧看不见。
"""

from __future__ import annotations

from collections.abc import Sequence

from alembic import op

from app.roles import APP_ROLE

revision: str = "0012"
down_revision: str = "0011"
branch_labels: Sequence[str] | None = None
depends_on: Sequence[str] | None = None

CREATE_STATEMENTS = (
    """
    CREATE TABLE bot_channel (
        id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
        workspace_id uuid NOT NULL REFERENCES workspace(id) ON DELETE CASCADE,
        kind varchar(32) NOT NULL DEFAULT 'wechat_clawbot',
        name varchar(64) NOT NULL DEFAULT '',
        token_hash varchar(64) NOT NULL,
        status varchar(16) NOT NULL DEFAULT 'active',
        created_by uuid REFERENCES app_user(id) ON DELETE SET NULL,
        last_seen_at timestamptz,
        last_error text,
        version integer NOT NULL DEFAULT 1,
        created_at timestamptz NOT NULL DEFAULT now(),
        updated_at timestamptz NOT NULL DEFAULT now()
    )
    """,
    """
    CREATE TABLE bot_message (
        id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
        workspace_id uuid NOT NULL REFERENCES workspace(id) ON DELETE CASCADE,
        channel_id uuid NOT NULL REFERENCES bot_channel(id) ON DELETE CASCADE,
        external_id varchar(128),
        sender varchar(128),
        text text NOT NULL DEFAULT '',
        action varchar(24) NOT NULL DEFAULT 'ignored',
        item_id uuid REFERENCES item(id) ON DELETE SET NULL,
        reply text NOT NULL DEFAULT '',
        raw jsonb NOT NULL DEFAULT '{}'::jsonb,
        version integer NOT NULL DEFAULT 1,
        created_at timestamptz NOT NULL DEFAULT now(),
        updated_at timestamptz NOT NULL DEFAULT now()
    )
    """,
)

INDEX_STATEMENTS = (
    "CREATE INDEX ix_bot_channel_ws ON bot_channel (workspace_id)",
    "CREATE UNIQUE INDEX uq_bot_channel_token ON bot_channel (token_hash)",
    "CREATE INDEX ix_bot_message_channel ON bot_message (channel_id, created_at)",
    "CREATE UNIQUE INDEX uq_bot_message_external ON bot_message (channel_id, external_id) "
    "WHERE external_id IS NOT NULL",
)

POLICY_SQL = (
    "ALTER TABLE bot_channel ENABLE ROW LEVEL SECURITY",
    "CREATE POLICY bot_channel_isolation ON bot_channel "
    "USING (workspace_id = app_ws_id() OR token_hash = current_setting('app.bot_token_hash', true)) "
    "WITH CHECK (workspace_id = app_ws_id())",
    "ALTER TABLE bot_message ENABLE ROW LEVEL SECURITY",
    "CREATE POLICY bot_message_isolation ON bot_message "
    "USING (workspace_id = app_ws_id()) WITH CHECK (workspace_id = app_ws_id())",
    f"GRANT SELECT, INSERT, UPDATE, DELETE ON bot_channel TO {APP_ROLE}",
    f"GRANT SELECT, INSERT, UPDATE, DELETE ON bot_message TO {APP_ROLE}",
)

COMMENT_SQL = (
    "COMMENT ON TABLE bot_channel IS '外部接入通道（微信 clawbot 等），令牌只存 sha256'",
    "COMMENT ON TABLE bot_message IS '外部接入收到并处理过的消息，用于支线排查与去重'",
)


def upgrade() -> None:
    for statement in CREATE_STATEMENTS:
        op.execute(statement)
    for statement in INDEX_STATEMENTS:
        op.execute(statement)
    for statement in POLICY_SQL:
        op.execute(statement)
    for statement in COMMENT_SQL:
        op.execute(statement)


def downgrade() -> None:
    op.execute("DROP TABLE IF EXISTS bot_message")
    op.execute("DROP TABLE IF EXISTS bot_channel")