-- BossAi 2.0 阶段三 — 风险推送表
-- TASK-021: risk_alerts 表
-- 幂等:可重复执行
-- 运行:psql -d mcp -f migrations/002_risk_alerts.sql

BEGIN;

CREATE TABLE IF NOT EXISTS risk_alerts (
    id                SERIAL PRIMARY KEY,
    user_phone        TEXT NOT NULL,                    -- 推送对象(手机号)
    level             TEXT NOT NULL,                    -- red / orange / blue
    title             TEXT NOT NULL,                    -- 标题
    content           TEXT NOT NULL,                    -- 详情
    source            TEXT NOT NULL DEFAULT 'knowledge', -- knowledge / doc_scan / system
    related_matter_id INTEGER,                          -- 可空,关联案卡
    read_at           TIMESTAMPTZ,                      -- 可空,标记已读时间
    created_at        TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX IF NOT EXISTS idx_risk_alerts_user ON risk_alerts(user_phone);
CREATE INDEX IF NOT EXISTS idx_risk_alerts_user_read ON risk_alerts(user_phone, read_at);
CREATE INDEX IF NOT EXISTS idx_risk_alerts_created ON risk_alerts(created_at DESC);

ALTER TABLE risk_alerts DROP CONSTRAINT IF EXISTS chk_risk_alerts_level;
ALTER TABLE risk_alerts ADD CONSTRAINT chk_risk_alerts_level CHECK (
    level IN ('red', 'orange', 'blue')
);

COMMIT;

-- 回滚:
-- DROP TABLE IF EXISTS risk_alerts;