import { query } from '../db/client.js'
import { nowIso } from '../utils/time.js'

/**
 * 管道水位：订单项级游标 + 按日水位 + 最近失败原因。
 *
 * 只在服务端使用，不依赖 scheduler，避免循环依赖。
 */

export type WatermarkPipeline =
  | 'channel_assign'
  | 'carrier_dispatch'
  | 'product_normalize'
  | 'cost_snapshot'
  | 'sales_facts'
  | 'ledger_post'

/** 读取订单项级游标；没有记录时返回 0。 */
export async function readWatermarkItemId(pipeline: WatermarkPipeline): Promise<number> {
  const result = await query<{ last_item_id: string }>(
    `SELECT last_item_id::text FROM finance_watermarks WHERE pipeline = $1`,
    [pipeline],
  )
  return Number(result.rows[0]?.last_item_id || 0)
}

/** 记录一次成功运行的水位。 */
export async function touchWatermark(
  pipeline: WatermarkPipeline,
  patch: { lastItemId?: number; lastStatDate?: string | null } = {},
): Promise<void> {
  const now = nowIso()
  await query(
    `
      INSERT INTO finance_watermarks (pipeline, last_item_id, last_stat_date, last_success_at, updated_at)
      VALUES ($1, $2, $3::date, $4, $4)
      ON CONFLICT (pipeline) DO UPDATE SET
        last_item_id = EXCLUDED.last_item_id,
        last_stat_date = COALESCE(EXCLUDED.last_stat_date, finance_watermarks.last_stat_date),
        last_success_at = EXCLUDED.last_success_at,
        last_error = '',
        updated_at = EXCLUDED.updated_at
    `,
    [pipeline, Math.max(0, Math.trunc(patch.lastItemId || 0)), patch.lastStatDate ?? null, now],
  )
}

/** 记录一次失败原因，不改水位。 */
export async function recordPipelineError(
  pipeline: WatermarkPipeline,
  error: unknown,
): Promise<void> {
  const message = error instanceof Error ? error.message : String(error)
  await query(
    `
      INSERT INTO finance_watermarks (pipeline, last_error, updated_at)
      VALUES ($1, $2, $3)
      ON CONFLICT (pipeline) DO UPDATE SET
        last_error = EXCLUDED.last_error,
        updated_at = EXCLUDED.updated_at
    `,
    [pipeline, message.slice(0, 500), nowIso()],
  )
}