// 浙江省油价历史: 走 Prisma 落库 + apizero price 接口写入
// 设计:
//   - 每天 04:00 cron 检查 schedule, 待定且 <= 昨天的调价日 -> 抓 price?province=浙江 存本表
//   - unique (date, province, fuel) 防重复
//   - 查询 API: 取某省某油品最近 N 天 (默认 180)
import { prisma } from '../db.js'
import * as client from './client.js'

const PROVINCE = '浙江'
// 油品 -> apizero prices 对象里的 key (price action 返回 "92号汽油" 这种带后缀的 key)
const FUEL_KEYS = {
  '92': '92号汽油',
  '95': '95号汽油',
  '0': '0号柴油',
}

// 解析 apizero price action 返回的 prices (中文 key) -> 标准 fuel code
function parsePrice(data) {
  if (!data || !data.prices) throw new Error('apizero 响应无 prices 字段')
  const out = {}
  for (const [fuel, label] of Object.entries(FUEL_KEYS)) {
    const raw = data.prices[label]
    if (typeof raw === 'string') {
      // "7.64 元/升" -> 7.64
      const m = raw.match(/^([\d.]+)/)
      if (m) out[fuel] = parseFloat(m[1])
    } else if (typeof raw === 'number') {
      out[fuel] = raw
    }
  }
  return out
}

// 抓一次浙江当前价并入库 (date = 今日)
// 返回 { inserted, skipped } (按 unique 约束: 已存在则 skip)
export async function fetchAndStore() {
  const data = await client.get('oil-price-forecast', { action: 'price', province: PROVINCE })
  const prices = parsePrice(data)
  if (Object.keys(prices).length === 0) {
    throw new Error('apizero 返回价格为空')
  }
  const date = new Date()
  // 抹掉时分秒, 便于按天比较
  date.setHours(0, 0, 0, 0)

  let inserted = 0
  let skipped = 0
  for (const [fuel, price] of Object.entries(prices)) {
    try {
      await prisma.oilPriceHistory.create({
        data: { date, province: PROVINCE, fuel, price, source: 'apizero' },
      })
      inserted++
    } catch (e) {
      // P2002: unique 冲突 -> 跳过
      if (e?.code === 'P2002') skipped++
      else throw e
    }
  }
  return { inserted, skipped, date: date.toISOString().slice(0, 10) }
}

// 查询某省某油品最近 N 天
//   province 必填, 默认 浙江
//   fuel 可选, 留空返回 4 个油品
//   days 默认 180
export async function query({ province = PROVINCE, fuel, days = 180 }) {
  const since = new Date()
  since.setDate(since.getDate() - days)
  since.setHours(0, 0, 0, 0)

  const where = { province, date: { gte: since } }
  if (fuel) where.fuel = fuel

  const rows = await prisma.oilPriceHistory.findMany({
    where,
    orderBy: [{ date: 'asc' }],
  })

  // 整形: Decimal -> number
  return rows.map((r) => ({
    date: r.date.toISOString().slice(0, 10),
    province: r.province,
    fuel: r.fuel,
    price: Number(r.price),
  }))
}