balloon-shop/estore/src/app/api/delivery-quote/route.ts

import { NextResponse } from 'next/server'
import { geocode, calcDelivery, inferTier } from '@/lib/delivery'
import { readDeliveryRates } from '@/lib/delivery-rates'

export async function POST(request: Request) {
  const { address, itemNames, rateOverride } = await request.json() as {
    address:      string
    itemNames:    string[]
    rateOverride?: { base: number; perMile: number }
  }

  if (!address?.trim()) {
    return NextResponse.json({ error: 'Address required' }, { status: 400 })
  }

  const coords = await geocode(address)
  if (!coords) {
    return NextResponse.json({ error: 'Address not found — please try a more specific address.' }, { status: 422 })
  }

  const tier  = inferTier(itemNames ?? [])
  const rates = readDeliveryRates()

  // Apply per-item rate override if provided (overrides just base and perMile for the inferred tier)
  if (rateOverride) {
    rates[tier] = {
      ...rates[tier],
      base:    rateOverride.base,
      perMile: rateOverride.perMile,
    }
  }

  const quote = await calcDelivery(coords.lat, coords.lng, tier, rates)

  if (quote.miles > 40) {
    return NextResponse.json(
      {
        error: `This address is ${quote.miles.toFixed(1)} miles away — online scheduling is available within 40 miles. Please contact us directly to arrange delivery.`,
        tooFar: true,
      },
      { status: 422 }
    )
  }

  return NextResponse.json(quote)
}