import { requireAuth, requireCap } from '../auth.js'
import { getConfig } from '../db.js'

async function fcFetch(path) {
  const apiKey  = await getConfig('forecasting_api_key')
  const baseUrl = (await getConfig('forecasting_url')) || 'http://10.10.10.113:3080'
  if (!apiKey) throw new Error('Forecasting API key not configured — add it in Settings')
  const res = await fetch(`${baseUrl}/forecasting/api/public${path}`, {
    headers: { 'X-API-Key': apiKey },
    signal: AbortSignal.timeout(15000),
  })
  if (!res.ok) throw new Error(`Forecasting API ${res.status} — ${path}`)
  return res.json()
}

function daysBetween(from, to) {
  const a = new Date(from + 'T00:00:00')
  const b = new Date(to   + 'T00:00:00')
  return Math.max(1, Math.ceil((b - a) / 86_400_000) + 1)
}

export async function netSalesRoutes(fastify) {
  fastify.addHook('preHandler', requireAuth)

  // Returns daily net sales and prior-year net sales for a date range.
  fastify.get('/api/net-sales', { preHandler: requireCap('view') }, async (request, reply) => {
    const { from, to } = request.query
    if (!from || !to) return reply.status(400).send({ error: 'from and to required' })

    const MAX_DAYS = 365
    const totalDays = daysBetween(from, to)
    const allDays = []

    // Batch into ≤365-day chunks if range exceeds API limit
    let batchStart = new Date(from + 'T00:00:00')
    const end      = new Date(to   + 'T00:00:00')
    while (batchStart <= end) {
      const remaining = Math.ceil((end - batchStart) / 86_400_000) + 1
      const batchDays = Math.min(remaining, MAX_DAYS)
      const startStr  = batchStart.toISOString().slice(0, 10)
      const data = await fcFetch(`/forecast/revenue?start_date=${startStr}&days=${batchDays}&type=all&dow_align=true`)
      for (const d of (data?.data ?? [])) {
        allDays.push({
          date:      d.date,
          net_sales: parseFloat(d.total?.otb         ?? 0),
          py_sales:  parseFloat(d.total?.prior_final  ?? 0),
          accom:     parseFloat(d.accom?.otb          ?? 0),
          dry:       parseFloat(d.dry?.otb            ?? 0),
          wet:       parseFloat(d.wet?.otb            ?? 0),
          is_past:   d.is_past ?? true,
        })
      }
      batchStart.setDate(batchStart.getDate() + batchDays)
    }

    return { days: allDays }
  })
}