import { requireAuth } from '../auth.js'

const FORECASTING_URL = process.env.FORECASTING_URL || 'http://10.10.10.113:3080'

async function fcFetch(path) {
  const apiKey = process.env.FORECASTING_API_KEY
  if (!apiKey) throw new Error('FORECASTING_API_KEY not configured')
  const res = await fetch(`${FORECASTING_URL}/forecasting/api/public${path}`, {
    headers: { 'X-API-Key': apiKey },
  })
  if (!res.ok) throw new Error(`Forecasting API ${res.status} — ${path}`)
  return res.json()
}

function toDateStr(d) {
  return d.toISOString().split('T')[0]
}

function addDays(d, n) {
  const r = new Date(d)
  r.setDate(r.getDate() + n)
  return r
}

function buildDayMap(data) {
  const m = {}
  for (const d of (data?.data ?? [])) m[d.date] = d
  return m
}

const DOW_NAMES = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat']
const MONTH_LABELS = ['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec']

function weekSummary(revDayMap, weekSundayDate, weekEndingDateStr) {
  let net = 0, budget = 0, ly = 0
  let net_rooms = 0, net_dry = 0, net_wet = 0
  let budget_rooms = 0, budget_dry = 0, budget_wet = 0
  let ly_rooms = 0, ly_dry = 0, ly_wet = 0

  for (let i = 0; i < 7; i++) {
    const dateStr = toDateStr(addDays(weekSundayDate, i))
    const rev = revDayMap[dateStr] || {}
    const r  = parseFloat(rev.accom?.otb         ?? 0)
    const d  = parseFloat(rev.dry?.otb           ?? 0)
    const w  = parseFloat(rev.wet?.otb           ?? 0)
    const br = parseFloat(rev.accom?.budget      ?? 0)
    const bd = parseFloat(rev.dry?.budget        ?? 0)
    const bw = parseFloat(rev.wet?.budget        ?? 0)
    const lr = parseFloat(rev.accom?.prior_final ?? 0)
    const ld = parseFloat(rev.dry?.prior_final   ?? 0)
    const lw = parseFloat(rev.wet?.prior_final   ?? 0)

    net_rooms    += r;  net_dry    += d;  net_wet    += w
    budget_rooms += br; budget_dry += bd; budget_wet += bw
    ly_rooms     += lr; ly_dry     += ld; ly_wet     += lw
    net += r + d + w;  budget += br + bd + bw;  ly += lr + ld + lw
  }

  return {
    week_ending: weekEndingDateStr,
    gross: net * 1.20,
    net,
    pct_to_budget: budget > 0 ? ((net - budget) / budget) * 100 : null,
    budget_net: budget,
    pct_to_ly: ly > 0 ? ((net - ly) / ly) * 100 : null,
    ly_net: ly,
    dept: {
      rooms: { net: net_rooms, budget: budget_rooms, ly: ly_rooms },
      dry:   { net: net_dry,   budget: budget_dry,   ly: ly_dry   },
      wet:   { net: net_wet,   budget: budget_wet,   ly: ly_wet   },
    },
  }
}

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

  // GET /api/weekly-actual/:date  (date = week ending Saturday, YYYY-MM-DD)
  fastify.get('/api/weekly-actual/:date', async (request, reply) => {
    const weekEndDate = new Date(request.params.date + 'T00:00:00')
    if (isNaN(weekEndDate.getTime())) return reply.status(400).send({ error: 'Invalid date' })

    // Week runs Sun → Sat
    const weekStartDate = addDays(weekEndDate, -6)
    const year  = weekEndDate.getFullYear()
    const month = weekEndDate.getMonth() + 1

    // 5-week window: start 4 weeks before this week's Sunday
    const fiveWeekStart = addDays(weekStartDate, -28)

    // Full calendar month (needed for daily chart — month progress filters by date)
    const monthStart  = new Date(year, month - 1, 1)
    const daysInMonth = new Date(year, month, 0).getDate()

    // 36 months of raw totals needed to compute rolling 12-month averages for
    // 12 display points (indices 23–35) plus their LY equivalents (indices 0–23)
    const trendMonths = []
    for (let i = 35; i >= 0; i--) {
      const d = new Date(year, month - 1 - i, 1)
      trendMonths.push({ year: d.getFullYear(), month: d.getMonth() + 1 })
    }

    // All API calls in parallel
    const results = await Promise.all([
      // 35 days of revenue (5 × 7 weeks)
      fcFetch(`/forecast/revenue?start_date=${toDateStr(fiveWeekStart)}&days=35&type=all`),
      // This week rooms (for occupancy table)
      fcFetch(`/forecast/rooms?start_date=${toDateStr(weekStartDate)}&days=7`),
      // Full month revenue (used for month progress totals + daily chart)
      fcFetch(`/forecast/revenue?start_date=${toDateStr(monthStart)}&days=${daysInMonth}&type=all`),
      // 12 monthly trend revenue calls
      ...trendMonths.map(({ year: y, month: m }) => {
        const firstDay  = new Date(y, m - 1, 1)
        const daysInMon = new Date(y, m, 0).getDate()
        return fcFetch(`/forecast/revenue?start_date=${toDateStr(firstDay)}&days=${daysInMon}&type=all`)
      }),
    ])

    const [fiveWeekRevRaw, thisWeekRoomsRaw, fullMonthRevRaw, ...trendRevRaw] = results

    const fiveWeekRevMap   = buildDayMap(fiveWeekRevRaw)
    const thisWeekRoomsMap = buildDayMap(thisWeekRoomsRaw)
    const fullMonthRevMap  = buildDayMap(fullMonthRevRaw)

    // ── Five week summaries ────────────────────────────────────────────────────
    const fiveWeeks = [0, 1, 2, 3, 4].map(w => {
      const sundayDate   = addDays(weekStartDate, -7 * w)
      const saturdayDate = addDays(sundayDate, 6)
      return weekSummary(fiveWeekRevMap, sundayDate, toDateStr(saturdayDate))
    })

    const thisWeek = fiveWeeks[0]
    const lastWeek = fiveWeeks[1]

    // ── Occupancy by DOW ──────────────────────────────────────────────────────
    let totalAvail = 0, totalSold = 0, totalAccomm = 0
    const daily = []

    for (let i = 0; i < 7; i++) {
      const d       = addDays(weekStartDate, i)
      const dateStr = toDateStr(d)
      const rev     = fiveWeekRevMap[dateStr] || {}
      const rm      = thisWeekRoomsMap[dateStr] || {}

      const available   = parseInt(rm.available_rooms ?? 0)
      const rooms_sold  = parseInt(rm.otb_rooms       ?? 0)
      const accomm      = parseFloat(rev.accom?.otb   ?? 0)

      totalAvail   += available
      totalSold    += rooms_sold
      totalAccomm  += accomm

      daily.push({
        date:      dateStr,
        dow:       DOW_NAMES[d.getDay()],
        available,
        rooms_sold,
        accomm,
        arr:      rooms_sold > 0 ? accomm / rooms_sold : null,
        occ_pct:  available  > 0 ? (rooms_sold / available) * 100 : null,
        revpar:   available  > 0 ? accomm / available : null,
      })
    }

    const occupancy = {
      daily,
      totals: {
        available:  totalAvail,
        rooms_sold: totalSold,
        accomm:     totalAccomm,
        arr:        totalSold  > 0 ? totalAccomm / totalSold  : null,
        occ_pct:    totalAvail > 0 ? (totalSold / totalAvail) * 100 : null,
        revpar:     totalAvail > 0 ? totalAccomm / totalAvail : null,
      },
    }

    // ── Month progress ─────────────────────────────────────────────────────────
    let mNet = { rooms: 0, dry: 0, wet: 0 }
    let mBud = { rooms: 0, dry: 0, wet: 0 }
    let mLy  = { rooms: 0, dry: 0, wet: 0 }

    for (let i = 0; i < daysInMonth; i++) {
      const d   = addDays(monthStart, i)
      if (d > weekEndDate) break
      const dateStr = toDateStr(d)
      const rev = fullMonthRevMap[dateStr] || {}

      mNet.rooms += parseFloat(rev.accom?.otb         ?? 0)
      mNet.dry   += parseFloat(rev.dry?.otb           ?? 0)
      mNet.wet   += parseFloat(rev.wet?.otb           ?? 0)
      mBud.rooms += parseFloat(rev.accom?.budget      ?? 0)
      mBud.dry   += parseFloat(rev.dry?.budget        ?? 0)
      mBud.wet   += parseFloat(rev.wet?.budget        ?? 0)
      mLy.rooms  += parseFloat(rev.accom?.prior_final ?? 0)
      mLy.dry    += parseFloat(rev.dry?.prior_final   ?? 0)
      mLy.wet    += parseFloat(rev.wet?.prior_final   ?? 0)
    }

    const mNetTotal = mNet.rooms + mNet.dry + mNet.wet
    const mBudTotal = mBud.rooms + mBud.dry + mBud.wet
    const mLyTotal  = mLy.rooms  + mLy.dry  + mLy.wet

    const month_progress = {
      year, month,
      date_to:    toDateStr(weekEndDate),
      gross:      mNetTotal * 1.20,
      net:        mNetTotal,
      budget_net: mBudTotal,
      ly_net:     mLyTotal,
      pct_to_budget: mBudTotal > 0 ? ((mNetTotal - mBudTotal) / mBudTotal) * 100 : null,
      pct_to_ly:     mLyTotal  > 0 ? ((mNetTotal - mLyTotal)  / mLyTotal)  * 100 : null,
      split: {
        rooms: { net: mNet.rooms, budget_net: mBud.rooms, ly_net: mLy.rooms,
          pct_to_budget: mBud.rooms > 0 ? ((mNet.rooms - mBud.rooms) / mBud.rooms) * 100 : null,
          pct_to_ly:     mLy.rooms  > 0 ? ((mNet.rooms - mLy.rooms)  / mLy.rooms)  * 100 : null },
        dry: { net: mNet.dry, budget_net: mBud.dry, ly_net: mLy.dry,
          pct_to_budget: mBud.dry > 0 ? ((mNet.dry - mBud.dry) / mBud.dry) * 100 : null,
          pct_to_ly:     mLy.dry  > 0 ? ((mNet.dry - mLy.dry)  / mLy.dry)  * 100 : null },
        wet: { net: mNet.wet, budget_net: mBud.wet, ly_net: mLy.wet,
          pct_to_budget: mBud.wet > 0 ? ((mNet.wet - mBud.wet) / mBud.wet) * 100 : null,
          pct_to_ly:     mLy.wet  > 0 ? ((mNet.wet - mLy.wet)  / mLy.wet)  * 100 : null },
      },
    }

    // ── Month daily (for cumulative progress line chart) ──────────────────────
    const weekEndStr  = toDateStr(weekEndDate)
    const month_daily = []
    for (let i = 0; i < daysInMonth; i++) {
      const d       = addDays(monthStart, i)
      const dateStr = toDateStr(d)
      const rev     = fullMonthRevMap[dateStr] || {}
      month_daily.push({
        day:      i + 1,
        date:     dateStr,
        ty_rooms: parseFloat(rev.accom?.otb         ?? 0),
        ty_dry:   parseFloat(rev.dry?.otb           ?? 0),
        ty_wet:   parseFloat(rev.wet?.otb           ?? 0),
        ly_rooms: parseFloat(rev.accom?.prior_final ?? 0),
        ly_dry:   parseFloat(rev.dry?.prior_final   ?? 0),
        ly_wet:   parseFloat(rev.wet?.prior_final   ?? 0),
        is_actual: dateStr <= weekEndStr,
      })
    }

    // ── Monthly trend (rolling 12-month average) ──────────────────────────────
    // Build raw monthly totals for all 36 months
    const allMonthTotals = trendMonths.map((_, i) => {
      const data = trendRevRaw[i]?.data ?? []
      let total = 0
      for (const d of data) {
        total += parseFloat(d.accom?.otb ?? 0)
                + parseFloat(d.dry?.otb   ?? 0)
                + parseFloat(d.wet?.otb   ?? 0)
      }
      return total
    })

    const rollingAvg = (arr, from, to) =>
      arr.slice(from, to + 1).reduce((s, v) => s + v, 0) / (to - from + 1)

    // Display points: indices 23–35 (the last 12 months)
    // TY rolling avg at index i = average of allMonthTotals[i-11 .. i]
    // LY rolling avg at index i = average of allMonthTotals[i-23 .. i-12]
    const monthly_trend = []
    for (let i = 23; i < 36; i++) {
      const tm = trendMonths[i]
      monthly_trend.push({
        label:         `${MONTH_LABELS[tm.month - 1]}-${String(tm.year).slice(2)}`,
        this_year_avg: rollingAvg(allMonthTotals, i - 11, i),
        last_year_avg: rollingAvg(allMonthTotals, i - 23, i - 12),
      })
    }

    // Monthly dept split for last 24 months (indices 12–35)
    // — previous 12 months followed by last 12 months
    const monthly_split = []
    for (let i = 12; i < 36; i++) {
      const tm   = trendMonths[i]
      const data = trendRevRaw[i]?.data ?? []
      let rooms = 0, dry = 0, wet = 0
      for (const d of data) {
        rooms += parseFloat(d.accom?.otb ?? 0)
        dry   += parseFloat(d.dry?.otb   ?? 0)
        wet   += parseFloat(d.wet?.otb   ?? 0)
      }
      monthly_split.push({
        label: `${MONTH_LABELS[tm.month - 1]}-${String(tm.year).slice(2)}`,
        rooms, dry, wet,
      })
    }

    return {
      week_ending: toDateStr(weekEndDate),
      week_start:  toDateStr(weekStartDate),
      this_week:   thisWeek,
      last_week:   lastWeek.dept,
      five_weeks:  fiveWeeks,
      occupancy,
      month_progress,
      month_daily,
      monthly_trend,
      monthly_split,
    }
  })
}