'use client'

import { useEffect, useState } from 'react'
import { Language } from '@/lib/types'
import { t } from '@/lib/i18n'
import GradientText from '../ui/GradientText'
import FadeInView from '../ui/FadeInView'
import GlassCard from '../ui/GlassCard'
import { TrendingUp, TrendingDown, Minus } from 'lucide-react'

interface AssumptionsSlideProps {
  lang: Language
  investorId?: string | null
  preferredScenarioId?: string | null
  isWandeldarlehen?: boolean
}

function fmtArr(v: number, de: boolean): string {
  if (v >= 1_000_000) {
    const m = (v / 1_000_000).toFixed(1)
    return de ? `~${m.replace('.', ',')} Mio. EUR` : `~EUR ${m}M`
  }
  return de ? `~${Math.round(v / 1000)}k EUR` : `~EUR ${Math.round(v / 1000)}k`
}

function fmtCash(v: number, de: boolean): string {
  if (Math.abs(v) >= 1_000_000) {
    const m = (v / 1_000_000).toFixed(1)
    return de ? `~${m.replace('.', ',')} Mio. EUR` : `~EUR ${m}M`
  }
  return de ? `~${Math.round(v / 1000)}k EUR` : `~EUR ${Math.round(v / 1000)}k`
}

interface SheetRow {
  row_label?: string
  values?: Record<string, number>
  values_total?: Record<string, number>
  is_sum_row?: boolean
}

export default function AssumptionsSlide({ lang, investorId, preferredScenarioId, isWandeldarlehen }: AssumptionsSlideProps) {
  const i = t(lang)
  const de = lang === 'de'

  // Load KPIs from fp_* tables (source of truth)
  const [baseKPIs, setBaseKPIs] = useState<Record<string, number>>({})

  useEffect(() => {
    async function load() {
      try {
        const scenarioParam = isWandeldarlehen ? '?scenarioId=c0000000-0000-0000-0000-000000000200' : ''
        const [guvRes, liqRes, persRes, kundenRes] = await Promise.all([
          fetch(`/api/finanzplan/guv${scenarioParam}`, { cache: 'no-store' }),
          fetch(`/api/finanzplan/liquiditaet${scenarioParam}`, { cache: 'no-store' }),
          fetch(`/api/finanzplan/personalkosten${scenarioParam}`, { cache: 'no-store' }),
          fetch(`/api/finanzplan/kunden${scenarioParam}`, { cache: 'no-store' }),
        ])
        const [guv, liq, pers, kunden] = await Promise.all([guvRes.json(), liqRes.json(), persRes.json(), kundenRes.json()])

        const findGuv = (label: string) => (guv.rows || []).find((r: SheetRow) => (r.row_label || '').includes(label))
        const findLiq = (label: string) => (liq.rows || []).find((r: SheetRow) => (r.row_label || '').includes(label))
        const kundenGesamt = (kunden.rows || []).find((r: SheetRow) => r.row_label === 'Bestandskunden gesamt')

        const arr = findGuv('Umsatzerlöse')?.values?.y2030 || 0
        const customers = kundenGesamt?.values?.m60 || 0
        const headcount = (pers.rows || []).filter((r: SheetRow) => ((r.values_total || r.values)?.m60 || 0) > 0).length
        const cash = findLiq('LIQUIDIT')?.values?.m60 || findLiq('LIQUIDITAET')?.values?.m60 || 0
        const ebit = findGuv('EBIT')?.values || {}
        // Find break-even year
        let breakEvenYear = '—'
        for (const y of [2026, 2027, 2028, 2029, 2030]) {
          if ((ebit[`y${y}`] || 0) > 0) { breakEvenYear = String(y); break }
        }

        setBaseKPIs({ arr, customers, headcount, cash, breakEvenYear: parseInt(breakEvenYear) || 0 })
      } catch { /* ignore */ }
    }
    load()
  }, [isWandeldarlehen])

  const baseCustomers = baseKPIs.customers || 0
  const baseArr = baseKPIs.arr || 0
  const baseEmployees = baseKPIs.headcount || 0
  const baseCash = baseKPIs.cash || 0
  const baseBreakEven = baseKPIs.breakEvenYear ? String(baseKPIs.breakEvenYear) : '—'

  // Bear/Bull scaled from Base
  const bearCustomers = Math.round(baseCustomers * 0.5)
  const bearArr = baseArr * 0.42
  const bearEmployees = Math.round(baseEmployees * 0.7)
  const bearCash = Math.round(baseCash * 0.3)
  const bearBreakEven = baseKPIs.breakEvenYear ? String(baseKPIs.breakEvenYear + 1) : '—'

  const bullCustomers = Math.round(baseCustomers * 1.7)
  const bullArr = baseArr * 1.8
  const bullEmployees = Math.round(baseEmployees * 1.3)
  const bullCash = Math.round(baseCash * 2.0)
  const bullBreakEven = baseKPIs.breakEvenYear ? String(baseKPIs.breakEvenYear - 1) : '—'

  const baseAssumptions = isWandeldarlehen
    ? (de ? [
        `Kundenwachstum: 8% monatlich (Slow), ab m32: 15%`,
        'Mix: 60% Starter, 25% Professional, 15% Enterprise',
        `Personalaufbau: 3→${baseEmployees} Personen (lean)`,
        'Serverkosten: 50€/Kunde + 300€ Basis',
        `Break-Even ${baseBreakEven}`,
      ] : [
        `Customer growth: 8% monthly (slow), from m32: 15%`,
        'Mix: 60% Starter, 25% Professional, 15% Enterprise',
        `Hiring: 3→${baseEmployees} people (lean)`,
        'Server costs: €50/customer + €300 base',
        `Break-even ${baseBreakEven}`,
      ])
    : (de ? [
        'Kundenwachstum wie geplant (5→1.200)',
        'Mix: 60% Starter, 25% Professional, 15% Enterprise',
        'Personalaufbau 5→10→17→25→35',
        'Serverkosten 100€ pro Kunde + 2.000€ Basis',
        'Break-Even Mitte 2029',
      ] : [
        'Customer growth as planned (5→1,200)',
        'Mix: 60% Starter, 25% Professional, 15% Enterprise',
        'Hiring 5→10→17→25→35',
        'Server costs €100 per customer + €2,000 base',
        'Break-even mid 2029',
      ])

  const cases = [
    {
      name: 'Bear Case',
      icon: TrendingDown,
      color: 'text-red-400',
      bg: 'bg-red-500/10 border-red-500/20',
      desc: de ? 'Langsames Wachstum, höhere Churn' : 'Slow growth, higher churn',
      assumptions: de ? [
        'Kundenwachstum 50% langsamer als Base',
        'Churn Rate 8% pro Monat (Startups)',
        'Durchschnittspreis 20% niedriger',
        'Personalaufbau verzögert um 6 Monate',
      ] : [
        'Customer growth 50% slower than base',
        'Churn rate 8% per month (startups)',
        'Average price 20% lower',
        'Hiring delayed by 6 months',
      ],
      kpis: {
        kunden2030: `~${bearCustomers.toLocaleString('de-DE')}`,
        arr2030: fmtArr(bearArr, de),
        ma2030: String(bearEmployees),
        breakEven: bearBreakEven,
        cash2030: fmtCash(bearCash, de),
      },
    },
    {
      name: 'Base Case',
      icon: Minus,
      color: 'text-indigo-400',
      bg: 'bg-indigo-500/10 border-indigo-500/20',
      desc: de ? 'Aktueller Finanzplan' : 'Current financial plan',
      assumptions: baseAssumptions,
      kpis: {
        kunden2030: `~${baseCustomers.toLocaleString('de-DE')}`,
        arr2030: fmtArr(baseArr, de),
        ma2030: String(baseEmployees),
        breakEven: baseBreakEven,
        cash2030: fmtCash(baseCash, de),
      },
    },
    {
      name: 'Bull Case',
      icon: TrendingUp,
      color: 'text-emerald-400',
      bg: 'bg-emerald-500/10 border-emerald-500/20',
      desc: de ? 'Beschleunigtes Wachstum' : 'Accelerated growth',
      assumptions: de ? [
        'Kundenwachstum 70% schneller (Regulierungsdruck)',
        'Enterprise-Anteil steigt auf 20%',
        'Durchschnittspreis 15% höher (Upselling)',
        'Channel-Partner ab Q1/2028',
      ] : [
        'Customer growth 70% faster (regulation pressure)',
        'Enterprise share rises to 20%',
        'Average price 15% higher (upselling)',
        'Channel partners from Q1/2028',
      ],
      kpis: {
        kunden2030: `~${bullCustomers.toLocaleString('de-DE')}`,
        arr2030: fmtArr(bullArr, de),
        ma2030: String(bullEmployees),
        breakEven: bullBreakEven,
        cash2030: fmtCash(bullCash, de),
      },
    },
  ]

  return (
    <div className="max-w-6xl mx-auto">
      <FadeInView className="text-center mb-6">
        <h2 className="text-3xl md:text-4xl font-bold mb-2">
          <GradientText>{i.annex.assumptions.title}</GradientText>
        </h2>
        <p className="text-sm text-white/50 max-w-2xl mx-auto">{i.annex.assumptions.subtitle}</p>
      </FadeInView>

      <div className="grid md:grid-cols-3 gap-4 mb-6">
        {cases.map((c, idx) => {
          const Icon = c.icon
          return (
            <FadeInView key={idx} delay={0.1 + idx * 0.1}>
              <GlassCard hover={false} className={`p-4 h-full ${c.bg} border`}>
                <div className="flex items-center gap-2 mb-2">
                  <Icon className={`w-5 h-5 ${c.color}`} />
                  <h3 className={`text-base font-bold ${c.color}`}>{c.name}</h3>
                </div>
                <p className="text-xs text-white/40 mb-3">{c.desc}</p>

                <div className="space-y-1.5 mb-4">
                  {c.assumptions.map((a, i) => (
                    <p key={i} className="text-xs text-white/60 pl-3 relative">
                      <span className={`absolute left-0 top-1 w-1.5 h-1.5 rounded-full ${c.color.replace('text-', 'bg-')}/60`} />
                      {a}
                    </p>
                  ))}
                </div>

                <div className="border-t border-white/10 pt-3 space-y-1.5">
                  {[
                    { label: de ? 'Kunden 2030' : 'Customers 2030', value: c.kpis.kunden2030 },
                    { label: 'ARR 2030', value: c.kpis.arr2030 },
                    { label: de ? 'Mitarbeiter' : 'Employees', value: c.kpis.ma2030 },
                    { label: 'Break-Even', value: c.kpis.breakEven },
                    { label: 'Cash 2030', value: c.kpis.cash2030 },
                  ].map((kpi, i) => (
                    <div key={i} className="flex justify-between text-xs">
                      <span className="text-white/40">{kpi.label}</span>
                      <span className={`font-mono font-bold ${c.color}`}>{kpi.value}</span>
                    </div>
                  ))}
                </div>
              </GlassCard>
            </FadeInView>
          )
        })}
      </div>

      {/* Comparison Table */}
      <FadeInView delay={0.5}>
        <GlassCard hover={false} className="p-4">
          <h3 className="text-xs font-bold text-white/40 uppercase tracking-wider mb-3">
            {de ? 'Szenario-Vergleich 2030' : 'Scenario Comparison 2030'}
          </h3>
          <table className="w-full text-xs">
            <thead>
              <tr className="border-b border-white/10">
                <th className="text-left py-2 text-white/40"></th>
                <th className="text-right py-2 text-red-400">Bear</th>
                <th className="text-right py-2 text-indigo-400 font-bold">Base</th>
                <th className="text-right py-2 text-emerald-400">Bull</th>
              </tr>
            </thead>
            <tbody>
              {[
                { label: de ? 'Kunden' : 'Customers', bear: cases[0].kpis.kunden2030, base: cases[1].kpis.kunden2030, bull: cases[2].kpis.kunden2030 },
                { label: 'ARR', bear: cases[0].kpis.arr2030, base: cases[1].kpis.arr2030, bull: cases[2].kpis.arr2030 },
                { label: de ? 'Mitarbeiter' : 'Employees', bear: cases[0].kpis.ma2030, base: cases[1].kpis.ma2030, bull: cases[2].kpis.ma2030 },
                { label: 'Break-Even', bear: cases[0].kpis.breakEven, base: cases[1].kpis.breakEven, bull: cases[2].kpis.breakEven },
                { label: 'Cash', bear: cases[0].kpis.cash2030, base: cases[1].kpis.cash2030, bull: cases[2].kpis.cash2030 },
              ].map((row, idx) => (
                <tr key={idx} className="border-b border-white/[0.03]">
                  <td className="py-1.5 text-white/60">{row.label}</td>
                  <td className="py-1.5 text-right text-red-400/70 font-mono">{row.bear}</td>
                  <td className="py-1.5 text-right text-indigo-300 font-mono font-bold">{row.base}</td>
                  <td className="py-1.5 text-right text-emerald-400/70 font-mono">{row.bull}</td>
                </tr>
              ))}
            </tbody>
          </table>
        </GlassCard>
      </FadeInView>
    </div>
  )
}
