'use client'

import React, { useState, useMemo } from 'react'
import type { FDVpsCalculatorBlock as FDVpsCalculatorBlockProps } from '@/payload-types'

const DEFAULT_PRICING = {
  windows: 250,
  cpuPerCore: 120,
  ramPerGb: 100,
  ssdPerGb: 4,
  hddPerGb: 1,
  adminFee: 200,
}

const formatKr = (n: number) => {
  // Format like "2 495 kr" with space as thousands separator
  return Math.round(n).toLocaleString('sv-SE') + ' kr'
}

// ─── Toggle switch ───────────────────────────────────────────────────────────
function Toggle({ active, onToggle }: { active: boolean; onToggle: () => void }) {
  return (
    <button
      type="button"
      onClick={onToggle}
      style={{ display: 'block', width: '3.5rem', height: '2rem', flexShrink: 0 }}
      className={`relative rounded-full transition-all duration-300 ${
        active ? 'bg-fd-yellow' : 'bg-[#e2e8f0]'
      }`}
      role="switch"
      aria-checked={active}
    >
      <div
        className={`absolute top-1 w-6 h-6 rounded-full bg-white shadow-sm transition-all duration-300 ${
          active ? 'left-7' : 'left-1'
        }`}
      />
    </button>
  )
}

// ─── Number stepper row ──────────────────────────────────────────────────────
function ResourceRow({
  label,
  value,
  onChange,
  min = 0,
  max = 999,
  step = 1,
  unit,
  priceLabel,
  isDark,
}: {
  label: string
  value: number
  onChange: (v: number) => void
  min?: number
  max?: number
  step?: number
  unit: string
  priceLabel: string
  isDark: boolean
}) {
  const borderColor = isDark ? 'rgba(255,255,255,0.1)' : 'rgba(14,35,56,0.08)'
  const labelColor = isDark ? 'text-white' : 'text-fd-navy'
  const subColor = isDark ? 'text-white/50' : 'text-fd-navy/50'
  const btnColor = isDark
    ? 'border-white/30 text-white hover:border-white/70'
    : 'border-fd-navy/20 text-fd-navy hover:border-fd-navy/60'
  const inputColor = isDark
    ? 'bg-white/10 border-white/20 text-white'
    : 'bg-fd-surface-alt border-fd-navy/15 text-fd-navy'
  const unitColor = isDark ? 'text-white/40' : 'text-fd-navy/40'

  return (
    <div
      className="flex items-center justify-between py-4"
      style={{ borderBottom: `1px solid ${borderColor}` }}
    >
      <div className="flex flex-col">
        <span className={`font-joey-bold text-fd-body ${labelColor}`}>{label}</span>
        <span className={`font-joey text-fd-small ${subColor}`}>{priceLabel}</span>
      </div>
      <div className="flex items-center gap-2">
        <button
          type="button"
          onClick={() => onChange(Math.max(min, value - step))}
          className={`w-9 h-9 rounded-full border-2 flex items-center justify-center font-joey-bold text-base transition-colors ${btnColor}`}
        >
          −
        </button>
        <input
          type="number"
          value={value}
          onChange={(e) => onChange(Math.max(min, Math.min(max, Number(e.target.value) || 0)))}
          className={`w-16 text-center font-joey-medium text-fd-body rounded-full px-2 py-1.5 border-2 ${inputColor} [&::-webkit-inner-spin-button]:appearance-none [&::-webkit-outer-spin-button]:appearance-none`}
          style={{ appearance: 'textfield' }}
        />
        <span className={`font-joey text-fd-small w-7 ${unitColor}`}>{unit}</span>
        <button
          type="button"
          onClick={() => onChange(Math.min(max, value + step))}
          className={`w-9 h-9 rounded-full border-2 flex items-center justify-center font-joey-bold text-base transition-colors ${btnColor}`}
        >
          +
        </button>
      </div>
    </div>
  )
}

// ─── Main component ──────────────────────────────────────────────────────────
export const FDVpsCalculatorBlockComponent: React.FC<FDVpsCalculatorBlockProps> = ({
  heading = 'Virtuell server — kalkylator',
  description,
  contactCtaText = 'Frågor? Kontakta oss',
  contactCtaLink = '/kontakt',
  orderCtaText = 'Beställ',
  orderCtaLink = '/kontakt?subject=vps-bestallning',
  sectionBackground = 'white',
  pricingCpuPerCore,
  pricingRamPerGb,
  pricingSsdPerGb,
  pricingHddPerGb,
  pricingWindowsLicense,
  discountPercent,
  showAdminFee,
  adminFeeAmount,
  additionalServices = [],
}) => {
  const pricing = {
    windows: pricingWindowsLicense ?? DEFAULT_PRICING.windows,
    cpuPerCore: pricingCpuPerCore ?? DEFAULT_PRICING.cpuPerCore,
    ramPerGb: pricingRamPerGb ?? DEFAULT_PRICING.ramPerGb,
    ssdPerGb: pricingSsdPerGb ?? DEFAULT_PRICING.ssdPerGb,
    hddPerGb: pricingHddPerGb ?? DEFAULT_PRICING.hddPerGb,
  }
  const feeAmount = adminFeeAmount ?? DEFAULT_PRICING.adminFee
  const discount = (discountPercent ?? 0) / 100

  const [os, setOs] = useState<'linux' | 'windows'>('linux')
  const [cpuCores, setCpuCores] = useState(2)
  const [ramGb, setRamGb] = useState(4)
  const [ssdGb, setSsdGb] = useState(50)
  const [hddGb, setHddGb] = useState(0)
  const [extraToggles, setExtraToggles] = useState<Record<number, boolean>>({})
  const toggleExtra = (i: number) => setExtraToggles((p) => ({ ...p, [i]: !p[i] }))

  const costs = useMemo(() => {
    const disc = (v: number) => v * (1 - discount)
    const licenseCost = os === 'windows' ? disc(pricing.windows) : 0
    const cpuCost = disc(cpuCores * pricing.cpuPerCore)
    const ramCost = disc(ramGb * pricing.ramPerGb)
    const ssdCost = disc(ssdGb * pricing.ssdPerGb)
    const hddCost = disc(hddGb * pricing.hddPerGb)
    // Admin fee is fixed — always on if enabled in CMS, not customer-controlled
    const feeCost = showAdminFee ? feeAmount : 0
    const extraCosts = (additionalServices ?? []).map((svc, i) =>
      extraToggles[i] ? (svc.price ?? 0) : 0
    )
    const extraTotal = extraCosts.reduce((a, b) => a + b, 0)
    const total = licenseCost + cpuCost + ramCost + ssdCost + hddCost + feeCost + extraTotal
    return { licenseCost, cpuCost, ramCost, ssdCost, hddCost, feeCost, extraCosts, total }
  }, [os, cpuCores, ramGb, ssdGb, hddGb, extraToggles, pricing, discount, feeAmount, showAdminFee, additionalServices])

  const isDark = sectionBackground === 'navy'
  const bgClass = isDark ? 'bg-fd-navy' : sectionBackground === 'gray' ? 'bg-fd-surface-alt' : 'bg-white'

  // Card styling
  const cardBg = isDark ? 'rgba(255,255,255,0.05)' : '#ffffff'
  const cardBorder = isDark ? 'rgba(255,255,255,0.12)' : '#e2e8f0'
  const cardStyle: React.CSSProperties = {
    background: cardBg,
    border: `6px solid ${cardBorder}`,
    borderRadius: 'clamp(28px, 4vw, 60px)',
  }

  // Colors
  const headingColor = isDark ? 'text-white' : 'text-fd-navy'
  const descColor = isDark ? 'text-white/60' : 'text-fd-navy/60'
  const sectionLabelColor = isDark ? 'text-white/40' : 'text-fd-navy/35'
  const dividerColor = isDark ? 'rgba(255,255,255,0.1)' : 'rgba(14,35,56,0.08)'
  const summaryLabelColor = isDark ? 'text-white' : 'text-fd-navy'
  const summaryValueColor = isDark ? 'text-white' : 'text-fd-navy'
  const categoryLabelColor = isDark ? 'text-white/40' : 'text-fd-navy/40'

  // OS toggle
  const osActiveClass = 'bg-fd-yellow text-fd-navy border-fd-yellow font-joey-bold'
  const osInactiveClass = isDark
    ? 'bg-transparent text-white/70 border-white/20 hover:border-white/50 font-joey'
    : 'bg-transparent text-fd-navy/70 border-fd-navy/20 hover:border-fd-navy/50 font-joey'

  const discStr = discount > 0 ? ` (${discountPercent}% rabatt)` : ''

  // Summary rows
  const baseRows = [
    ...(os === 'windows' ? [{ label: 'Licens (Windows)', cost: costs.licenseCost }] : []),
    { label: `CPU (${cpuCores} ${cpuCores === 1 ? 'kärna' : 'kärnor'})`, cost: costs.cpuCost },
    { label: `RAM (${ramGb} GB)`, cost: costs.ramCost },
    { label: `SSD NVMe (${ssdGb} GB)`, cost: costs.ssdCost },
    ...(hddGb > 0 ? [{ label: `HDD (${hddGb} GB)`, cost: costs.hddCost }] : []),
    ...(showAdminFee ? [{ label: 'Adminavgift', cost: costs.feeCost }] : []),
  ]

  const tillvalRows = (additionalServices ?? []).flatMap((svc, i) =>
    extraToggles[i] ? [{ label: svc.label ?? 'Tilläggstjänst', cost: costs.extraCosts[i] ?? 0 }] : []
  )

  const hasTillval = (additionalServices ?? []).length > 0

  return (
    <section className={`fd-section ${bgClass}`}>
      <div className="fd-container">

        {/* Section heading */}
        {(heading || description) && (
          <div className="text-center mb-10 md:mb-14">
            {heading && (
              <h2 className={`font-joey-heavy text-fd-h1 mb-3 ${headingColor}`}>{heading}</h2>
            )}
            {description && (
              <p className={`font-joey text-fd-body-lg max-w-[600px] mx-auto ${descColor}`}>
                {description}
              </p>
            )}
            {discount > 0 && (
              <span className="inline-block mt-3 px-4 py-1 bg-fd-mint text-fd-navy font-joey-bold text-fd-small rounded-full">
                {discountPercent}% rabatt på alla resurser
              </span>
            )}
          </div>
        )}

        <div className="grid grid-cols-1 lg:grid-cols-5 gap-6 lg:gap-8">

          {/* ── Left: Config ── */}
          <div className="lg:col-span-3 p-7 md:p-9" style={cardStyle}>

            {/* OS */}
            <p className={`font-joey-medium text-fd-small tracking-widest uppercase mb-3 ${sectionLabelColor}`}>
              Operativsystem
            </p>
            <div className="flex gap-3 mb-6">
              {(['linux', 'windows'] as const).map((opt) => (
                <button
                  key={opt}
                  type="button"
                  onClick={() => setOs(opt)}
                  className={`flex-1 py-3 rounded-full text-fd-body border-2 transition-all duration-200 ${
                    os === opt ? osActiveClass : osInactiveClass
                  }`}
                >
                  {opt === 'linux' ? 'Linux (gratis)' : `Windows (+${pricing.windows}kr)`}
                </button>
              ))}
            </div>

            {/* Resources */}
            <div>
              <ResourceRow label="CPU-kärnor" value={cpuCores} onChange={setCpuCores} min={1} max={32} unit="st" priceLabel={`${pricing.cpuPerCore} kr/kärna${discStr}`} isDark={isDark} />
              <ResourceRow label="RAM" value={ramGb} onChange={setRamGb} min={1} max={256} unit="GB" priceLabel={`${pricing.ramPerGb} kr/GB${discStr}`} isDark={isDark} />
              <ResourceRow label="SSD NVMe" value={ssdGb} onChange={setSsdGb} min={0} max={4000} step={10} unit="GB" priceLabel={`${pricing.ssdPerGb} kr/GB${discStr}`} isDark={isDark} />
              <ResourceRow label="HDD" value={hddGb} onChange={setHddGb} min={0} max={10000} step={100} unit="GB" priceLabel={`${pricing.hddPerGb} kr/GB${discStr}`} isDark={isDark} />
            </div>

            {/* Admin fee — fixed line, not customer-controlled */}
            {showAdminFee && (
              <div className="flex items-center justify-between py-4" style={{ borderBottom: `1px solid ${dividerColor}` }}>
                <span className={`font-joey-bold text-fd-body ${isDark ? 'text-white' : 'text-fd-navy'}`}>
                  Adminavgift
                </span>
                <span className={`font-joey-medium text-fd-body ${isDark ? 'text-white/70' : 'text-fd-navy/70'}`}>
                  {formatKr(feeAmount)}
                </span>
              </div>
            )}

            {/* Tillvalstjänster */}
            {hasTillval && (
              <div className="mt-7">
                <p className={`font-joey-medium text-fd-small tracking-widest uppercase mb-1 ${sectionLabelColor}`}>
                  Tillvalstjänster
                </p>
                {(additionalServices ?? []).map((svc, i) => (
                  <div
                    key={i}
                    className="flex items-center gap-4 py-4"
                    style={{ borderBottom: `1px solid ${dividerColor}` }}
                  >
                    <div className="flex-1 min-w-0">
                      <span className={`font-joey-bold text-fd-body ${isDark ? 'text-white' : 'text-fd-navy'}`}>
                        {svc.label}
                      </span>
                      {svc.price != null && (
                        <span className={`block font-joey text-fd-small ${isDark ? 'text-white/50' : 'text-fd-navy/50'}`}>
                          {svc.price} kr/mån
                        </span>
                      )}
                    </div>
                    <div className="flex-shrink-0 w-14">
                      <Toggle active={!!extraToggles[i]} onToggle={() => toggleExtra(i)} />
                    </div>
                  </div>
                ))}
              </div>
            )}
          </div>

          {/* ── Right: Summary ── */}
          <div className="lg:col-span-2 p-7 md:p-9 flex flex-col" style={cardStyle}>
            <h3 className={`font-joey-heavy text-fd-h2 mb-6 ${headingColor}`}>
              Kostnadsöversikt
            </h3>

            {/* Base cost rows */}
            <div className="flex-1 space-y-0">
              {baseRows.map((row, i) => (
                <div
                  key={i}
                  className="flex justify-between items-center py-2.5"
                  style={{ borderBottom: `1px solid ${dividerColor}` }}
                >
                  <span className={`font-joey text-fd-body ${summaryLabelColor}`}>{row.label}</span>
                  <span className={`font-joey-bold text-fd-body ${summaryValueColor}`}>
                    {formatKr(row.cost)}
                  </span>
                </div>
              ))}

              {/* Tillval section in summary */}
              {tillvalRows.length > 0 && (
                <>
                  <div className="pt-4 pb-1">
                    <span className={`font-joey text-fd-small ${categoryLabelColor}`}>Tillval</span>
                  </div>
                  {tillvalRows.map((row, i) => (
                    <div
                      key={i}
                      className="flex justify-between items-center py-2.5"
                      style={{ borderBottom: `1px solid ${dividerColor}` }}
                    >
                      <span className={`font-joey text-fd-body ${summaryLabelColor}`}>{row.label}</span>
                      <span className={`font-joey-bold text-fd-body ${summaryValueColor}`}>
                        {formatKr(row.cost)}
                      </span>
                    </div>
                  ))}
                </>
              )}
            </div>

            {/* Total */}
            <div className="mt-6 pt-5" style={{ borderTop: `2px solid ${dividerColor}` }}>
              <div className="flex justify-between items-baseline">
                <span className={`font-joey text-fd-body ${summaryLabelColor}`}>Totalt per månad</span>
                <span className={`font-joey-heavy text-fd-h1 ${isDark ? 'text-white' : 'text-fd-navy'}`}>
                  {formatKr(costs.total)}
                </span>
              </div>
              <p className={`text-right font-joey text-fd-small mt-1 ${categoryLabelColor}`}>exkl. moms</p>
            </div>

            {/* CTAs */}
            <div className="mt-7 space-y-3">
              <a href={orderCtaLink || '#'} className="fd-btn-primary w-full justify-center">
                {orderCtaText}
              </a>
              <a
                href={contactCtaLink || '#'}
                className={`${isDark ? 'fd-btn-secondary-dark' : 'fd-btn-secondary'} w-full justify-center`}
              >
                {contactCtaText}
              </a>
            </div>
          </div>

        </div>
      </div>
    </section>
  )
}