'use client'

import type { MortgageSummary } from '@/lib/mortgage-engine'
import type { MortgageState } from '@/lib/mortgage-types'

interface Props {
  state: MortgageState
  summary: MortgageSummary
}

function fmt(n: number): string {
  return new Intl.NumberFormat('en-US', { style: 'currency', currency: 'USD', maximumFractionDigits: 0 }).format(n)
}

function fmtPct(n: number): string {
  return `${n.toFixed(1)}%`
}

export default function ComparisonPanel({ state, summary }: Props) {
  const repaidPct = state.totalPrincipal > 0
    ? (state.totalPrincipalPaid / state.totalPrincipal) * 100
    : 0

  return (
    <div className="flex flex-col gap-4 text-sm">
      {/* Progress */}
      <div>
        <h3 className="text-xs font-semibold text-slate-400 uppercase tracking-wider mb-2">Progress</h3>
        <div className="grid grid-cols-2 gap-2">
          <StatCard label="Principal Repaid" value={fmt(state.totalPrincipalPaid)} sub={fmtPct(repaidPct)} />
          <StatCard label="Remaining" value={fmt(state.totalPrincipalRemaining)} />
          <StatCard label="Interest Paid" value={fmt(state.totalInterestPaid)} color="text-amber-400" />
          <StatCard label="Tranches Done" value={`${state.tranchesRepaid} / ${state.tranches.length}`} color="text-emerald-400" />
        </div>
        {/* Overall progress bar */}
        <div className="mt-2">
          <div className="h-2 bg-slate-700 rounded-full overflow-hidden">
            <div
              className="h-full bg-gradient-to-r from-sky-500 to-emerald-500 rounded-full transition-all duration-300"
              style={{ width: `${Math.min(100, repaidPct)}%` }}
            />
          </div>
        </div>
      </div>

      {/* Community Fund */}
      {state.communityFundBalance > 0 && (
        <div>
          <h3 className="text-xs font-semibold text-slate-400 uppercase tracking-wider mb-2">Community Fund</h3>
          <div className="bg-emerald-900/30 rounded p-3 border border-emerald-800/50">
            <div className="text-lg font-mono text-emerald-400">{fmt(state.communityFundBalance)}</div>
            <div className="text-xs text-slate-400 mt-1">Overflow directed to community resilience</div>
          </div>
        </div>
      )}

      {/* Comparison */}
      <div>
        <h3 className="text-xs font-semibold text-slate-400 uppercase tracking-wider mb-2">
          rMortgage vs Traditional
        </h3>
        <div className="space-y-3">
          <CompareRow
            label="Monthly Payment"
            myco={fmt(summary.mycoMonthlyPayment)}
            trad={fmt(summary.tradMonthlyPayment)}
          />
          <CompareRow
            label="Total Interest"
            myco={fmt(summary.mycoTotalInterest)}
            trad={fmt(summary.tradTotalInterest)}
            highlight={summary.interestSaved > 0}
          />
          <CompareRow
            label="Payoff"
            myco={`${Math.ceil(summary.mycoPayoffMonths / 12)}y`}
            trad={`${Math.ceil(summary.tradPayoffMonths / 12)}y`}
            highlight={summary.monthsSaved > 0}
          />
          <CompareRow
            label="Avg Lender Yield"
            myco={fmtPct(summary.avgLenderYield)}
            trad="N/A (bank)"
          />
        </div>
      </div>

      {/* Key insight */}
      <div className="bg-gradient-to-br from-sky-900/40 to-emerald-900/40 rounded-lg p-4 border border-sky-800/30">
        <h4 className="text-xs font-semibold text-sky-300 uppercase mb-2">Community Wealth</h4>
        <div className="text-2xl font-mono text-emerald-400 mb-1">{fmt(summary.communityRetained)}</div>
        <p className="text-xs text-slate-400">
          Interest that stays in the community instead of flowing to a distant institution.
          {summary.interestSaved > 0 && (
            <> Plus {fmt(summary.interestSaved)} saved through distributed rates.</>
          )}
        </p>
      </div>
    </div>
  )
}

function StatCard({ label, value, sub, color }: { label: string; value: string; sub?: string; color?: string }) {
  return (
    <div className="bg-slate-800 rounded p-2">
      <div className="text-[10px] text-slate-500 uppercase">{label}</div>
      <div className={`text-sm font-mono ${color ?? 'text-white'}`}>
        {value}
        {sub && <span className="text-xs text-slate-400 ml-1">{sub}</span>}
      </div>
    </div>
  )
}

function CompareRow({ label, myco, trad, highlight }: { label: string; myco: string; trad: string; highlight?: boolean }) {
  return (
    <div className="grid grid-cols-3 gap-2 items-center">
      <div className="text-xs text-slate-400">{label}</div>
      <div className={`text-xs font-mono text-center px-2 py-1 rounded ${
        highlight ? 'bg-emerald-900/40 text-emerald-400' : 'bg-slate-800 text-white'
      }`}>
        {myco}
      </div>
      <div className="text-xs font-mono text-center px-2 py-1 rounded bg-slate-800 text-slate-400">
        {trad}
      </div>
    </div>
  )
}