import React, { useState } from 'react';
import { safetyCheck, budgetCalc } from '../../../api';
import { tierMeta, formatMoney, formatRatio } from '../listingsUtils';

const DEAL_TYPES = ['전세', '반전세', '매매'];

/* ── 안전마진 체커 ── */
const SafetyCard = () => {
  const [form, setForm] = useState({ area: '', deal_type: '전세', amount: '', dong: '' });
  const [res, setRes] = useState(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');
  const set = (k, v) => setForm((f) => ({ ...f, [k]: v }));

  const submit = async (e) => {
    e.preventDefault();
    if (!form.area || !form.amount) return;
    setLoading(true); setError(''); setRes(null);
    try {
      const r = await safetyCheck({
        area: Number(form.area), deal_type: form.deal_type,
        amount: Number(form.amount), dong: form.dong || undefined,
      });
      setRes(r);
    } catch (e2) { setError(e2?.message ?? String(e2)); }
    finally { setLoading(false); }
  };

  const isSale = form.deal_type === '매매';
  const meta = res ? tierMeta(isSale ? 'valuation' : 'safety', res.tier) : null;

  return (
    <section className="lst-panel">
      <h3 className="lst-panel__title">안전마진 체커</h3>
      <p className="lst-panel__sub">면적·거래유형·금액으로 전세가율/호가율 적정성을 즉시 판정합니다.</p>
      <form className="lst-form" onSubmit={submit}>
        <input className="lst-input" placeholder="면적(m²)" value={form.area}
          onChange={(e) => set('area', e.target.value)} />
        <select className="lst-input" value={form.deal_type} onChange={(e) => set('deal_type', e.target.value)}>
          {DEAL_TYPES.map((d) => <option key={d} value={d}>{d}</option>)}
        </select>
        <input className="lst-input" placeholder="금액(만원)" value={form.amount}
          onChange={(e) => set('amount', e.target.value)} />
        <input className="lst-input" placeholder="동(선택)" value={form.dong}
          onChange={(e) => set('dong', e.target.value)} />
        <button className="lst-filter-btn is-primary" type="submit" disabled={loading || !form.area || !form.amount}>
          {loading ? '판정 중…' : '판정'}
        </button>
      </form>
      {error && <p className="lst-error">{error}</p>}
      {res && (
        <div className="lst-result">
          <div className="lst-result__row">
            <span className="lst-tier" style={{ color: meta.color }}>{meta.emoji} {meta.label}</span>
            {res.ratio != null && <span>비율 {formatRatio(res.ratio)}</span>}
            {res.median != null && <span>중앙값 {formatMoney(res.median)}</span>}
            {res.sample != null && <span>표본 {res.sample}건</span>}
            {res.is_toheo && <span className="lst-flag">토지거래허가</span>}
          </div>
          {res.disclaimer && <p className="lst-disclaimer">※ {res.disclaimer}</p>}
        </div>
      )}
    </section>
  );
};

/* ── 예산 계산기 ── */
const BudgetCard = () => {
  const [form, setForm] = useState({
    equity: '', annual_income: '', is_homeless: true, is_householder: true, is_first_home: false, target_dong: '',
  });
  const [res, setRes] = useState(null);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState('');
  const set = (k, v) => setForm((f) => ({ ...f, [k]: v }));

  const submit = async (e) => {
    e.preventDefault();
    if (!form.equity) return;
    setLoading(true); setError(''); setRes(null);
    try {
      const r = await budgetCalc({
        equity: Number(form.equity),
        annual_income: form.annual_income ? Number(form.annual_income) : null,
        is_homeless: form.is_homeless ? 1 : 0,
        is_householder: form.is_householder ? 1 : 0,
        is_first_home: form.is_first_home ? 1 : 0,
        target_dong: form.target_dong || undefined,
      });
      setRes(r);
    } catch (e2) { setError(e2?.message ?? String(e2)); }
    finally { setLoading(false); }
  };

  return (
    <section className="lst-panel">
      <h3 className="lst-panel__title">예산 계산기</h3>
      <p className="lst-panel__sub">자기자본·소득 기준 전세/매매 한도와 지역 규제를 계산합니다.</p>
      <form className="lst-form" onSubmit={submit}>
        <input className="lst-input" placeholder="자기자본(만원)" value={form.equity}
          onChange={(e) => set('equity', e.target.value)} />
        <input className="lst-input" placeholder="연소득(만원, 선택)" value={form.annual_income}
          onChange={(e) => set('annual_income', e.target.value)} />
        <input className="lst-input" placeholder="대상 동(선택)" value={form.target_dong}
          onChange={(e) => set('target_dong', e.target.value)} />
        <label className="lst-check"><input type="checkbox" checked={form.is_homeless}
          onChange={(e) => set('is_homeless', e.target.checked)} /> 무주택</label>
        <label className="lst-check"><input type="checkbox" checked={form.is_householder}
          onChange={(e) => set('is_householder', e.target.checked)} /> 세대주</label>
        <label className="lst-check"><input type="checkbox" checked={form.is_first_home}
          onChange={(e) => set('is_first_home', e.target.checked)} /> 생애최초</label>
        <button className="lst-filter-btn is-primary" type="submit" disabled={loading || !form.equity}>
          {loading ? '계산 중…' : '계산'}
        </button>
      </form>
      {error && <p className="lst-error">{error}</p>}
      {res && (
        <div className="lst-result">
          {res.jeonse && (
            <div className="lst-result__block">
              <strong>전세</strong>
              <span>대출한도 {formatMoney(res.jeonse.loan_limit)}</span>
              <span>최대 보증금 {formatMoney(res.jeonse.max_deposit)}</span>
              {res.jeonse.notes && <span className="lst-note">{res.jeonse.notes}</span>}
            </div>
          )}
          {res.purchase && (
            <div className="lst-result__block">
              <strong>매매</strong>
              {res.purchase.ltv_pct != null && <span>LTV {res.purchase.ltv_pct}%</span>}
              <span>대출한도 {formatMoney(res.purchase.loan_cap)}</span>
              <span>최대 매수가 {formatMoney(res.purchase.max_price)}</span>
              {res.purchase.dsr_note && <span className="lst-note">{res.purchase.dsr_note}</span>}
              {Array.isArray(res.purchase.regulation_flags) && res.purchase.regulation_flags.length > 0 && (
                <div className="lst-flags">{res.purchase.regulation_flags.map((f, i) => <span key={i} className="lst-flag">{f}</span>)}</div>
              )}
            </div>
          )}
          {res.region && (
            <div className="lst-result__block">
              <strong>지역</strong>
              {res.region.is_toheo && <span className="lst-flag">토지거래허가</span>}
              {res.region.is_regulated && <span className="lst-flag">규제지역</span>}
              {res.region.notes && <span className="lst-note">{res.region.notes}</span>}
            </div>
          )}
          {res.disclaimer && <p className="lst-disclaimer">※ {res.disclaimer}</p>}
        </div>
      )}
    </section>
  );
};

const ToolsTab = () => (
  <div className="lst-tools">
    <SafetyCard />
    <BudgetCard />
  </div>
);

export default ToolsTab;