import React, { useEffect, useMemo, useState } from 'react';
import {
  loadStrategies,
  loadLiveStrategySettings,
  type LiveStrategySettingsDto,
  type PaperSummaryDto,
  type StrategyDto,
} from '../../utils/backendApi';
import { loadVirtualSession, type VirtualTargetItem } from '../../utils/virtualTradingStorage';
import { resolveVirtualTargetNames } from '../../utils/virtualTargetNames';
import type { TickerData } from '../../hooks/useMarketTicker';
import { fmtKrw } from '../TradeOrderPanel';
import PaperSplitPanel from './PaperSplitPanel';

interface Props {
  market: string;
  summary: PaperSummaryDto | null;
  /** 가상매매 투자대상 — 보유 목록은 이 종목만 표시 */
  virtualTargets?: VirtualTargetItem[];
  tickers?: Map<string, TickerData>;
  paperAutoTradeEnabled?: boolean;
  onMarketSelect?: (market: string) => void;
}

const PaperLeftStrategyTab: React.FC<Props> = ({
  market,
  summary,
  virtualTargets = [],
  tickers,
  paperAutoTradeEnabled = false,
  onMarketSelect,
}) => {
  const [strategies, setStrategies] = useState<StrategyDto[]>([]);
  const [settings, setSettings] = useState<LiveStrategySettingsDto | null>(null);
  const [virtualRunning, setVirtualRunning] = useState(() => loadVirtualSession().running);

  useEffect(() => {
    loadStrategies().then(setStrategies).catch(() => setStrategies([]));
  }, []);

  useEffect(() => {
    const refreshVirtual = () => setVirtualRunning(loadVirtualSession().running);
    window.addEventListener('gc_virtual_session_changed', refreshVirtual);
    window.addEventListener('storage', refreshVirtual);
    return () => {
      window.removeEventListener('gc_virtual_session_changed', refreshVirtual);
      window.removeEventListener('storage', refreshVirtual);
    };
  }, []);

  useEffect(() => {
    let cancelled = false;
    loadLiveStrategySettings(market)
      .then(s => { if (!cancelled) setSettings(s); })
      .catch(() => {
        if (!cancelled) {
          setSettings({
            market,
            strategyId: null,
            isLiveCheck: false,
            executionType: 'CANDLE_CLOSE',
            positionMode: 'LONG_ONLY',
          });
        }
      });
    return () => { cancelled = true; };
  }, [market, virtualRunning]);

  const selected = strategies.find(s => s.id === settings?.strategyId);
  const execLabel = settings?.executionType === 'REALTIME_TICK' ? '실시간 틱 (3초)' : '봉 마감 직후';

  const top = (
    <>
      <div className="ptd-asset-inline">
        <div className="ptd-asset-total ptd-asset-total--sm">
          {summary ? fmtKrw(summary.totalAsset) : '—'} <span>KRW</span>
        </div>
        <div className={`ptd-asset-ret ptd-asset-ret--sm ${(summary?.totalReturnPct ?? 0) >= 0 ? 'up' : 'down'}`}>
          {summary ? `${(summary.totalReturnPct ?? 0) >= 0 ? '+' : ''}${summary.totalReturnPct.toFixed(2)}%` : '—'}
        </div>
      </div>
      <div className="ptd-left-section">
        <p className="ptd-left-hint">
          실시간 전략·체크 대상 종목은 <strong>가상투자</strong> 화면에서 설정합니다.
          {virtualRunning ? ' (세션 실행 중)' : ''}
        </p>
        {settings?.isLiveCheck && selected && (
          <p className="ptd-left-hint">
            {market.replace(/^KRW-/, '')}: {selected.name} · {execLabel}
          </p>
        )}
      </div>
      <p className={`ptd-left-status ${paperAutoTradeEnabled ? 'ptd-left-status--on' : ''}`}>
        {paperAutoTradeEnabled
          ? '자동매매 ON — 가상 Match 후 서버가 전략 시그널·모의 체결(화면 꺼져도 동작)'
          : '자동매매 OFF — 수동 주문만 모의 계좌에 체결'}
      </p>
    </>
  );

  const targetMarkets = useMemo(
    () => new Set(virtualTargets.map(t => t.market)),
    [virtualTargets],
  );

  const positions = useMemo(() => {
    const all = (summary?.positions ?? []).filter(p => p.quantity > 0);
    if (targetMarkets.size === 0) return [];
    const order = virtualTargets.map(t => t.market);
    return all
      .filter(p => targetMarkets.has(p.symbol))
      .sort((a, b) => {
        const ia = order.indexOf(a.symbol);
        const ib = order.indexOf(b.symbol);
        return (ia < 0 ? 999 : ia) - (ib < 0 ? 999 : ib);
      });
  }, [summary?.positions, targetMarkets, virtualTargets]);

  const bottom = (
    <div className="ptd-item-card-section ptd-holdings-card-section">
      <div className="vtd-target-list-head">
        <span>보유 목록</span>
        <span className="vtd-target-count">{positions.length}종목</span>
      </div>
      {targetMarkets.size === 0 ? (
        <p className="ptd-muted ptd-item-card-empty">가상매매 투자대상이 없습니다. 가상투자에서 종목을 추가하세요.</p>
      ) : positions.length === 0 ? (
        <p className="ptd-muted ptd-item-card-empty">투자대상 종목 중 보유 수량이 있는 종목이 없습니다.</p>
      ) : (
        <div className="ptd-item-card-scroll">
          <div className="vtd-target-list ptd-item-card-list">
            {positions.map(p => {
              const ticker = tickers?.get(p.symbol);
              const vt = virtualTargets.find(t => t.market === p.symbol);
              const { koreanName: ko, englishName: en } = resolveVirtualTargetNames(
                p.symbol,
                p.koreanName ?? vt?.koreanName ?? ticker?.koreanName,
                vt?.englishName,
              );
              const up = (p.profitLoss ?? 0) >= 0;
              const selected = market === p.symbol;
              const retPct = p.profitLossPct;

              return (
                <div
                  key={p.symbol}
                  className={[
                    'vtd-target-item',
                    'ptd-item-card',
                    'ptd-holding-card',
                    selected ? 'vtd-target-item--active' : '',
                  ].filter(Boolean).join(' ')}
                  role="button"
                  tabIndex={0}
                  onClick={() => onMarketSelect?.(p.symbol)}
                  onKeyDown={e => {
                    if (e.key === 'Enter' || e.key === ' ') {
                      e.preventDefault();
                      onMarketSelect?.(p.symbol);
                    }
                  }}
                >
                  <div className="vtd-target-item-main">
                    <div className="vtd-target-names">
                      <span className="vtd-target-ko">{ko}</span>
                      <span className="vtd-target-en">{en}</span>
                    </div>
                    {p.profitLoss != null && (
                      <div className="vtd-target-item-actions">
                        <span className={`vtd-target-price ${up ? 'vtd-target-up' : 'vtd-target-dn'}`}>
                          {up ? '+' : ''}{fmtKrw(p.profitLoss)}
                        </span>
                      </div>
                    )}
                  </div>

                  <div className="ptd-item-card-metrics">
                    <div className="vtd-target-strategy-field">
                      <span className="vtd-target-strategy-label">보유수량</span>
                      <span className="vtd-trade-meta-value">{p.quantity.toFixed(4)}</span>
                    </div>
                    <div className="vtd-target-strategy-field">
                      <span className="vtd-target-strategy-label">평단가</span>
                      <span className="vtd-trade-meta-value">{fmtKrw(p.avgPrice)}</span>
                    </div>
                    {p.evalAmount != null && (
                      <div className="vtd-target-strategy-field">
                        <span className="vtd-target-strategy-label">평가금액</span>
                        <span className="vtd-trade-meta-value">{fmtKrw(p.evalAmount)}</span>
                      </div>
                    )}
                    {retPct != null && (
                      <div className="vtd-target-strategy-field">
                        <span className="vtd-target-strategy-label">수익률</span>
                        <span className={`vtd-trade-meta-value ${retPct >= 0 ? 'vtd-target-up' : 'vtd-target-dn'}`}>
                          {retPct >= 0 ? '+' : ''}{retPct.toFixed(2)}%
                        </span>
                      </div>
                    )}
                  </div>
                </div>
              );
            })}
          </div>
        </div>
      )}
    </div>
  );

  return (
    <PaperSplitPanel
      className="ptd-split-panel--left"
      topTitle="전략 · 자산"
      bottomTitle="보유 종목"
      top={top}
      bottom={bottom}
    />
  );
};

export default PaperLeftStrategyTab;