/**
 * Upbit Korean exchange ticker (no auth).
 *
 * GET https://api.upbit.com/v1/ticker?markets=KRW-BTC,KRW-ETH
 *
 * Upbit denominates KRW pairs natively, so this is the easiest way to fetch
 * Korean-won-denominated crypto prices.
 */

if (markets == null || markets === '') throw new Error('markets required');
const url = 'https://api.upbit.com/v1/ticker?markets=' + encodeURIComponent(markets);

const resp = await fetch(url, {
  headers: { 'Accept': 'application/json' },
  maxLength: 1_000_000,
});
if (!resp.ok) return { success: false, status: resp.status, message: resp.text() };

return (resp.json() || []).map(t => ({
  market:            t.market,
  tradePrice:        t.trade_price,
  openingPrice:      t.opening_price,
  highPrice:         t.high_price,
  lowPrice:          t.low_price,
  change:            t.change,
  changeRate:        t.change_rate,
  accTradeVolume24h: t.acc_trade_volume_24h,
  timestamp:         t.timestamp,
}));

/**
 * Upbit live orderbook (no auth).
 *
 * GET https://api.upbit.com/v1/orderbook?markets=KRW-BTC,KRW-ETH
 *
 * Returns top-N bid/ask units for each market. `level` is optional and
 * controls aggregation in the upstream API (omit for raw).
 */

if (markets == null || markets === '') throw new Error('markets required');
let url = 'https://api.upbit.com/v1/orderbook?markets=' + encodeURIComponent(markets);
if (level != null && level !== '') url += '&level=' + encodeURIComponent(String(level));

const resp = await fetch(url, {
  headers: { 'Accept': 'application/json' },
  maxLength: 1_000_000,
});
if (!resp.ok) return { success: false, status: resp.status, message: resp.text() };

return (resp.json() || []).map(b => ({
  market:           b.market,
  timestamp:        b.timestamp,
  totalAskSize:     b.total_ask_size,
  totalBidSize:     b.total_bid_size,
  units: (b.orderbook_units || []).map(u => ({
    askPrice: u.ask_price,
    bidPrice: u.bid_price,
    askSize:  u.ask_size,
    bidSize:  u.bid_size,
  })),
}));

/**
 * Upbit OHLCV candles (no auth).
 *
 * GET https://api.upbit.com/v1/candles/days?market=KRW-BTC&count=10
 * GET https://api.upbit.com/v1/candles/minutes/{unit}?market=KRW-BTC&count=10
 *
 * `interval` accepts: 'days' (default), 'weeks', 'months', or 'minutes/N'
 *   where N is one of 1, 3, 5, 10, 15, 30, 60, 240.
 * `count` caps at 200 upstream.
 */

if (market == null || market === '') throw new Error('market required');
const itv  = (interval == null || interval === '') ? 'days' : String(interval);
const cnt  = (count == null || count === '') ? 30 : Math.max(1, Math.min(200, parseInt(count, 10)));

let path;
if (itv.startsWith('minutes/')) path = 'minutes/' + encodeURIComponent(itv.slice('minutes/'.length));
else if (itv === 'days' || itv === 'weeks' || itv === 'months') path = itv;
else throw new Error("interval must be 'days', 'weeks', 'months', or 'minutes/N'");

const url = 'https://api.upbit.com/v1/candles/' + path
          + '?market=' + encodeURIComponent(market)
          + '&count='  + cnt;

const resp = await fetch(url, {
  headers: { 'Accept': 'application/json' },
  maxLength: 2_000_000,
});
if (!resp.ok) return { success: false, status: resp.status, message: resp.text() };

return (resp.json() || []).map(c => ({
  market:                 c.market,
  candleDateTimeKst:      c.candle_date_time_kst,
  candleDateTimeUtc:      c.candle_date_time_utc,
  openingPrice:           c.opening_price,
  highPrice:              c.high_price,
  lowPrice:               c.low_price,
  tradePrice:             c.trade_price,
  candleAccTradeVolume:   c.candle_acc_trade_volume,
  candleAccTradePrice:    c.candle_acc_trade_price,
}));

/**
 * Upbit market catalog (no auth).
 *
 * GET https://api.upbit.com/v1/market/all?isDetails=false
 *
 * Lists every tradable market on Upbit. Pass `quote` (e.g. 'KRW', 'BTC',
 * 'USDT') to filter by quote currency. Useful to discover what coins are
 * available before calling ticker/candles.
 */

const resp = await fetch('https://api.upbit.com/v1/market/all?isDetails=false', {
  headers: { 'Accept': 'application/json' },
  maxLength: 2_000_000,
});
if (!resp.ok) return { success: false, status: resp.status, message: resp.text() };

let rows = (resp.json() || []).map(m => ({
  market:       m.market,
  koreanName:   m.korean_name,
  englishName:  m.english_name,
}));

if (quote != null && quote !== '') {
  const prefix = String(quote).toUpperCase() + '-';
  rows = rows.filter(r => r.market && r.market.startsWith(prefix));
}

return { count: rows.length, markets: rows };

/**
 * Bithumb Korean exchange public ticker.
 *
 * GET https://api.bithumb.com/public/ticker/{symbol}_KRW
 *
 * The KRW pair is implicit in the URL path. No auth, no rate-limit listed
 * but be polite.
 */

if (symbol == null || symbol === '') throw new Error('symbol required');
const url = 'https://api.bithumb.com/public/ticker/' + encodeURIComponent(symbol) + '_KRW';

const resp = await fetch(url, {
  headers: { 'Accept': 'application/json' },
  maxLength: 500_000,
});
if (!resp.ok) return { success: false, status: resp.status, message: resp.text() };
const d = resp.json();
if (d.status !== '0000') return { success: false, status: d.status, message: d.message || 'bithumb error' };
const t = d.data || {};
return {
  symbol:            String(symbol).toUpperCase(),
  openingPrice:      Number(t.opening_price),
  closingPrice:      Number(t.closing_price),
  minPrice:          Number(t.min_price),
  maxPrice:          Number(t.max_price),
  unitsTraded24h:    Number(t.units_traded_24H),
  accTradeValue24h:  Number(t.acc_trade_value_24H),
  fluctate24h:       Number(t.fluctate_24H),
  fluctateRate24h:   Number(t.fluctate_rate_24H),
};

/**
 * Bithumb public orderbook depth (no auth).
 *
 * GET https://api.bithumb.com/public/orderbook/{symbol}_KRW?count=5
 *
 * Returns top bids/asks for a KRW pair. `count` defaults to 5, max 30.
 */

if (symbol == null || symbol === '') throw new Error('symbol required');
const cnt = (count == null || count === '') ? 5 : Math.max(1, Math.min(30, parseInt(count, 10)));
const url = 'https://api.bithumb.com/public/orderbook/'
          + encodeURIComponent(symbol) + '_KRW?count=' + cnt;

const resp = await fetch(url, {
  headers: { 'Accept': 'application/json' },
  maxLength: 500_000,
});
if (!resp.ok) return { success: false, status: resp.status, message: resp.text() };
const d = resp.json();
if (d.status !== '0000') return { success: false, status: d.status, message: d.message || 'bithumb error' };
const t = d.data || {};
const lift = arr => (arr || []).map(o => ({ price: Number(o.price), quantity: Number(o.quantity) }));
return {
  symbol:        String(symbol).toUpperCase(),
  paymentCurrency: t.payment_currency,
  orderCurrency:   t.order_currency,
  timestamp:     t.timestamp,
  bids:          lift(t.bids),
  asks:          lift(t.asks),
};