import { ensurePair, validateLimit, createMeta } from '../lib/validate.js';
import { ok, fail } from '../lib/result.js';
import { formatSummary, formatTimestampJST } from '../lib/formatter.js';
import { toIsoTime } from '../lib/datetime.js';
import { fetchJson, BITBANK_API_BASE } from '../lib/http.js';
import { getErrorMessage, isAbortError } from '../lib/error.js';
import { GetOrderbookOutputSchema } from '../src/schemas.js';
import type { Result, GetOrderbookData, GetOrderbookMeta, OrderbookLevelWithCum } from '../src/types/domain.d.ts';
export interface GetOrderbookOptions {
timeoutMs?: number;
}
function toLevels(arr: unknown[], n: number): OrderbookLevelWithCum[] {
const out = (arr || []).slice(0, n).map((item) => {
const [p, s] = item as [unknown, unknown];
return {
price: Number(p),
size: Number(s),
cumSize: 0,
};
});
let cum = 0;
for (const lvl of out) {
cum += Number.isFinite(lvl.size) ? lvl.size : 0;
lvl.cumSize = Number(cum.toFixed(8));
}
return out;
}
export default async function getOrderbook(
pair: string,
topN: number = 5,
{ timeoutMs = 2500 }: GetOrderbookOptions = {}
): Promise<Result<GetOrderbookData, GetOrderbookMeta>> {
const chk = ensurePair(pair);
if (!chk.ok) return fail(chk.error.message, chk.error.type);
const limitCheck = validateLimit(topN, 1, 200, 'opN');
if (!limitCheck.ok) return fail(limitCheck.error.message, limitCheck.error.type);
const url = `${BITBANK_API_BASE}/${chk.pair}/depth`;
try {
const json: unknown = await fetchJson(url, { timeoutMs, retries: 2 });
const jsonObj = json as { data?: { asks?: unknown[]; bids?: unknown[]; timestamp?: number } };
const d = jsonObj?.data ?? {};
const asks = toLevels(d.asks ?? [], limitCheck.value);
const bids = toLevels(d.bids ?? [], limitCheck.value);
const bestAsk = asks[0]?.price ?? null;
const bestBid = bids[0]?.price ?? null;
const spread = bestAsk != null && bestBid != null ? Number((bestAsk - bestBid).toFixed(0)) : null;
const mid = bestAsk != null && bestBid != null ? Number(((bestAsk + bestBid) / 2).toFixed(2)) : null;
const timestamp = d.timestamp ?? Date.now();
const summary = formatSummary({
pair: chk.pair,
latest: mid ?? undefined,
extra: `bid=${bestBid ?? 'N/A'} ask=${bestAsk ?? 'N/A'} spread=${spread ?? 'N/A'}`,
});
// タイムスタンプ付きテキスト出力
const text = [
`📸 ${formatTimestampJST(timestamp)}`,
'',
summary,
'',
`📊 板情報 (上位${limitCheck.value}層):`,
`中値: ${mid?.toLocaleString() ?? 'N/A'}円`,
`スプレッド: ${spread?.toLocaleString() ?? 'N/A'}円`,
'',
`🟢 買い板 (Bids): ${bids.length}層`,
...bids.slice(0, 5).map((b, i) => ` ${i + 1}. ${b.price.toLocaleString()}円 ${b.size.toFixed(4)} BTC (累計: ${b.cumSize.toFixed(4)} BTC)`),
bids.length > 5 ? ` ... 他 ${bids.length - 5}層` : '',
'',
`🔴 売り板 (Asks): ${asks.length}層`,
...asks.slice(0, 5).map((a, i) => ` ${i + 1}. ${a.price.toLocaleString()}円 ${a.size.toFixed(4)} BTC (累計: ${a.cumSize.toFixed(4)} BTC)`),
asks.length > 5 ? ` ... 他 ${asks.length - 5}層` : '',
].filter(Boolean).join('\n');
const data: GetOrderbookData = {
raw: json,
normalized: {
pair: chk.pair,
bestBid,
bestAsk,
spread,
mid,
bids,
asks,
timestamp: d.timestamp ?? null,
isoTime: toIsoTime(d.timestamp),
},
};
const meta: GetOrderbookMeta = createMeta(chk.pair, {
topN: limitCheck.value,
count: asks.length + bids.length,
}) as GetOrderbookMeta;
return GetOrderbookOutputSchema.parse(ok(text, data, meta)) as unknown as Result<GetOrderbookData, GetOrderbookMeta>;
} catch (err: unknown) {
const isAbort = isAbortError(err);
const message = isAbort ? `タイムアウト (${timeoutMs}ms)` : getErrorMessage(err) || 'ネットワークエラー';
return GetOrderbookOutputSchema.parse(fail(message, isAbort ? 'timeout' : 'network')) as unknown as Result<GetOrderbookData, GetOrderbookMeta>;
}
}
