/**
 * @file chart-utils.ts
 * @description StockLineChart에서 사용하는 유틸리티 함수 모음
 */

import type { UTCTimestamp } from "lightweight-charts";
import type {
  DashboardChartTimeframe,
  StockCandlePoint,
} from "@/features/dashboard/types/dashboard.types";

const KRW_FORMATTER = new Intl.NumberFormat("ko-KR");

// ─── 타입 ──────────────────────────────────────────────────

export type ChartBar = {
  time: UTCTimestamp;
  open: number;
  high: number;
  low: number;
  close: number;
  volume: number;
};

// ─── StockCandlePoint → ChartBar 변환 ─────────────────────

/**
 * candles 배열을 ChartBar 배열로 정규화 (무효값 필터 + 병합 + 정렬)
 */
export function normalizeCandles(
  candles: StockCandlePoint[],
  timeframe: DashboardChartTimeframe,
): ChartBar[] {
  const rows = candles
    .map((c) => convertCandleToBar(c, timeframe))
    .filter((b): b is ChartBar => Boolean(b));
  return mergeBars([], rows);
}

/**
 * 단일 candle → ChartBar 변환. 유효하지 않으면 null
 */
export function convertCandleToBar(
  candle: StockCandlePoint,
  timeframe: DashboardChartTimeframe,
): ChartBar | null {
  const close = candle.close ?? candle.price;
  if (!Number.isFinite(close) || close <= 0) return null;

  const open = candle.open ?? close;
  const high = candle.high ?? Math.max(open, close);
  const low = candle.low ?? Math.min(open, close);
  const volume = candle.volume ?? 0;
  const time = resolveBarTimestamp(candle, timeframe);
  if (!time) return null;

  return {
    time,
    open,
    high: Math.max(high, open, close),
    low: Math.min(low, open, close),
    close,
    volume,
  };
}

// ─── 타임스탬프 해석/정렬 ─────────────────────────────────

function resolveBarTimestamp(
  candle: StockCandlePoint,
  timeframe: DashboardChartTimeframe,
): UTCTimestamp | null {
  // timestamp 필드가 있으면 우선 사용
  if (
    typeof candle.timestamp === "number" &&
    Number.isFinite(candle.timestamp)
  ) {
    return alignTimestamp(candle.timestamp, timeframe);
  }

  const text = typeof candle.time === "string" ? candle.time.trim() : "";
  if (!text) return null;

  // "MM/DD" 형식 (일봉)
  if (/^\d{2}\/\d{2}$/.test(text)) {
    const [mm, dd] = text.split("/");
    const year = new Date().getFullYear();
    const ts = Math.floor(
      new Date(`${year}-${mm}-${dd}T09:00:00+09:00`).getTime() / 1000,
    );
    return alignTimestamp(ts, timeframe);
  }

  // "HH:MM" 또는 "HH:MM:SS" 형식 (분봉)
  if (/^\d{2}:\d{2}(:\d{2})?$/.test(text)) {
    const [hh, mi, ss] = text.split(":");
    const now = new Date();
    const y = now.getFullYear();
    const m = `${now.getMonth() + 1}`.padStart(2, "0");
    const d = `${now.getDate()}`.padStart(2, "0");
    const ts = Math.floor(
      new Date(`${y}-${m}-${d}T${hh}:${mi}:${ss ?? "00"}+09:00`).getTime() /
        1000,
    );
    return alignTimestamp(ts, timeframe);
  }

  return null;
}

/**
 * 타임스탬프를 타임프레임 버킷 경계에 정렬
 * - 1m: 그대로
 * - 30m/1h: 분 단위를 버킷에 정렬
 * - 1d: 00:00:00
 * - 1w: 월요일 00:00:00
 */
function alignTimestamp(
  timestamp: number,
  timeframe: DashboardChartTimeframe,
): UTCTimestamp {
  const d = new Date(timestamp * 1000);

  if (timeframe === "30m" || timeframe === "1h") {
    const bucket = timeframe === "30m" ? 30 : 60;
    d.setUTCMinutes(Math.floor(d.getUTCMinutes() / bucket) * bucket, 0, 0);
  } else if (timeframe === "1d") {
    d.setUTCHours(0, 0, 0, 0);
  } else if (timeframe === "1w") {
    const day = d.getUTCDay();
    d.setUTCDate(d.getUTCDate() + (day === 0 ? -6 : 1 - day));
    d.setUTCHours(0, 0, 0, 0);
  }

  return Math.floor(d.getTime() / 1000) as UTCTimestamp;
}

// ─── 봉 병합 ──────────────────────────────────────────────

/**
 * 두 ChartBar 배열을 시간 기준으로 병합. 같은 시간대는 OHLCV 통합
 */
export function mergeBars(left: ChartBar[], right: ChartBar[]): ChartBar[] {
  const map = new Map<number, ChartBar>();
  for (const bar of [...left, ...right]) {
    const prev = map.get(bar.time);
    if (!prev) {
      map.set(bar.time, bar);
      continue;
    }
    map.set(bar.time, {
      time: bar.time,
      open: prev.open,
      high: Math.max(prev.high, bar.high),
      low: Math.min(prev.low, bar.low),
      close: bar.close,
      volume: Math.max(prev.volume, bar.volume),
    });
  }
  return [...map.values()].sort((a, b) => a.time - b.time);
}

/**
 * 실시간 봉 업데이트: 같은 시간이면 기존 봉에 병합, 새 시간이면 추가
 */
export function upsertRealtimeBar(
  prev: ChartBar[],
  incoming: ChartBar,
): ChartBar[] {
  if (prev.length === 0) return [incoming];
  const last = prev[prev.length - 1];

  if (incoming.time > last.time) return [...prev, incoming];
  if (incoming.time < last.time) return prev;

  return [
    ...prev.slice(0, -1),
    {
      time: last.time,
      open: last.open,
      high: Math.max(last.high, incoming.high),
      low: Math.min(last.low, incoming.low),
      close: incoming.close,
      volume: Math.max(last.volume, incoming.volume),
    },
  ];
}

// ─── 포맷터 ───────────────────────────────────────────────

export function formatPrice(value: number) {
  return KRW_FORMATTER.format(Math.round(value));
}

export function formatSignedPercent(value: number) {
  const sign = value > 0 ? "+" : "";
  return `${sign}${value.toFixed(2)}%`;
}

/**
 * 분봉 타임프레임인지 판별
 */
export function isMinuteTimeframe(tf: DashboardChartTimeframe) {
  return tf === "1m" || tf === "30m" || tf === "1h";
}