/** 신고가·신저가 — 단일(보조) 지표: 종가/고가 vs 직전 N봉 최고·최저 */
import type { ConditionDSL } from './strategyTypes';
import { parseDonchianPeriod } from './compositeIndicators';

export function isPriceExtremeIndicator(ind?: string): boolean {
  return ind === 'NEW_HIGH' || ind === 'NEW_LOW';
}

export function nhPriorField(period: number): string {
  return `NH_PRIOR_${Math.max(1, Math.round(period))}`;
}

export function nlPriorField(period: number): string {
  return `NL_PRIOR_${Math.max(1, Math.round(period))}`;
}

export function parsePriorExtremePeriod(field?: string): number | null {
  if (!field) return null;
  const m = field.match(/^(?:NH|NL)_PRIOR_(\d+)$/);
  if (m) {
    const n = parseInt(m[1], 10);
    return Number.isFinite(n) && n > 0 ? n : null;
  }
  return parseDonchianPeriod(field);
}

export function priorExtremeField(ind: string, period: number): string {
  return ind === 'NEW_LOW' ? nlPriorField(period) : nhPriorField(period);
}

/** 단일 지표 — 기간에 맞춰 직전 N봉 신고가/신저가선 필드 동기화 */
export function syncPriceExtremeSimpleFields(cond: ConditionDSL): ConditionDSL {
  if (!isPriceExtremeIndicator(cond.indicatorType)) return cond;
  const period = cond.period
    ?? parsePriorExtremePeriod(cond.rightField)
    ?? parsePriorExtremePeriod(cond.leftField)
    ?? 9;
  const p = Math.max(1, Math.min(500, Math.round(period)));
  const band = priorExtremeField(cond.indicatorType, p);
  const priceFields = new Set(['CLOSE_PRICE', 'HIGH_PRICE', 'LOW_PRICE', 'OPEN_PRICE']);
  let leftField = cond.leftField;
  let rightField = cond.rightField;
  if (cond.indicatorType === 'NEW_HIGH') {
    leftField = leftField && priceFields.has(leftField) ? leftField : 'CLOSE_PRICE';
    rightField = band;
  } else {
    leftField = leftField && priceFields.has(leftField) ? leftField : 'CLOSE_PRICE';
    rightField = band;
  }
  return {
    ...cond,
    composite: false,
    period: p,
    leftPeriod: undefined,
    rightPeriod: undefined,
    leftCandleType: undefined,
    rightCandleType: undefined,
    leftField,
    rightField,
  };
}

/** 저장 DSL — 복합지표 승격·DC_UPPER_N 필드를 단일 신고가/신저가로 정규화 */
export function migratePriceExtremeCondition(cond: ConditionDSL): ConditionDSL {
  const ind = cond.indicatorType;
  if (!isPriceExtremeIndicator(ind)) return cond;

  if (cond.composite && isPriceExtremeIndicator(ind)) {
    const period = cond.leftPeriod ?? cond.rightPeriod ?? 9;
    const priceFields = new Set(['CLOSE_PRICE', 'HIGH_PRICE', 'LOW_PRICE', 'OPEN_PRICE']);
    const leftField = cond.leftField && priceFields.has(cond.leftField)
      ? cond.leftField
      : 'CLOSE_PRICE';
    const rightField = priorExtremeField(ind, period);
    let conditionType = cond.conditionType;
    if (conditionType === 'CROSS_UP' && ind === 'NEW_HIGH' && !rightField.startsWith('NH_PRIOR_')) {
      conditionType = 'GTE';
    } else if (conditionType === 'CROSS_DOWN' && ind === 'NEW_LOW' && !rightField.startsWith('NL_PRIOR_')) {
      conditionType = 'LTE';
    }
    return syncPriceExtremeSimpleFields({
      ...cond,
      composite: false,
      leftField,
      rightField,
      period,
      conditionType,
    });
  }

  if (!isPriceExtremeIndicator(ind)) return cond;

  const fromRight = parsePriorExtremePeriod(cond.rightField);
  const fromLeft = parsePriorExtremePeriod(cond.leftField);
  const period = cond.period ?? fromRight ?? fromLeft ?? 9;
  let migrated = syncPriceExtremeSimpleFields({ ...cond, period });

  if (migrated.rightField?.startsWith('DC_UPPER_') || migrated.rightField?.startsWith('DC_LOWER_')) {
    migrated = syncPriceExtremeSimpleFields({
      ...migrated,
      period: parseDonchianPeriod(migrated.rightField) ?? period,
    });
  }

  if (migrated.conditionType === 'CROSS_UP' && ind === 'NEW_HIGH'
      && !migrated.rightField?.startsWith('NH_PRIOR_')) {
    migrated = { ...migrated, conditionType: 'GTE' };
  }
  if (migrated.conditionType === 'CROSS_DOWN' && ind === 'NEW_LOW'
      && !migrated.rightField?.startsWith('NL_PRIOR_')) {
    migrated = { ...migrated, conditionType: 'LTE' };
  }

  // 종가 vs NH/NL_PRIOR — GTE/LTE 유지형은 봉마다 시그널 → CROSS 돌파 1봉으로 정규화
  if (ind === 'NEW_HIGH' && migrated.leftField === 'CLOSE_PRICE'
      && migrated.conditionType === 'GTE'
      && migrated.rightField?.startsWith('NH_PRIOR_')) {
    migrated = { ...migrated, conditionType: 'CROSS_UP' };
  }
  if (ind === 'NEW_LOW' && migrated.leftField === 'CLOSE_PRICE'
      && migrated.conditionType === 'LTE'
      && migrated.rightField?.startsWith('NL_PRIOR_')) {
    migrated = { ...migrated, conditionType: 'CROSS_DOWN' };
  }

  return migrated;
}

export function priceExtremePeriodLabel(ind: string, period: number): string {
  return ind === 'NEW_LOW' ? `${period}일 신저가선` : `${period}일 신고가선`;
}