export const findBounds = (
  data: any[],
  fctCd: string,
  dataCode: string,
  qtyCode:string,
  qty: number
): { lower: any; upper: any } => {


  const filtered = data.filter((item) => item[dataCode] === fctCd);

  const lowers = filtered.filter((item) => Number(item[qtyCode]) <= qty);
  const uppers = filtered.filter((item) => Number(item[qtyCode]) > qty);

  const lower =
    lowers.length > 0
      ? lowers.reduce((acc, curr) =>
          Number(curr[qtyCode]) > Number(acc[qtyCode]) ? curr : acc
        )
      : undefined;

  const upper =
    uppers.length > 0
      ? uppers.reduce((acc, curr) =>
          Number(curr[qtyCode]) < Number(acc[qtyCode]) ? curr : acc
        )
      : undefined;

  // ✅ 바운더리 하나만 있을 경우 대체 처리
  if (!lower && upper) return { lower: upper, upper };
  if (!upper && lower) return { lower, upper: lower };

  // ✅ 정상 보간 구간
  if (lower && upper) return { lower, upper };

  // ❌ 둘 다 없을 경우 (fctCd 필터 결과가 없음)
  throw new Error(`No matching bounds found for fctCd: ${fctCd}, qty: ${qty}`);
};


// (기울기) a = (y2 - y1) / (x2 - x1)
// (절편)   b = y1 - a * x1
//          ↓
// 결과값 y = a * x + b


export const getInterpolation = (
  Upper: { stdCost: number; fctCpc: number },
  Lower: { stdCost: number; fctCpc: number },
  qtyYear: number
): number => {
  const x1 = Number(Lower.fctCpc);     // 최소 처리 용량
  const y1 = Number(Lower.stdCost);    // 최소 공사비/요율
  const x2 = Number(Upper.fctCpc);     // 최대 처리 용량
  const y2 = Number(Upper.stdCost);    // 최대 공사비/요율

  if (qtyYear <= x1) return y1;        // 최소 이하면 y1 반환
  if (qtyYear >= x2) return y2;        // 최대 이상이면 y2 반환

  const slope = (y2 - y1) / (x2 - x1); // 기울기 a
  const intercept = y1 - slope * x1;  // 절편 b

  return slope * qtyYear + intercept; // 보간 계산
};

export const transformAndInterpolate = (
  rawData: any,
  dmndQtyYear: number
): any => {
  const result: any = {};

  for (const key in rawData) {
    const item = rawData[key];

    const range = {
      Lower: {
        fctCpc: item.lower?.stdCost,
        stdCost: item.lower?.rt,
      },
      Upper: {
        fctCpc: item.upper?.stdCost,
        stdCost: item.upper?.rt,
      },
    };
    result[key] = getInterpolation(range.Upper, range.Lower, dmndQtyYear);
  }

  return result;
};

export const getConstFctCode = (fctCd: string) => {
  const fctMap: { [key: string]: string } = {
    총인처리시설: "001",
    염소소독: "002",
    UV소독: "003",
    전처리시설: "004",
    RO: "005",
  };

  return fctMap[fctCd];
};