/** 시도별 노후관로 현황의 연도 그룹형 엑셀 데이터를 생성한다. */
"use client";

import * as XLSX from "xlsx";
import { getRawJson } from "@/shared/api/sewerage-api";
import {
  getAgedPipeStatusByCtpvValidationMessage,
  normalizeAgedPipeStatusByCtpvFilters,
  type AgedPipeStatusByCtpvFilters,
  type AgedPipeStatusByCtpvResponse,
} from "./aged-pipe-status-by-ctpv-utils";

/** 적용조건의 시도별 노후관로현황 전체를 조회해 연도 그룹 Excel로 생성한다. */
export const downloadAgedPipeStatusByCtpvExcel = async (
  filters: AgedPipeStatusByCtpvFilters,
) => {
  const validationMessage = getAgedPipeStatusByCtpvValidationMessage(filters);
  if (validationMessage) throw new Error(validationMessage);
  const normalized = normalizeAgedPipeStatusByCtpvFilters(filters);
  const params = new URLSearchParams({
    startYear: String(normalized.startYear),
    endYear: String(normalized.endYear),
    elapsedYears: String(normalized.elapsedYears),
  });
  const response: any = await getRawJson(
    `v1/swagePpl/agedStatusByCtpv?${params.toString()}`,
  );
  const payload = (response?.data ?? response) as AgedPipeStatusByCtpvResponse;
  const years = Array.isArray(payload?.years)
    ? payload.years.map(Number).filter(Number.isFinite)
    : [];
  const rows = Array.isArray(payload?.rows) ? payload.rows : [];
  if (rows.length === 0) throw new Error("다운로드할 데이터가 없습니다.");

  const headers = ["순번", "시도"];
  years.forEach((year) => headers.push(`${year}년`, "", ""));
  const subHeaders = ["", ""];
  years.forEach(() =>
    subHeaders.push("전체관로연장(km)", "노후관로연장(km)", "노후화율(%)"),
  );
  const data = rows.map((row, rowIndex) => {
    const statsByYear = new Map(
      (row.yearStats ?? []).map((stat) => [Number(stat.year), stat]),
    );
    const values: Array<string | number> = [rowIndex + 1, row.ctpvNm || "-"];
    years.forEach((year) => {
      const stat = statsByYear.get(year);
      values.push(
        stat ? Number(stat.totalLengthKm ?? 0) : "-",
        stat ? Number(stat.agedLengthKm ?? 0) : "-",
        stat ? Number(stat.agedRate ?? 0) : "-",
      );
    });
    return values;
  });

  const worksheet = XLSX.utils.aoa_to_sheet([headers, subHeaders, ...data]);
  worksheet["!merges"] = [
    { s: { r: 0, c: 0 }, e: { r: 1, c: 0 } },
    { s: { r: 0, c: 1 }, e: { r: 1, c: 1 } },
    ...years.map((_, index) => ({
      s: { r: 0, c: 2 + index * 3 },
      e: { r: 0, c: 4 + index * 3 },
    })),
  ];
  worksheet["!cols"] = [
    { wch: 8 },
    { wch: 18 },
    ...years.flatMap(() => [{ wch: 18 }, { wch: 18 }, { wch: 14 }]),
  ];
  worksheet["!autofilter"] = {
    ref: `A2:${XLSX.utils.encode_col(headers.length - 1)}${data.length + 2}`,
  };
  const workbook = XLSX.utils.book_new();
  XLSX.utils.book_append_sheet(workbook, worksheet, "시도별 노후관로현황");
  XLSX.writeFile(workbook, "시도별_노후관로현황.xlsx", {
    bookType: "xlsx",
    compression: true,
    cellStyles: true,
  });
};