let accounts = [];
let retainedEarnings = null;
let isLocked = false;

// 科目グループ定義（小計付き）
const GROUPS = [
  {
    key: "asset",
    label: "資産",
    subGroups: [
      { label: "現金・預金合計", codes: ["101", "102", "103", "104"] },
      { label: "売上債権合計", codes: ["201"] },
      {
        label: "流動資産合計",
        codes: [
          "101",
          "102",
          "103",
          "104",
          "201",
          "202",
          "203",
          "204",
          "205",
          "206",
        ],
      },
      {
        label: "固定資産合計",
        codes: [
          "301",
          "401",
          "402",
          "403",
          "404",
          "405",
          "406",
          "407",
          "408",
          "410",
        ],
      },
    ],
  },
  {
    key: "liability",
    label: "負債",
    subGroups: [
      { label: "仕入債務合計", codes: ["501"] },
      {
        label: "流動負債合計",
        codes: ["501", "502", "503", "504", "505", "506", "507", "508"],
      },
      { label: "固定負債合計", codes: ["509"] },
    ],
  },
  {
    key: "equity",
    label: "純資産",
    subGroups: [
      { label: "株主資本合計", codes: ["601", "602"] },
      { label: "純資産合計", codes: ["601", "602"] },
    ],
  },
];

function formatNumber(n) {
  return Number(n || 0).toLocaleString();
}

function parseNumber(str) {
  // カンマを除去して数値に変換
  return Number(String(str).replace(/,/g, "")) || 0;
}

function recalcTotals() {
  let debit = 0;
  let credit = 0;

  // 先算：不含繰越利益剰余金
  accounts.forEach((a) => {
    if (a.account_name === "繰越利益剰余金" || a.account_name === "繰越利益")
      return;
    debit += Number(a.opening_debit || 0);
    credit += Number(a.opening_credit || 0);
  });

  const diff = debit - credit;

  console.log("Debug: debit=", debit, "credit=", credit, "diff=", diff);
  console.log("Debug: retainedEarnings=", retainedEarnings);

  // 自动计算 繰越利益剰余金
  if (retainedEarnings) {
    if (diff > 0) {
      retainedEarnings.opening_debit = 0;
      retainedEarnings.opening_credit = diff;
    } else {
      retainedEarnings.opening_debit = -diff;
      retainedEarnings.opening_credit = 0;
    }
    console.log("Debug: retainedEarnings after calc=", retainedEarnings);

    // DOM入力フィールドを更新
    const retainedIndex = accounts.indexOf(retainedEarnings);
    const inputs = document.querySelectorAll("#balanceTable tbody input");
    inputs.forEach((input) => {
      const match = input
        .getAttribute("onchange")
        ?.match(/accounts\[(\d+)\]\.opening_(debit|credit)/);
      if (match && parseInt(match[1]) === retainedIndex) {
        const field = match[2]; // "debit" or "credit"
        input.value = formatNumber(retainedEarnings[`opening_${field}`]);
      }
    });
  }

  // 再算一次（包含繰越利益）
  let finalDebit = 0;
  let finalCredit = 0;

  accounts.forEach((a) => {
    finalDebit += Number(a.opening_debit || 0);
    finalCredit += Number(a.opening_credit || 0);
  });

  document.getElementById("totalDebit").innerText = formatNumber(finalDebit);
  document.getElementById("totalCredit").innerText = formatNumber(finalCredit);
  document.getElementById("diff").innerText = formatNumber(
    finalDebit - finalCredit
  );

  // 小計行を更新
  updateSubtotalRows();
}

function updateSubtotalRows() {
  GROUPS.forEach((group) => {
    group.subGroups.forEach((subGroup) => {
      const subGroupTotal = accounts
        .filter((acc) => subGroup.codes.includes(acc.account_code))
        .reduce(
          (sum, acc) => ({
            debit: sum.debit + Number(acc.opening_debit || 0),
            credit: sum.credit + Number(acc.opening_credit || 0),
          }),
          { debit: 0, credit: 0 }
        );

      // 対応する小計行を探して更新
      const rows = document.querySelectorAll("#balanceTable tbody tr");
      rows.forEach((row) => {
        const labelCell = row.cells[1];
        if (labelCell && labelCell.textContent === subGroup.label) {
          row.cells[2].textContent = formatNumber(subGroupTotal.debit);
          row.cells[3].textContent = formatNumber(subGroupTotal.credit);
        }
      });
    });
  });
}

async function loadOpeningBalances() {
  const year = document.getElementById("fiscalYear").value;

  const data = await apiGet("/opening-balances", { fiscal_year: year });

  accounts = data;
  retainedEarnings = accounts.find(
    (a) => a.account_name === "繰越利益剰余金" || a.account_name === "繰越利益"
  );

  const tbody = document.querySelector("#balanceTable tbody");
  tbody.innerHTML = "";

  GROUPS.forEach((group) => {
    // 分组标题行
    const headerTr = document.createElement("tr");
    headerTr.innerHTML = `
    <td colspan="4" style="background:#ddd; font-weight:bold;">
      ${group.label}
    </td>
  `;
    tbody.appendChild(headerTr);

    const groupAccounts = accounts.filter((a) => a.account_type === group.key);

    groupAccounts.forEach((a, idx) => {
      const i = accounts.indexOf(a);
      const isRetained =
        a.account_name === "繰越利益剰余金" || a.account_name === "繰越利益";
      const tr = document.createElement("tr");

      tr.innerHTML = `
      <td>${a.account_code}</td>
      <td>${a.account_name}</td>
      <td>
        <input type="text" value="${formatNumber(a.opening_debit)}"
          ${isRetained ? "readonly" : ""}
          onchange="accounts[${i}].opening_debit=parseNumber(this.value); this.value=formatNumber(accounts[${i}].opening_debit); recalcTotals();">
      </td>
      <td>
        <input type="text" value="${formatNumber(a.opening_credit)}"
          ${isRetained ? "readonly" : ""}
          onchange="accounts[${i}].opening_credit=parseNumber(this.value); this.value=formatNumber(accounts[${i}].opening_credit); recalcTotals();">
      </td>
    `;

      tbody.appendChild(tr);

      // 小計行の追加
      group.subGroups.forEach((subGroup) => {
        const isLastInSubGroup =
          subGroup.codes.includes(a.account_code) &&
          !groupAccounts
            .slice(idx + 1)
            .some((nextAcc) => subGroup.codes.includes(nextAcc.account_code));

        if (isLastInSubGroup) {
          const subGroupTotal = accounts
            .filter((acc) => subGroup.codes.includes(acc.account_code))
            .reduce(
              (sum, acc) => ({
                debit: sum.debit + Number(acc.opening_debit || 0),
                credit: sum.credit + Number(acc.opening_credit || 0),
              }),
              { debit: 0, credit: 0 }
            );

          const totalTr = document.createElement("tr");
          totalTr.style.backgroundColor = "#d0d0d0";
          totalTr.style.fontWeight = "bold";
          totalTr.innerHTML = `
            <td></td>
            <td>${subGroup.label}</td>
            <td>${formatNumber(subGroupTotal.debit)}</td>
            <td>${formatNumber(subGroupTotal.credit)}</td>
          `;
          tbody.appendChild(totalTr);
        }
      });
    });
  });

  // 年度锁定チェック
  fetch(
    `http://127.0.0.1:18080/opening-balances/lock-status?fiscal_year=${year}`
  )
    .then((res) => res.json())
    .then((data) => {
      isLocked = data.is_locked;
      document.querySelector(
        "button[onclick='saveOpeningBalances()']"
      ).disabled = isLocked;
      if (isLocked) {
        alert("この会計年度の期首残高は確定されています。");
      }
    });

  recalcTotals();
}

async function saveOpeningBalances() {
  if (isLocked) {
    alert("この会計年度の期首残高は確定されているため、保存できません。");
    return;
  }
  const year = Number(document.getElementById("fiscalYear").value);

  const balances = accounts
    // ❗ 排除 繰越利益剰余金
    .filter(
      (a) =>
        a.account_name !== "繰越利益剰余金" &&
        a.account_name !== "繰越利益" &&
        (Number(a.opening_debit) !== 0 || Number(a.opening_credit) !== 0)
    )
    .map((a) => ({
      account_id: a.account_id,
      debit: Number(a.opening_debit || 0),
      credit: Number(a.opening_credit || 0),
    }));

  try {
    await fetch("http://127.0.0.1:18080/opening-balances", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        fiscal_year: year,
        balances: balances,
      }),
    }).then(async (res) => {
      if (!res.ok) {
        const data = await res.json();
        throw new Error(data.detail);
      }
    });

    alert("期首残高を保存しました");
  } catch (e) {
    alert(e.message);
  }
}