R47 A1-A8：完成薪资管理模块

server/src/services/payroll.js

@@ -0,0 +1,276 @@
+function parseDateOnly(value) {
+  return value ? new Date(`${value}T00:00:00.000Z`) : null;
+}
+
+function formatDateOnly(value) {
+  return value?.toISOString?.()?.slice(0, 10) ?? null;
+}
+
+function parsePayMonth(value) {
+  if (typeof value !== "string" || !/^\d{4}-\d{2}$/.test(value)) {
+    return null;
+  }
+
+  const [yearText, monthText] = value.split("-");
+  const year = Number(yearText);
+  const month = Number(monthText);
+  if (!Number.isInteger(year) || !Number.isInteger(month) || month < 1 || month > 12) {
+    return null;
+  }
+
+  const startDate = new Date(Date.UTC(year, month - 1, 1));
+  const endDate = new Date(Date.UTC(year, month, 0, 23, 59, 59, 999));
+  return {
+    value,
+    startDate,
+    endDate,
+  };
+}
+
+function formatPayMonth(value) {
+  return value?.toISOString?.()?.slice(0, 7) ?? null;
+}
+
+function shiftMonth(startDate, delta) {
+  return new Date(Date.UTC(startDate.getUTCFullYear(), startDate.getUTCMonth() + delta, 1));
+}
+
+function sortSalaryItems(items) {
+  return [...(items ?? [])].sort((left, right) => {
+    if ((left.sort_order ?? 0) !== (right.sort_order ?? 0)) {
+      return (left.sort_order ?? 0) - (right.sort_order ?? 0);
+    }
+    return String(left.name ?? "").localeCompare(String(right.name ?? ""));
+  });
+}
+
+function normalizeMoneyInput(value) {
+  if (typeof value === "number") {
+    if (!Number.isFinite(value) || value < 0) {
+      return null;
+    }
+    const rounded = Number(value.toFixed(2));
+    if (Math.abs(value - rounded) > 1e-9) {
+      return null;
+    }
+    return rounded.toFixed(2);
+  }
+
+  if (typeof value === "string") {
+    const trimmed = value.trim();
+    if (!/^\d+(\.\d{1,2})?$/.test(trimmed)) {
+      return null;
+    }
+    return Number(trimmed).toFixed(2);
+  }
+
+  return null;
+}
+
+function moneyTextToCents(value) {
+  const normalized = normalizeMoneyInput(value);
+  if (!normalized) {
+    return null;
+  }
+  const [integerPart, decimalPart] = normalized.split(".");
+  return Number(integerPart) * 100 + Number(decimalPart);
+}
+
+function centsToMoneyText(value) {
+  return (value / 100).toFixed(2);
+}
+
+function centsToNumber(value) {
+  return Number(centsToMoneyText(value));
+}
+
+function toNumber(value) {
+  return value == null ? null : Number(value);
+}
+
+function mapSalaryItem(item) {
+  return {
+    id: item.id,
+    name: item.name,
+    itemType: item.item_type,
+    sortOrder: item.sort_order,
+    enabled: item.enabled,
+    createdAt: item.created_at?.toISOString?.() ?? null,
+    createdBy: item.created_by ?? null,
+    updatedAt: item.updated_at?.toISOString?.() ?? null,
+    updatedBy: item.updated_by ?? null,
+  };
+}
+
+function mapEmployeeSalarySnapshotRows(rows) {
+  const snapshots = new Map();
+
+  for (const row of rows) {
+    const key = formatDateOnly(row.effective_date);
+    if (!snapshots.has(key)) {
+      snapshots.set(key, {
+        effectiveDate: key,
+        createdAt: row.created_at?.toISOString?.() ?? null,
+        createdBy: row.created_by ?? null,
+        updatedAt: row.updated_at?.toISOString?.() ?? null,
+        updatedBy: row.updated_by ?? null,
+        items: [],
+      });
+    }
+
+    snapshots.get(key).items.push({
+      salaryItemId: row.salary_item.id,
+      name: row.salary_item.name,
+      itemType: row.salary_item.item_type,
+      sortOrder: row.salary_item.sort_order,
+      monthlyAmount: toNumber(row.monthly_amount) ?? 0,
+    });
+  }
+
+  return [...snapshots.values()]
+    .map((snapshot) => ({
+      ...snapshot,
+      items: snapshot.items.sort((left, right) => left.sortOrder - right.sortOrder || left.name.localeCompare(right.name)),
+    }))
+    .sort((left, right) => right.effectiveDate.localeCompare(left.effectiveDate));
+}
+
+function calculatePayslipTotals(items) {
+  let grossCents = 0;
+  let deductionCents = 0;
+
+  for (const item of items) {
+    const cents = moneyTextToCents(item.amount);
+    if (cents == null) {
+      throw new Error("invalid_money_value");
+    }
+
+    if (item.itemType === "deduction") {
+      deductionCents += cents;
+    } else {
+      grossCents += cents;
+    }
+  }
+
+  const netCents = grossCents - deductionCents;
+  return {
+    grossAmount: centsToNumber(grossCents),
+    deductionAmount: centsToNumber(deductionCents),
+    netAmount: centsToNumber(netCents),
+    grossAmountText: centsToMoneyText(grossCents),
+    deductionAmountText: centsToMoneyText(deductionCents),
+    netAmountText: centsToMoneyText(netCents),
+  };
+}
+
+function mapPayslipItem(item) {
+  return {
+    salaryItemId: item.salary_item.id,
+    name: item.salary_item.name,
+    itemType: item.salary_item.item_type,
+    sortOrder: item.salary_item.sort_order,
+    amount: toNumber(item.amount) ?? 0,
+  };
+}
+
+function mapPayslip(payslip) {
+  return {
+    id: payslip.id,
+    employeeId: payslip.employee_id,
+    payMonth: formatPayMonth(payslip.pay_month),
+    status: payslip.status,
+    grossAmount: toNumber(payslip.gross_amount) ?? 0,
+    deductionAmount: toNumber(payslip.deduction_amount) ?? 0,
+    netAmount: toNumber(payslip.net_amount) ?? 0,
+    issuedAt: payslip.issued_at?.toISOString?.() ?? null,
+    createdAt: payslip.created_at?.toISOString?.() ?? null,
+    createdBy: payslip.created_by ?? null,
+    updatedAt: payslip.updated_at?.toISOString?.() ?? null,
+    updatedBy: payslip.updated_by ?? null,
+    employee: payslip.employee
+      ? {
+          id: payslip.employee.id,
+          employeeNo: payslip.employee.employee_no,
+          name: payslip.employee.name,
+          title: payslip.employee.title,
+          department: payslip.employee.department
+            ? {
+                id: payslip.employee.department.id,
+                name: payslip.employee.department.name,
+              }
+            : null,
+        }
+      : null,
+    items: [...(payslip.items ?? [])]
+      .sort((left, right) => {
+        const leftOrder = left.salary_item?.sort_order ?? 0;
+        const rightOrder = right.salary_item?.sort_order ?? 0;
+        if (leftOrder !== rightOrder) {
+          return leftOrder - rightOrder;
+        }
+        return String(left.salary_item?.name ?? "").localeCompare(String(right.salary_item?.name ?? ""));
+      })
+      .map(mapPayslipItem),
+  };
+}
+
+async function loadMonthlyPayslips(prisma, monthStart) {
+  const payslips = await prisma.payslip.findMany({
+    where: { pay_month: monthStart },
+    orderBy: [{ created_at: "asc" }, { id: "asc" }],
+    include: {
+      employee: {
+        select: {
+          id: true,
+          employee_no: true,
+          name: true,
+          title: true,
+          department: { select: { id: true, name: true } },
+        },
+      },
+      items: {
+        include: {
+          salary_item: true,
+        },
+      },
+    },
+  });
+
+  const salaryItemMap = new Map();
+  for (const payslip of payslips) {
+    for (const item of payslip.items ?? []) {
+      if (item.salary_item && !salaryItemMap.has(item.salary_item.id)) {
+        salaryItemMap.set(item.salary_item.id, item.salary_item);
+      }
+    }
+  }
+
+  return {
+    salaryItems: sortSalaryItems([...salaryItemMap.values()]).map(mapSalaryItem),
+    payslips: payslips
+      .map(mapPayslip)
+      .sort(
+        (left, right) =>
+          String(left.employee?.employeeNo ?? "").localeCompare(String(right.employee?.employeeNo ?? "")) ||
+          String(left.id).localeCompare(String(right.id)),
+      ),
+  };
+}
+
+module.exports = {
+  calculatePayslipTotals,
+  centsToMoneyText,
+  formatDateOnly,
+  formatPayMonth,
+  loadMonthlyPayslips,
+  mapEmployeeSalarySnapshotRows,
+  mapPayslip,
+  mapSalaryItem,
+  moneyTextToCents,
+  normalizeMoneyInput,
+  parseDateOnly,
+  parsePayMonth,
+  shiftMonth,
+  sortSalaryItems,
+  toNumber,
+};