const { formatDateOnly } = require("../leave");
const { toMoneyString } = require("../../utils/workflow");

function normalizeWorkflowEntityType(entityType) {
  return entityType === "procurement" ? "purchase_request" : entityType;
}

function formatAmount(value) {
  return toMoneyString(value) ?? "-";
}

function formatRequestedDays(value) {
  const numeric = Number(value ?? 0);
  if (!Number.isFinite(numeric)) {
    return "-";
  }
  return Number.isInteger(numeric) ? String(numeric) : numeric.toFixed(1);
}

function formatDateRange(startDate, endDate) {
  const start = startDate ? formatDateOnly(startDate) : null;
  const end = endDate ? formatDateOnly(endDate) : null;

  if (start && end) {
    return start === end ? start : `${start} ~ ${end}`;
  }

  return start ?? end ?? null;
}

function buildReference(normalizedEntityType, entityRecord, entityId) {
  if (normalizedEntityType === "reimbursement") {
    return entityRecord?.form_number ?? entityId;
  }

  if (normalizedEntityType === "leave") {
    return formatDateRange(entityRecord?.start_date, entityRecord?.end_date) ?? entityId;
  }

  if (normalizedEntityType === "purchase_request") {
    return entityRecord?.request_no ?? entityId;
  }

  if (normalizedEntityType === "travel_request") {
    return entityRecord?.request_no ?? entityId;
  }

  return entityId;
}

function buildWorkflowEntityMeta(entityType, entityRecord, entityId) {
  const normalizedEntityType = normalizeWorkflowEntityType(entityType);

  if (normalizedEntityType === "reimbursement") {
    return {
      entityType: normalizedEntityType,
      label: "报销单",
      reference: buildReference(normalizedEntityType, entityRecord, entityId),
      targetType: "reimbursement_form",
      detailPath: `/reimbursements/${entityId}`,
      summary: {
        applicantName: entityRecord?.owner?.name ?? null,
        amount: formatAmount(entityRecord?.total_amount),
      },
    };
  }

  if (normalizedEntityType === "leave") {
    return {
      entityType: normalizedEntityType,
      label: "请假单",
      reference: buildReference(normalizedEntityType, entityRecord, entityId),
      targetType: "leave_request",
      detailPath: "/leave-requests",
      summary: {
        applicantName: entityRecord?.owner?.name ?? null,
        leaveTypeName: entityRecord?.leave_type?.name ?? null,
        requestedDays: formatRequestedDays(entityRecord?.requested_days),
        dateRange: formatDateRange(entityRecord?.start_date, entityRecord?.end_date) ?? "-",
      },
    };
  }

  if (normalizedEntityType === "purchase_request") {
    return {
      entityType: normalizedEntityType,
      label: "采购申请",
      reference: buildReference(normalizedEntityType, entityRecord, entityId),
      targetType: "purchase_request",
      detailPath: "/purchase-requests",
      summary: {
        applicantName: entityRecord?.applicant?.name ?? null,
        amount: formatAmount(entityRecord?.total_amount),
      },
    };
  }

  if (normalizedEntityType === "travel_request") {
    return {
      entityType: normalizedEntityType,
      label: "差旅申请",
      reference: buildReference(normalizedEntityType, entityRecord, entityId),
      targetType: "travel_request",
      detailPath: `/travel-requests?id=${entityId}`,
      summary: {
        applicantName: entityRecord?.applicant?.name ?? null,
        estimatedAmount: formatAmount(entityRecord?.estimated_amount),
      },
    };
  }

  return {
    entityType: normalizedEntityType,
    label: "审批单",
    reference: entityId,
    targetType: normalizedEntityType,
    detailPath: `/workflow/tasks/${entityId}`,
    summary: {},
  };
}

function buildSummaryLines(entityMeta) {
  if (entityMeta.entityType === "reimbursement") {
    return [
      `申请人：${entityMeta.summary.applicantName ?? "未知申请人"}`,
      `金额：${entityMeta.summary.amount ?? "-"}`,
      `单号：${entityMeta.reference}`,
    ];
  }

  if (entityMeta.entityType === "leave") {
    return [
      `申请人：${entityMeta.summary.applicantName ?? "未知申请人"}`,
      `假种：${entityMeta.summary.leaveTypeName ?? "请假"}`,
      `天数：${entityMeta.summary.requestedDays ?? "-"} 天`,
      `起止日期：${entityMeta.summary.dateRange ?? "-"}`,
    ];
  }

  if (entityMeta.entityType === "purchase_request") {
    return [
      `申请人：${entityMeta.summary.applicantName ?? "未知申请人"}`,
      `金额：${entityMeta.summary.amount ?? "-"}`,
      `单号：${entityMeta.reference}`,
    ];
  }

  if (entityMeta.entityType === "travel_request") {
    return [
      `申请人：${entityMeta.summary.applicantName ?? "未知申请人"}`,
      `预估金额：${entityMeta.summary.estimatedAmount ?? "-"}`,
      `单号：${entityMeta.reference}`,
    ];
  }

  return [`单据：${entityMeta.reference}`];
}

function buildSubject(entityMeta) {
  return entityMeta.reference ? `${entityMeta.label} ${entityMeta.reference}` : entityMeta.label;
}

function buildBody(entityMeta, resultLine) {
  return [...buildSummaryLines(entityMeta), resultLine].join("\n");
}

function buildPendingTaskCopy(entityMeta, { transfer = false } = {}) {
  return {
    title: `【待办】${buildSubject(entityMeta)} ${transfer ? "转审待处理" : "待审批"}`,
    body: buildBody(
      entityMeta,
      transfer ? "动作：该审批已转审给你，请及时处理。" : "动作：请及时处理审批任务。",
    ),
  };
}

function buildRemindedTaskCopy(entityMeta) {
  return {
    title: `【催办】${buildSubject(entityMeta)} 待审批`,
    body: buildBody(entityMeta, "动作：申请人已催办，请及时处理审批任务。"),
  };
}

function buildOverdueTaskCopy(entityMeta) {
  return {
    title: `【超时提醒】${buildSubject(entityMeta)} 待审批`,
    body: buildBody(entityMeta, "动作：该审批已超时，请尽快处理。"),
  };
}

function buildApprovedCopy(entityMeta) {
  return {
    title: `【已批准】${buildSubject(entityMeta)}`,
    body: buildBody(
      entityMeta,
      entityMeta.targetType === "reimbursement_form"
        ? "结果：已审批通过，等待财务付款。"
        : "结果：已审批通过。",
    ),
  };
}

function buildRejectedCopy(entityMeta, comment) {
  const safeComment = String(comment ?? "").trim() || "无";
  return {
    title: `【已驳回】${buildSubject(entityMeta)}`,
    body: buildBody(entityMeta, `结果：已驳回：${safeComment}`),
  };
}

function buildReturnedCopy(entityMeta, comment) {
  const safeComment = String(comment ?? "").trim() || "无";
  return {
    title: `【已退回】${buildSubject(entityMeta)}`,
    body: buildBody(entityMeta, `结果：已退回：${safeComment}`),
  };
}

module.exports = {
  buildApprovedCopy,
  buildOverdueTaskCopy,
  buildPendingTaskCopy,
  buildRejectedCopy,
  buildRemindedTaskCopy,
  buildReturnedCopy,
  buildWorkflowEntityMeta,
  normalizeWorkflowEntityType,
};