import { deptTreeSelect, userListNoPageByTenantId } from "@/api/system/user.js";

/** 下拉选项来源（写入 formConfig，提交页按来源拉取数据） */
export const SELECT_OPTION_SOURCE = {
  STATIC: "static",
  USER: "user",
  DEPT: "dept",
};

export const SELECT_OPTION_SOURCE_OPTIONS = [
  { value: SELECT_OPTION_SOURCE.STATIC, label: "手动配置", desc: "在模板中自定义选项文本与值" },
  { value: SELECT_OPTION_SOURCE.USER, label: "人员列表", desc: "从系统用户中选择，值为用户 ID" },
  { value: SELECT_OPTION_SOURCE.DEPT, label: "部门列表", desc: "从组织架构中选择，值为部门 ID" },
];

export function selectOptionSourceLabel(source) {
  return SELECT_OPTION_SOURCE_OPTIONS.find((x) => x.value === source)?.label || "—";
}

export function isDynamicOptionSource(source) {
  return source === SELECT_OPTION_SOURCE.USER || source === SELECT_OPTION_SOURCE.DEPT;
}

function unwrapArray(payload) {
  if (Array.isArray(payload)) return payload;
  if (payload?.data && Array.isArray(payload.data)) return payload.data;
  if (payload?.rows && Array.isArray(payload.rows)) return payload.rows;
  return [];
}

function isActiveUser(u) {
  if (u.delFlag === "2" || u.delFlag === 2) return false;
  if (u.status == null) return true;
  return String(u.status) === "0";
}

/** 用户 → 下拉 option */
export function mapUserToSelectOption(u) {
  const value = u.userId ?? u.id;
  return {
    label: u.nickName || u.userName || `用户${value}`,
    value,
  };
}

/** 部门树拍平为下拉 option */
export function flattenDeptToSelectOptions(nodes, result = []) {
  (nodes || []).forEach((node) => {
    const value = node.id ?? node.deptId ?? node.value;
    if (value != null && value !== "") {
      result.push({
        label: node.label ?? node.deptName ?? node.name ?? String(value),
        value,
      });
    }
    if (node.children?.length) flattenDeptToSelectOptions(node.children, result);
  });
  return result;
}

function filterDisabledDept(deptList) {
  if (!Array.isArray(deptList)) return [];
  return deptList.filter((dept) => {
    if (dept.disabled) return false;
    if (dept.children?.length) {
      dept.children = filterDisabledDept(dept.children);
    }
    return true;
  });
}

/** 按字段配置解析下拉 options（需传入已加载的缓存） */
export function resolveFieldSelectOptions(field, caches = {}) {
  const source = field?.optionSource || SELECT_OPTION_SOURCE.STATIC;
  if (source === SELECT_OPTION_SOURCE.USER) {
    return (caches.users || []).map(mapUserToSelectOption);
  }
  if (source === SELECT_OPTION_SOURCE.DEPT) {
    return caches.deptOptions || [];
  }
  return (field?.options || []).filter((o) => o.value !== "" && o.value != null);
}

/** 根据已解析的 options 反查展示文本 */
export function resolveSelectDisplayLabel(field, val, caches = {}) {
  if (val == null || val === "") return "—";
  const options = resolveFieldSelectOptions(field, caches);
  const hit = options.find((o) => String(o.value) === String(val));
  return hit?.label || String(val);
}

/** 加载人员 / 部门缓存（多处复用） */
export async function fetchSelectOptionCaches(sources = []) {
  const needUser = sources.includes(SELECT_OPTION_SOURCE.USER);
  const needDept = sources.includes(SELECT_OPTION_SOURCE.DEPT);
  const caches = { users: [], deptOptions: [] };

  if (!needUser && !needDept) return caches;

  const tasks = [];
  if (needUser) {
    tasks.push(
      userListNoPageByTenantId()
        .then((res) => {
          caches.users = unwrapArray(res).filter(isActiveUser);
        })
        .catch(() => {
          caches.users = [];
        })
    );
  }
  if (needDept) {
    tasks.push(
      deptTreeSelect()
        .then((res) => {
          let tree = unwrapArray(res);
          tree = tree.length ? filterDisabledDept(JSON.parse(JSON.stringify(tree))) : [];
          if (!tree.length) tree = unwrapArray(res);
          caches.deptOptions = flattenDeptToSelectOptions(tree);
        })
        .catch(() => {
          caches.deptOptions = [];
        })
    );
  }

  await Promise.all(tasks);
  return caches;
}

/** 从字段列表收集需要预加载的动态来源 */
export function collectOptionSourcesFromFields(fields) {
  const set = new Set();
  (fields || []).forEach((f) => {
    if (f?.type === "select" && isDynamicOptionSource(f.optionSource)) {
      set.add(f.optionSource);
    }
  });
  return [...set];
}