import { computed, ref } from "vue";
import { fetchPermissionTemplates, type PermissionTemplate } from "@/api/projectPermissions";
import { compareProjectPermissionRoles } from "@/utils/projectPermissionRoles";

const FALLBACK_ROLE_META: Record<string, { label: string; icon: string; desc: string }> = {
  ADMIN: { label: "管理员", icon: "🛡️", desc: "系统管理员" },
  PM: { label: "PM", icon: "👑", desc: "项目负责人，统筹项目全局，协调进度、资源与关键决策。" },
  CRA: { label: "CRA", icon: "📋", desc: "负责各中心临床监查执行，跟进现场质量、数据和问题闭环。" },
  PV: { label: "PV", icon: "🔍", desc: "负责药物警戒相关工作，跟踪安全性事件并支持风险评估。" },
  QA: { label: "QA", icon: "🏥", desc: "负责医学审核与稽查，关注质量风险、合规性和医学一致性。" },
  CTA: { label: "CTA", icon: "📦", desc: "负责合同、药品及相关项目事务管理，保障执行支持与物资协同。" },
};

const templates = ref<PermissionTemplate[]>([]);
const loading = ref(false);
let pendingLoad: Promise<void> | null = null;

export const useRoleTemplateMeta = () => {
  const templateByRole = computed(() => {
    const result: Record<string, PermissionTemplate> = {};
    for (const template of templates.value) {
      if (template.category) result[template.category] = template;
    }
    return result;
  });

  const roleLabel = (role?: string | null) => {
    if (!role) return "";
    return templateByRole.value[role]?.name || FALLBACK_ROLE_META[role]?.label || role;
  };

  const roleDescription = (role?: string | null) => {
    if (!role) return "";
    return templateByRole.value[role]?.description || FALLBACK_ROLE_META[role]?.desc || "自定义项目角色";
  };

  const roleIcon = (role?: string | null) => {
    if (!role) return "🔧";
    return FALLBACK_ROLE_META[role]?.icon || "🔧";
  };

  const roleOptionsFor = (roles: string[]) =>
    roles.map((role) => ({
      value: role,
      key: role,
      label: roleLabel(role),
      icon: roleIcon(role),
      desc: roleDescription(role),
    }));

  const roleOrder = computed(() => {
    const result: Record<string, number> = {};
    templates.value.forEach((template, index) => {
      if (template.category && result[template.category] === undefined) {
        result[template.category] = index;
      }
    });
    return result;
  });

  const compareRolesByTemplateOrder = (a: string, b: string) => {
    if (a === "PM" || b === "PM") return compareProjectPermissionRoles(a, b);
    const order = roleOrder.value;
    const aOrder = order[a] ?? Number.MAX_SAFE_INTEGER;
    const bOrder = order[b] ?? Number.MAX_SAFE_INTEGER;
    if (aOrder !== bOrder) return aOrder - bOrder;
    return a.localeCompare(b);
  };

  const loadRoleTemplates = async () => {
    if (pendingLoad) return pendingLoad;
    loading.value = true;
    pendingLoad = fetchPermissionTemplates()
      .then((res) => {
        templates.value = res.data;
      })
      .finally(() => {
        loading.value = false;
        pendingLoad = null;
      });
    return pendingLoad;
  };

  return {
    templates,
    loading,
    templateByRole,
    roleLabel,
    roleDescription,
    roleIcon,
    roleOptionsFor,
    compareRolesByTemplateOrder,
    loadRoleTemplates,
  };
};