import { Search } from "@element-plus/icons-vue";
import dayjs from "dayjs";
import { ElMessageBox } from "element-plus";
import { computed, reactive, ref, watch } from "vue";
import {
  createEmptyTemplateForm,
  createInitialMockTemplates,
  flowNodesSummary,
  getBuiltinTemplates,
  loadStoredTemplates,
  nodeSignModeLabel,
  saveStoredTemplates,
  validateTemplateForm,
} from "./approveTemplateConstants.js";

export function useApproveTemplate() {
  const stored = loadStoredTemplates();
  const allTemplates = ref(stored?.length ? stored : createInitialMockTemplates());

  const activeTab = ref("custom");
  const builtinTemplates = getBuiltinTemplates();

  const searchForm = reactive({
    keyword: "",
    enabledOnly: false,
  });

  const tableLoading = ref(false);
  const page = reactive({ current: 1, size: 10, total: 0 });

  const formDialog = reactive({ visible: false, title: "", mode: "add" });
  const form = reactive(createEmptyTemplateForm());
  const formRef = ref();

  const detailDialog = reactive({ visible: false });
  const detailRow = ref({});

  const filteredList = computed(() => {
    let list = [...allTemplates.value];
    const kw = (searchForm.keyword || "").trim().toLowerCase();
    if (kw) {
      list = list.filter((r) => {
        const name = (r.templateName || "").toLowerCase();
        const desc = (r.description || "").toLowerCase();
        return name.includes(kw) || desc.includes(kw);
      });
    }
    if (searchForm.enabledOnly) {
      list = list.filter((r) => r.enabled !== false);
    }
    return list.sort((a, b) => (String(a.updateTime) < String(b.updateTime) ? 1 : -1));
  });

  watch(
    filteredList,
    (list) => {
      page.total = list.length;
      const maxPage = Math.max(1, Math.ceil(list.length / page.size) || 1);
      if (page.current > maxPage) page.current = maxPage;
    },
    { immediate: true }
  );

  const tableData = computed(() => {
    const start = (page.current - 1) * page.size;
    return filteredList.value.slice(start, start + page.size);
  });

  const formRules = {
    templateName: [{ required: true, message: "请输入模板名称", trigger: "blur" }],
  };

  const tableColumn = ref([
    { label: "模板名称", prop: "templateName", minWidth: 140 },
    { label: "说明", prop: "description", minWidth: 160, showOverflowTooltip: true },
    {
      label: "节点数",
      prop: "flowNodes",
      width: 80,
      align: "center",
      formatData: (v) => (Array.isArray(v) ? v.length : 0),
    },
    {
      label: "流程概要",
      prop: "flowNodes",
      minWidth: 220,
      showOverflowTooltip: true,
      formatData: (v) => flowNodesSummary(v),
    },
    {
      label: "状态",
      prop: "enabled",
      width: 90,
      align: "center",
      dataType: "tag",
      formatData: (v) => (v !== false ? "启用" : "停用"),
      formatType: (v) => (v !== false ? "success" : "info"),
    },
    { label: "更新时间", prop: "updateTime", width: 170 },
    {
      dataType: "action",
      label: "操作",
      align: "center",
      fixed: "right",
      width: 200,
      operation: [
        { name: "详情", type: "text", clickFun: (row) => openDetail(row) },
        { name: "编辑", type: "text", clickFun: (row) => openFormDialog("edit", row) },
        { name: "删除", type: "text", clickFun: (row) => removeTemplate(row) },
      ],
    },
  ]);

  function persist() {
    saveStoredTemplates(allTemplates.value);
  }

  function handleQuery() {
    tableLoading.value = true;
    page.current = 1;
    setTimeout(() => {
      tableLoading.value = false;
    }, 150);
  }

  function resetSearch() {
    searchForm.keyword = "";
    searchForm.enabledOnly = false;
    handleQuery();
  }

  function pagination({ page: p, limit }) {
    page.current = p;
    page.size = limit;
  }

  function resetForm(row) {
    const base = createEmptyTemplateForm();
    if (!row) {
      Object.assign(form, base);
      return;
    }
    Object.assign(form, {
      ...base,
      id: row.id,
      templateName: row.templateName || "",
      description: row.description || "",
      enabled: row.enabled !== false,
      flowNodes: JSON.parse(JSON.stringify(row.flowNodes || [base.flowNodes[0]])),
    });
  }

  function openFormDialog(mode, row) {
    formDialog.mode = mode;
    formDialog.title = mode === "add" ? "新建自定义审批模板" : "编辑自定义审批模板";
    resetForm(mode === "edit" ? row : null);
    formDialog.visible = true;
  }

  function openDetail(row) {
    detailRow.value = { ...row };
    detailDialog.visible = true;
  }

  function isNameDuplicate(name, excludeId) {
    const n = (name || "").trim();
    return allTemplates.value.some((t) => t.templateName?.trim() === n && t.id !== excludeId);
  }

  async function submitForm() {
    if (!formRef.value) return false;
    try {
      await formRef.value.validate();
    } catch {
      return false;
    }
    const validated = validateTemplateForm(form);
    if (!validated.ok) {
      return { message: validated.message };
    }
    if (isNameDuplicate(validated.name, form.id)) {
      return { message: "模板名称已存在，请更换名称" };
    }
    const now = dayjs().format("YYYY-MM-DD HH:mm:ss");
    if (formDialog.mode === "add") {
      allTemplates.value.unshift({
        id: `tpl_${Date.now()}`,
        templateName: validated.name,
        description: (form.description || "").trim(),
        enabled: form.enabled !== false,
        createTime: now,
        updateTime: now,
        flowNodes: validated.nodes,
      });
    } else {
      const hit = allTemplates.value.find((t) => t.id === form.id);
      if (!hit) return { message: "模板不存在或已删除" };
      hit.templateName = validated.name;
      hit.description = (form.description || "").trim();
      hit.enabled = form.enabled !== false;
      hit.flowNodes = validated.nodes;
      hit.updateTime = now;
    }
    persist();
    formDialog.visible = false;
    page.current = 1;
    return { ok: true };
  }

  async function removeTemplate(row) {
    try {
      await ElMessageBox.confirm(`确定删除模板「${row.templateName}」吗？`, "提示", {
        type: "warning",
        confirmButtonText: "删除",
        cancelButtonText: "取消",
      });
    } catch {
      return;
    }
    const idx = allTemplates.value.findIndex((t) => t.id === row.id);
    if (idx >= 0) {
      allTemplates.value.splice(idx, 1);
      persist();
    }
  }

  function toggleEnabled(row) {
    const hit = allTemplates.value.find((t) => t.id === row.id);
    if (!hit) return;
    hit.enabled = !hit.enabled;
    hit.updateTime = dayjs().format("YYYY-MM-DD HH:mm:ss");
    persist();
  }

  return {
    Search,
    activeTab,
    builtinTemplates,
    nodeSignModeLabel,
    flowNodesSummary,
    searchForm,
    tableLoading,
    page,
    tableData,
    tableColumn,
    formDialog,
    form,
    formRef,
    formRules,
    detailDialog,
    detailRow,
    handleQuery,
    resetSearch,
    pagination,
    openFormDialog,
    openDetail,
    submitForm,
    toggleEnabled,
  };
}