import { h } from "vue";
import { Checkbox, Input, InputNumber, Select } from "antdv-next";

function resolveOption(option, row) {
  return typeof option === "function" ? option(row) : option;
}

export function createEditableCellRenderer({ getRowKey, getActiveRowKey, getActiveColKey }) {
  // 每个单元格独立的 debounce timer，避免每次击键都触发
  // onChange → emitUpdate → emit → parent drafts → watch → localData 新引用
  // → FmsTable dataSource 新引用 → StkTable 全量虚拟滚动重算 → 卡顿。
  // 150ms debounce 让连续打字期间只触发一次同步。
  const changeTimers = new Map();

  // 追踪已聚焦过的单元格 key，避免在同一个编辑会话内重复 focus+select
  //（例如父组件数据变化导致行重渲染时不应打断正在输入的用户）。
  // 与旧实现不同：不依赖 DOM dataset，因为优化后编辑组件始终驻留 DOM。
  const focusedCells = new Map();

  // 缓存每个 cellKey 的 focusRef 闭包引用，避免每次渲染创建新引用导致
  // Vue ref 回调反复触发（ref 变化 → ref(null) → ref(instance) → focus+select）。
  const focusRefCache = new Map();

  // 稳定引用：Vue VNode diff 按引用比较 props，每次 render 创建新函数/对象
  // 会触发事件监听器重绑定和样式对比。提到外面让引用恒定，消除击键时的无意义 diff。
  const stopPropagation = (e) => e.stopPropagation();
  const fullWidth = { width: "100%" };

  function getFocusRef(cellKey, enabled) {
    if (!enabled) return undefined;
    let fn = focusRefCache.get(cellKey);
    if (!fn) {
      fn = (instance) => {
        if (!instance) return;
        if (focusedCells.get(cellKey)) return;
        focusedCells.set(cellKey, true);
        const el = instance.$el;
        const target = instance.focus ? instance : el;
        target?.focus?.({ preventScroll: true });
        const inputEl = el?.matches?.("input") ? el : el?.querySelector?.("input");
        inputEl?.select?.();
      };
      focusRefCache.set(cellKey, fn);
    }
    return fn;
  }

  return function EditableCell({ row, col, cellValue }) {
    const editor = typeof col.editor === "string" ? { type: col.editor } : col.editor || {};
    const rowKey = String(getRowKey(row));
    const activeRowKey = getActiveRowKey();
    const isEditing = activeRowKey != null && String(activeRowKey) === rowKey;
    const activeColKey = getActiveColKey?.();
    const shouldFocus = isEditing && (activeColKey == null || col.dataIndex === activeColKey);
    const cellKey = `${rowKey}_${col.dataIndex}`;

    const update = (value) => {
      row[col.dataIndex] = value;
      if (editor.onChange) {
        const timerKey = `${rowKey}_${col.dataIndex}`;
        clearTimeout(changeTimers.get(timerKey));
        changeTimers.set(
          timerKey,
          setTimeout(() => {
            changeTimers.delete(timerKey);
            editor.onChange?.(value, row, col);
          }, 150),
        );
      }
    };

    // checkbox 始终可交互（显示态与编辑态一致）
    if (editor.type === "checkbox") {
      const checkedValue = editor.checkedValue ?? 1;
      const uncheckedValue = editor.uncheckedValue ?? 0;
      return h(Checkbox, {
        checked: cellValue === checkedValue,
        disabled: resolveOption(editor.disabled, row),
        onClick: (event) => event.stopPropagation(),
        "onUpdate:checked": (checked) => update(checked ? checkedValue : uncheckedValue),
      });
    }

    // 文本态内容
    const textContent =
      editor.type === "select"
        ? ((resolveOption(editor.options, row) || []).find((item) => item.value === cellValue)
            ?.label ??
          cellValue ??
          "")
        : (cellValue ?? "");

    // 始终同时渲染文本 span 和编辑组件，仅通过 CSS display 切换可见性。
    // 这样 Vue diff 看到的是同一个 div 容器 + 同一对子 VNode 类型，
    // 跨行切换时只更新 props/style，不触发组件卸载/挂载。
    // （之前 if(!isEditing) return span else return Input → 不同类型 VNode
    //  → 强制 mount/unmount Ant Design 组件，是键盘导航时 FPS 暴跌的另一主因。）

    const textSpan = h(
      "span",
      {
        class: "fms-cell-text",
        style: { display: isEditing ? "none" : "inline-block" },
      },
      textContent,
    );

    const common = {
      size: "small",
      style: { ...fullWidth, display: isEditing ? "inline-block" : "none" },
      onClick: stopPropagation,
      ref: getFocusRef(cellKey, shouldFocus),
    };

    let editComponent;
    if (editor.type === "number") {
      editComponent = h(InputNumber, {
        ...common,
        value: cellValue,
        min: resolveOption(editor.min, row),
        max: resolveOption(editor.max, row),
        precision: resolveOption(editor.precision, row),
        disabled: resolveOption(editor.disabled, row),
        "onUpdate:value": update,
      });
    } else if (editor.type === "select") {
      editComponent = h(Select, {
        ...common,
        value: cellValue,
        options: resolveOption(editor.options, row) || [],
        disabled: resolveOption(editor.disabled, row),
        "onUpdate:value": update,
      });
    } else {
      editComponent = h(Input, {
        ...common,
        value: cellValue,
        disabled: resolveOption(editor.disabled, row),
        maxlength: resolveOption(editor.maxlength, row),
        placeholder: resolveOption(editor.placeholder, row),
        status: resolveOption(editor.status, row),
        allowClear: editor.allowClear ?? false,
        "onUpdate:value": update,
      });
    }

    return h("div", { class: "fms-editable-cell-wrap" }, [textSpan, editComponent]);
  };
}