import { nextTick, watch } from 'vue';

export interface DraggableOptions {
  /** 拖拽手柄选择器，默认 '.ant-modal-header' */
  handle?: string;
  /** 弹窗内容选择器，默认 '.ant-modal-content' */
  modalSelector?: string;
  /** 是否限制在可视区域内，默认 true */
  boundary?: boolean;
  /** 打开弹窗时是否自动重置到居中位置，默认 true */
  resetOnOpen?: boolean;
}

export function useDraggable(
  openRef: { value: boolean },
  options: DraggableOptions = {}
) {
  console.log(openRef);
  const {
    handle = '.ant-modal-header',
    modalSelector = '.ant-modal-content',
    boundary = true,
    resetOnOpen = true
  } = options;

  let cleanup: (() => void) | null = null;

  const initDrag = (): (() => void) | null => {
    const modalContent = document.querySelector(
      modalSelector
    ) as HTMLElement | null;
    const dragHandle = document.querySelector(handle) as HTMLElement | null;
    if (!modalContent || !dragHandle) return null;

    // 重置位置到居中
    if (resetOnOpen) {
      modalContent.style.position = '';
      modalContent.style.left = '';
      modalContent.style.top = '';
      modalContent.style.margin = '';
      modalContent.style.transform = '';
    }

    let isDragging = false;
    let startX = 0;
    let startY = 0;
    let startLeft = 0;
    let startTop = 0;

    const getPointerPos = (e: MouseEvent | TouchEvent) => {
      if (e instanceof TouchEvent) {
        const touch = e.touches[0];
        return { clientX: touch.clientX, clientY: touch.clientY };
      }
      return { clientX: e.clientX, clientY: e.clientY };
    };

    const onPointerDown = (e: MouseEvent | TouchEvent) => {
      if (
        e.target instanceof HTMLElement &&
        (e.target.closest('.ant-modal-close') ||
          e.target.closest('button') ||
          e.target.closest('input') ||
          e.target.closest('select') ||
          e.target.closest('textarea') ||
          e.target.closest('a'))
      )
        return;

      e.preventDefault();
      isDragging = true;
      const rect = modalContent.getBoundingClientRect();
      startLeft = rect.left;
      startTop = rect.top;
      const pos = getPointerPos(e);
      startX = pos.clientX - startLeft;
      startY = pos.clientY - startTop;

      // --- 新增：固定宽度 ---
      const currentWidth = modalContent.offsetWidth;
      modalContent.style.width = currentWidth + 'px';

      modalContent.style.userSelect = 'none';
      modalContent.style.webkitUserSelect = 'none';
      modalContent.style.position = 'fixed';
      modalContent.style.margin = '0';
      modalContent.style.transform = 'none';

      document.addEventListener('mousemove', onPointerMove, { passive: false });
      document.addEventListener('mouseup', onPointerUp);
      document.addEventListener('touchmove', onPointerMove, { passive: false });
      document.addEventListener('touchend', onPointerUp);
    };
    const onPointerMove = (e: MouseEvent | TouchEvent) => {
      if (!isDragging) return;
      e.preventDefault();
      const pos = getPointerPos(e);
      let newLeft = pos.clientX - startX;
      let newTop = pos.clientY - startY;

      if (boundary) {
        const maxX = window.innerWidth - modalContent.offsetWidth;
        const maxY = window.innerHeight - modalContent.offsetHeight;
        newLeft = Math.max(0, Math.min(newLeft, maxX));
        newTop = Math.max(0, Math.min(newTop, maxY));
      }

      modalContent.style.left = `${newLeft}px`;
      modalContent.style.top = `${newTop}px`;
    };

    const onPointerUp = () => {
      isDragging = false;
      modalContent.style.userSelect = '';
      modalContent.style.webkitUserSelect = '';
      document.removeEventListener('mousemove', onPointerMove);
      document.removeEventListener('mouseup', onPointerUp);
      document.removeEventListener('touchmove', onPointerMove);
      document.removeEventListener('touchend', onPointerUp);
    };

    dragHandle.addEventListener('mousedown', onPointerDown);
    dragHandle.addEventListener('touchstart', onPointerDown, {
      passive: false
    });

    return () => {
      dragHandle.removeEventListener('mousedown', onPointerDown);
      dragHandle.removeEventListener('touchstart', onPointerDown);
      document.removeEventListener('mousemove', onPointerMove);
      document.removeEventListener('mouseup', onPointerUp);
      document.removeEventListener('touchmove', onPointerMove);
      document.removeEventListener('touchend', onPointerUp);
    };
  };

  watch(
    openRef,
    newVal => {
      if (newVal) {
        nextTick(() => {
          cleanup = initDrag();
        });
      } else {
        cleanup?.();
        cleanup = null;
      }
    },
    { immediate: true }
  );

  return { initDrag };
}