import { onMounted, onUnmounted, watch } from 'vue';
import type { Ref } from 'vue';

interface Constraints {
  top: number;
  right: number;
  bottom: number;
  left: number;
}

interface ResizeOptions {
  onResize: (data: { x: number; y: number; width: number; height: number; }) => void;
  onResizeStart?: () => void;
  onResizeEnd?: () => void;
  initialSize: { width: number; height: number; };
  initialPosition: { x: number; y: number; };
  constraints?: Ref<Constraints | undefined>;
  enabled: Ref<boolean>;
}

export function useResizable(
  target: Ref<HTMLElement | null>,
  options: ResizeOptions
) {
  const { onResize, onResizeStart, onResizeEnd, initialSize, initialPosition, constraints, enabled } = options;

  let activeHandle: string | null = null;
  let initialMouseX = 0;
  let initialMouseY = 0;
  let initialRect = { x: 0, y: 0, width: 0, height: 0 };

  const handleMouseDown = (event: MouseEvent) => {
    if (!enabled.value) return;

    const handle = (event.target as HTMLElement).dataset.direction;
    if (!handle) return;

    event.preventDefault();
    event.stopPropagation();

    if (onResizeStart) onResizeStart();

    activeHandle = handle;
    initialMouseX = event.clientX;
    initialMouseY = event.clientY;
    initialRect = {
      ...initialSize,
      ...initialPosition,
    };

    document.addEventListener('mousemove', handleMouseMove);
    document.addEventListener('mouseup', handleMouseUp);
  };

  const handleMouseMove = (event: MouseEvent) => {
    if (!activeHandle) return;

    const dx = event.clientX - initialMouseX;
    const dy = event.clientY - initialMouseY;

    let { x, y, width, height } = initialRect;

    if (activeHandle.includes('e')) {
      width = initialRect.width + dx;
    }
    if (activeHandle.includes('w')) {
      width = initialRect.width - dx;
      x = initialRect.x + dx;
    }
    if (activeHandle.includes('s')) {
      height = initialRect.height + dy;
    }
    if (activeHandle.includes('n')) {
      height = initialRect.height - dy;
      y = initialRect.y + dy;
    }

    if (constraints?.value) {
      const { top, right, bottom, left } = constraints.value;
      if (x < left) { width -= (left - x); x = left; }
      if (y < top) { height -= (top - y); y = top; }
      if (x + width > right) { width = right - x; }
      if (y + height > bottom) { height = bottom - y; }
    }
    
    width = Math.max(200, width);
    height = Math.max(150, height);

    onResize({ x, y, width, height });
  };

  const handleMouseUp = () => {
    if (onResizeEnd) onResizeEnd();

    activeHandle = null;
    document.removeEventListener('mousemove', handleMouseMove);
    document.removeEventListener('mouseup', handleMouseUp);
  };

  const addListener = () => {
    if (target.value) {
      target.value.addEventListener('mousedown', handleMouseDown);
    }
  };

  const removeListener = () => {
    if (target.value) {
      target.value.removeEventListener('mousedown', handleMouseDown);
    }
  };

  // Watch both the target and the enabled flag
  watch([target, enabled], ([newTarget, isEnabled]) => {
    if (newTarget) {
      if (isEnabled) {
        addListener();
      } else {
        removeListener();
      }
    }
  }, { immediate: true });


  onUnmounted(() => {
    removeListener();
    document.removeEventListener('mousemove', handleMouseMove);
    document.removeEventListener('mouseup', handleMouseUp);
  });
}