import {RefObject} from 'react';
import {
  interactableEvent,
  InteractableEvent,
  InteractableRect,
} from './interactable-event';
import {usePointerEvents, UsePointerEventsProps} from './use-pointer-events';
import {activeInteraction, setActiveInteraction} from './active-interaction';
import {calcNewSizeFromAspectRatio} from './utils/calc-new-size-from-aspect-ratio';
import {restrictResizableWithinBoundary} from './utils/restrict-resizable-within-boundary';
import {domRectToObj} from './utils/dom-rect-to-obj';

export enum resizeHandlePosition {
  topLeft = 'topLeft',
  topRight = 'topRight',
  bottomLeft = 'bottomLeft',
  bottomRight = 'bottomRight',
}

type AspectRatio = number | null | undefined;
type InitialAspectRatio = AspectRatio | 'initial';

interface ResizeState {
  currentRect?: InteractableRect;
  resizeDir?: resizeHandlePosition;
  initialAspectRatio?: AspectRatio;
  boundaryRect?: InteractableRect;
}

let state: ResizeState = {};

const resetState = (value: ResizeState = {}) => {
  setActiveInteraction(null);
  state = value;
};

interface UseResizeProps {
  boundaryRect?: InteractableRect;
  boundaryRef?: RefObject<HTMLElement> | null;
  restrictWithinBoundary?: boolean;
  aspectRatio?: InitialAspectRatio;
  onResizeStart?: (e: InteractableEvent) => void;
  onResize?: (e: InteractableEvent) => void;
  onResizeEnd?: (e: InteractableEvent) => void;
  minWidth?: number;
  minHeight?: number;
}
export function useResize({
  aspectRatio,
  boundaryRef,
  boundaryRect,
  restrictWithinBoundary = true,
  minWidth = 50,
  minHeight = 50,
  ...props
}: UseResizeProps) {
  const pointerProps: UsePointerEventsProps = {
    onMoveStart: (e, resizable) => {
      const target = e.target as HTMLElement;

      if (!target.dataset.resizeHandle || activeInteraction) {
        return false;
      }

      resetState({
        currentRect: domRectToObj(resizable.getBoundingClientRect()),
        resizeDir: target.dataset.resizeHandle as resizeHandlePosition,
      });
      if (!state.currentRect) {
        return false;
      }
      setActiveInteraction('resize');

      if (boundaryRect) {
        state.boundaryRect = boundaryRect;
      } else if (boundaryRef?.current) {
        state.boundaryRect = domRectToObj(
          boundaryRef.current.getBoundingClientRect()
        );
      }

      // if we have a boundary, x, y will be relative to that boundary, otherwise it will be relative to window
      if (state.currentRect && state.boundaryRect) {
        state.currentRect.left -= state.boundaryRect.left;
        state.currentRect.top -= state.boundaryRect.top;
      }
      state.initialAspectRatio =
        state.currentRect.width / state.currentRect!.height;
      props.onResizeStart?.(interactableEvent({rect: state.currentRect, e}));
    },
    onMove: (e, deltaX, deltaY) => {
      if (!state.resizeDir || !state.currentRect) return;

      const ratio =
        aspectRatio === 'initial' ? state.initialAspectRatio : aspectRatio;
      const newRect = resizeRect(state.currentRect, deltaX, deltaY, ratio);
      const boundedRect = applyBounds(newRect, minWidth, minHeight, ratio);

      props.onResize?.(
        interactableEvent({rect: boundedRect, e, deltaX, deltaY})
      );

      state.currentRect = newRect;
    },
    onMoveEnd: e => {
      if (state.currentRect) {
        props.onResizeEnd?.(interactableEvent({rect: state.currentRect, e}));
      }
      resetState();
    },
  };

  const {domProps} = usePointerEvents(pointerProps);

  return {resizeProps: domProps};
}

function resizeRect(
  rect: InteractableRect,
  deltaX: number,
  deltaY: number,
  ratio: AspectRatio
): InteractableRect {
  const prevRect = {...rect};
  const newRect = {...rect};

  if (state.resizeDir === resizeHandlePosition.topRight) {
    newRect.width = Math.floor(newRect.width + deltaX);
    if (ratio) {
      newRect.height = Math.floor(newRect.width / ratio);
    } else {
      newRect.height = Math.floor(newRect.height - deltaY);
    }
    newRect.top = Math.floor(newRect.top + (prevRect.height - newRect.height));
  } else if (state.resizeDir === resizeHandlePosition.bottomRight) {
    newRect.width = Math.floor(newRect.width + deltaX);
    if (ratio) {
      newRect.height = Math.floor(newRect.width / ratio);
    } else {
      newRect.height = Math.floor(newRect.height + deltaY);
    }
  } else if (state.resizeDir === resizeHandlePosition.topLeft) {
    newRect.width = Math.floor(newRect.width - deltaX);
    if (ratio) {
      newRect.height = Math.floor(newRect.width / ratio);
    } else {
      newRect.height = Math.floor(newRect.height - deltaY);
    }
    newRect.left = Math.floor(newRect.left + (prevRect.width - newRect.width));
    newRect.top = Math.floor(newRect.top + (prevRect.height - newRect.height));
  } else if (state.resizeDir === resizeHandlePosition.bottomLeft) {
    newRect.width = Math.floor(newRect.width - deltaX);
    if (ratio) {
      newRect.height = Math.floor(newRect.width / ratio);
    } else {
      newRect.height = Math.floor(newRect.height + deltaY);
    }
    newRect.left = Math.floor(newRect.left + deltaX);
  }

  return newRect;
}

function applyBounds(
  rect: InteractableRect,
  minWidth: number,
  minHeight: number,
  ratio: AspectRatio
): InteractableRect {
  const isLeftSideHandle =
    state.resizeDir === resizeHandlePosition.bottomLeft ||
    state.resizeDir === resizeHandlePosition.topLeft;
  const isTopSideHandle =
    state.resizeDir === resizeHandlePosition.topRight ||
    state.resizeDir === resizeHandlePosition.topLeft;

  // bound width and height
  let boundedRect = {...rect};
  boundedRect.width = Math.max(minWidth, rect.width);
  boundedRect.height = Math.max(minHeight, rect.height);

  // compensate left when width is bounded
  const widthRestriction = boundedRect.width - rect.width;
  if (isLeftSideHandle && widthRestriction > 0) {
    boundedRect.left -= widthRestriction;
  }

  // compensate top when height is bounded
  const heightRestriction = boundedRect.height - rect.height;
  if (isTopSideHandle && heightRestriction > 0) {
    boundedRect.top -= heightRestriction;
  }

  if (state.boundaryRect) {
    boundedRect = restrictResizableWithinBoundary(
      boundedRect,
      state.boundaryRect
    );
  }

  if (ratio) {
    // adjust width/height based on specified aspect ratio
    const oldWidth = boundedRect.width;
    const oldHeight = boundedRect.height;
    const size = calcNewSizeFromAspectRatio(
      ratio,
      boundedRect.width,
      boundedRect.height
    );
    boundedRect.width = size.width;
    boundedRect.height = size.height;

    // compensate top/left that was bound previously
    if (isTopSideHandle) {
      boundedRect.top += oldHeight - boundedRect.height;
    }

    if (isLeftSideHandle) {
      boundedRect.left += oldWidth - boundedRect.width;
    }
  }

  return boundedRect;
}