---

import classNames from 'classnames';
import { Button } from 'exchange-elements/v2';
import { useEffect, useRef, useState } from 'react';

import { GearIcon, LockIcon, LockOpenIcon, TrashIcon } from '@src/components/Icon';

import styles from './index.module.scss';

import type { Drawing } from '@core/Drawings';
import type { PointerEvent as ReactPointerEvent, SyntheticEvent } from 'react';
import type { Observable } from 'rxjs';

interface FloatingDrawingToolbarProps {
  selectedDrawing$: Observable<Drawing | null>;
  onToggleLock: () => void;
  onOpenSettings: () => void;
  onDelete: () => void;
}

interface Position {
  x: number;
  y: number;
}

interface DragState {
  pointerId: number;
  startX: number;
  startY: number;
  initialX: number;
  initialY: number;
}

const INITIAL_POSITION: Position = {
  x: 12,
  y: 12,
};

export function FloatingDrawingToolbar({
  selectedDrawing$,
  onToggleLock,
  onOpenSettings,
  onDelete,
}: FloatingDrawingToolbarProps) {
  const toolbarRef = useRef<HTMLDivElement | null>(null);
  const dragStateRef = useRef<DragState | null>(null);

  const [selectedDrawing, setSelectedDrawing] = useState<Drawing | null>(null);
  const [isLocked, setIsLocked] = useState(false);
  const [position, setPosition] = useState<Position>(INITIAL_POSITION);

  useEffect(() => {
    const subscription = selectedDrawing$.subscribe(setSelectedDrawing);

    return () => {
      subscription.unsubscribe();
    };
  }, [selectedDrawing$]);

  useEffect(() => {
    if (!selectedDrawing) {
      setIsLocked(false);

      return;
    }

    const subscription = selectedDrawing.subscribeIsLocked(setIsLocked);

    return () => {
      subscription.unsubscribe();
    };
  }, [selectedDrawing]);

  const clampPosition = (x: number, y: number): Position => {
    const toolbar = toolbarRef.current;
    const container = toolbar?.parentElement;

    if (!toolbar || !container) {
      return { x, y };
    }

    return {
      x: Math.max(0, Math.min(x, container.clientWidth - toolbar.offsetWidth)),
      y: Math.max(0, Math.min(y, container.clientHeight - toolbar.offsetHeight)),
    };
  };

  const handleDragStart = (event: ReactPointerEvent<HTMLButtonElement>): void => {
    if (event.button !== 0) {
      return;
    }

    event.preventDefault();
    event.currentTarget.setPointerCapture(event.pointerId);

    dragStateRef.current = {
      pointerId: event.pointerId,
      startX: event.clientX,
      startY: event.clientY,
      initialX: position.x,
      initialY: position.y,
    };
  };

  const handleDrag = (event: ReactPointerEvent<HTMLButtonElement>): void => {
    const dragState = dragStateRef.current;

    if (!dragState || dragState.pointerId !== event.pointerId) {
      return;
    }

    event.preventDefault();

    setPosition(
      clampPosition(
        dragState.initialX + event.clientX - dragState.startX,
        dragState.initialY + event.clientY - dragState.startY,
      ),
    );
  };

  const handleDragEnd = (event: ReactPointerEvent<HTMLButtonElement>): void => {
    if (dragStateRef.current?.pointerId !== event.pointerId) {
      return;
    }

    if (event.currentTarget.hasPointerCapture(event.pointerId)) {
      event.currentTarget.releasePointerCapture(event.pointerId);
    }

    dragStateRef.current = null;
  };

  const stopPropagation = (event: SyntheticEvent): void => {
    event.stopPropagation();
  };

  if (!selectedDrawing) {
    return null;
  }

  return (
    <div
      ref={toolbarRef}
      className={styles.toolbar}
      style={{
        transform: `translate3d(${position.x}px, ${position.y}px, 0)`,
      }}
      onClick={stopPropagation}
      onContextMenu={stopPropagation}
      onDoubleClick={stopPropagation}
      onPointerCancel={stopPropagation}
      onPointerDown={stopPropagation}
      onPointerMove={stopPropagation}
      onPointerUp={stopPropagation}
    >
      <button
        type="button"
        className={styles.toolbar_handle}
        onPointerCancel={handleDragEnd}
        onPointerDown={handleDragStart}
        onPointerMove={handleDrag}
        onPointerUp={handleDragEnd}
      >
        <span />
        <span />
        <span />
        <span />
        <span />
        <span />
      </button>

      {selectedDrawing.hasSettings() && (
        <Button
          size="sm"
          className={styles.button}
          onClick={onOpenSettings}
          label={<GearIcon />}
        />
      )}

      <Button
        size="sm"
        className={classNames(styles.button, { [styles.pressed]: isLocked })}
        onClick={onToggleLock}
        label={isLocked ? <LockIcon /> : <LockOpenIcon />}
      />

      <Button
        size="sm"
        className={styles.button}
        onClick={onDelete}
        label={<TrashIcon />}
      />
    </div>
  );
}