import type { Point, FurnitureItem } from '@house-plan-maker/shared';
import { generateLocalId } from '../utils/geometry';
import type { FurnitureDef } from '../symbols/furniture';

export interface FurniturePlacementPreview {
  readonly x: number;
  readonly y: number;
  readonly width: number;
  readonly depth: number;
  readonly rotation: number;
  readonly isValid: boolean;
}

/**
 * Compute furniture placement preview.
 * The x,y represents the top-left corner of the furniture piece.
 * The cursor world point is treated as the desired center, so we offset
 * by half-width and half-depth to get the top-left corner.
 */
export function computeFurniturePreview(
  worldPoint: Point,
  furnitureDef: FurnitureDef,
  rotation: number = 0,
): FurniturePlacementPreview {
  return {
    x: worldPoint.x - furnitureDef.width / 2,
    y: worldPoint.y - furnitureDef.depth / 2,
    width: furnitureDef.width,
    depth: furnitureDef.depth,
    rotation,
    isValid: true,
  };
}

/**
 * Create a FurnitureItem from placement data.
 */
export function createFurnitureItemFromPlacement(
  roomId: string,
  preview: FurniturePlacementPreview,
  furnitureDef: FurnitureDef,
): FurnitureItem {
  return {
    id: generateLocalId(),
    roomId,
    type: furnitureDef.type,
    x: preview.x,
    y: preview.y,
    width: preview.width,
    depth: preview.depth,
    height: furnitureDef.height,
    rotation: preview.rotation,
    elevationFromFloor: furnitureDef.type === 'AC_UNIT' ? 2.2 : furnitureDef.height <= 0.05 ? 1.2 : 0,
    label: furnitureDef.label,
  };
}

/** Rotate a furniture item by the given delta in degrees. */
export function rotateFurniture(item: FurnitureItem, deltaDeg: number): FurnitureItem {
  return {
    ...item,
    rotation: (item.rotation + deltaDeg) % 360,
  };
}

/** Move a furniture item to a new position. */
export function moveFurniture(item: FurnitureItem, newPos: Point): FurnitureItem {
  return {
    ...item,
    x: newPos.x,
    y: newPos.y,
  };
}