import Point from './Point';
import { isNumber } from '../core/util/common';

export type JsonSize = {
    width: number;
    height: number;
}

export type ArraySize = [number, number];

/**
 * A {@link Size} object
 *
 * @category basic types
 *
 * @example
 * ```ts
 * let size1 = new Size(100, 100);
 * let size2 = [100，100];
 * let size3 = { width: 100, height: 100 };
 * ```
 */
export type SizeLike = Size | JsonSize;

/**
 * 表示一个大小的实现类
 *
 * @english
 * Represents a size.
 * @category basic types
 *
 * @example
 *
 * ```ts
 * const a1 = new Size(1, 2);
 * const a2 = new Size([1, 2]);
 * const a3 = new Size({ width: 1, height: 2 });
 * const a4 = new Size(a3);
 * ```
 */
class Size {
    public width: number;
    public height: number;

    /**
     * @param width - width value
     */
    constructor(width: SizeLike)
    /**
     * @param width - width value
     */
    constructor(width: ArraySize)
    /**
     * @param width - width value
     * @param height - height value
     */
    constructor(width: number, height: number)
    constructor(width: any, height?: any) {
        if (isNumber(width) && isNumber(height)) {
            /**
             * @property width - width
             */
            this.width = width;
            /**
             * @property height - height
             */
            this.height = height;
        } else if (isNumber(width['width'])) {
            this.width = width.width;
            this.height = width.height;
        } else if (Array.isArray(width)) {
            this.width = width[0];
            this.height = width[1];
        }
    }

    /**
     * 返回 `Size` 的拷贝
     * @english
     * Returns a copy of the size
     */
    copy() {
        return new Size(this['width'], this['height']);
    }

    /**
     * @overload
     *
     * 返回当前`Size` 与另一个 `Size` 相加的结果
     *
     * @english
     * Returns the result of addition of another size.
     * @param x - Size
     * @returns result
     */
    add(x: Size): Size
    /**
     * @overload
     *
     * 返回当前`Size` 的 xy 与传入的 xy 相加的结果
     *
     * @english
     * Returns the result of addition of another size.
     * @param x - x
     * @param y - y
     * @returns result
     */
    add(x: number, y: number): Size
    /**
     * 返回当前`Size` 与另一个 `Size` 相加的结果
     *
     * @english
     * Returns the result of addition of another size.
     * @param x - x value
     * @param y - y value
     * @returns result
     */
    add(x: any, y?: any) {
        let w: number, h: number;
        if (x instanceof Size) {
            w = this.width + x.width;
            h = this.height + x.height;
        } else {
            w = this.width + x;
            h = this.height + y;
        }
        return new Size(w, h);
    }

    /**
     * 与另一个 `Size` 进行比较，以判断它们是否相等。
     *
     * @english
     * Compare with another size to see whether they are equal.
     * @param size - size to compare
     */
    equals(size: Size) {
        return this['width'] === size['width'] && this['height'] === size['height'];
    }

    /**
     * 返回当前大小与给定数字相乘的结果，返回一个新的 Size 对象
     * @english
     * Returns the result of multiplication of the current size by the given number.
     * @param ratio - ratio to multi
     * @returns result
     */
    multi(ratio: number): Size {
        return new Size(this['width'] * ratio, this['height'] * ratio);
    }

    /**
     * 返回当前大小与给定数字相乘的结果
     * @english
     * Returns the result of multiplication of the current size by the given number.
     * @param ratio - ratio to multi
     * @returns result
     */
    _multi(ratio: number) {
        this['width'] *= ratio;
        this['height'] *= ratio;
        return this;
    }

    _round() {
        this['width'] = Math.round(this['width']);
        this['height'] = Math.round(this['height']);
        return this;
    }

    /**
     * 将当前 `Size` 对象转为一个点对象 {@link Point}
     * @english
     * Converts the size object to a {@link Point}
     * @returns point
     */
    toPoint(): Point {
        return new Point(this['width'], this['height']);
    }

    /**
     * 将 `Size` 对象转换为数组
     * @english
     * Converts the size object to an array [width, height]
     */
    toArray(): ArraySize {
        return [this['width'], this['height']];
    }

    /**
     * 将 `Size` 实例对象转换为 包含 `width` 和 `height` 的 json 对象
     * @english
     * Convert the size object to a json object {width : ., height : .}
     * @returns json
     */
    toJSON(): JsonSize {
        return {
            'width': this['width'],
            'height': this['height']
        };
    }
}

export default Size;