import uuid from "react-native-uuid";
import convert, { Area, Length } from "convert";
import { Transform } from "class-transformer";

export type Id = string;

export type Currency = "USD";

export type ProductAttributes = {
    id?: string,
    name?: string,
    image?: string,
    description?: string,
    depth?: string,
    currency?: Currency,
    // [index:string]: any,
}
export type length_t = {
    l: number, u: Length
}

export type area_t = length_t & {
    w: number,
}

export type dimensions_t = area_t | length_t;

export type ProductData = {
    id?: Id,
    pricePerUnit: number,
    dimensions: dimensions_t,
    attributes?: ProductAttributes,
};


export type product_type_t = "area" | "length";

export const isArea = (d: dimensions_t) => ("width" in d);
export const isLength = (d: dimensions_t) => (!("width" in d));
export const dimensionType = (d: dimensions_t) => isArea(d) ? "area" : "length"

export function matchDimensions(d1: dimensions_t, d2: dimensions_t) {
    if (!
        (
            (isArea(d1) && isArea(d2)) ||
            (isLength(d1) && isLength(d2))
        )
    ) {
        throw new Error(`Dimension mismatch: ${JSON.stringify(d1)} / ${JSON.stringify(d1)}`);
    }

    return {
        l: convert(d1.l, d1.u).to(d2.u),
        u: d2.u,
        ...(
            "w" in d1 ?
                { w: convert(d1.w, d1.u).to(d2.u), }
                : {}
        )
    }
}

export function dimensionArea(d: dimensions_t) {
    return "w" in d ? d.w * d.l : 0;
}

export class Product {

    public id?: Id;

    constructor(public pricePerUnit: number, public dimensions: dimensions_t, public attributes: ProductAttributes = {},
        id?: Id,
    ) {
        this.id = id || uuid.v4().toString();
    }

    public priceFor(dimensions: dimensions_t, damage : number): number {
        if (Number.isNaN(damage)) damage = 0;
        const dim = matchDimensions(dimensions, this.dimensions);
        return (
            dim.w ? dimensionArea(dim) / dimensionArea(this.dimensions) * this.pricePerUnit
                : (dim.l / this.dimensions.l) * this.pricePerUnit
        ) * (1.0 - damage);
    }

    get priceDisplay() {
        return this.pricePerUnit.toLocaleString(undefined, {
            minimumFractionDigits: 2,
            maximumFractionDigits: 2,
        })
    }

    get pricePerUnitDisplay() {
        const p = this.priceDisplay;
        const { l, u } = this.dimensions;
        const w = (this.dimensions as area_t).w || null;
        const d = w ? `${l}${u} x ${w}${u}` : `${l}${u}`;
        return `$${p} per ${d}`
    }

    get attributesAsList() {
        return Object.entries(this.attributes).map(([key, value]) => {
            return { key, value }
        })
    }

    public removeAttribute(key: string) {
        this.attributes = Object.fromEntries(
            Object.entries(this.attributes).filter(
                ([k, v]) => {
                    k == key;
                }
            )
        );
    }

    get asObject(): ProductData {
        return {
            id: this.id,
            pricePerUnit: this.pricePerUnit,
            dimensions: this.dimensions,
            attributes: this.attributes,
        }
    }

    static fromObject({ id, pricePerUnit, dimensions, attributes }: ProductData) {
        return new Product(
            pricePerUnit,
            dimensions,
            attributes,
            id,
        )
    }
}