import { BaseType } from "./BaseType";
import { uniqueTypeArray } from "../Utils/uniqueTypeArray";

export class UnionType extends BaseType {
    private readonly types: BaseType[];

    public constructor(types: readonly (BaseType | undefined)[]) {
        super();
        this.types = uniqueTypeArray(
            types.reduce((flatTypes, type) => {
                if (type instanceof UnionType) {
                    flatTypes.push(...type.getTypes());
                } else if (type !== undefined) {
                    flatTypes.push(type);
                }
                return flatTypes;
            }, [] as BaseType[])
        );
    }

    public getId(): string {
        return `(${this.types.map((type) => type.getId()).join("|")})`;
    }

    public getName(): string {
        return `(${this.types.map((type) => type.getName()).join("|")})`;
    }

    public getTypes(): BaseType[] {
        return this.types;
    }

    public normalize(): BaseType | undefined {
        if (this.types.length === 0) {
            return undefined;
        } else if (this.types.length === 1) {
            return this.types[0];
        } else {
            return this;
        }
    }
}