import { $NAME, MetaContext, MetaObject } from '../../MetaContext';

export const $HASH = '$hash';

export type Hash<T> = (obj: T, seed?: number) => number;

export type $Hash<T> = { [$HASH]: Hash<T> };

export type HashString = { hashString(str: string, seed?: number): number };

export type HashNumber = { hashNumber(value: number, seed?: number): number };

export const withHash = <TMetaContextBase extends new (...args: any[]) => MetaContext & HashString & HashNumber>(MetaContextBase: TMetaContextBase) => class extends MetaContextBase {
    [$HASH]<T>(value: T, seed?: number) {
        return this.resolveValue(value)[$HASH](value, seed, this) as number;
    }
};

export type GenericHash<T, U> = (obj: T, hashfn: Hash<U>, seed: number, context: any) => number;

export function deepHash<T, U = T>(hash: GenericHash<T, U>) {
    return function $hash(this: MetaObject, obj: T, seed: number, context: MetaContext & $Hash<U>) {
        const hashfn = context[$HASH];
        return (this[$HASH] = function $hash(this: MetaObject, obj: T, seed: number, context: MetaContext & $Hash<U>) {
            return hash(obj, hashfn, seed, context);
        }).call(this, obj, seed, context) as number;
    };
}

export function hashMetaObjectName(metaObject: MetaObject, seed: number, context: MetaContext & HashString & HashNumber) {
    return context.hashNumber(context.hashString(metaObject[$NAME]), seed);
}