import type { CommonKeys } from "./CommonKeys"


export type Extend<Super, Self> =
    Extendable<Super, Self> extends true
        ? Omit<Super, CommonKeys<Self, Super>> & Self
        : never

export type Extendable<Super, Self> =
    Pick<Self, CommonKeys<Self, Super>> extends Pick<Super, CommonKeys<Self, Super>>
        ? true
        : false


export type ExtendAll<T extends readonly object[]> =
    T extends readonly [
        infer Super,
        infer Self,
        ...infer Rest extends readonly object[],
    ]
        ? Extendable<Super, Self> extends true
            ? ExtendAll<readonly [Extend<Super, Self>, ...Rest]>
            : never
        : T extends readonly [infer Self]
            ? Self
            : {}

export type ExtendableAll<T extends readonly object[]> =
    T extends readonly [
        infer Super,
        infer Self,
        ...infer Rest extends readonly object[],
    ]
        ? Extendable<Super, Self> extends true
            ? ExtendableAll<readonly [Extend<Super, Self>, ...Rest]>
            : false
        : true

// export type NonExtendableKeys<T extends readonly object[]> = (
//     T extends readonly [
//         infer Super   extends object,
//         infer Self    extends object,
//         ...infer Rest extends readonly object[],
//     ]
//         ? {[K in keyof Super & keyof Self]: Self[K] extends Super[K]
//             ? never
//             : K
//         }[keyof Super & keyof Self]
//         | NonExtendableKeys<readonly [
//             Super & Self,
//             ...Rest,
//         ]>
//         : void
// )