import { Value, is, preserves, strip } from '../src/index';
import '../src/node_support';

declare global {
    namespace jest {
        interface Matchers<R> {
            is<T extends object>(expected: Value<T>): R;
            toThrowFilter(f: (e: Error) => boolean): R;
        }
    }
}

expect.extend({
    is(actual, expected) {
        return is(actual, expected)
            ? { message: () => preserves`expected ${actual} not to be Preserves.is to ${expected}`,
                pass: true }
            : { message: () => preserves`expected ${actual} to be Preserves.is to ${expected}`,
                pass: false };
    },

    toThrowFilter(thunk, f) {
        try {
            thunk();
            return { message: () => preserves`expected an exception`, pass: false };
        } catch (e) {
            if (f(e)) {
                return { message: () => preserves`expected an exception not matching the filter`,
                         pass: true };
            } else {
                return { message: () => preserves`expected an exception matching the filter: ${e.constructor.name}`,
                         pass: false };
            }
        }
    }
});

export class Pointer {
    v: Value<Pointer>;

    constructor(v: Value<Pointer>) {
        this.v = v;
    }

    equals(other: any, is: (a: any, b: any) => boolean) {
        return Object.is(other.constructor, this.constructor) && is(this.v, other.v);
    }

    asPreservesText(): string {
        return '#!' + this.v.asPreservesText();
    }
}

export function decodePointer(v: Value<Pointer>): Pointer {
    return new Pointer(strip(v));
}

export function encodePointer(w: Pointer): Value<Pointer> {
    return w.v;
}