import { isPrimitive, primitive } from "../safe";
import { ActivationContext } from "./ActivationContext";
import { Constructor, Factory } from "../interfaces";

export interface Descriptor<S = any, T = any> {
    activate(context: ActivationContext<S>): T;
}

export function isDescriptor(x: any): x is Descriptor {
    return (!isPrimitive(x)) &&
        (x.activate instanceof Function);
}

export type ServiceMap<S, S2 extends S = S> = {
    [k in keyof S2]: Descriptor<S, S2[k]>;
};

export type PartialServiceMap<S, S2 extends S = S> = Partial<ServiceMap<S, S2>>;

export enum ActivationType {
    Singleton = 1,
    Container,
    Hierarchy,
    Context,
    Call
}

export interface RegistrationWithServices<S> {
    services?: ServiceMap<S>;
}

export interface ServiceRegistration<T, P, S> extends RegistrationWithServices<S> {

    activation?: "singleton" | "container" | "hierarchy" | "context" | "call";

    params?: P;

    inject?: object | object[];

    cleanup?: ((instance: T) => void) | string;
}

export interface TypeRegistration<T, P, S> extends ServiceRegistration<T, P, S> {
    $type: string | Constructor<T>;
}

export interface FactoryRegistration<T, P, S> extends ServiceRegistration<T, P, S> {
    $factory: string | Factory<T>;
}

export interface ValueRegistration<T> {
    $value: T;
    parse?: boolean;
}

export interface DependencyRegistration<S, K extends keyof S> extends RegistrationWithServices<S> {
    $dependency: K;
    lazy?: boolean;
    optional?: boolean;
    default?: S[K];
}

export type Parse<T> = T extends primitive ? T:
        T extends Descriptor<infer V> ? V :
        { [K in keyof T]: Parse<T[K]> };

export interface Resolver<S> {
    resolve<K extends keyof ContainerServices<S>, T extends ContainerServices<S>[K] = ContainerServices<S>[K]>(name: K, def?: T): T;
}
export type ContainerServices<S> = S & {
    container: Resolver<S>;
};

export function isTypeRegistration(x: any): x is TypeRegistration<any, any, any> {
    return (!isPrimitive(x)) && ("$type" in x);
}

export function isFactoryRegistration(x: any): x is FactoryRegistration<any, any, any> {
    return (!isPrimitive(x)) && ("$factory" in x);
}

export function isValueRegistration(x: any): x is ValueRegistration<any> {
    return (!isPrimitive(x)) && ("$value" in x);
}

export function isDependencyRegistration<S>(x: any): x is DependencyRegistration<S, keyof S> {
    return (!isPrimitive(x)) && ("$dependency" in x);
}