import { ValidationOptions } from "../ValidationOptions";
import { ValidationMetadataArgs } from "../../metadata/ValidationMetadataArgs";
import { ValidationMetadata } from "../../metadata/ValidationMetadata";
import { getMetadataStorage } from "../../metadata/MetadataStorage";
import { ValidationTypes } from "../../validation/ValidationTypes";
import { ConstraintMetadata } from "../../metadata/ConstraintMetadata";

/**
 * Registers custom validator class.
 */
export function ValidatorConstraint(options?: { name?: string; async?: boolean }) {
    return function (target: Function): void {
        const isAsync = options && options.async;
        let name = options && options.name ? options.name : "";
        if (!name) {
            name = (target as any).name;
            if (!name) // generate name if it was not given
                name = name.replace(/\.?([A-Z]+)/g, (x, y) => "_" + y.toLowerCase()).replace(/^_/, "");
        }
        const metadata = new ConstraintMetadata(target, name, isAsync);
        getMetadataStorage().addConstraintMetadata(metadata);
    };
}

/**
 * Performs validation based on the given custom validation class.
 * Validation class must be decorated with ValidatorConstraint decorator.
 */
export function Validate(constraintClass: Function, validationOptions?: ValidationOptions): PropertyDecorator;
export function Validate(constraintClass: Function, constraints?: any[], validationOptions?: ValidationOptions): PropertyDecorator;
export function Validate(constraintClass: Function, constraintsOrValidationOptions?: any[] | ValidationOptions, maybeValidationOptions?: ValidationOptions): PropertyDecorator {
    return function (object: object, propertyName: string): void {
        const args: ValidationMetadataArgs = {
            type: ValidationTypes.CUSTOM_VALIDATION,
            target: object.constructor,
            propertyName: propertyName,
            constraintCls: constraintClass,
            constraints: constraintsOrValidationOptions instanceof Array ? constraintsOrValidationOptions : undefined,
            validationOptions: !(constraintsOrValidationOptions instanceof Array) ? constraintsOrValidationOptions : maybeValidationOptions
        };
        getMetadataStorage().addValidationMetadata(new ValidationMetadata(args));
    };
}