import {ValidationMetadata} from "../metadata/ValidationMetadata";
import {ValidationTypes} from "./ValidationTypes";
import {ValidationError} from "./ValidationError";
import {ValidatorOptions} from "./ValidatorOptions";
import {ValidationExecutor} from "./ValidationExecutor";
import {ValidationOptions} from "../decorator/ValidationOptions";
import * as validator from "validator";

/**
 * Validator performs validation of the given object based on its metadata.
 */
export class Validator {
    // -------------------------------------------------------------------------
    // Public Methods
    // -------------------------------------------------------------------------

    /**
     * Performs validation of the given object based on decorators used in given object class.
     */
    validate(object: object, options?: ValidatorOptions): Promise<ValidationError[]>;

    /**
     * Performs validation of the given object based on validation schema.
     */
    validate(schemaName: string, object: object, options?: ValidatorOptions): Promise<ValidationError[]>;

    /**
     * Performs validation of the given object based on decorators or validation schema.
     */
    validate(objectOrSchemaName: object|string, objectOrValidationOptions: object|ValidationOptions, maybeValidatorOptions?: ValidatorOptions): Promise<ValidationError[]> {
        return this.coreValidate(objectOrSchemaName, objectOrValidationOptions, maybeValidatorOptions);
    }

    /**
     * Performs validation of the given object based on decorators used in given object class and reject on error.
     */
    validateOrReject(object: object, options?: ValidatorOptions): Promise<void>;

    /**
     * Performs validation of the given object based on validation schema and reject on error.
     */
    validateOrReject(schemaName: string, object: object, options?: ValidatorOptions): Promise<void>;

    /**
     * Performs validation of the given object based on decorators or validation schema and reject on error.
     */
    async validateOrReject(objectOrSchemaName: object|string, objectOrValidationOptions: object|ValidationOptions, maybeValidatorOptions?: ValidatorOptions): Promise<void> {
        const errors = await this.coreValidate(objectOrSchemaName, objectOrValidationOptions, maybeValidatorOptions);
        if (errors.length)
            return Promise.reject(errors);
    }

    /**
     * Performs validation of the given object based on decorators used in given object class.
     * NOTE: This method completely ignores all async validations.
     */
    validateSync(object: object, options?: ValidatorOptions): ValidationError[];

    /**
     * Performs validation of the given object based on validation schema.
     */
    validateSync(schemaName: string, object: object, options?: ValidatorOptions): ValidationError[];

    /**
     * Performs validation of the given object based on decorators or validation schema.
     */
    validateSync(objectOrSchemaName: object|string, objectOrValidationOptions: object|ValidationOptions, maybeValidatorOptions?: ValidatorOptions): ValidationError[] {
        const object = typeof objectOrSchemaName === "string" ? objectOrValidationOptions as object : objectOrSchemaName;
        const options = typeof objectOrSchemaName === "string" ? maybeValidatorOptions : objectOrValidationOptions as ValidationOptions;
        const schema = typeof objectOrSchemaName === "string" ? objectOrSchemaName : undefined;

        const executor = new ValidationExecutor(this, options);
        executor.ignoreAsyncValidations = true;
        const validationErrors: ValidationError[] = [];
        executor.execute(object, schema, validationErrors);
        return executor.stripEmptyErrors(validationErrors);
    }

    // -------------------------------------------------------------------------
    // Private Properties
    // -------------------------------------------------------------------------
    /**
     * Performs validation of the given object based on decorators or validation schema.
     * Common method for `validateOrReject` and `validate` methods.
     */
    private coreValidate(objectOrSchemaName: object|string, objectOrValidationOptions: object|ValidationOptions, maybeValidatorOptions?: ValidatorOptions): Promise<ValidationError[]> {
        const object = typeof objectOrSchemaName === "string" ? objectOrValidationOptions as object : objectOrSchemaName;
        const options = typeof objectOrSchemaName === "string" ? maybeValidatorOptions : objectOrValidationOptions as ValidationOptions;
        const schema = typeof objectOrSchemaName === "string" ? objectOrSchemaName : undefined;

        const executor = new ValidationExecutor(this, options);
        const validationErrors: ValidationError[] = [];
        executor.execute(object, schema, validationErrors);

        return Promise.all(executor.awaitingPromises).then(() => {
            return executor.stripEmptyErrors(validationErrors);
        });
    }
}