diaspora-orm/diaspora

import { isNil, chain, flattenDeep, get, concat, reject } from 'lodash';

import { IEntityAttributes } from './../types/entity';
import { _ModelDescription } from '../types/modelDescription';

/**
 * The PathStack class allows model validation to follow different paths in model description & entity.
 */
export class PathStack {
    public segmentsEntity: string[];
    public segmentsValidation: string[];
    
    public constructor( segments?: string[] );
    /**
     * Constructs a pathstack.
     *
     * @author gerkin
     */
    public constructor( segmentsEntity?: string[], segmentsValidation?: string[] ) {
        if ( isNil( segmentsEntity ) ) {
            segmentsEntity = [];
        }
        if ( isNil( segmentsValidation ) ) {
            segmentsValidation = segmentsEntity;
        }
        
        this.segmentsEntity = segmentsEntity;
        this.segmentsValidation = segmentsValidation;
    }
    
    /**
     * Add a path segment for entity navigation.
     *
     * @param   prop - Properties to add.
     * @returns Returns `this`.
     */
    public pushEntityProp( ...prop: string[] ): this {
        this.segmentsEntity = reject(
            concat( this.segmentsEntity, flattenDeep( prop ) ),
            isNil
        );
        return this;
    }
    
    /**
     * Add a path segment for model description navigation.
     *
     * @param   prop - Properties to add.
     * @returns Returns `this`.
     */
    public pushValidationProp( ...prop: string[] ): this {
        this.segmentsValidation = reject(
            concat( this.segmentsValidation, flattenDeep( prop ) ),
            isNil
        );
        return this;
    }
    
    /**
     * Add a path segment for both entity & model description navigation.
     *
     * @param   prop - Properties to add.
     * @returns Returns `this`.
     */
    public pushProp( ...prop: string[] ): this {
        return this.pushEntityProp( ...prop ).pushValidationProp( ...prop );
    }
    
    /**
     * Get a string version of entity segments.
     *
     * @returns String representation of path in entity.
     */
    public toValidatePath(): string {
        return this.segmentsEntity.join( '.' );
    }
    
    /**
     * Cast this PathStack to its representing arrays.
     */
    public toArray(): string[][] {
        return [this.segmentsEntity.slice(), this.segmentsValidation.slice()];
    }
    
    /**
     * Duplicate this PathStack, detaching its state from the new.
     *
     * @returns Clone of caller PathStack.
     */
    public clone(): PathStack {
        return new PathStack( ...this.toArray() );
    }
    
    /**
     * Applies the path stack to retrieve the attribute description in the provided attributes description
     * 
     * @author gerkin
     * @param desc - Attributes description to retrieve field from
     */
    public getDesc( desc: _ModelDescription.AttributesDescription ){
        return this.segmentsValidation.length > 0 ? get( desc, this.segmentsValidation ) : desc;
    }
    
    /**
     * Applies the path stack to retrieve the field in the provided entity attributes
     * 
     * @author gerkin
     * @param entity - Entity to retrieve field from
     */
    public getProp( entity: IEntityAttributes ){
        return this.segmentsEntity.length > 0 ? get( entity, this.segmentsEntity ) : entity;
    }
}