/** @module refer */
import { Descriptor } from './Descriptor';

/**
 * Contains a reference to a component and locator to find it.
 * It is used by [[References]] to store registered component references.
 */
export class Reference {
    private _locator: any;
    private _component: any;

    /**
     * Create a new instance of the reference object and assigns its values.
     * 
     * @param locator         a locator to find the reference.
     * @param reference     a reference to component.
     */
    public constructor(locator: any, component: any) {
        if (component == null) {
            throw new Error("Component cannot be null");
        }
        
        this._locator = locator;
        this._component = component;
    }
    
    /**
     * Matches locator to this reference locator.
     * 
     * Descriptors are matched using equal method.
     * All other locator types are matched using direct comparison.
     * 
     * @param locator     the locator to match. 
     * @return true if locators are matching and false it they don't.
     * 
     * @see [[Descriptor]]
     */
    public match(locator: any): boolean {
        // Locate by direct reference matching
        if (this._component == locator) {
            return true;
        }
        // Locate by direct locator matching
        else if (this._locator instanceof Descriptor) {
            return (<Descriptor>this._locator).equals(locator);
        }
        // Locate by direct locator matching
        else if (this._locator != null) {
            return this._locator == locator;
        } else {
            return false;
        }
    }
    
    /**
     * Gets the stored component reference.
     * 
     * @return the component's references.
     */
    public getComponent(): any { 
        return this._component; 
    }

    /**
     * Gets the stored component locator.
     * 
     * @return the component's locator.
     */
    public getLocator(): any {
        return this._locator;
    }
}