import { Injectable } from '@angular/core';

/**
 * handles assets requests
 * 
 * ensure the requested assets is valid or returns a valid alternative
 * atleast try to save the situation
 * fails silently, if the matter cannot be helped
 */
@Injectable()
export class AssetService{

    location: string = 'assets';
    type: 'image' | 'video' | 'audio' | 'text' = 'image';
    defaultName?: string;
    group: string;
    name: string;

    changeLocation(newLocation: string){
        this.location = newLocation;
        return this;
    }

    default(defaultName: string){
        this.defaultName = defaultName;
        return this;
    }
    
    image(name: string, defaultName?: string){
        return this.make(this.location, 'image', name, defaultName);
    }

    video(name: string, defaultName?: string){
        return this.make(this.location, 'video', name, defaultName);
    }

    audio(name: string, defaultName?: string){
        return this.make(this.location, 'audio', name, defaultName);
    }

    /**
     * 
     * @param location 
     * @param type must be the singular of the corresponding directory name
     * @param defaultName 
     * @param name 
     */
    make(location: string, type: 'image' | 'video' | 'audio' | 'text', name: string, defaultName?: string){
        this.location = location;
        this.type = type;
        this.defaultName = defaultName;
        this.name = name;

        let path = this.location + '/' + this.type + 's/';
        // path += (!this.check(path) && this.defaultName) ? 'default/' + this.defaultName : this.name;
        path += (!this.name && this.defaultName) ? 'default/' + this.defaultName : this.name;
        return path;
    }

    /**
     * check if the image url is valid
     * returns true if the url is valid
     * 
     * use to decide weather to return a default alternative for an image request
     */
    check(path: string){
        return true;
    }

}