model.js

/**
 * Model module for Schokofinder
 * @model model
 */

/*
 * JSON array for chocolate entries
 * 
 * format as follows:
 *   [
 *     {
 *       "name": "Milka Mmmax Toffee Ganznuss",                               -> String
 *       "typ": "milch",                                                      -> String
 *       "geschmack": "suß",                                                  -> String
 *       "preis": "billig",                                                   -> String
 *       "ort": "deutschland",                                                -> String
 *       "hersteller": "milka",                                               -> String
 *       "inhalt": ["karamel"],                                               -> Array (of strings)
 *       "url": "https://www.milka.de/produkte/milka-mmmax-toffee-ganznuss"   -> String
 *     },
 *   ]
 */
let chocolate = require("./src/schokolade.json");

module.exports = {
	
    findChocolate: (typ, geschmack, preis, inhalt) => {
		return findChocolate(typ, geschmack, preis, inhalt);
    },

	/**
	 * returns all entries in schokolade.json
	 * @returns {array} an array of chocolate objects 
	 */
    returnAllEntries: () => {
        return chocolate;
    }
}

/**
 * searches through chocolate entries to find a suitable match according to the criteria
 * @param {string} typ - the type of chocolate ("hell", "dunkel", "milch")
 * @param {string} geschmack - the preferred taste ("bitter", "suß", "neutral")
 * @param {string} preis - target price range ("teuer", "billig", "neutral")
 * @param {array} inhalt - a list of chocolate fills
 * @returns {array} an array of best matching chocolate objects
 */
function findChocolate(typ, geschmack, preis, inhalt) {
	//the number of criteria that have to match
	let i, requiredMatches = 4;
	let matchFound = false;
	let matches = [];
	
	//continue until we find a suitable chocolate
	while (!matchFound) {
		//loop through the entries
		for (i = 0; i < chocolate.length; i++) {
			let entry = chocolate[i];
			//find how well the given chocolate entry matches the criteria
			let matchConfidence = compareChocolateBase([typ, geschmack, preis], entry);
			if (compareChocolateFilling(inhalt, entry)) {
//                    console.log(`matched ${ inhalt } with ${ entry.inhalt }`);
				matchConfidence++;
			} else {
//                    console.log(`did not match ${ inhalt } with ${ entry.inhalt }`);
				//prevent matching chocolate with filling 
				matchConfidence = 0;
			}
			
			//check if the chocolate matches well enough
			if (matchConfidence >= requiredMatches) {
				//push the given chocolate and stop searching
				matches.push(entry);
				matchFound = true;
				//we don't break here because there could be more possible matches
			}
		}
		//decrement amount of required matches and try again
		// > 1 prevents the 0 pass from happening, where every chocolate would get matched
		if (requiredMatches <= 0) {
			//break out of loop, as no suitable chocolate exists
			break;
		} else {
			requiredMatches = (matchFound) ? requiredMatches : requiredMatches - 1;
		}
	}
  
	console.log(`Found ${ matches.length } results with an overlap of ${ requiredMatches }`);
	return matches;
}

/**
 * compares the base critera (type, taste, price) given to the chocolate entry
 * @param {array} criteria - contains type, taste, price, and filling
 * @param {object} chocolate - the chocolate entry
 * @returns {int} the amount of criteria that match
 */
function compareChocolateBase(criteria, chocolate) {
    let i, matches = 0;
    //iterate through all criteria
    for (i = 0; i < criteria.length; i++) {
        //if the criteria is neutral then any result matches
        if (criteria[i] == "neutral") {
            matches++;
        } else {
            //iterate through each element of the chocolate object
            for (let key in chocolate) {
                //if the attribute is not the url or name
                if (!(["url", "name", "inhalt"].includes(key))) {
                    //if we find the criterion in the attribute 
                    if (chocolate[key].search(criteria[i]) >= 0) {
                        //we count this as a match and stop searching
                        matches++;
                        break;
                    }
                }
            }
        }
    }
    return matches;
}

/**
 * compares the filling(s) to the given chocolate entry
 * @param {array} filling - a list of valid fillings
 * @param {object} chocolate - the chocolate entry
 * @returns {bool} true if the filling is in the chocolate, otherwise false
 */
function compareChocolateFilling(filling, chocolate) {
    let i, match = false;
  
    //match for filling type
    for (i = 0; i < filling.length; i++) {
        if (chocolate.inhalt.includes(filling[i])) {
            //the chocolate entry has said filling, stop searching
            match = true;
            break;
        }
    }
  
    return match;
}