Grocery List App Brainstorm

GroceryLogic.dart

/*
 * The basic idea is to make a Grocery List progressive web app in Dartlang,
 * using Firestore (https://firebase.google.com/docs/firestore/) as the backend.
 * This pad is a quick sketch of the logic necessary to get the app working.
 */

enum Categories {
  produce,
  dairy,
  household,
  canned,
  meat,
  bakery,
  frozen,
  unknown
}

enum AmountType {
  oz,      // ounces/ fluid ounces
  lb,      // pounds
  cup,     // cups
  quart,   // quarts
  num,     // count
  pkg,     // normal sized package
  ml,      // milliliters
  gram,    // grams
  unknown  // no good existing amount type
}

class GroceryItem {
  String name;
  int amount;
  AmountType amountType;

  GroceryItem(String name, int amount, AmountType amountType) {
    this.name = name.toLowerCase();
    this.amount = amount;
    this.amountType = amountType;
  }

  GroceryItem.fromString(String description) {
    List<String> parts = description.split(" ");
    this.amount = int.parse(parts[0]);
    this.amountType =  fromAmountTypeString(parts[1]); 
    this.name = parts.sublist(2).join(" ").toLowerCase();
  }
  
  AmountType fromAmountTypeString(String amountTypePart) {
    return AmountType.values.firstWhere(
      (a) => a.toString().substring(a.toString().indexOf('.')+1) == amountTypePart.toLowerCase(),
      orElse: () => AmountType.unknown
    );
  }

  String toString() {
    return "{ Amount: ${this.amount}, Type: ${this.amountType}, Name: ${this.name} }";
  }
}

// Instances of this class comprise the main DB collection, which allows for the core
// functionality of creating and updating grocery lists
class GroceryList {
  DateTime datetime;
  int totalCost;
  List<GroceryItem> list;
  
  GroceryList(this.datetime, this.totalCost, this.list);
  GroceryList.newList() {
    this.datetime = DateTime.now();
    this.totalCost = 0;
    this.list = [];
  }
  
  void addItem(GroceryItem item) {
    list.add(item);
  }
  
  List<GroceryItem> items() {
    return list;
  }
}

class GroceryCategory {
  String normalizedName;
  Categories category;
  int priority;
  
  GroceryCategory(this.normalizedName, this.category, this.priority);
  GroceryCategory.unknown(String name) {
    normalizedName = name;
    category = Categories.unknown;
    priority = 0;
  }
}

// Instances of this class comprise the secondary DB collection, which allows for
// grocery list ordering based on the categorizations and prioritizations of
// individual groceries.
class GroceryCategorizer {
  String normalize(String groceryName) {
    // remove pluralization?
    // fix spacing?
    // deal with apostrophes, dashes, etc.
    // how much normalization to we want to do at the item level,
    // and how much do we want to do internally (hidden from the user)
    return groceryName.toLowerCase();
  }
  
  Map<String, GroceryCategory> groceryCategories; // populate with the contents from the db

  GroceryCategory categorize(String groceryName) {
    String normalizedGroceryName = normalize(groceryName);
    if (groceryCategories.containsKey(normalizedGroceryName)) {
      return groceryCategories[normalizedGroceryName];
    } else {
      return GroceryCategory.unknown(normalizedGroceryName);
    }
  }
}

void main() {
  GroceryList groceryList = GroceryList.newList();
  
  groceryList.addItem(GroceryItem.fromString("3 num bananas"));
  groceryList.addItem(GroceryItem.fromString("16 oz cream"));
  groceryList.addItem(GroceryItem.fromString("2 lb chicken"));
  groceryList.addItem(GroceryItem.fromString("2 pkg hot dogs"));
  
  for (GroceryItem item in groceryList.items()) {
    print(item);
  }
}

Interactive version: https://dartpad.dartlang.org/4e3cce6e94a3a94edff417d9f329e0d1