The following ERD was made using Gleek.io diagram maker
Users
string userId PK
string firebaseUid UK
string username UK
string email UK
string picture
UserFavourites
string firebaseUid FK
ArrayOfString recipeIds FK
UserSearchHistory
string firebaseUid FK
ArrayOfSearch history FK
Search
string recipeId FK
Date searchedAt
Recipes
string recipeId PK
string sourceId FK
string source
string title
string image
string summary
bool vegetarian
bool vegan
bool glutenFree
bool dairyFree
int preparationMinutes
int cookingMinutes
int readyInMinutes
int likes
int servings
ArrayOfString cuisines
ArrayOfString dishTypes
ArrayOfString diets
ArrayOfIngredient ingredients
ArrayOfString instructions
Ingredients
string ingredientId PK
string title
string image
float amount
string unit
Users {1}--{0..n} UserFavourites
UserFavourites {1..n}--{1} Recipes
Users {1}--{0..n} Recipes
Users {1}--{0..n} UserSearchHistory