using Models;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Runtime.Serialization;

namespace LocalEndpoint
{

    internal class RecipesDatabase
    {

        private static readonly DataContractSerializer RECIPES_SERIALIZER = new DataContractSerializer(typeof(List<Recipe>));
        
        private readonly Dictionary<Guid, Recipe> recipes = new Dictionary<Guid, Recipe>();
        private readonly string dbPath;

        public RecipesDatabase(string path)
        {
            dbPath = path;
           
            
            if (!File.Exists(dbPath))
            {
                File.Create(dbPath);
            }
            if (new FileInfo(dbPath).Length == 0)
                return; //file is empty thus there is nothing to deserialize
            Console.WriteLine(File.ReadAllText(dbPath));

            using (var stream = File.OpenRead(dbPath)) { 
                var recipes = RECIPES_SERIALIZER.ReadObject(stream) as List<Recipe>;
                recipes.ForEach(recipe =>  this.recipes.Add(recipe.Info.Id, recipe));
            }
        }

        private void SaveAll()
        {
            using (var stream = File.OpenWrite(dbPath))
            {
                RECIPES_SERIALIZER.WriteObject(stream, recipes.Values.ToList());
            }
        }

        public Recipe? Lookup(Guid id)
        {
            Recipe? recipe;
            recipes.TryGetValue(id, out recipe);
            return recipe;
        }


        public Recipe Get(Guid id)
        {
            return recipes[id];
        }

        public void Insert(Recipe recipe)
        {
            recipes[recipe.Info.Id] = recipe;
            SaveAll();
        }

        public void Remove(Guid id)
        {
            recipes.Remove(id);
            SaveAll();
        }

        public ImmutableList<Recipe> ListAll()
        {
            return recipes.Values.ToImmutableList();
        }

    }
}