using System;
using System.Collections.Generic;
using System.Linq;
using UnityEditor.Tilemaps;

public delegate string NameCallback();

public abstract class IInventory
{
    private List<Action> changeCallbacks = new List<Action>();

    public abstract IReadOnlyDictionary<string, float> Items { get; }

    public abstract float Capacity { get; set; }

    public float Load => Items.Sum(kvp => kvp.Value);

    public float Free => Capacity < 0 ? int.MaxValue : Capacity - Load;

    public abstract float GetAmount(string item);

    protected abstract int DoClear();
    protected abstract float DoAdd(string item, float amount, bool allowPartialAdd = false);
    protected abstract float DoRemove(string item, float amount, bool allowPartialRemoval = false);

    public float Clear()
    {
        var cleared = DoClear();
        if (cleared > 0)
            InvokeOnChange();
        return cleared;
    }

    public float Add(string item, float amount, bool allowPartialAdd = false)
    {
        var added = DoAdd(item, amount, allowPartialAdd);
        if (added > 0)
            InvokeOnChange();
        return added;
    }

    public float Remove(string item, float amount, bool allowPartialRemoval = false)
    {
        var removed = DoRemove(item, amount, allowPartialRemoval);
        if (removed > 0)
            InvokeOnChange();
        return removed;
    }

    public void RegisterOnChangeCallback(Action callback)
    {
        changeCallbacks.Add(callback);
    }

    public void UnregisterOnChangeCallback(Action callback)
    {
        changeCallbacks.Remove(callback);
    }

    protected void InvokeOnChange()
    {
        // Debug.Log(
        //     $"Resources: {String.Join("; ", resources.Values.ToArray().Select(r => r.Resource.Name + "=" + r.Amount + (r.Unlocked ? "" : "(locked)")))}"
        // );

        changeCallbacks.ForEach(a =>
        {
            try
            {
                a.Invoke();
            }
            catch { }
        });
    }
}

[Serializable]
public class Inventory2 : IInventory, IDataPersistence<InventoryData>
{
    private Dictionary<string, float> items = new Dictionary<string, float>();

    public Inventory2(float capacity)
    {
        _capacity = capacity;
    }

    public override IReadOnlyDictionary<string, float> Items => items;

    private float _capacity;

    public override float Capacity
    {
        get { return _capacity; }
        set
        {
            _capacity = value;
            InvokeOnChange();
        }
    }

    public override string ToString()
    {
        return this.ToString(Environment.NewLine);
    }

    public string ToString(string delimiter = "\n")
    {
        string text = string.Join(delimiter, items);
        text += delimiter + $"Занято {Load}";
        if (Capacity >= 0)
            text += $", свободно {Capacity - Load}";

        return text;
    }

    public override float GetAmount(string item)
    {
        return items.ContainsKey(item) ? items[item] : 0;
    }

    protected override int DoClear()
    {
        var itemCount = items.Count;
        items.Clear();
        return itemCount;
    }

    protected override float DoAdd(string item, float amount, bool allowPartialAdd = false)
    {
        if (!allowPartialAdd && (Capacity >= 0) && (Capacity < Load + amount))
            return 0;

        amount = Math.Min(amount, Free);

        if (items.ContainsKey(item))
            items[item] += amount;
        else
            items[item] = amount;

        return amount;
    }

    protected override float DoRemove(string item, float amount, bool allowPartialRemoval = false)
    {
        var presentAmount = GetAmount(item);

        if (!allowPartialRemoval && presentAmount < amount)
            return 0;

        amount = Math.Min(amount, presentAmount);

        items[item] -= amount;
        if (items[item] == 0)
            items.Remove(item);

        return amount;
    }

    public void LoadData(InventoryData data)
    {
        items = data.items;
        _capacity = data.capacity;
    }

    public void SaveData(InventoryData data)
    {
        data.items = new SerializableDictionary<string, float>(items);
        data.capacity = _capacity;
    }

    public Inventory2 Clone()
    {
        var clone = new Inventory2(Capacity);
        foreach (var kvp in items)
            clone.items.Add(kvp.Key, kvp.Value);

        return clone;
    }

    public void OverrideItemsFrom(Inventory2 source)
    {
        Clear();
        foreach (var kvp in source.Items)
            items.Add(kvp.Key, kvp.Value);
    }
}