using System;
using System.Collections.Generic;
using UnityEngine;

public sealed class ScoringSystem : MonoBehaviour
{
    [Header("Modifiers")]
    [SerializeField] private List<ScoreModifier> activeModifiers = new();

    public event Action<YachtCategory, int> OnCategoryScored;
    public event Action<int> OnAllCategoriesScored;

    private readonly Dictionary<YachtCategory, int> scorecard = new();
    private readonly HashSet<YachtCategory> usedCategories = new();

    public bool IsCategoryUsed(YachtCategory category) => usedCategories.Contains(category);

    public int GetCategoryScore(YachtCategory category)
    {
        return scorecard.TryGetValue(category, out int score) ? score : -1;
    }

    public int TotalScore
    {
        get
        {
            int total = 0;
            foreach (var kvp in scorecard) total += kvp.Value;
            return total;
        }
    }

    public int CategoriesFilledCount => usedCategories.Count;

    public int TotalCategoryCount => Enum.GetValues(typeof(YachtCategory)).Length;

    public bool IsComplete => CategoriesFilledCount >= TotalCategoryCount;

    public void AddModifier(ScoreModifier modifier)
    {
        if (modifier != null && !activeModifiers.Contains(modifier))
            activeModifiers.Add(modifier);
    }

    public void RemoveModifier(ScoreModifier modifier)
    {
        activeModifiers.Remove(modifier);
    }

    public IReadOnlyList<ScoreModifier> ActiveModifiers => activeModifiers;

    public ScoreResult PreviewScore(int[] diceValues, YachtCategory category)
    {
        int baseScore = CategoryScorer.Calculate(diceValues, category);
        ScoreResult result = ScoreResult.Create(baseScore, diceValues, category);
        ApplyModifiers(ref result);
        return result;
    }

    public ScoreResult ScoreCategory(int[] diceValues, YachtCategory category)
    {
        if (usedCategories.Contains(category))
            throw new InvalidOperationException($"Category {category} has already been scored.");

        ScoreResult result = PreviewScore(diceValues, category);

        int finalScore = result.FinalScore;
        scorecard[category] = finalScore;
        usedCategories.Add(category);

        OnCategoryScored?.Invoke(category, finalScore);

        if (IsComplete)
            OnAllCategoriesScored?.Invoke(TotalScore);

        return result;
    }

    private void ApplyModifiers(ref ScoreResult result)
    {
        // Pass 1: Additive
        for (int i = 0; i < activeModifiers.Count; i++)
        {
            if (activeModifiers[i] == null) continue;
            if (activeModifiers[i].Phase == ScoreModifier.ModifierPhase.Additive)
                activeModifiers[i].Apply(ref result);
        }

        // Pass 2: Multiplicative
        for (int i = 0; i < activeModifiers.Count; i++)
        {
            if (activeModifiers[i] == null) continue;
            if (activeModifiers[i].Phase == ScoreModifier.ModifierPhase.Multiplicative)
                activeModifiers[i].Apply(ref result);
        }
    }

    public void ResetScorecard()
    {
        scorecard.Clear();
        usedCategories.Clear();
    }
}