using System.Collections.Generic;
using YachtDice.Scoring;

namespace YachtDice.Modifiers
{
    public delegate void ModifierHandler(ModifierData data, ref ScoreResult result);

    public static class ModifierEffect
    {
        private static readonly Dictionary<ModifierEffectType, ModifierHandler> Handlers = new()
        {
            { ModifierEffectType.AddPerDieValue, ApplyAddPerDieValue },
            { ModifierEffectType.AddFlatToFinalScore, ApplyAddFlat },
            { ModifierEffectType.MultiplyPerDieValue, ApplyMultiplyPerDieValue },
            { ModifierEffectType.MultiplyFinalScore, ApplyMultiplyFinal }
        };

        public static void Apply(ModifierData data, ref ScoreResult result)
        {
            if (Handlers.TryGetValue(data.EffectType, out var handler))
                handler(data, ref result);
        }

        private static void ApplyAddPerDieValue(ModifierData data, ref ScoreResult result)
        {
            int targetValue = data.Target.DieValue;
            int count = 0;

            for (int i = 0; i < result.DiceValues.Length; i++)
            {
                if (targetValue == 0 || result.DiceValues[i] == targetValue)
                    count++;
            }

            result.FlatBonus += (int)(data.EffectValue * count);
        }

        private static void ApplyAddFlat(ModifierData data, ref ScoreResult result)
        {
            result.FlatBonus += (int)data.EffectValue;
        }

        private static void ApplyMultiplyPerDieValue(ModifierData data, ref ScoreResult result)
        {
            int targetValue = data.Target.DieValue;

            for (int i = 0; i < result.DiceValues.Length; i++)
            {
                if (targetValue == 0 || result.DiceValues[i] == targetValue)
                    result.Multiplier *= data.EffectValue;
            }
        }

        private static void ApplyMultiplyFinal(ModifierData data, ref ScoreResult result)
        {
            result.Multiplier *= data.EffectValue;
        }
    }
}