using System.Collections.Generic;
using NUnit.Framework;
using UnityEngine;
using YachtDice.Modifiers;
using YachtDice.Scoring;

namespace YachtDice.Tests
{
    public class ModifierPipelineTests
    {
        [Test]
        public void Apply_AdditiveBeforeMultiplicative()
        {
            var addMod = ModifierData.CreateForTest("add", ModifierScope.SelectedCategory,
                ModifierEffectType.AddFlatToFinalScore, 10f);
            var mulMod = ModifierData.CreateForTest("mul", ModifierScope.SelectedCategory,
                ModifierEffectType.MultiplyFinalScore, 2f);

            var modifiers = new List<ModifierData> { mulMod, addMod };
            var result = ScoreResult.Create(20, new[] { 1, 2, 3, 4, 5 }, YachtCategory.Chance);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            // (20 + 10) * 2 = 60
            Assert.AreEqual(60, result.FinalScore);
        }

        [Test]
        public void Apply_CategoryLevelBeforeFinalScore()
        {
            var perDie = ModifierData.CreateForTest("perDie", ModifierScope.SelectedCategory,
                ModifierEffectType.AddPerDieValue, 5f, dieValue: 1);
            var flat = ModifierData.CreateForTest("flat", ModifierScope.SelectedCategory,
                ModifierEffectType.AddFlatToFinalScore, 100f);

            var modifiers = new List<ModifierData> { flat, perDie };
            var result = ScoreResult.Create(3, new[] { 1, 1, 1, 2, 3 }, YachtCategory.Ones);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            // FlatBonus = 15 (perDie: 5*3) + 100 (flat) = 115
            // FinalScore = (3 + 115) * 1 = 118
            Assert.AreEqual(118, result.FinalScore);
        }

        [Test]
        public void Apply_ScopeFiltering_SkipsWrongScope()
        {
            var mod = ModifierData.CreateForTest("any", ModifierScope.AnyCategoryClosed,
                ModifierEffectType.AddFlatToFinalScore, 50f);

            var modifiers = new List<ModifierData> { mod };
            var result = ScoreResult.Create(10, new[] { 1, 2, 3, 4, 5 }, YachtCategory.Chance);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            Assert.AreEqual(0, result.FlatBonus);
            Assert.AreEqual(10, result.FinalScore);
        }

        [Test]
        public void Apply_CategoryFilter_SkipsWrongCategory()
        {
            var mod = ModifierData.CreateForTest("fh", ModifierScope.SelectedCategory,
                ModifierEffectType.AddFlatToFinalScore, 15f,
                targetCategory: YachtCategory.FullHouse, hasCategoryFilter: true);

            var modifiers = new List<ModifierData> { mod };
            var result = ScoreResult.Create(5, new[] { 1, 1, 1, 1, 1 }, YachtCategory.Ones);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            Assert.AreEqual(0, result.FlatBonus);
        }

        [Test]
        public void Apply_CategoryFilter_AppliesMatchingCategory()
        {
            var mod = ModifierData.CreateForTest("fh", ModifierScope.SelectedCategory,
                ModifierEffectType.AddFlatToFinalScore, 15f,
                targetCategory: YachtCategory.FullHouse, hasCategoryFilter: true);

            var modifiers = new List<ModifierData> { mod };
            var result = ScoreResult.Create(25, new[] { 3, 3, 3, 2, 2 }, YachtCategory.FullHouse);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            Assert.AreEqual(15, result.FlatBonus);
            Assert.AreEqual(40, result.FinalScore);
        }

        [Test]
        public void Apply_MultipleModifiers_CorrectOrder()
        {
            var perDieAdd = ModifierData.CreateForTest("pda", ModifierScope.SelectedCategory,
                ModifierEffectType.AddPerDieValue, 2f, dieValue: 3);
            var perDieMul = ModifierData.CreateForTest("pdm", ModifierScope.SelectedCategory,
                ModifierEffectType.MultiplyPerDieValue, 1.5f, dieValue: 3);
            var flatAdd = ModifierData.CreateForTest("fa", ModifierScope.SelectedCategory,
                ModifierEffectType.AddFlatToFinalScore, 10f);
            var finalMul = ModifierData.CreateForTest("fm", ModifierScope.SelectedCategory,
                ModifierEffectType.MultiplyFinalScore, 2f);

            var modifiers = new List<ModifierData> { finalMul, flatAdd, perDieMul, perDieAdd };
            // dice: [3, 3, 3, 1, 2] — 3 threes
            var result = ScoreResult.Create(9, new[] { 3, 3, 3, 1, 2 }, YachtCategory.Threes);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            // Pass 1 (cat additive): perDieAdd: +2*3 = +6 FlatBonus
            // Pass 2 (cat multiplicative): perDieMul: 1.5^3 = 3.375 Multiplier
            // Pass 3 (final additive): flatAdd: +10 FlatBonus → total FlatBonus = 16
            // Pass 4 (final multiplicative): finalMul: 3.375 * 2 = 6.75 Multiplier
            // FinalScore = floor((9 + 16) * 6.75) = floor(168.75) = 168
            Assert.AreEqual(6, result.FlatBonus + 10); // just check pipeline ran; full calc below
            Assert.AreEqual(168, result.FinalScore);
        }

        [Test]
        public void Apply_NullModifiers_DoesNotThrow()
        {
            var result = ScoreResult.Create(10, new[] { 1, 2, 3, 4, 5 }, YachtCategory.Chance);

            Assert.DoesNotThrow(() =>
                ModifierPipeline.Apply(null, ref result, ModifierScope.SelectedCategory));

            Assert.AreEqual(10, result.FinalScore);
        }

        [Test]
        public void Apply_EmptyList_NoChange()
        {
            var modifiers = new List<ModifierData>();
            var result = ScoreResult.Create(10, new[] { 1, 2, 3, 4, 5 }, YachtCategory.Chance);

            ModifierPipeline.Apply(modifiers, ref result, ModifierScope.SelectedCategory);

            Assert.AreEqual(10, result.FinalScore);
        }
    }
}