using System.Collections.Generic;
using NUnit.Framework;
using NightclubArcadia.Skills;
using UnityEngine;

namespace NightclubArcadia.Skills.Tests
{
    public class SkillCheckSystemTests
    {
        sealed class FixedRollSource : IRollSource
        {
            readonly int _value;
            public FixedRollSource(int value) => _value = value;
            public int Roll(int sides) => _value;
        }

        SkillDatabase CreateDatabase(params (string id, string display, int rank)[] skills)
        {
            var db = ScriptableObject.CreateInstance<SkillDatabase>();
            var list = new List<SkillDefinition>();
            foreach (var (id, display, rank) in skills)
            {
                var def = ScriptableObject.CreateInstance<SkillDefinition>();
                def.EditorSet(id, display, SkillDomain.Presence, string.Empty, rank, Color.white);
                list.Add(def);
            }

            db.EditorSetSkills(list);
            return db;
        }

        [Test]
        public void Resolve_SumsModifiers_AndSucceedsWhenTotalMeetsDc()
        {
            var db = CreateDatabase(("persuasion", "Persuasion", 2));
            var skills = new PlayerSkills(db);
            var state = new SkillStateModifiers();
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(10));

            var result = system.Resolve("persuasion", 12, 1);

            Assert.AreEqual(13, result.Total);
            Assert.IsTrue(result.Success);
            Assert.AreEqual(SkillCheckDegree.Success, result.Degree);
            Assert.AreEqual(2, result.RankMod);
            Assert.AreEqual(1, result.SituationalMod);
            Assert.AreEqual(0, result.StateMod);
        }

        [Test]
        public void Resolve_NaturalOne_IsCriticalFailureEvenIfModifiersWouldPass()
        {
            var db = CreateDatabase(("persuasion", "Persuasion", 10));
            var skills = new PlayerSkills(db);
            var state = new SkillStateModifiers();
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(1));

            var result = system.Resolve("persuasion", 5, 5);

            Assert.IsFalse(result.Success);
            Assert.AreEqual(SkillCheckDegree.CriticalFailure, result.Degree);
        }

        [Test]
        public void Resolve_NaturalTwenty_IsCriticalSuccessEvenIfBelowDc()
        {
            var db = CreateDatabase(("persuasion", "Persuasion", 0));
            var skills = new PlayerSkills(db);
            var state = new SkillStateModifiers();
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(20));

            var result = system.Resolve("persuasion", 25, 0);

            Assert.IsTrue(result.Success);
            Assert.AreEqual(SkillCheckDegree.CriticalSuccess, result.Degree);
        }

        [Test]
        public void Resolve_ExactDc_IsSuccess()
        {
            var db = CreateDatabase(("persuasion", "Persuasion", 1));
            var skills = new PlayerSkills(db);
            var state = new SkillStateModifiers();
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(10));

            var result = system.Resolve("persuasion", 11, 0);

            Assert.AreEqual(11, result.Total);
            Assert.IsTrue(result.Success);
        }

        [Test]
        public void Resolve_AppliesNegativeAndWildcardStateModifiers()
        {
            var db = CreateDatabase(("reflexes", "Reflexes", 1));
            var skills = new PlayerSkills(db);
            var state = new SkillStateModifiers();
            state.Set("drunk", "reflexes", -2);
            state.Set("crowd", "*", -1);
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(10));

            var result = system.Resolve("reflexes", 5, 0);

            Assert.AreEqual(-3, result.StateMod);
            Assert.AreEqual(8, result.Total);
        }

        [Test]
        public void Resolve_UnknownSkill_DoesNotThrow_AndUsesZeroRank()
        {
            var db = CreateDatabase(("persuasion", "Persuasion", 3));
            var skills = new PlayerSkills(db);
            var state = new SkillStateModifiers();
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(10));

            SkillCheckResult result = default;
            Assert.DoesNotThrow(() => result = system.Resolve("nosuchskill", 10, 0));
            Assert.AreEqual(0, result.RankMod);
            Assert.AreEqual("NOSUCHSKILL", result.SkillDisplayName);
        }

        [Test]
        public void Resolve_DoesNotMutatePlayerSkills()
        {
            var db = CreateDatabase(("persuasion", "Persuasion", 2));
            var skills = new PlayerSkills(db);
            var before = skills.GetRank("persuasion");
            var state = new SkillStateModifiers();
            var system = new SkillCheckSystem(db, skills, state, new FixedRollSource(10));

            system.Resolve("persuasion", 10, 0);

            Assert.AreEqual(before, skills.GetRank("persuasion"));
            Assert.AreEqual(1, skills.AllRanks.Count);
        }
    }
}