using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using BumpCombat.Constants;
using BumpCombat.Core;
using BumpCombat.Defense.Comparison;
using BumpCombat.Enemies;
using NUnit.Framework;
using UnityEditor;
using UnityEngine;
using UnityEngine.TestTools;
using Object = UnityEngine.Object;

namespace BumpCombat.Tests
{
    public sealed class Defense25DMonsterCombatAdapterPlayModeTests
    {
        private const string SettingsPath = "Assets/_Project/Constants/Defense25DComparison/ComparisonSettings.asset";
        private const string PoolPath = "Assets/_Project/Constants/Defense25DComparison/MonsterPools.asset";
        private Defense25DComparison world;
        private Defense25DComparisonSettings settings;
        private readonly List<Object> temporaryObjects = new();
        private float previousTimeScale;

        [UnitySetUp]
        public IEnumerator SetUp()
        {
            previousTimeScale = Time.timeScale;
            Time.timeScale = 1f;
            settings = Object.Instantiate(AssetDatabase.LoadAssetAtPath<Defense25DComparisonSettings>(SettingsPath));
            Assert.That(settings, Is.Not.Null);
            world = new GameObject("Monster combat adapter under test").AddComponent<Defense25DComparison>();
            world.Initialize(settings);
            world.AutoSpawn = false;
            world.ReadInput = false;
            world.SetPaused(false);
            Time.timeScale = 0f;
            SetGameTime(0f);
            yield return null;
        }

        [UnityTearDown]
        public IEnumerator TearDown()
        {
            for (int i = temporaryObjects.Count - 1; i >= 0; i--)
                if (temporaryObjects[i] != null) Object.Destroy(temporaryObjects[i]);
            temporaryObjects.Clear();
            if (world != null) Object.Destroy(world.gameObject);
            if (settings != null) Object.Destroy(settings);
            Time.timeScale = previousTimeScale;
            yield return null;
        }

        [UnityTest]
        public IEnumerator ContactAttackWarnsBeforeApplyingOneRealActorDamageEvent()
        {
            Defense25DMonsterPoolEntry entry = FindEntry("Slime");
            Assert.That(entry.CombatProfile.Archetype, Is.EqualTo(Defense25DMonsterAttackArchetype.Contact));
            Defense25DEnemy enemy = world.Enemies[0];
            enemy.Spawn(Vector2.zero);
            world.Player.ResetAt(enemy.Actor.Center + Vector2.right * .05f);
            Physics.SyncTransforms();

            Sprite frame = CreateFrame();
            var motion = CreateMotion(entry, frame);
            var warningEvents = new List<Defense25DMonsterCombatWarning>();
            var adapter = new Defense25DMonsterCombatAdapter();
            Assert.That(adapter.Bind(entry, enemy.Actor, motion, () => world.Player, out string error,
                setWarning: warningEvents.Add), Is.True, error);

            Assert.That(adapter.Step(.001f, moving: false), Is.True);
            Assert.That(warningEvents.Last().Visible, Is.True);
            Assert.That(world.Player.DamageEvents, Is.Zero, "Starting a telegraph cannot apply damage.");

            adapter.Step(entry.CombatProfile.WarningSeconds - .002f, moving: false);
            Assert.That(world.Player.DamageEvents, Is.Zero, "The configured warning duration must remain safe.");

            adapter.Step(.003f, moving: false);
            Assert.That(warningEvents.Last().Visible, Is.False);
            Assert.That(world.Player.DamageEvents, Is.EqualTo(1));
            float damagedHealth = world.Player.CurrentHealth;
            Assert.That(damagedHealth, Is.LessThan(world.Player.MaxHealth));
            adapter.Step(.02f, moving: false);
            Assert.That(world.Player.DamageEvents, Is.EqualTo(1), "One contact attack can damage only once.");
            Assert.That(world.Player.CurrentHealth, Is.EqualTo(damagedHealth),
                "The later attack frame cannot reapply its contact damage.");

            adapter.Cancel();
            yield return null;
        }

        [UnityTest]
        public IEnumerator ContactAttackAppliesTheAttackerAttackDamageModifiers()
        {
            Defense25DMonsterPoolEntry entry = FindEntry("Slime");
            Defense25DEnemy enemy = world.Enemies[0];
            enemy.Spawn(Vector2.zero);
            Assert.That(enemy.Actor.AddModifier(new StatModifier("test-attack-flat",
                CharacterStat.AttackDamage, ModifierOperation.Flat, 7f)), Is.True);
            float expectedDamage = enemy.Actor.CalculateAttackDamage(
                entry.CombatProfile.AttackDamage * entry.Definition.GetAttackPattern(0).DamageMultiplier);

            world.Player.ResetAt(enemy.Actor.Center + Vector2.right * .05f);
            Physics.SyncTransforms();
            var adapter = new Defense25DMonsterCombatAdapter();
            Assert.That(adapter.Bind(entry, enemy.Actor, CreateMotion(entry, CreateFrame()),
                () => world.Player, out string error), Is.True, error);

            adapter.Step(.001f, moving: false);
            adapter.Step(entry.CombatProfile.WarningSeconds + .002f, moving: false);

            Assert.That(world.Player.DamageEvents, Is.EqualTo(1));
            Assert.That(world.Player.MaxHealth - world.Player.CurrentHealth,
                Is.EqualTo(expectedDamage).Within(.01f));
            adapter.Cancel();
            yield return null;
        }

        [UnityTest]
        public IEnumerator ProjectileAttackOnlyDamagesAfterItsTravelSegmentReachesThePlayer()
        {
            Defense25DMonsterPoolEntry entry = FindEntry("SkeletonArcher");
            Defense25DMonsterCombatProfile profile = entry.CombatProfile;
            Assert.That(profile.Archetype, Is.EqualTo(Defense25DMonsterAttackArchetype.Projectile));
            Assert.That(profile.ProjectileSpeed, Is.GreaterThan(0f));
            Defense25DEnemy enemy = world.Enemies[0];
            enemy.Spawn(Vector2.zero);
            float targetDistance = Mathf.Min(profile.AttackRange * .75f, 2f);
            world.Player.ResetAt(enemy.Actor.Center + Vector2.right * targetDistance);
            Physics.SyncTransforms();

            Sprite frame = CreateFrame();
            var motion = CreateMotion(entry, frame);
            var projectileEvents = new List<Defense25DMonsterProjectileVisual>();
            var adapter = new Defense25DMonsterCombatAdapter();
            Assert.That(adapter.Bind(entry, enemy.Actor, motion, () => world.Player, out string error,
                setProjectile: projectileEvents.Add), Is.True, error);

            adapter.Step(.001f, moving: false);
            adapter.Step(profile.WarningSeconds + .001f, moving: false);
            Assert.That(projectileEvents.Any(projectile => projectile.Active), Is.True,
                "The authored projectile starts at the end of the warning.");
            Assert.That(world.Player.DamageEvents, Is.Zero, "Firing is not an immediate hit.");

            adapter.Step(.02f, moving: false);
            Assert.That(world.Player.DamageEvents, Is.Zero,
                "The projectile must not damage before its swept path reaches the target.");

            adapter.Step(1f, moving: false);
            Assert.That(world.Player.DamageEvents, Is.EqualTo(1));
            Assert.That(projectileEvents.Last().Active, Is.False);
            adapter.Cancel();
            yield return null;
        }

        private Defense25DMonsterPoolEntry FindEntry(string id)
        {
            Defense25DMonsterPoolDefinition pool = AssetDatabase.LoadAssetAtPath<Defense25DMonsterPoolDefinition>(PoolPath);
            Assert.That(pool, Is.Not.Null);
            Assert.That(pool.TryValidate(out string error), Is.True, error);
            return pool.Tiers.SelectMany(tier => tier.Entries).Single(entry => entry.EnemyDefinitionId == id);
        }

        private Defense25DMonsterSourceMotion CreateMotion(Defense25DMonsterPoolEntry entry, Sprite frame)
        {
            return new Defense25DMonsterSourceMotion(
                entry.SourceCharacterId,
                new[] { frame },
                new[] { frame },
                new Dictionary<string, Sprite[]> { [entry.CombatProfile.AttackAction] = new[] { frame } },
                entry.CombatProfile.IsFlying ? new[] { frame } : null,
                .1f,
                new[] { frame });
        }

        private Sprite CreateFrame()
        {
            Texture2D texture = new Texture2D(1, 1);
            temporaryObjects.Add(texture);
            Sprite frame = Sprite.Create(texture, new Rect(0f, 0f, 1f, 1f), new Vector2(.5f, .5f));
            temporaryObjects.Add(frame);
            return frame;
        }

        private void SetGameTime(float value)
        {
            typeof(Defense25DComparison).GetProperty(nameof(Defense25DComparison.GameTime))
                .GetSetMethod(true).Invoke(world, new object[] { value });
        }
    }
}