using BumpCombat.Constants;
using UnityEngine;

namespace BumpCombat.Defense
{
    [DisallowMultipleComponent]
    public sealed class DefenseTower : MonoBehaviour
    {
        private DefensePrototypeController owner;
        private DefenseConstants tuning;
        private float attackCooldown;
        private TextMesh label;
        private LineRenderer effectRange;
        private static Material effectMaterial;
        private int summonCount;

        public DefenseTowerKind Kind { get; private set; }
        public DefenseTowerBranch Branch { get; private set; }
        public int Tier { get; private set; } = 1;
        public int PadIndex { get; private set; }
        public bool IsOperational => isActiveAndEnabled
            && owner != null
            && owner.CanOperateTowers;
        public bool IsDamaging => Kind != DefenseTowerKind.Empowering;

        public void Configure(
            DefensePrototypeController controller,
            DefenseTowerKind kind,
            int padIndex,
            DefenseConstants constants)
        {
            owner = controller;
            Kind = kind;
            PadIndex = padIndex;
            tuning = constants;
            Tier = 1;
            Branch = DefenseTowerBranch.None;
            CreateVisuals();
            if (Kind == DefenseTowerKind.Summon)
            {
                AddSummonUnits(tuning.SummonUnitCount);
            }
        }

        public bool Upgrade(DefenseTowerBranch branch)
        {
            if (Tier >= 4 || (Tier < 3 && branch != DefenseTowerBranch.None)
                || (Tier == 3 && branch != DefenseTowerBranch.First
                    && branch != DefenseTowerBranch.Second))
            {
                return false;
            }

            Tier++;
            if (Tier == 4)
            {
                Branch = branch;
            }

            if (Kind == DefenseTowerKind.Summon)
            {
                if (Tier == 4 && Branch == DefenseTowerBranch.First)
                {
                    foreach (DefenseSummonUnit unit in GetComponentsInChildren<DefenseSummonUnit>())
                    {
                        unit.enabled = false;
                        Destroy(unit.gameObject);
                    }
                    summonCount = 0;
                    AddSummonUnits(1);
                }
                else
                {
                    AddSummonUnits(Tier == 4 ? 2 : 1);
                }
            }

            UpdateLabel();
            UpdateEffectRange();
            return true;
        }

        private void Update()
        {
            if (!IsOperational || Kind == DefenseTowerKind.Summon
                || Kind == DefenseTowerKind.Empowering)
            {
                return;
            }

            attackCooldown -= Time.deltaTime;
            if (attackCooldown > 0f)
            {
                return;
            }

            if (owner.TryAttackFromTower(this))
            {
                float interval = Kind switch
                {
                    DefenseTowerKind.Direct => tuning.DirectTowerAttackInterval,
                    DefenseTowerKind.Lightning => tuning.LightningInterval,
                    DefenseTowerKind.Cold => tuning.ColdInterval,
                    _ => tuning.SeismicInterval,
                };
                if (Tier == 4 && Kind == DefenseTowerKind.Direct
                    && Branch == DefenseTowerBranch.Second)
                {
                    interval *= 0.4f;
                }

                attackCooldown = Mathf.Max(0.05f,
                    interval / (1f + 0.15f * (Tier - 1))
                    * owner.GetTowerAttackIntervalMultiplier(this));
            }
        }

        public bool TryPulse()
        {
            if (!IsOperational || Kind == DefenseTowerKind.Empowering
                || Kind == DefenseTowerKind.Summon)
            {
                return false;
            }

            float range = GetEffectRange();
            DefenseRouteAgent target = owner.FindNearestTarget(
                transform.position, range, Kind,
                Kind == DefenseTowerKind.Cold || Kind == DefenseTowerKind.Seismic);
            if (target == null)
            {
                return false;
            }

            Vector2 center = target.transform.position;
            float scale = 1f + tuning.TowerDamageBonusPerTier * (Tier - 1);
            float impactRadius = 0f;
            bool cone = false;
            bool applied;
            switch (Kind)
            {
                case DefenseTowerKind.Direct:
                    if (Tier == 4 && Branch == DefenseTowerBranch.Second)
                    {
                        cone = true;
                        impactRadius = range;
                        applied = AttackCone(center - (Vector2)transform.position,
                            range, tuning.DirectTowerDamage * scale * 0.4f);
                    }
                    else if (Tier == 4)
                    {
                        impactRadius = 1.8f;
                        applied = AttackArea(center, impactRadius,
                            tuning.DirectTowerDamage * scale * 1.6f);
                    }
                    else
                    {
                        applied = owner.TryApplyTowerDamage(this, target,
                            tuning.DirectTowerDamage * scale);
                    }
                    break;

                case DefenseTowerKind.Lightning:
                    impactRadius = Tier == 4
                        ? (Branch == DefenseTowerBranch.First ? 3f : 2.4f)
                        : tuning.LightningRadius;
                    applied = AttackArea(center, impactRadius,
                        tuning.LightningDamage * scale
                        * (Tier == 4 && Branch == DefenseTowerBranch.Second ? 1.4f : 1f),
                        Tier == 4 && Branch == DefenseTowerBranch.First ? 3 : int.MaxValue);
                    break;

                case DefenseTowerKind.Cold:
                    if (Tier == 4 && Branch == DefenseTowerBranch.Second)
                    {
                        impactRadius = 1.65f;
                        applied = AttackArea(center, impactRadius,
                            tuning.ColdDamage * scale * 0.5f,
                            int.MaxValue, tuning.ColdSlowSeconds * 1.5f,
                            tuning.ColdSlowFraction, 0.35f);
                    }
                    else
                    {
                        bool slowed = owner.TryApplyTowerSlow(this, target,
                            tuning.ColdSlowSeconds * (1f + 0.25f * (Tier - 1)),
                            tuning.ColdSlowFraction);
                        bool damaged = owner.TryApplyTowerDamage(this, target,
                            tuning.ColdDamage * scale * (Tier == 4 ? 1.8f : 1f));
                        if (Tier == 4)
                        {
                            owner.TryApplyTowerStun(this, target, 0.3f);
                        }
                        applied = slowed || damaged;
                    }
                    break;

                case DefenseTowerKind.Seismic:
                    impactRadius = Tier == 4
                        ? (Branch == DefenseTowerBranch.Second ? 2.2f : 1.8f)
                        : tuning.SeismicRadius;
                    applied = Tier == 4 && Branch == DefenseTowerBranch.Second
                        ? AttackArea(center, impactRadius,
                            tuning.SeismicDamage * scale, int.MaxValue, 2f, 0.5f)
                        : AttackArea(center, impactRadius,
                            tuning.SeismicDamage * scale, int.MaxValue,
                            0f, 0f,
                            tuning.SeismicStunSeconds * (Tier == 4 ? 2f : 1f));
                    break;

                default:
                    return false;
            }

            if (applied)
            {
                ShowAttackEffect(center, impactRadius, cone);
            }
            return applied;
        }

        private bool AttackCone(Vector2 direction, float range, float damage)
        {
            bool applied = false;
            Vector2 facing = direction.normalized;
            foreach (DefenseRouteAgent agent in owner.GetTargetsInRange(
                transform.position, range))
            {
                Vector2 toAgent = ((Vector2)agent.transform.position
                    - (Vector2)transform.position).normalized;
                if (toAgent.sqrMagnitude < 0.000001f
                    || Vector2.Dot(facing, toAgent) >= 0.5f)
                {
                    applied |= owner.TryApplyTowerDamage(this, agent, damage);
                }
            }

            return applied;
        }

        private bool AttackArea(
            Vector2 center,
            float radius,
            float damage,
            int maxTargets = int.MaxValue,
            float slowSeconds = 0f,
            float slowFraction = 0f,
            float stunSeconds = 0f)
        {
            bool applied = false;
            int count = 0;
            foreach (DefenseRouteAgent agent in owner.GetTargetsInRange(center, radius))
            {
                if (count++ >= maxTargets)
                {
                    break;
                }

                bool damaged = owner.TryApplyTowerDamage(this, agent, damage);
                bool slowed = slowSeconds > 0f
                    && owner.TryApplyTowerSlow(this, agent, slowSeconds, slowFraction);
                bool stunned = stunSeconds > 0f
                    && owner.TryApplyTowerStun(this, agent, stunSeconds);
                applied |= damaged || slowed || stunned;
            }

            return applied;
        }

        public bool TryAttack(DefenseRouteAgent target)
        {
            if (target == null || owner == null || !IsOperational)
            {
                return false;
            }

            float damage = Kind == DefenseTowerKind.Summon
                ? tuning.SummonDamage : tuning.DirectTowerDamage;
            damage *= 1f + tuning.TowerDamageBonusPerTier * (Tier - 1);
            if (Tier == 4 && Kind == DefenseTowerKind.Summon
                && Branch == DefenseTowerBranch.First)
            {
                damage *= 1.8f;
            }

            bool hit = owner.TryApplyTowerDamage(this, target, damage);
            if (hit && Tier == 4 && Kind == DefenseTowerKind.Summon
                && Branch == DefenseTowerBranch.First)
            {
                owner.TryApplyTowerStun(this, target, 0.3f);
            }

            return hit;
        }

        public void ShowSummonAttackEffect(Vector2 origin, Vector2 target)
        {
            if (IsOperational && Kind == DefenseTowerKind.Summon)
            {
                ShowAttackEffect(target, 0f, false, origin);
            }
        }

        private float GetEffectRange()
        {
            if (Kind == DefenseTowerKind.Summon)
            {
                return tuning.SummonAreaRadius;
            }
            if (Kind == DefenseTowerKind.Empowering)
            {
                return tuning.SupportRadius;
            }
            return Kind == DefenseTowerKind.Direct && Tier == 4
                && Branch == DefenseTowerBranch.Second
                ? tuning.TowerRange * 0.5f : tuning.TowerRange;
        }

        private void CreateEffectRange()
        {
            GameObject rangeObject = new("Effect Range");
            rangeObject.transform.SetParent(transform, false);
            effectRange = rangeObject.AddComponent<LineRenderer>();
            effectRange.useWorldSpace = false;
            effectRange.loop = true;
            effectRange.positionCount = 48;
            effectRange.sharedMaterial = GetEffectMaterial();
            effectRange.sortingOrder = 3;
            Color color = GetComponent<SpriteRenderer>().color;
            color.a = Kind == DefenseTowerKind.Empowering ? 0.35f : 0.22f;
            effectRange.startColor = color;
            effectRange.endColor = color;
            UpdateEffectRange();
        }

        private void UpdateEffectRange()
        {
            if (effectRange == null)
            {
                return;
            }
            float worldScale = Mathf.Max(0.001f, transform.lossyScale.x);
            float radius = GetEffectRange() / worldScale;
            effectRange.startWidth = 0.055f / worldScale;
            effectRange.endWidth = effectRange.startWidth;
            for (int i = 0; i < effectRange.positionCount; i++)
            {
                float angle = i * Mathf.PI * 2f / effectRange.positionCount;
                effectRange.SetPosition(i, new Vector3(
                    Mathf.Cos(angle) * radius,
                    Mathf.Sin(angle) * radius, 0f));
            }
        }

        private void ShowAttackEffect(
            Vector2 center, float radius, bool cone, Vector2? source = null)
        {
            Vector2 origin = source ?? (Vector2)transform.position;
            GameObject effect = new($"{Kind} Attack Effect");
            effect.transform.SetParent(transform.parent, false);
            effect.transform.position = center;
            Color color = GetComponent<SpriteRenderer>().color;
            color.a = 0.9f;
            Vector2 direction = center - origin;

            if (Kind == DefenseTowerKind.Lightning && direction.sqrMagnitude > 0.001f)
            {
                LineRenderer bolt = CreateEffectLine(effect.transform, "Bolt", color, 0.13f);
                bolt.positionCount = 5;
                Vector2 side = new(-direction.y, direction.x);
                side.Normalize();
                for (int i = 0; i < 5; i++)
                {
                    float fraction = i / 4f;
                    float offset = i == 1 ? 0.22f : i == 2 ? -0.16f
                        : i == 3 ? 0.18f : 0f;
                    bolt.SetPosition(i, origin - center
                        + direction * fraction + side * offset);
                }
            }
            else if (Kind != DefenseTowerKind.Seismic
                && direction.sqrMagnitude > 0.001f)
            {
                SpriteRenderer shot = CreateEffectSprite(
                    effect.transform, "Shot Sprite",
                    origin + direction * 0.5f,
                    new Vector2(direction.magnitude,
                        Kind == DefenseTowerKind.Direct ? 0.2f : 0.13f), color);
                shot.transform.rotation = Quaternion.Euler(
                    0f, 0f, Mathf.Atan2(direction.y, direction.x)
                        * Mathf.Rad2Deg);
            }

            CreateEffectSprite(effect.transform, "Impact Sprite",
                center, new Vector2(0.42f, 0.42f), color);
            if (cone)
            {
                LineRenderer outline = CreateEffectLine(
                    effect.transform, "Cone Radius", color, 0.07f);
                outline.positionCount = 3;
                Vector2 forward = direction.normalized * radius;
                outline.SetPosition(0, origin - center);
                outline.SetPosition(1, origin - center
                    + (Vector2)(Quaternion.Euler(0f, 0f, -60f) * forward));
                outline.SetPosition(2, origin - center
                    + (Vector2)(Quaternion.Euler(0f, 0f, 60f) * forward));
            }
            else if (radius > 0f)
            {
                LineRenderer area = CreateEffectLine(
                    effect.transform, "Impact Radius", color, 0.07f);
                area.loop = true;
                area.positionCount = 40;
                for (int i = 0; i < area.positionCount; i++)
                {
                    float angle = i * Mathf.PI * 2f / area.positionCount;
                    area.SetPosition(i, new Vector3(
                        Mathf.Cos(angle) * radius,
                        Mathf.Sin(angle) * radius, 0f));
                }
            }

            Destroy(effect, 0.22f);
        }

        private static SpriteRenderer CreateEffectSprite(
            Transform parent, string name, Vector2 position,
            Vector2 size, Color color)
        {
            GameObject shape = new(name);
            shape.transform.SetParent(parent, false);
            shape.transform.position = position;
            shape.transform.localScale = new Vector3(size.x, size.y, 1f);
            SpriteRenderer renderer = shape.AddComponent<SpriteRenderer>();
            renderer.sprite = DefensePrototypeController.WhiteSprite;
            renderer.color = color;
            renderer.sortingOrder = 15;
            return renderer;
        }

        private static LineRenderer CreateEffectLine(
            Transform parent, string name, Color color, float width)
        {
            GameObject shape = new(name);
            shape.transform.SetParent(parent, false);
            LineRenderer line = shape.AddComponent<LineRenderer>();
            line.useWorldSpace = false;
            line.sharedMaterial = GetEffectMaterial();
            line.startWidth = width;
            line.endWidth = width;
            line.startColor = color;
            line.endColor = color;
            line.sortingOrder = 14;
            return line;
        }

        private static Material GetEffectMaterial()
        {
            if (effectMaterial == null)
            {
                effectMaterial = new Material(Shader.Find("Sprites/Default"));
                effectMaterial.hideFlags = HideFlags.HideAndDontSave;
            }
            return effectMaterial;
        }

        private void AddSummonUnits(int count)
        {
            for (int i = 0; i < count; i++)
            {
                int unitIndex = summonCount++;
                GameObject unitObject = new($"Summon Unit {unitIndex + 1}");
                unitObject.transform.SetParent(transform, false);
                unitObject.transform.localPosition = new Vector3(
                    (unitIndex % 3 - 1) * 0.42f, -0.5f - 0.25f * (unitIndex / 3), 0f);
                DefenseSummonUnit unit = unitObject.AddComponent<DefenseSummonUnit>();
                unit.Configure(this, owner, unitObject.transform.localPosition);
            }
        }

        private void CreateVisuals()
        {
            SpriteRenderer renderer = gameObject.GetComponent<SpriteRenderer>();
            if (renderer == null)
            {
                renderer = gameObject.AddComponent<SpriteRenderer>();
            }
            renderer.sprite = DefensePrototypeController.WhiteSprite;
            renderer.color = Kind switch
            {
                DefenseTowerKind.Direct => new Color32(240, 96, 65, 255),
                DefenseTowerKind.Summon => new Color32(244, 154, 74, 255),
                DefenseTowerKind.Lightning => new Color32(238, 218, 83, 255),
                DefenseTowerKind.Cold => new Color32(65, 211, 240, 255),
                DefenseTowerKind.Seismic => new Color32(175, 141, 100, 255),
                _ => new Color32(148, 228, 122, 255),
            };
            renderer.sortingOrder = 8;
            transform.localScale = new Vector3(0.72f, 0.72f, 1f);

            GameObject crown = new("Tower Crown");
            crown.transform.SetParent(transform, false);
            crown.transform.localPosition = new Vector3(0f, 0.42f, 0f);
            crown.transform.localScale = new Vector3(0.42f, 0.22f, 1f);
            SpriteRenderer crownRenderer = crown.AddComponent<SpriteRenderer>();
            crownRenderer.sprite = DefensePrototypeController.WhiteSprite;
            crownRenderer.color = Color.white;
            crownRenderer.sortingOrder = 9;

            GameObject labelObject = new("Tower Label");
            labelObject.transform.SetParent(transform, false);
            labelObject.transform.localPosition = new Vector3(0f, 0.85f, 0f);
            label = labelObject.AddComponent<TextMesh>();
            label.anchor = TextAnchor.MiddleCenter;
            label.alignment = TextAlignment.Center;
            label.characterSize = 0.16f;
            label.fontSize = 32;
            label.color = Color.white;
            label.GetComponent<MeshRenderer>().sortingOrder = 10;
            UpdateLabel();
            CreateEffectRange();
        }

        private void UpdateLabel()
        {
            if (label == null)
            {
                return;
            }

            string family = Kind == DefenseTowerKind.Direct ? "FIRE" : Kind.ToString().ToUpperInvariant();
            string branchName = Tier == 4
                ? GetBranchName(Kind, Branch) : string.Empty;
            label.text = Tier == 4
                ? $"{family} IV\n{branchName}"
                : $"{family} {Tier}";
        }

        public static string GetBranchName(DefenseTowerKind kind, DefenseTowerBranch branch)
        {
            bool first = branch == DefenseTowerBranch.First;
            return kind switch
            {
                DefenseTowerKind.Direct => first ? "METEOR" : "FLAMETHROWER",
                DefenseTowerKind.Lightning => first ? "ARC" : "LIGHTNING STORM",
                DefenseTowerKind.Cold => first ? "FREEZEBOLT" : "GLACIAL CAGE",
                DefenseTowerKind.Seismic => first ? "STONE GAZE" : "TEMPORAL",
                DefenseTowerKind.Summon => first ? "SENTINEL" : "SCOUT",
                _ => first ? "IMBUING" : "SMOTHERING",
            };
        }
    }
}