using UnityEngine;

namespace BumpCombat.Defense
{
    [DisallowMultipleComponent]
    public sealed class DefenseSummonUnit : MonoBehaviour
    {
        private static Sprite[] idleFrames;
        private static Sprite[] attackFrames;

        private DefenseTower owner;
        private DefensePrototypeController controller;
        private Vector2 anchorLocalPosition;
        private SpriteRenderer spriteRenderer;
        private float attackCooldown;
        private float attackAnimationTime = -1f;

        public void Configure(
            DefenseTower tower,
            DefensePrototypeController prototypeController,
            Vector2 localAnchor)
        {
            owner = tower;
            controller = prototypeController;
            anchorLocalPosition = localAnchor;
            spriteRenderer = gameObject.AddComponent<SpriteRenderer>();
            idleFrames ??= Resources.LoadAll<Sprite>("Tutorial/Swordsman_Idle");
            attackFrames ??= Resources.LoadAll<Sprite>("Tutorial/Swordsman_BumpAttack-v1");
            if (idleFrames.Length > 0)
            {
                spriteRenderer.sprite = idleFrames[0];
            }
            spriteRenderer.color = new Color32(255, 234, 137, 255);
            spriteRenderer.sortingOrder = 11;
            float scale = owner.Tier == 4 && owner.Branch == DefenseTowerBranch.First
                ? 1.35f : 0.9f;
            transform.localScale = new Vector3(scale, scale, 1f);
        }

        private void Update()
        {
            UpdateAttackSprite();
            if (owner == null
                || !owner.isActiveAndEnabled
                || controller == null
                || !controller.CanOperateTowers)
            {
                return;
            }

            attackCooldown = Mathf.Max(0f, attackCooldown - Time.deltaTime);
            Vector2 anchor = owner.transform.TransformPoint(anchorLocalPosition);
            DefenseRouteAgent target = controller.FindNearestTarget(
                anchor,
                controller.Tuning.SummonAreaRadius,
                DefenseTowerKind.Summon);
            if (target == null)
            {
                transform.position = Vector2.MoveTowards(
                    transform.position,
                    anchor,
                    controller.Tuning.SummonUnitMoveSpeed * Time.deltaTime);
                return;
            }

            Vector2 targetPosition = target.transform.position;
            spriteRenderer.flipX = targetPosition.x < transform.position.x;
            transform.position = Vector2.MoveTowards(
                transform.position,
                targetPosition,
                controller.Tuning.SummonUnitMoveSpeed * Time.deltaTime);
            float attackRange = controller.Tuning.SummonAttackRange
                * (owner.Tier == 4 && owner.Branch == DefenseTowerBranch.Second ? 2.5f : 1f);
            if (attackCooldown <= 0f
                && (targetPosition - (Vector2)transform.position).sqrMagnitude
                    <= attackRange * attackRange
                && owner.TryAttack(target))
            {
                PlayAttackSprite();
                owner.ShowSummonAttackEffect(transform.position, targetPosition);
                attackCooldown = controller.Tuning.SummonAttackInterval
                    / (1f + 0.15f * (owner.Tier - 1))
                    * controller.GetTowerAttackIntervalMultiplier(owner);
            }
        }

        private void PlayAttackSprite()
        {
            if (attackFrames.Length == 0)
            {
                return;
            }
            attackAnimationTime = 0f;
            spriteRenderer.sprite = attackFrames[0];
        }

        private void UpdateAttackSprite()
        {
            if (attackAnimationTime < 0f || attackFrames == null
                || attackFrames.Length == 0)
            {
                return;
            }

            attackAnimationTime += Time.deltaTime;
            int frame = Mathf.FloorToInt(attackAnimationTime * 12f);
            if (frame >= attackFrames.Length)
            {
                attackAnimationTime = -1f;
                if (idleFrames != null && idleFrames.Length > 0)
                {
                    spriteRenderer.sprite = idleFrames[0];
                }
                return;
            }
            spriteRenderer.sprite = attackFrames[frame];
        }
    }
}