using System.Collections;
using UnityEngine;

namespace BumpCombat.Defense
{
    public sealed class Defense25DPreview : MonoBehaviour
    {
        private const string BodyKey = "Bodies/Fire/T3-Idle";
        private const string FlightKey = "Effects/Fire/Meteor-Flight";
        private const string ImpactKey = "Effects/Fire/Meteor-Impact";
        private const float AuraFrameSeconds = 0.14f;

        [SerializeField] private SpriteRenderer body, auraBack, auraFront, meteor;
        [SerializeField] private Sprite[] auraBackFrames, auraFrontFrames, meteorFlightFrames, meteorImpactFrames, bodyFrames;
        [SerializeField] private Transform groundAnchor, bodyVisual;
        [SerializeField] private float flightHeight = 1.7f;

        public SpriteRenderer Body => body;
        public SpriteRenderer AuraBack => auraBack;
        public SpriteRenderer AuraFront => auraFront;
        public SpriteRenderer Meteor => meteor;
        public Sprite[] AuraBackFrames => auraBackFrames;
        public Sprite[] AuraFrontFrames => auraFrontFrames;
        public Sprite[] MeteorFlightFrames => meteorFlightFrames;
        public Sprite[] MeteorImpactFrames => meteorImpactFrames;
        public Sprite[] BodyFrames => bodyFrames;
        public Transform GroundAnchor => groundAnchor;
        public Transform BodyVisual => bodyVisual;
        public float CurrentMeteorHeight { get; private set; }
        public Vector2 CurrentMeteorGround { get; private set; }

        public void Configure(Sprite[] back, Sprite[] front, Sprite[] flight, Sprite[] impact, Sprite[] character)
        {
            auraBackFrames = back; auraFrontFrames = front; meteorFlightFrames = flight;
            meteorImpactFrames = impact; bodyFrames = character;
        }

        public static Vector3 ProjectGroundAndHeight(Vector2 groundPosition, float height) =>
            new Vector3(groundPosition.x - height, groundPosition.y + height, 0f);

        private IEnumerator Start()
        {
            StartCoroutine(AnimateAura());
            StartCoroutine(AnimateBody());
            StartCoroutine(MoveTarget());
            while (true)
            {
                yield return new WaitForSeconds(0.25f);
                yield return PlayMeteor();
                yield return new WaitForSeconds(0.55f);
            }
        }

        private IEnumerator MoveTarget()
        {
            while (true)
            {
                Vector3 p = groundAnchor.position;
                p.x = Mathf.Sin(Time.time * 0.7f) * 0.65f;
                groundAnchor.position = p;
                yield return null;
            }
        }

        private IEnumerator AnimateAura()
        {
            int frame = 0;
            while (true)
            {
                auraBack.sprite = auraBackFrames[frame];
                auraFront.sprite = auraFrontFrames[frame];
                frame = (frame + 1) % auraBackFrames.Length;
                yield return new WaitForSeconds(AuraFrameSeconds);
            }
        }

        private IEnumerator AnimateBody()
        {
            int frame = 0;
            while (true)
            {
                body.sprite = bodyFrames[frame];
                frame = (frame + 1) % bodyFrames.Length;
                yield return new WaitForSeconds(DefenseTowerArt.FrameSeconds(BodyKey, frame == 0 ? bodyFrames.Length - 1 : frame - 1));
            }
        }

        private IEnumerator PlayMeteor()
        {
            CurrentMeteorGround = groundAnchor.position;
            meteor.enabled = true;
            CurrentMeteorHeight = flightHeight;
            float flightDuration = 0f;
            for (int i = 0; i < meteorFlightFrames.Length; i++) flightDuration += DefenseTowerArt.FrameSeconds(FlightKey, i);

            float elapsed = 0f;
            for (int i = 0; i < meteorFlightFrames.Length; i++)
            {
                meteor.sprite = meteorFlightFrames[i];
                float frameSeconds = DefenseTowerArt.FrameSeconds(FlightKey, i);
                float frameElapsed = 0f;
                while (frameElapsed < frameSeconds)
                {
                    CurrentMeteorHeight = flightHeight * (1f - elapsed / flightDuration);
                    meteor.transform.position = ProjectGroundAndHeight(CurrentMeteorGround, CurrentMeteorHeight);
                    float dt = Mathf.Min(Time.deltaTime, frameSeconds - frameElapsed);
                    frameElapsed += dt;
                    elapsed += dt;
                    yield return null;
                }
            }

            CurrentMeteorHeight = 0f;
            meteor.transform.position = ProjectGroundAndHeight(CurrentMeteorGround, 0f);
            for (int i = 0; i < meteorImpactFrames.Length; i++)
            {
                meteor.sprite = meteorImpactFrames[i];
                yield return new WaitForSeconds(DefenseTowerArt.FrameSeconds(ImpactKey, i));
            }
            meteor.enabled = false;
        }
    }
}