using System.Collections;
using UnityEngine;

[RequireComponent(typeof(LineRenderer))]
public class ChaseLaserBeam : MonoBehaviour
{
    [Header("Laser Setup")]
    public Transform laserOrigin;
    public float maxDistance = 20f;
    public LayerMask collisionMask;
    public Color laserColor = Color.red;
    public float laserWidth = 0.05f;

    [Header("Visuals")]
    public float scrollSpeed = 1f;
    public float emissionStrength = 5f;

    [Header("Performance")]
    public float updateRate = 0.02f;

    [Header("Pulse (On/Off)")]
    public bool pulsing = true;
    public bool startOn = true;
    public float onDuration = 1.5f;
    public float offDuration = 1.5f;
    public float fadeIn = 0.15f;
    public float fadeOut = 0.15f;
    public float startDelay = 0f;
    public float randomStartOffset = 0f;

    [Header("Lethality")]
    [Range(0f, 1f)] public float lethalThreshold = 0.9f;

    private LineRenderer line;
    private Vector3 laserStart, laserEnd;
    private Material matInstance;

    private float currentIntensity = 0f;
    private bool isActiveVisual = false;
    private bool isEnabled = false;
    private Coroutine pulseCo;

    void Awake()
    {
        line = GetComponent<LineRenderer>();
        SetupLaserRenderer();
    }

    void OnEnable()
    {
        isEnabled = true;
        line.enabled = true;
        InvokeRepeating(nameof(UpdateLaser), 0f, updateRate);

        if (pulsing) pulseCo = StartCoroutine(PulseRoutine());
        else
        {
            currentIntensity = 1f;
            isActiveVisual = true;
            ApplyIntensity(currentIntensity);
        }
    }

    void OnDisable()
    {
        isEnabled = false;
        CancelInvoke(nameof(UpdateLaser));
        if (pulseCo != null) StopCoroutine(pulseCo);
        if (line != null) line.enabled = false;
    }

    void UpdateLaser()
    {
        if (!isActiveVisual || currentIntensity <= 0.001f)
        {
            if (line.enabled) line.enabled = false;
            return;
        }

        laserStart = laserOrigin ? laserOrigin.position : transform.position;
        Vector3 direction = transform.forward;

        if (Physics.Raycast(laserStart, direction, out RaycastHit hit, maxDistance, collisionMask))
        {
            laserEnd = hit.point;

            if (/*currentIntensity >= lethalThreshold && */hit.collider.CompareTag("Player"))
            {
                // Use Shared_DieZibu for laser kill
                var die = hit.collider.GetComponent<Shared_DieZibu>() ?? hit.collider.GetComponentInParent<Shared_DieZibu>();
                if (die != null)
                {
                    // optional: stop the runner’s local movement flags if present
                    var runner = die.GetComponent<ChasePlayerController>();
                    if (runner != null)
                    {
                        runner.StartCoroutine(runner.PlayStateAndGameOver(runner.fallingStateName, runner.fallingShortHash));
                    }
                    die.KillByLaser();

                }
                else
                {
                    // Fallback: if no Shared_DieZibu found, keep old behavior (optional)
                    var runner = hit.collider.GetComponent<ChasePlayerController>() ?? hit.collider.GetComponentInParent<ChasePlayerController>();
                    if (runner != null /*&& !runner.waitingForGameOver*/)
                    {
                        runner.moveSpeed = 0;
                        runner.waitingForGameOver = true;
                        runner.StartCoroutine(runner.PlayStateAndGameOver(runner.fallingStateName, runner.fallingShortHash));
                    }
                }
            }
        }
        else
        {
            laserEnd = laserStart + direction * maxDistance;
        }

        if (!line.enabled) line.enabled = true;
        line.SetPosition(0, laserStart);
        line.SetPosition(1, laserEnd);
    }

    void SetupLaserRenderer()
    {
        line.useWorldSpace = true;
        line.positionCount = 2;
        line.loop = false;
        line.widthMultiplier = laserWidth;
        line.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off;
        line.receiveShadows = false;

        Shader laserShader = Shader.Find("Custom/EmissiveLaser");
        if (laserShader != null)
        {
            matInstance = new Material(laserShader);
            matInstance.SetColor("_Color", laserColor);
            matInstance.SetFloat("_Emission", 0f);
            matInstance.SetFloat("_ScrollSpeed", scrollSpeed);
            line.material = matInstance;
        }
        else
        {
            matInstance = new Material(Shader.Find("Sprites/Default"));
            matInstance.color = laserColor * 0f;
            line.material = matInstance;
        }

        line.startColor = laserColor;
        line.endColor = laserColor;
    }

    IEnumerator PulseRoutine()
    {
        float jitter = (randomStartOffset > 0f) ? Random.Range(-randomStartOffset, randomStartOffset) : 0f;
        if (startDelay + jitter > 0f) yield return new WaitForSeconds(startDelay + jitter);

        bool stateOn = startOn;

        while (isEnabled)
        {
            if (stateOn)
            {
                if (fadeIn > 0f) yield return FadeIntensity(1f, fadeIn);
                else { currentIntensity = 1f; ApplyIntensity(currentIntensity); }

                isActiveVisual = true;
                if (onDuration > 0f) yield return new WaitForSeconds(onDuration);
            }
            else
            {
                if (fadeOut > 0f) yield return FadeIntensity(0f, fadeOut);
                else { currentIntensity = 0f; ApplyIntensity(currentIntensity); }

                isActiveVisual = false;
                if (offDuration > 0f) yield return new WaitForSeconds(offDuration);
            }

            stateOn = !stateOn;
        }
    }

    IEnumerator FadeIntensity(float target, float time)
    {
        float start = currentIntensity;
        float t = 0f;
        isActiveVisual = (target > 0f) || (start > 0f);

        while (t < 1f)
        {
            t += Time.deltaTime / Mathf.Max(0.0001f, time);
            currentIntensity = Mathf.Lerp(start, target, t);
            ApplyIntensity(currentIntensity);
            yield return null;
        }

        currentIntensity = target;
        ApplyIntensity(currentIntensity);

        if (currentIntensity <= 0.001f && line.enabled) line.enabled = false;
    }

    void ApplyIntensity(float normalized)
    {
        line.widthMultiplier = Mathf.Max(0.0001f, laserWidth * Mathf.Lerp(0.35f, 1f, normalized));

        if (matInstance != null)
        {
            if (matInstance.HasProperty("_Emission"))
            {
                matInstance.SetFloat("_Emission", emissionStrength * normalized);
            }
            else
            {
                Color c = laserColor;
                c.a = Mathf.Clamp01(normalized);
                matInstance.color = c;
            }
        }
    }

    public void SetPulsing(bool enabled)
    {
        pulsing = enabled;

        if (!isEnabled) return;

        if (pulseCo != null) { StopCoroutine(pulseCo); pulseCo = null; }

        if (pulsing) pulseCo = StartCoroutine(PulseRoutine());
        else
        {
            currentIntensity = 1f;
            ApplyIntensity(currentIntensity);
            isActiveVisual = true;
        }
    }

    public void ForceOff()
    {
        if (pulseCo != null) { StopCoroutine(pulseCo); pulseCo = null; }
        pulsing = false;
        currentIntensity = 0f;
        ApplyIntensity(0f);
        isActiveVisual = false;
        if (line) line.enabled = false;
    }

    public void ForceOn()
    {
        if (pulseCo != null) { StopCoroutine(pulseCo); pulseCo = null; }
        pulsing = false;
        currentIntensity = 1f;
        ApplyIntensity(1f);
        isActiveVisual = true;
        if (line && !line.enabled) line.enabled = true;
    }
}