using UnityEngine;

[RequireComponent(typeof(LineRenderer))]
public class LaserBeam : MonoBehaviour
{
    [Header("Laser Settings")]
    public float maxDistance = 20f;
    public LayerMask collisionMask = ~0;
    public float chargeDuration = 3f;
    public float fireDuration = 1f;

    [Header("Laser Appearance")]
    public Color laserColor = Color.red;
    public Color warningColor = new Color(1f, 0.5f, 0f); // Orange
    public float laserWidth = 0.05f;
    public float emissionStrength = 5f;
    public float scrollSpeed = 1f;

    [Header("Player Hit")]
    public string playerTag = "Player";
    [Tooltip("Approximate beam thickness for hit tests.")]
    public float hitRadius = 0.1f;
    [Tooltip("Should raycasts consider trigger colliders? (Player often uses triggers)")]
    public QueryTriggerInteraction queryTriggerMode = QueryTriggerInteraction.Collide;

    [Header("Intro Show")]
    public bool showIntro = true;
    public float initialShowDuration = 3f;
    [Tooltip("If true, the intro beam can kill the player too.")]
    public bool introIsDeadly = true;

    [Header("Debug")]
    public bool debugDraw = false;

    private LineRenderer line;
    private float timer = 0f;

    private enum LaserState { Idle, Charging, Firing }
    private LaserState currentState = LaserState.Idle;

    private Vector3 laserStart;
    private Vector3 laserEnd;

    private bool introRunning = false;
    private bool hasTriggeredDeathThisBurst = false;

    // cache root to ignore self-hits
    Transform _selfRoot;
    [Header("Deflection")]
    public bool enableDeflection = true;
    public string deflectTag = "Box";
    [Tooltip("How far the beam travels after deflection.")]
    public float deflectDistance = 10f;
    [Tooltip("Push along the deflected direction to avoid re-hitting the same face.")]
    public float deflectEdgePush = 0.02f;

    // runtime cache so the left/right choice doesn't flicker
    Collider _currentDeflectCol;
    int _currentDeflectSign = 1;   // +1 = right, -1 = left
    bool _isDeflecting;
    Vector3 _bouncePoint;
    Vector3 _bounceEnd;
    [Header("Deflection (Box side center)")]
    [Tooltip("Tiny push so the second segment isn't inside the face.")]

    // runtime
    bool _segmented;
    [Header("Deflection (Box side center)")]
    public bool deflectFromBoxSides = true;
    public string boxTag = "Box";
    public float outDistance = 12f;
    public float sideExitPush = 0.02f;   // push outward from side face
    public float entryPush = 0.005f;     // push outward from front face so it shows

    // runtime
    bool _routeViaSide;
    Vector3 _entryPoint;   // front-face hit
    Vector3 _midPoint;     // side-face center
    Collider _lastBox;
    int _sideSign = 1;     // -1 = left, +1 = right (box local right axis)

    void Awake()
    {
        _selfRoot = transform.root;
        SetupLaserRenderer();
    }

    void Start()
    {
        if (showIntro)
            StartCoroutine(IntroShow());
    }

    void Update()
    {
        if (introRunning) return;

        timer += Time.deltaTime;

        switch (currentState)
        {
            case LaserState.Idle:
                hasTriggeredDeathThisBurst = false; // reset per cycle
                if (timer >= chargeDuration)
                {
                    timer = 0f;
                    currentState = LaserState.Charging;
                    StartCharging();
                }
                break;

            case LaserState.Charging:
                if (timer >= 1f)
                {
                    timer = 0f;
                    currentState = LaserState.Firing;
                    FireLaser();
                }
                else
                {
                    BlinkWarning();
                }
                break;

            case LaserState.Firing:
                if (timer >= fireDuration)
                {
                    timer = 0f;
                    currentState = LaserState.Idle;
                    DisableLaser();
                }
                else
                {
                    UpdateLaserPath();
                    CheckHit();
                }
                break;
        }

        if (debugDraw)
        {
            Debug.DrawLine(laserStart, laserEnd, Color.cyan, 0f, false);
        }
    }

    // ---------------- Intro show ----------------
    System.Collections.IEnumerator IntroShow()
    {
        introRunning = true;

        float t = 0f;
        line.enabled = true;
        SetLineColor(laserColor);

        hasTriggeredDeathThisBurst = false;

        while (t < initialShowDuration)
        {
            UpdateLaserPath();
            if (introIsDeadly && !hasTriggeredDeathThisBurst)
                CheckHit();

            t += Time.deltaTime;
            yield return null;
        }

        line.enabled = false;
        timer = 0f;
        currentState = LaserState.Idle;
        introRunning = false;
    }

    // ---------------- States ----------------
    void StartCharging()
    {
        UpdateLaserPath();
        line.enabled = true;
        SetLineColor(warningColor);
    }

    void BlinkWarning()
    {
        float blink = Mathf.PingPong(Time.time * 5f, 1f);
        Color blinkColor = Color.Lerp(Color.clear, warningColor, blink);
        SetLineColor(blinkColor);
    }

    void FireLaser()
    {
        UpdateLaserPath();
        SetLineColor(laserColor);

        hasTriggeredDeathThisBurst = false;
        CheckHit(); // initial frame
    }

    void DisableLaser()
    {
        line.enabled = false;
    }

    // ---------------- Hit Detection (robust) ----------------
    //void CheckHit()
    //{
    //    if (hasTriggeredDeathThisBurst) return;

    //    Vector3 dir = (laserEnd - laserStart).normalized;
    //    float distToEnd = Vector3.Distance(laserStart, laserEnd);

    //    // Cast along visible beam, then pick the nearest valid hit
    //    RaycastHit[] hits = Physics.SphereCastAll(
    //        laserStart, hitRadius, dir,
    //        distToEnd, collisionMask, queryTriggerMode
    //    );

    //    if (hits == null || hits.Length == 0) return;

    //    float bestDist = float.MaxValue;
    //    Transform best = null;

    //    foreach (var h in hits)
    //    {
    //        // Ignore self (any collider in our own hierarchy)
    //        if (h.collider && h.collider.GetComponentInParent<LaserBeam>() == this)
    //            continue;
    //        // Keep the nearest hit under our visible segment
    //        if (h.distance < bestDist)
    //        {
    //            bestDist = h.distance;
    //            best = h.collider.transform;
    //        }
    //    }

    //    if (best == null) return;

    //    // Player detection: check both object and its root
    //    bool isPlayer =
    //        best.CompareTag(playerTag) ||
    //        (best.root != null && best.root.CompareTag(playerTag));

    //    if (isPlayer)
    //    {
    //        Debug.Log("Laser hit player: " + best.name);
    //        hasTriggeredDeathThisBurst = true;
    //        CrateEscapeGameManager.Instance?.OnPlayerHitByLaser();
    //    }
    //}
    void CheckHit()
    {
        if (hasTriggeredDeathThisBurst) return;

        bool CheckSegment(Vector3 a, Vector3 b)
        {
            Vector3 d = b - a;
            float len = d.magnitude;
            if (len <= 0.0001f) return false;
            d /= len;

            var hits = Physics.SphereCastAll(a, hitRadius, d, len, collisionMask, queryTriggerMode);
            if (hits == null || hits.Length == 0) return false;

            float best = float.MaxValue;
            Transform bestT = null;
            foreach (var h in hits)
            {
                if (h.collider && h.collider.GetComponentInParent<LaserBeam>() == this) continue;
                if (h.distance < best) { best = h.distance; bestT = h.collider.transform; }
            }
            if (!bestT) return false;

            bool isPlayer = bestT.CompareTag(playerTag) || (bestT.root && bestT.root.CompareTag(playerTag));
            if (isPlayer)
            {
                hasTriggeredDeathThisBurst = true;
                CrateEscapeGameManager.Instance?.OnPlayerHitByLaser();
                return true;
            }
            return false;
        }

        if (_routeViaSide)
        {
            if (CheckSegment(laserStart, _entryPoint)) return;
            if (CheckSegment(_entryPoint, _midPoint)) return;
            CheckSegment(_midPoint, laserEnd);
        }
        else
        {
            CheckSegment(laserStart, laserEnd);
        }
    }

    void UpdateLaserPath()
    {
        laserStart = transform.position;
        Vector3 dir = transform.forward;

        float radius = Mathf.Max(0.0001f, hitRadius);

        // first: straight cast to find the first collider
        RaycastHit[] hits = Physics.SphereCastAll(laserStart, radius, dir, maxDistance, collisionMask, queryTriggerMode);

        Vector3 straightEnd = laserStart + dir * maxDistance;
        RaycastHit bestHit = default;
        float bestDist = float.MaxValue;
        bool gotHit = false;

        if (hits != null)
        {
            foreach (var h in hits)
            {
                if (!h.collider) continue;
                if (h.collider.GetComponentInParent<LaserBeam>() == this) continue;
                if (h.distance < bestDist)
                {
                    bestDist = h.distance;
                    bestHit = h;
                    gotHit = true;
                    straightEnd = h.point;
                }
            }
        }

        // default: straight line
        _routeViaSide = false;
        laserEnd = straightEnd;
        line.positionCount = 2;
        line.SetPosition(0, laserStart);
        line.SetPosition(1, laserEnd);

        // route via side center only for tagged Box with a BoxCollider
        if (!deflectFromBoxSides || !gotHit || !bestHit.collider.CompareTag(boxTag))
            return;

        var box = bestHit.collider.GetComponent<BoxCollider>();
        if (!box) return;

        // choose/stabilize left/right per box
        if (_lastBox != bestHit.collider)
        {
            _lastBox = bestHit.collider;
            _sideSign = (Random.value < 0.5f) ? -1 : 1;
        }

        Transform t = box.transform;

        // 1) ENTRY POINT on the FRONT face (push a hair outward so it's visible)
        _entryPoint = bestHit.point + bestHit.normal * entryPush;

        // 2) SIDE-CENTER (left/right in box local space), and outward direction
        Vector3 centerW = t.TransformPoint(box.center);
        Vector3 half = Vector3.Scale(box.size * 0.5f, t.lossyScale);
        Vector3 rightW = t.right.normalized;
        Vector3 outDir = rightW * _sideSign;
        _midPoint = centerW + rightW * (_sideSign * half.x);

        // 3) SECOND LEG: from side-center outward
        // remaining distance after traveling to entry + to side-center
        float traveled = bestHit.distance + Vector3.Distance(bestHit.point, _midPoint);
        float remain = Mathf.Max(0f, maxDistance - traveled);
        float leg = Mathf.Min(outDistance, remain);

        Vector3 secondStart = _midPoint + outDir * sideExitPush;
        Vector3 secondEnd = secondStart + outDir * leg;

        if (Physics.SphereCast(secondStart, radius, outDir, out var h2, leg, collisionMask, queryTriggerMode))
        {
            if (!(h2.collider && h2.collider.GetComponentInParent<LaserBeam>() == this))
                secondEnd = h2.point;
        }

        // draw the full polyline: START -> ENTRY -> SIDE-CENTER -> OUT
        _routeViaSide = true;
        laserEnd = secondEnd;

        line.positionCount = 4;
        line.SetPosition(0, laserStart);
        line.SetPosition(1, _entryPoint);
        line.SetPosition(2, _midPoint);
        line.SetPosition(3, laserEnd);
    }

    //void UpdateLaserPath()
    //{
    //    laserStart = transform.position;
    //    Vector3 dir = transform.forward;

    //    // SphereCast to find the FIRST valid hit along the visible beam,
    //    // ignoring ONLY this laser's own colliders.
    //    float radius = Mathf.Max(0.0001f, hitRadius);
    //    RaycastHit[] hits = Physics.SphereCastAll(
    //        laserStart, radius, dir, maxDistance, collisionMask, queryTriggerMode
    //    );

    //    Vector3 end = laserStart + dir * maxDistance;
    //    float bestDist = float.MaxValue;

    //    if (hits != null && hits.Length > 0)
    //    {
    //        foreach (var h in hits)
    //        {
    //            if (!h.collider) continue;

    //            // Ignore ONLY this LaserBeam's colliders (not the whole root/level)
    //            if (h.collider.GetComponentInParent<LaserBeam>() == this)
    //                continue;

    //            if (h.distance < bestDist)
    //            {
    //                bestDist = h.distance;
    //                end = h.point;
    //            }
    //        }
    //    }

    //    laserEnd = end;

    //    line.SetPosition(0, laserStart);
    //    line.SetPosition(1, laserEnd);
    //}

    // ---------------- Utils ----------------
    void SetLineColor(Color c)
    {
        line.material.color = c;
        line.startColor = c;
        line.endColor = c;
    }

    public void SetupLaserRenderer()
    {
        line = GetComponent<LineRenderer>();
        if (!line) line = gameObject.AddComponent<LineRenderer>();

        line.positionCount = 2;
        line.useWorldSpace = true;
        line.loop = false;
        line.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.Off;
        line.receiveShadows = false;
        line.widthMultiplier = laserWidth;

        Shader laserShader = Shader.Find("Custom/EmissiveLaser");
        if (laserShader != null)
        {
            Material laserMat = new Material(laserShader);
            laserMat.SetColor("_Color", laserColor);
            laserMat.SetFloat("_Emission", emissionStrength);
            laserMat.SetFloat("_ScrollSpeed", scrollSpeed);
            line.material = laserMat;
        }
        else
        {
            Debug.LogWarning("Custom/EmissiveLaser shader not found. Using fallback.");
            line.material = new Material(Shader.Find("Sprites/Default"));
            line.material.color = laserColor;
        }

        line.enabled = false;
    }

    void OnDrawGizmosSelected()
    {
        if (!debugDraw) return;
        Gizmos.color = Color.magenta;
        Gizmos.DrawWireSphere(transform.position, hitRadius);
    }
}