using UnityEngine;

// Greybox practice bot built from primitives: a capsule body and a sphere head, each with a
// ShootingTargetHitbox so the shooter knows which zone was hit. Dies at 0 HP and respawns
// after a delay, like the Valorant range bots. Purely local (not networked).
// Procedural animations: flinch away from each hit, fall over on death, pop back up on respawn.
public class ShootingTarget : MonoBehaviour
{
    public float maxHealth = 150f;
    public float respawnDelay = 2f;

    [Header("Strafing (0 = static)")]
    public float strafeDistance = 0f;
    public float strafeSpeed = 3f;

    static readonly Color BodyColor = new Color(0.85f, 0.25f, 0.25f);
    static readonly Color HeadColor = new Color(0.95f, 0.8f, 0.3f);
    static readonly Color FlashColor = Color.white;
    const float DeathFallTime = 0.35f;
    const float RespawnPopTime = 0.25f;

    public float Health { get; private set; }
    public bool IsDead { get; private set; }

    Transform visual;       // pivot at the feet; every animation rotates/scales this
    Renderer[] renderers;
    Material[][] originalMaterials;
    Material[][] flashMaterials;
    bool flashApplied;
    Renderer plateRenderer;
    bool hiddenForIntro;
    Material flashMaterial;
    Collider[] colliders;
    TextMesh healthLabel;
    Vector3 startPosition;
    float flashUntil;
    float respawnAt;
    float diedAt;
    float respawnedAt = -10f;

    // Flinch: a tilt axis/amount that springs back to 0.
    Vector3 flinchAxis = Vector3.right;
    float flinchAngle;
    float flinchVelocity;
    Vector3 deathAxis = Vector3.right;

    public static ShootingTarget Create(Transform parent, string name, Vector3 position, float strafeDistance = 0f)
    {
        var root = new GameObject(name);
        root.transform.SetParent(parent, false);
        root.transform.localPosition = position;

        var target = root.AddComponent<ShootingTarget>();
        target.strafeDistance = strafeDistance;
        target.Build();
        return target;
    }

    void Build()
    {
        flashMaterial = ShootingFx.GetMaterial(FlashColor, 1.5f);

        visual = new GameObject("Visual").transform;
        visual.SetParent(transform, false);

        // Real model (Quaternius CC0 practice dummy) with invisible box hitboxes fitted to its
        // head/torso; falls back to the capsule + sphere bot if the model is missing.
        var model = Resources.Load<GameObject>(ModelPath);
        if (model != null) BuildFromModel(model);
        else BuildPrimitive();

        renderers = visual.GetComponentsInChildren<Renderer>();
        originalMaterials = new Material[renderers.Length][];
        flashMaterials = new Material[renderers.Length][];
        for (int i = 0; i < renderers.Length; i++)
        {
            originalMaterials[i] = renderers[i].sharedMaterials;
            flashMaterials[i] = new Material[originalMaterials[i].Length];
            for (int m = 0; m < flashMaterials[i].Length; m++) flashMaterials[i][m] = flashMaterial;
        }

        // Base plate so the bot reads as a range dummy.
        var plate = ShootingFx.CreateVisual(PrimitiveType.Cylinder, "Base", transform, new Vector3(0f, 0.02f, 0f),
            new Vector3(0.9f, 0.02f, 0.9f), ShootingFx.GetMaterial(new Color(0.2f, 0.2f, 0.22f)));
        plateRenderer = plate.GetComponent<Renderer>();
        plateRenderer.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.On;

        var label = new GameObject("HealthLabel");
        label.transform.SetParent(transform, false);
        label.transform.localPosition = new Vector3(0f, 2.25f, 0f);
        healthLabel = label.AddComponent<TextMesh>();
        healthLabel.font = Resources.GetBuiltinResource<Font>("LegacyRuntime.ttf");
        label.GetComponent<MeshRenderer>().sharedMaterial = healthLabel.font.material;
        healthLabel.characterSize = 0.08f;
        healthLabel.fontSize = 48;
        healthLabel.anchor = TextAnchor.MiddleCenter;
        healthLabel.alignment = TextAlignment.Center;

        colliders = visual.GetComponentsInChildren<Collider>();
        startPosition = transform.localPosition;
        Respawn();
    }

    const string ModelPath = "Targets/PracticeDummy";

    // Hitbox zones measured from the dummy mesh (1.85 m tall): torso 0.46–1.57 m, head 1.57–1.85 m.
    void BuildFromModel(GameObject model)
    {
        var instance = Instantiate(model, visual, false);
        instance.name = model.name;
        foreach (var c in instance.GetComponentsInChildren<Collider>()) Destroy(c);
        foreach (var r in instance.GetComponentsInChildren<Renderer>()) r.shadowCastingMode = UnityEngine.Rendering.ShadowCastingMode.On;

        AddBoxHitbox("Body", new Vector3(0f, 1.02f, 0f), new Vector3(0.66f, 1.1f, 0.5f), isHead: false);
        AddBoxHitbox("Head", new Vector3(0f, 1.71f, 0f), new Vector3(0.36f, 0.3f, 0.34f), isHead: true);
    }

    void AddBoxHitbox(string name, Vector3 center, Vector3 size, bool isHead)
    {
        var go = new GameObject(name);
        go.transform.SetParent(visual, false);
        go.transform.localPosition = center;
        go.AddComponent<BoxCollider>().size = size;
        go.AddComponent<ShootingTargetHitbox>().Init(this, isHead);
    }

    void BuildPrimitive()
    {
        var body = GameObject.CreatePrimitive(PrimitiveType.Capsule);
        body.name = "Body";
        body.transform.SetParent(visual, false);
        body.transform.localPosition = new Vector3(0f, 0.75f, 0f);
        body.transform.localScale = new Vector3(0.7f, 0.75f, 0.7f);
        body.AddComponent<ShootingTargetHitbox>().Init(this, isHead: false);
        body.GetComponent<Renderer>().sharedMaterial = ShootingFx.GetMaterial(BodyColor);

        var head = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        head.name = "Head";
        head.transform.SetParent(visual, false);
        head.transform.localPosition = new Vector3(0f, 1.73f, 0f);
        head.transform.localScale = Vector3.one * 0.36f;
        head.AddComponent<ShootingTargetHitbox>().Init(this, isHead: true);
        head.GetComponent<Renderer>().sharedMaterial = ShootingFx.GetMaterial(HeadColor);
    }

    void ApplyFlash(bool flashing)
    {
        if (flashing == flashApplied) return;
        flashApplied = flashing;
        for (int i = 0; i < renderers.Length; i++)
            renderers[i].sharedMaterials = flashing ? flashMaterials[i] : originalMaterials[i];
    }

    // Returns true if this hit killed the target. hitDirection is the bullet's travel direction.
    public bool TakeDamage(float damage, Vector3 hitDirection, bool headshot)
    {
        if (IsDead) return false;

        Health = Mathf.Max(0f, Health - damage);
        flashUntil = Time.time + 0.08f;

        // Tilt away from the shot: rotate around the horizontal axis perpendicular to it.
        Vector3 flat = Vector3.ProjectOnPlane(hitDirection, Vector3.up);
        if (flat.sqrMagnitude > 0.0001f)
        {
            flinchAxis = Vector3.Cross(Vector3.up, flat.normalized);
            deathAxis = flinchAxis;
        }
        flinchVelocity += headshot ? 260f : 140f;

        if (Health <= 0f)
        {
            IsDead = true;
            diedAt = Time.time;
            respawnAt = Time.time + respawnDelay;
            foreach (var c in colliders) c.enabled = false;
            healthLabel.gameObject.SetActive(false);
            return true;
        }

        return false;
    }

    // Intro cinematic: the bot starts fully hidden, then PopIn() beams it in.
    public void HideForIntro()
    {
        hiddenForIntro = true;
        visual.localScale = Vector3.one * 0.0001f;
        plateRenderer.enabled = false;
        healthLabel.gameObject.SetActive(false);
        foreach (var c in colliders) c.enabled = false;
    }

    public void PopIn()
    {
        if (!hiddenForIntro) return;
        hiddenForIntro = false;
        plateRenderer.enabled = true;
        Respawn();
        ShootingFx.SpawnBeam(transform.position);
    }

    void Update()
    {
        if (hiddenForIntro) return;

        if (IsDead)
        {
            AnimateDeath();
            if (Time.time >= respawnAt) Respawn();
            return;
        }

        if (strafeDistance > 0f)
        {
            float offset = Mathf.PingPong(Time.time * strafeSpeed, strafeDistance * 2f) - strafeDistance;
            transform.localPosition = startPosition + Vector3.right * offset;
        }

        // Damped spring back to upright.
        const float stiffness = 180f;
        const float damping = 14f;
        flinchVelocity += (-stiffness * flinchAngle - damping * flinchVelocity) * Time.deltaTime;
        flinchAngle += flinchVelocity * Time.deltaTime;

        float pop = Mathf.Clamp01((Time.time - respawnedAt) / RespawnPopTime);
        float scale = EaseOutBack(pop);
        visual.localScale = new Vector3(1f, Mathf.Max(0.01f, scale), 1f);
        visual.rotation = Quaternion.AngleAxis(flinchAngle, flinchAxis);

        bool flashing = Time.time < flashUntil;
        ApplyFlash(flashing);

        healthLabel.text = Mathf.CeilToInt(Health).ToString();
        healthLabel.color = Color.Lerp(Color.red, Color.green, Health / maxHealth);

        var cam = Camera.main;
        if (cam != null)
            healthLabel.transform.rotation = cam.transform.rotation;
    }

    // Topple over backwards (away from the shooter), then sink into the floor.
    void AnimateDeath()
    {
        float t = Time.time - diedAt;
        float fall = Mathf.Clamp01(t / DeathFallTime);
        float angle = Mathf.Lerp(0f, 90f, fall * fall); // accelerate like it's falling
        visual.rotation = Quaternion.AngleAxis(angle, deathAxis);

        float sink = Mathf.Clamp01((t - DeathFallTime - 0.6f) / 0.5f);
        visual.localPosition = Vector3.down * sink * 0.8f;

        bool flashing = Time.time < flashUntil;
        ApplyFlash(flashing);
    }

    void Respawn()
    {
        Health = maxHealth;
        IsDead = false;
        respawnedAt = Time.time;
        flinchAngle = 0f;
        flinchVelocity = 0f;
        visual.localPosition = Vector3.zero;
        visual.rotation = Quaternion.identity;
        foreach (var c in colliders) c.enabled = true;
        healthLabel.gameObject.SetActive(true);
    }

    static float EaseOutBack(float x)
    {
        const float c1 = 1.70158f;
        const float c3 = c1 + 1f;
        return 1f + c3 * Mathf.Pow(x - 1f, 3f) + c1 * Mathf.Pow(x - 1f, 2f);
    }
}