using UnityEngine;

/// <summary>
/// Attach to any pickup object. Spins + bobs like MGS rations.
/// Assign an ItemDefinition asset for full weapon/equip support,
/// or just fill itemName for a simple non-weapon pickup.
/// </summary>
public class PickupItem : MonoBehaviour
{
    [Header("Item")]
    [Tooltip("Preferred: drag an ItemDefinition ScriptableObject here.")]
    public ItemDefinition definition;

    [Tooltip("Fallback name if no ItemDefinition is set.")]
    public string itemName = "Item";
    public Sprite itemIcon;

    [Header("Spin & Bob")]
    public float spinSpeed = 120f;
    public float bobHeight = 0.18f;
    public float bobSpeed  = 2.2f;

    [Header("Pickup")]
    public float   pickupRadius = 2.0f;
    public KeyCode pickupKey    = KeyCode.E;

    [Header("FX")]
    public GameObject pickupParticlesPrefab;
    public AudioClip  pickupSound;

    // ─────────────────────────────────────────
    private Vector3     _startPos;
    private Transform   _playerTransform;
    private Inventory   _inventory;
    private AudioSource _audioSource;
    private bool        _collected = false;

    // Prompt display
    private bool _inRange = false;

    void Start()
    {
        _startPos = transform.position;

        Player player = FindObjectOfType<Player>();
        if (player != null)
        {
            _playerTransform = player.transform;
            _inventory       = player.GetComponent<Inventory>();
        }

        _audioSource = gameObject.AddComponent<AudioSource>();
        _audioSource.spatialBlend = 1f;
        _audioSource.playOnAwake  = false;

        // If we have a definition, use its name/icon
        if (definition != null)
        {
            itemName = definition.itemName;
            itemIcon = definition.icon;
        }
    }

    void Update()
    {
        if (_collected) return;

        // ── Spin ──────────────────────────────
        transform.Rotate(Vector3.up, spinSpeed * Time.deltaTime, Space.World);

        // ── Bob ───────────────────────────────
        float newY = _startPos.y + Mathf.Sin(Time.time * bobSpeed * Mathf.PI * 2f) * bobHeight;
        transform.position = new Vector3(transform.position.x, newY, transform.position.z);

        // ── Pickup check ─────────────────────
        if (_playerTransform == null) return;

        float dist = Vector3.Distance(transform.position, _playerTransform.position);
        _inRange = dist <= pickupRadius;

        if (_inRange && Input.GetKeyDown(pickupKey))
            Collect();
    }

    void OnGUI()
    {
        if (_collected || !_inRange) return;

        // World-to-screen prompt
        Vector3 screenPos = Camera.main != null
            ? Camera.main.WorldToScreenPoint(_startPos + Vector3.up * (bobHeight + 0.4f))
            : Vector3.zero;

        if (screenPos.z < 0) return; // behind camera

        float sx = screenPos.x;
        float sy = Screen.height - screenPos.y; // flip y

        string label  = definition != null ? definition.itemName : itemName;
        bool isWeapon = definition != null && definition.type == ItemDefinition.ItemType.Weapon;
        string prompt = $"[{pickupKey}] Pick up {label}";

        GUIStyle bg = new GUIStyle(GUI.skin.box);
        bg.fontSize  = 12;
        bg.fontStyle = FontStyle.Bold;
        bg.normal.textColor = isWeapon ? new Color(1f, 0.85f, 0.2f) : Color.white;

        Vector2 size    = bg.CalcSize(new GUIContent(prompt));
        Rect    bgRect  = new Rect(sx - size.x * 0.5f - 6f, sy - size.y - 4f, size.x + 12f, size.y + 6f);

        // Dark backing box
        Color prev = GUI.color;
        GUI.color = new Color(0, 0, 0, 0.65f);
        GUI.DrawTexture(bgRect, Texture2D.whiteTexture);
        GUI.color = prev;

        GUI.Label(bgRect, "  " + prompt + "  ", bg);
    }

    void OnDrawGizmosSelected()
    {
        Gizmos.color = Color.yellow;
        Gizmos.DrawWireSphere(transform.position, pickupRadius);
    }

    void Collect()
    {
        _collected = true;
        _inRange   = false;

        if (_inventory != null)
        {
            if (definition != null)
                _inventory.AddItem(definition, autoEquip: true);
            else
                _inventory.AddItem(itemName, itemIcon);
        }
        else
        {
            Debug.LogWarning("PickupItem: No Inventory found on player!");
        }

        if (pickupParticlesPrefab != null)
            Instantiate(pickupParticlesPrefab, transform.position, Quaternion.identity);

        if (pickupSound != null)
        {
            _audioSource.PlayOneShot(pickupSound);
            Destroy(gameObject, pickupSound.length);
        }
        else
        {
            Destroy(gameObject);
        }
    }
}