using TMPro;
using UnityEngine;

namespace Ashwild.UI
{
    /// <summary>
    /// Stamps the current build version onto a TextMeshPro label. Reads <see cref="Application.version"/>
    /// (authored in Project Settings ▸ Player ▸ Version) so the displayed string always matches the
    /// real build without anyone editing the scene. Drop this on any UGUI element that carries a
    /// TextMeshProUGUI — typically a small corner label on the main menu, pause or loading canvas.
    /// </summary>
    [DisallowMultipleComponent]
    [RequireComponent(typeof(TextMeshProUGUI))]
    public class VersionLabel : MonoBehaviour
    {
        #region Serialized Fields

        [Header("Target")]
        [Tooltip("The label to write the version into. Auto-filled from this GameObject if left empty.")]
        [SerializeField] private TextMeshProUGUI label;

        [Header("Format")]
        [Tooltip("Wraps the version. Use {0} as the placeholder for Application.version, e.g. \"v{0}\".")]
        [SerializeField] private string format = "v{0}";

        #endregion

        #region Unity Lifecycle

        /// <summary>
        /// Caches the label reference so the component works even when assigned by RequireComponent.
        /// </summary>
        private void Awake()
        {
            if (label == null)
                label = GetComponent<TextMeshProUGUI>();
        }

        /// <summary>
        /// Writes the version each time the object is enabled, so re-opening a menu always shows it.
        /// </summary>
        private void OnEnable()
        {
            Refresh();
        }

        #endregion

        #region Public API

        /// <summary>
        /// Composes the version string from the format and pushes it onto the label. Guards against a
        /// missing label and logs the culprit so the broken object is selectable from the console.
        /// </summary>
        public void Refresh()
        {
            if (label == null)
            {
                Debug.LogError($"[VersionLabel] '{name}' has no TextMeshProUGUI assigned — cannot show version.", this);
                return;
            }

            label.text = string.Format(format, Application.version);
        }

        #endregion
    }
}