using UnityEngine;
using UnityEngine.UI;
using TMPro;
using Ashwild.Network;
using Ashwild.Player;

namespace Ashwild.UI
{
    /// <summary>
    /// Lets the player paste a friend's session code and connect to their room. Validates the
    /// code, launches the join through NetworkSessionManager, and mirrors the connection
    /// progress (connecting / error) from the PlayerEvents bus into an on-screen status line.
    /// </summary>
    public class JoinPanel : UIPanel
    {
        #region Serialized Fields

        [Header("Code")]
        [Tooltip("Where the player types/pastes the host's session code.")]
        [SerializeField] private TMP_InputField codeInput;

        [Header("Buttons")]
        [SerializeField] private Button joinButton;
        [SerializeField] private Button backButton;

        [Header("Feedback")]
        [Tooltip("Shows 'connecting…' / error messages. Optional.")]
        [SerializeField] private TMP_Text statusText;

        #endregion

        #region State

        /// <summary>
        /// True while a connection attempt is in flight (buttons locked, status shown).
        /// </summary>
        private bool isConnecting;

        #endregion

        #region Unity Lifecycle

        /// <summary>
        /// Wires the buttons and submit-on-enter; runs once.
        /// </summary>
        protected override void Awake()
        {
            base.Awake();
            joinButton.onClick.AddListener(AttemptJoin);
            backButton.onClick.AddListener(() => UIManager.Instance.Back());

            if (codeInput != null)
                codeInput.onSubmit.AddListener(_ => AttemptJoin());
        }

        /// <summary>
        /// Subscribes to the session bus and resets the panel each time it is shown.
        /// </summary>
        public override void Show()
        {
            base.Show();

            PlayerEvents.SessionJoining += HandleSessionJoining;
            PlayerEvents.SessionJoined += HandleSessionJoined;
            PlayerEvents.SessionError += HandleSessionError;

            ResetForInput();
        }

        /// <summary>
        /// Unsubscribes — mirrors Show exactly so the panel never reacts while hidden.
        /// </summary>
        public override void Hide()
        {
            PlayerEvents.SessionJoining -= HandleSessionJoining;
            PlayerEvents.SessionJoined -= HandleSessionJoined;
            PlayerEvents.SessionError -= HandleSessionError;

            base.Hide();
        }

        #endregion

        #region Event Handlers

        /// <summary>
        /// Connection attempt reached the transport — show progress.
        /// </summary>
        private void HandleSessionJoining(string code) => SetStatus($"Connexion à {code}…");

        /// <summary>
        /// Connected to the host — the networked scene load takes over from here.
        /// </summary>
        private void HandleSessionJoined() => SetStatus("Connecté ! Chargement…");

        /// <summary>
        /// Connection failed — surface the reason and re-enable input.
        /// </summary>
        private void HandleSessionError(string reason)
        {
            SetStatus(reason);
            isConnecting = false;
            SetInteractable(true);
        }

        #endregion

        #region Internal Helpers

        /// <summary>
        /// Validates the typed code and launches the join through NetworkSessionManager.
        /// </summary>
        private void AttemptJoin()
        {
            if (isConnecting) return;

            string code = codeInput != null ? codeInput.text.Trim() : string.Empty;
            if (string.IsNullOrEmpty(code))
            {
                SetStatus("Entre un code de session.");
                return;
            }

            if (NetworkSessionManager.Instance == null)
            {
                Debug.LogError("[JoinPanel] NetworkSessionManager introuvable — la MenuScene doit contenir le NetworkManager.", this);
                SetStatus("Erreur interne (NetworkManager manquant).");
                return;
            }

            GameSession.Mode = GameSession.LaunchMode.Join;
            GameSession.JoinCode = code;

            isConnecting = true;
            SetInteractable(false);
            SetStatus("Connexion…");

            NetworkSessionManager.Instance.JoinSession(code);
        }

        /// <summary>
        /// Clears the status line and re-enables input — used each time the panel opens.
        /// </summary>
        private void ResetForInput()
        {
            isConnecting = false;
            SetInteractable(true);
            SetStatus(string.Empty);
        }

        /// <summary>
        /// Enables/disables the code field and join button during a connection attempt.
        /// </summary>
        private void SetInteractable(bool interactable)
        {
            if (codeInput != null) codeInput.interactable = interactable;
            if (joinButton != null) joinButton.interactable = interactable;
        }

        /// <summary>
        /// Writes a message to the optional status line.
        /// </summary>
        private void SetStatus(string message)
        {
            if (statusText != null) statusText.text = message;
        }

        #endregion
    }
}