using System.Collections.Generic;
using UnityEngine;
using Unity.Cinemachine;
#if ENABLE_INPUT_SYSTEM
using UnityEngine.InputSystem;
#endif

/// <summary>
/// Switches the game between high-level modes. The switch key (Tab) cycles to the next registered
/// mode. The mode set is scoped to the local avatar's <see cref="PlayerRole"/> when it spawns
/// (Hunter: First Person + Paint; Hider: Player Control + Paint + Free Cam); a non-networked scene
/// uses the full set. Attach to a single, persistent scene GameObject.
/// </summary>
[DisallowMultipleComponent]
public class GameModeManager : MonoBehaviour
{
    [Header("Controlled Systems")]
    [Tooltip("Player movement controller. Empty = found automatically.")]
    public PlayerCharacterController player;

    [Tooltip("Third-person orbit camera input. Empty = found automatically.")]
    public ThirdPersonOrbitInput cameraInput;

    [Tooltip("Mesh painter. Empty = found automatically.")]
    public MeshPainter painter;

    [Tooltip("Free-fly spectator camera. Empty = found automatically. Absent = Free Cam is left out of the cycle.")]
    public FreeCamController freeCam;

    [Tooltip("First-person camera. Empty = found automatically. Absent = First Person is left out of the cycle.")]
    public FirstPersonController firstPerson;

    //[Tooltip("Insect / surface-walk controller. Empty = found automatically.")]
    //public InsectController insect;

    [Header("Switching")]
    [Tooltip("Key that cycles to the next mode.")]
#if ENABLE_INPUT_SYSTEM
    public Key switchKey = Key.Tab;
#else
    public KeyCode switchKey = KeyCode.Tab;
#endif

    [Tooltip("Mode active at startup (0 = Player Control).")]
    public int startModeIndex = 0;

    public PlayerCharacterController Player => player;
    public ThirdPersonOrbitInput CameraInput => cameraInput;
    public MeshPainter Painter => painter;
    public FreeCamController FreeCam => freeCam;
    public FirstPersonController FirstPerson => firstPerson;
    //public InsectController Insect => insect;

    /// <summary>Raised after a mode switch finishes (the new mode's Enter has already run).
    /// Argument = the now-active mode. Used by UI (e.g. the paint HUD) to follow the mode.</summary>
    public event System.Action<GameMode> ModeChanged;

    /// <summary>Raised when the painter the HUD should edit changes - i.e. when the local
    /// networked avatar spawns and <see cref="BindLocalPlayer"/> binds its per-avatar painter.
    /// With spawn-on-connect there is no painter at scene start, so the paint HUD follows this
    /// to (re)bind its widgets to the live painter once it exists.</summary>
    public event System.Action<MeshPainter> PainterChanged;

    private readonly List<GameMode> _modes = new List<GameMode>();
    private int _activeIndex = -1;

    /// <summary>The currently active mode (null before startup).</summary>
    public GameMode ActiveMode =>
        (_activeIndex >= 0 && _activeIndex < _modes.Count) ? _modes[_activeIndex] : null;

    private void Awake()
    {
        if (!player) player = FindFirstObjectByType<PlayerCharacterController>();
        if (!cameraInput) cameraInput = FindFirstObjectByType<ThirdPersonOrbitInput>();
        if (!painter) painter = FindFirstObjectByType<MeshPainter>();
        // Include inactive so a freecam rig that starts disabled is still found and wired.
        if (!freeCam) freeCam = FindFirstObjectByType<FreeCamController>(FindObjectsInactive.Include);
        if (!firstPerson) firstPerson = FindFirstObjectByType<FirstPersonController>(FindObjectsInactive.Include);
        //if (!insect) insect = FindFirstObjectByType<InsectController>();

        BuildModes();
    }

    private void Start()
    {
        if (_modes.Count > 0)
            SwitchTo(Mathf.Clamp(startModeIndex, 0, _modes.Count - 1));
    }

    /// <summary>Registers the modes for the current context. Without a role (no networked avatar yet,
    /// or a non-networked scene) the full set is built from whichever rigs are present. With a role the
    /// set is scoped to that side and ordered so index 0 is its intended start mode. Add new modes here.</summary>
    private void BuildModes() => BuildModes(null);

    private void BuildModes(PlayerRole? role)
    {
        _modes.Clear();

        switch (role)
        {
            case PlayerRole.Hunter:
                // Hunter: first person + paint. Index 0 (First Person, if its rig exists) is the start mode.
                if (firstPerson) _modes.Add(new FirstPersonMode());
                _modes.Add(new PaintMode());
                break;

            case PlayerRole.Hider:
                // Hider: third person (player control) + paint + free cam. Index 0 (Player Control) is the start.
                if (player) _modes.Add(new PlayerControlMode());
                _modes.Add(new PaintMode());
                if (freeCam) _modes.Add(new FreeCamMode());
                break;

            default:
                // No role: legacy full set, gated on whichever rigs exist. Player Control only joins when a
                // gravity player is present (player-less pre-spawn stays in Paint, not a dead frozen mode);
                // Free Cam / First Person only when their rigs exist, so non-networked scenes are unchanged.
                if (player) _modes.Add(new PlayerControlMode());
                _modes.Add(new PaintMode());
                if (freeCam) _modes.Add(new FreeCamMode());
                if (firstPerson) _modes.Add(new FirstPersonMode());
                break;
        }

        foreach (var m in _modes)
            m.Bind(this);
    }

    /// <summary>
    /// Binds the scene singletons (this manager, the orbit/first-person cameras, the painter) to the
    /// locally-owned networked player after it spawns, then enters Player Control. Called from
    /// <see cref="NetworkPlayerSetup"/> on the owning client. Before this runs the scene has no player,
    /// so the cycle sits in a player-less mode (Paint); this promotes it once the avatar exists.
    /// </summary>
    public void BindLocalPlayer(PlayerCharacterController localPlayer)
    {
        if (!localPlayer) return;
        player = localPlayer;

        // The painter lives on the player (per-avatar), so bind the local one - UNCONDITIONALLY. On a
        // lobby->match respawn the previous avatar is despawned and the role variant spawned in the same
        // server frame; the old painter is Destroy-pending (still non-null) when this runs, so a
        // `if (!painter)` guard would keep the stale reference and the new avatar's painter would never be
        // mode-toggled - it would paint in every mode. Always re-point to the freshly spawned avatar.
        painter = localPlayer.GetComponentInChildren<MeshPainter>(true);
        PainterChanged?.Invoke(painter);

        Transform camTarget = localPlayer.transform.Find("CameraTarget");

        // Re-point the third-person orbit camera (Cinemachine Follow/LookAt) at the local avatar.
        if (cameraInput)
        {
            var vcam = cameraInput.GetComponent<CinemachineCamera>();
            if (vcam) { vcam.Follow = camTarget; vcam.LookAt = camTarget; }
        }

        if (firstPerson)
            firstPerson.SetPlayer(localPlayer);

        // Tear down the pre-spawn (player-less) mode and rebuild scoped to this avatar's role.
        ActiveMode?.Exit();
        _activeIndex = -1;

        // Lobby/neutral avatar (base Player prefab) -> full mode set; match avatar (Hunter/Hider
        // variant) -> only its role's modes. Baked per prefab, so no replicated-phase timing race.
        var setup = localPlayer.GetComponent<NetworkPlayerSetup>();
        if (setup && setup.ScopedModes)
            BuildModes(setup.Role);
        else
            BuildModes(null);

        // Role lists are ordered so index 0 is the start mode (Hunter -> First Person, Hider -> Player
        // Control); the full lobby set starts at Player Control too.
        SwitchTo(0);
    }

    private void Update()
    {
        if (_modes.Count == 0) return;

        if (WasSwitchPressed())
            SwitchTo((_activeIndex + 1) % _modes.Count);

        ActiveMode?.Tick();
    }

    /// <summary>Activates the mode at <paramref name="index"/> (Exit old, Enter new).</summary>
    public void SwitchTo(int index)
    {
        if (index < 0 || index >= _modes.Count || index == _activeIndex) return;

        ActiveMode?.Exit();
        _activeIndex = index;
        ActiveMode.Enter();

        Debug.Log($"[GameModeManager] Mode -> {ActiveMode.DisplayName}", this);
        ModeChanged?.Invoke(ActiveMode);
    }

    private bool WasSwitchPressed()
    {
#if ENABLE_INPUT_SYSTEM
        return Keyboard.current != null && Keyboard.current[switchKey].wasPressedThisFrame;
#else
        return Input.GetKeyDown(switchKey);
#endif
    }
}