using System;
using Unity.Netcode;
using UnityEngine;

public enum RoundPhase : byte
{
    WaitingForPlayers,
    DayInProgress,
    WaitingForPlayersToReturn
}

[RequireComponent(typeof(NetworkObject))]
public sealed class RoundGameLoopController : NetworkBehaviour
{
    [Header("Day")]
    [SerializeField, Min(1f)] private float dayDurationSeconds = 300f;
    [SerializeField, Min(0.05f)] private float timerSyncInterval = 0.1f;

    private readonly NetworkVariable<RoundPhase> phase = new(
        RoundPhase.WaitingForPlayers,
        NetworkVariableReadPermission.Everyone,
        NetworkVariableWritePermission.Server);

    private readonly NetworkVariable<int> dayNumber = new(
        0,
        NetworkVariableReadPermission.Everyone,
        NetworkVariableWritePermission.Server);

    private readonly NetworkVariable<float> remainingDaySeconds = new(
        0f,
        NetworkVariableReadPermission.Everyone,
        NetworkVariableWritePermission.Server);

    private StartRoomZone startRoom;
    private float dayEndTime;
    private float nextTimerSyncTime;

    public RoundPhase Phase => phase.Value;
    public int DayNumber => dayNumber.Value;
    public float RemainingDaySeconds => remainingDaySeconds.Value;

    public event Action<RoundPhase> PhaseChanged;
    public event Action<int> DayStarted;
    public event Action<float> DayTimerChanged;

    public override void OnNetworkSpawn()
    {
        phase.OnValueChanged += HandlePhaseChanged;
        dayNumber.OnValueChanged += HandleDayNumberChanged;
        remainingDaySeconds.OnValueChanged += HandleTimerChanged;

        startRoom = FindFirstObjectByType<StartRoomZone>();

        if (IsServer)
        {
            phase.Value = RoundPhase.WaitingForPlayers;
            remainingDaySeconds.Value = 0f;
        }
    }

    public override void OnNetworkDespawn()
    {
        phase.OnValueChanged -= HandlePhaseChanged;
        dayNumber.OnValueChanged -= HandleDayNumberChanged;
        remainingDaySeconds.OnValueChanged -= HandleTimerChanged;
    }

    private void Update()
    {
        if (!IsServer)
            return;

        if (startRoom == null)
            startRoom = FindFirstObjectByType<StartRoomZone>();

        if (startRoom == null || Time.time < nextTimerSyncTime)
            return;

        nextTimerSyncTime = Time.time + timerSyncInterval;

        switch (phase.Value)
        {
            case RoundPhase.WaitingForPlayers:
            case RoundPhase.WaitingForPlayersToReturn:
                if (AreAllPlayersInStartRoom())
                    StartNextDay();
                break;

            case RoundPhase.DayInProgress:
                float secondsLeft = Mathf.Max(0f, dayEndTime - Time.time);
                remainingDaySeconds.Value = secondsLeft;

                if (secondsLeft <= 0f)
                {
                    phase.Value = RoundPhase.WaitingForPlayersToReturn;
                    remainingDaySeconds.Value = 0f;
                }
                break;
        }
    }

    private bool AreAllPlayersInStartRoom()
    {
        if (NetworkManager == null || NetworkManager.ConnectedClients.Count == 0)
            return false;

        foreach (NetworkClient client in NetworkManager.ConnectedClients.Values)
        {
            if (client.PlayerObject == null || !startRoom.Contains(client.PlayerObject.transform.position))
                return false;
        }

        return true;
    }

    private void StartNextDay()
    {
        dayNumber.Value++;
        dayEndTime = Time.time + dayDurationSeconds;
        remainingDaySeconds.Value = dayDurationSeconds;
        phase.Value = RoundPhase.DayInProgress;
    }

    private void HandlePhaseChanged(RoundPhase _, RoundPhase current) =>
        PhaseChanged?.Invoke(current);

    private void HandleDayNumberChanged(int _, int current) =>
        DayStarted?.Invoke(current);

    private void HandleTimerChanged(float _, float current) =>
        DayTimerChanged?.Invoke(current);
}