using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


using ServerCore; using ServerBase;


namespace ServerBase;

public abstract class EntityTicker : EntityBase, ITaskTicker
{
    private double m_tick_interval_milliseconds;

    private PeriodicTaskTimer? m_timer_nullable;

    private readonly CancellationTokenSource m_cancel_token;

    private readonly bool m_is_cancel_by_self;

    public EntityTicker( EntityType entityType
                       , double onTickIntervalMilliseconds, CancellationTokenSource? toCancelToken ) 
        : base(entityType) 
    {
        m_tick_interval_milliseconds = onTickIntervalMilliseconds;

        if(null == toCancelToken)
        {
            m_cancel_token = new();
            m_is_cancel_by_self = true;
        }
        else
        {
            m_cancel_token = toCancelToken;
            m_is_cancel_by_self = false;
        }
    }

    public EntityTicker(EntityType entityType, EntityBase parent, Int32 onTickIntervalMilliseconds, CancellationTokenSource toCancelToken)
        : base(entityType, parent)
    {
        m_tick_interval_milliseconds = onTickIntervalMilliseconds;

        if(null == toCancelToken)
        {
            m_cancel_token = new();
            m_is_cancel_by_self = true;
        }
        else
        {
            m_cancel_token = toCancelToken;
            m_is_cancel_by_self = false;
        }
    }
    
    public override async Task<Result> onInit()
    {
        return await onCreateTask();
    }

    public virtual async Task<Result> onCreateTask()
    {
        await Task.CompletedTask;

        var result = new Result();

        try
        {
            m_timer_nullable = new PeriodicTaskTimer( GetType().Name
                                                    , getOnTickIntervalMilliseconds()
                                                    , getCancelToken(), onTaskTick );
        }
        catch(Exception e)
        {
            var err_msg = $"Exception !!!, new PeriodicTaskTimer() : exception:{e} - {toBasicString()}";
            result.setFail(ServerErrorCode.TryCatchException, err_msg);

            return result;
        }

        return result;
    }

    public abstract Task onTaskTick();

    public async Task onTaskWait()
    {
        if (m_timer_nullable != null)
            await m_timer_nullable.getTask();
    }            

    public void cancel()
    {
        if(true == m_is_cancel_by_self)
        {
            m_timer_nullable?.cancelTimer();
        }
    }

    public double getOnTickIntervalMilliseconds() => m_tick_interval_milliseconds;

    public CancellationTokenSource getCancelToken() => m_cancel_token;

    public PeriodicTaskTimer? getPeriodicTaskTimer() => m_timer_nullable;
}