using UnityEngine;
using UnityEngine.UI;
using System;
using System.Collections;
using System.Collections.Generic;
using UltraCombos;

namespace uc
{
    public class ActivityManager : MonoBehaviour
    {
        [Header("General")]
        public Activity initialActivity;
        Stack<Activity> activity_history = new Stack<Activity>();
        public virtual Activity current_activity { get { return (activity_history.Count > 0) ? activity_history.Peek() : null; } }
        public bool isIdleMode = false;

        protected const string module = "<color=maroon>Activity Manager</color>";
        
        void Start()
        {
            PushActivity(initialActivity);
            Misc.Verbose(module, string.Format("init with activity: {0}", current_activity.name));
        }

        void Update()
        {
            CheckIdle();
        }

        protected void CheckIdle()
        {
            if (current_activity != null && isIdleMode)
            {
                if (current_activity.isIdle)
                    PopToInitial();
            }
        }


        #region PUSH
        public virtual void PushActivity(Activity newActivity)
        {
            if (newActivity == null)
                return;

            if (current_activity != null)
            {
                current_activity.Leave();
            }
            activity_history.Push(Clone(newActivity));
            current_activity.Enter();
        }
        #endregion

        #region POP
        public virtual void PopToActivity(Activity targetActivity)
        {
            if (targetActivity != null)
            {
                while (current_activity.source != targetActivity && activity_history.Count > 1)
                {
                    current_activity.Killed();
                    activity_history.Pop();
                }
            }
            else
            {
                if (activity_history.Count > 1)
                {
                    current_activity.Killed();
                    activity_history.Pop();
                }
            }
            current_activity.Enter();
        }

        public virtual void PopActivity()
        {
            PopToActivity(null);
        }

        public virtual void PopToInitial()
        {
            PopToActivity(initialActivity);
        }
        #endregion

        Activity Clone(Activity newActivity)
        {
            var obj = Instantiate(newActivity.gameObject);
            obj.transform.SetParent(transform, false);
            Activity act = obj.GetComponent<Activity>();
            act.source = newActivity;
            return act;
        }
    }
}