using UnityEngine;
using System;
using System.Collections;
using System.Collections.Generic;

/// <summary>
/// Extending MonoBehaviour to add some extra functionality
/// Exception handling from: http://twistedoakstudios.com/blog/Post83_coroutines-more-than-you-want-to-know
/// 
/// 2013 Tim Tregubov
/// </summary>
public class TTMonoBehaviour : MonoBehaviour
{
  private LockQueue LockedCoroutineQueue { get; set; }
          
  /// <summary>
  /// Coroutine with return value AND exception handling on the return value. 
  /// </summary>
  public Coroutine<T> StartCoroutine<T>(IEnumerator coroutine)
  {
      Coroutine<T> coroutineObj = new Coroutine<T>();
      coroutineObj.coroutine = base.StartCoroutine(coroutineObj.InternalRoutine(coroutine));
      return coroutineObj;
  }
  
  /// <summary>
  /// Lockable coroutine. Can either wait for a previous coroutine to finish or a timeout or just bail if previous one isn't done.
  /// Caution: the default timeout is 10 seconds. Coroutines that timeout just drop so if its essential increase this timeout.
  /// Set waitTime to 0 for no wait
  /// </summary>
  public Coroutine<T> StartCoroutine<T>(IEnumerator coroutine, string lockID, float waitTime = 10f)
  {
      if (LockedCoroutineQueue == null) LockedCoroutineQueue = new LockQueue();
      Coroutine<T> coroutineObj = new Coroutine<T>(lockID, waitTime, LockedCoroutineQueue);
      coroutineObj.coroutine = base.StartCoroutine(coroutineObj.InternalRoutine(coroutine));
      return coroutineObj;
  }
  
  /// <summary>
  /// Coroutine with return value AND exception handling AND lockable
  /// </summary>
  public class Coroutine<T>
  {
      private T returnVal;
      private Exception e;
      private string lockID;
      private float waitTime;
      
      private LockQueue lockedCoroutines; //reference to objects lockdict
      private bool lockable;
      
      public Coroutine coroutine;
      public T Value
      {
          get
          {
              if (e != null)
              {
                  throw e;
              }
              return returnVal;
          }
      }
      
      public Coroutine() { lockable = false; }
      public Coroutine(string lockID, float waitTime, LockQueue lockedCoroutines)
      {
          this.lockable = true;
          this.lockID = lockID;
          this.lockedCoroutines = lockedCoroutines;
          this.waitTime = waitTime;
      }
      
      public IEnumerator InternalRoutine(IEnumerator coroutine)
      {
          if (lockable && lockedCoroutines != null)
          {        
              if (lockedCoroutines.Contains(lockID))
              {
                  if (waitTime == 0f)
                  {
                      //Debug.Log(this.GetType().Name + ": coroutine already running and wait not requested so exiting: " + lockID);
                      yield break;
                  }
                  else
                  {
                      //Debug.Log(this.GetType().Name + ": previous coroutine already running waiting max " + waitTime + " for my turn: " + lockID);
                      float starttime = Time.time;
                      float counter = 0f;
                      lockedCoroutines.Add(lockID, coroutine);
                      while (!lockedCoroutines.First(lockID, coroutine) && (Time.time - starttime) < waitTime)
                      {
                          yield return null;
                          counter += Time.deltaTime;
                      }
                      if (counter >= waitTime)
                      {
                          string error = this.GetType().Name + ": coroutine " + lockID + " bailing! due to timeout: " + counter;
                          Debug.LogError(error);
                          this.e = new Exception(error);
                          lockedCoroutines.Remove(lockID, coroutine);
                          yield break;
                      }
                  }
              }
              else
              {
                  lockedCoroutines.Add(lockID, coroutine);
              }
          }
          
          while (true)
          {
              try
              {
                  if (!coroutine.MoveNext())
                  {
                      if (lockable) lockedCoroutines.Remove(lockID, coroutine);
                      yield break;
                  }
              }
              catch (Exception e)
              {
                  this.e = e;
                  Debug.LogError(this.GetType().Name + ": caught Coroutine exception! " + e.Message + "\n" + e.StackTrace);
                  if (lockable) lockedCoroutines.Remove(lockID, coroutine);
                  yield break;
              }
              
              object yielded = coroutine.Current;
              if (yielded != null && yielded.GetType() == typeof(T))
              {
                  returnVal = (T)yielded;
                  if (lockable) lockedCoroutines.Remove(lockID, coroutine);
                  yield break;
              }
              else
              {
                  yield return coroutine.Current;
              }
          }
      }
  }
  
  
  /// <summary>
  /// coroutine lock and queue
  /// </summary>
  public class LockQueue
  {
      private Dictionary<string, List<IEnumerator>> LockedCoroutines { get; set; }
      
      public LockQueue()
      {
          LockedCoroutines = new Dictionary<string, List<IEnumerator>>();
      }
      
      /// <summary>
      /// check if LockID is locked
      /// </summary>
      public bool Contains(string lockID)
      {
          return LockedCoroutines.ContainsKey(lockID);
      }
      
      /// <summary>
      /// check if given coroutine is first in the queue
      /// </summary>
      public bool First(string lockID, IEnumerator coroutine)
      {
          bool ret = false;
          if (Contains(lockID))
          {
              if (LockedCoroutines[lockID].Count > 0)
              {
                  ret = LockedCoroutines[lockID][0] == coroutine;
              }
          }
          return ret;
      }
      
      /// <summary>
      /// Add the specified lockID and coroutine to the coroutine lockqueue
      /// </summary>
      public void Add(string lockID, IEnumerator coroutine)
      {
          if (!LockedCoroutines.ContainsKey(lockID))
          {
              LockedCoroutines.Add(lockID, new List<IEnumerator>());
          }
          
          if (!LockedCoroutines[lockID].Contains(coroutine))
          {
              LockedCoroutines[lockID].Add(coroutine);
          }
      }
      
      /// <summary>
      /// Remove the specified coroutine and queue if empty
      /// </summary>
      public bool Remove(string lockID, IEnumerator coroutine)
      {
          bool ret = false;
          if (LockedCoroutines.ContainsKey(lockID))
          {
              if (LockedCoroutines[lockID].Contains(coroutine))
              {
                  ret = LockedCoroutines[lockID].Remove(coroutine);
              }
              
              if (LockedCoroutines[lockID].Count == 0)
              {
                  ret = LockedCoroutines.Remove(lockID);
              }
          }
          return ret;
      }
      
  }

}