// Copyright (c) Pixel Crushers. All rights reserved.

using UnityEngine;
using System.Collections;

namespace PixelCrushers.DialogueSystem.SequencerCommands
{
    
    /// <summary>
    /// Implements sequencer command: AudioWaitOnce(audioClip[, subject[, audioClips...]])
    /// This command will check for an internal lua variable of the entrytag/audioclip name, and 
    /// if it exists/is true, the audio will be skipped. after one playback, the variable
    /// will be created and marked as true.
	/// Contributed by Franklin Kester.
    /// </summary>
    [AddComponentMenu("")] // Hide from menu.
    public class SequencerCommandAudioWaitOnce : SequencerCommand
    {
        static private string _VarPrefix = "once_";
        private float _stopTime = 0;
        private AudioSource _audioSource = null;
        private int _nextClipIndex = 2;
        private AudioClip _currentClip = null;
        private AudioClip _originalClip = null;
		private bool _restoreOriginalClip = false; // Don't restore original; could stop next entry's AudioWait that runs same frame.
        protected bool isLoadingAudio = false;

        public IEnumerator Start()
        {
            string audioClipName = GetParameter(0);

            Transform subject = GetSubject(1);
            _nextClipIndex = 2;

            if (audioClipName == null || audioClipName.Length < 1)
            {
                if (DialogueDebug.logWarnings)
                {
                    Debug.LogWarningFormat("{0}: Sequencer: AudioWaitOnce(): no audio clip name given", DialogueDebug.Prefix);
                }
                if (!this.hasNextClip()) { Stop(); }
            }
            
            if (DialogueDebug.logInfo)
            {
                Debug.LogFormat("{0}: Sequencer: AudioWaitOnce({1}) on {2}", DialogueDebug.Prefix, GetParameters(), subject);
            }

            if (this.hasPlayedAlready(audioClipName))
            {
                if (DialogueDebug.logInfo)
                {
                    Debug.LogFormat("{0}: Sequencer: AudioWaitOnce(): clip {1} already played, skipping", DialogueDebug.Prefix, audioClipName);
                    if (!this.hasNextClip()) { Stop(); }
                }
            }
            
            _audioSource = SequencerTools.GetAudioSource(subject);
            if (_audioSource == null)
            {
                if (DialogueDebug.logWarnings)
                {
                    Debug.LogWarningFormat("{0}: Sequencer: AudioWaitOnce(): can't find or add AudioSource to {1}.", DialogueDebug.Prefix, subject.name );
                }
                //  doesn't matter if we have other clips, no audio source means no play
                Stop();
            }
            else
            {
                _originalClip = _audioSource.clip;
                _stopTime = DialogueTime.time + 1; // Give time for yield return null.
                yield return null;
                _originalClip = _audioSource.clip;
                TryAudioClip(audioClipName);
            }
        }

        private void TryAudioClip(string audioClipName)
        {
            try
            {
                if (string.IsNullOrEmpty(audioClipName))
                {
                    if (DialogueDebug.logWarnings) Debug.LogWarning(string.Format("{0}: Sequencer: AudioWait() command: Audio clip name is blank.", new System.Object[] { DialogueDebug.Prefix }));
                    _stopTime = 0;
                }
                else if (this.hasPlayedAlready(audioClipName))
                {
                    Debug.LogFormat("{0}: Sequencer: AudioWaitOnce(): clip {1} already played, skipping", DialogueDebug.Prefix, audioClipName);
                    _stopTime = DialogueTime.time;
                    //  this prevents stop time from being overwritten below
                    return;
                }
                else
                {
                    isLoadingAudio = true;
                    DialogueManager.LoadAsset(audioClipName, typeof(AudioClip),
                        (asset) =>
                        {
                            isLoadingAudio = false;
                            markAsPlayedAlready(audioClipName);
                            var audioClip = asset as AudioClip;
                            if (audioClip == null)
                            {
                                if (DialogueDebug.logWarnings && Sequencer.reportMissingAudioFiles) Debug.LogWarning(string.Format("{0}: Sequencer: AudioWait() command: Clip '{1}' wasn't found.", new System.Object[] { DialogueDebug.Prefix, audioClipName }));
                                _stopTime = 0;
                            }
                            else
                            {
                                if (IsAudioMuted())
                                {
                                    if (DialogueDebug.logInfo) Debug.Log(string.Format("{0}: Sequencer: AudioWait(): waiting but not playing '{1}'; audio is muted.", new System.Object[] { DialogueDebug.Prefix, audioClipName }));
                                }
                                else if (_audioSource != null) // Check in case AudioSource was destroyed while loading Addressable.
                                {
                                    if (DialogueDebug.logInfo) Debug.Log(string.Format("{0}: Sequencer: AudioWait(): playing '{1}'.", new System.Object[] { DialogueDebug.Prefix, audioClipName }));
                                    _currentClip = audioClip;
                                    _audioSource.clip = audioClip;
                                    _audioSource.Play();
                                }
                                _stopTime = DialogueTime.time + SequencerCommandAudioWait.GetAudioClipLength(_audioSource, audioClip);
                            }
                        });
                }

            }
            catch (System.Exception)
            {
                _stopTime = 0;
            }
        }

        /// <summary>
        /// returns a new string prefixed by the internal _VarPrefix, and appended by given audioClipName
        /// </summary>
        /// <param name="audioClipName">audio clip name to use for append</param>
        /// <returns></returns>
        private string buildOnceVarName(string audioClipName)
        {
            return _VarPrefix + audioClipName;
        }

        /// <summary>
        /// checks for an internal lua variable of the given audio clip name to see if it's been played already.
        /// returns true if yes, false if no or not found
        /// </summary>
        /// <param name="audioClipName">audio clip name to test</param>
        /// <returns></returns>
        private bool hasPlayedAlready(string audioClipName)
        {
            return DialogueLua.GetVariable(this.buildOnceVarName(audioClipName)).asBool;
        }

        /// <summary>
        /// sets the internal variable that dictates the given audio clip was already played
        /// </summary>
        /// <param name="audioClipName"></param>
        private void markAsPlayedAlready(string audioClipName)
        {
            DialogueLua.SetVariable(this.buildOnceVarName(audioClipName), true);
        }

        /// <summary>
        /// checks to see if the next parameter clip index is valid (ie there's another clip waiting to be played)
        /// </summary>
        /// <returns></returns>
        private bool hasNextClip()
        {
            return _nextClipIndex < parameters.Length;
        }

        public void Update()
        {
            if (DialogueTime.time >= _stopTime)
            {
                DialogueManager.UnloadAsset(_currentClip);
                _currentClip = null;
                if (!isLoadingAudio)
                {
                    if (this.hasNextClip())
                    {
                        TryAudioClip(GetParameter(_nextClipIndex));
                        _nextClipIndex++;
                    }
                    else
                    {
                        _currentClip = null;
                        Stop();
                    }
                }
            }
        }

        public void OnDialogueSystemPause()
        {
            if (_audioSource == null) { return; }
            _audioSource.Pause();
        }

        public void OnDialogueSystemUnpause()
        {
            if (_audioSource == null) { return; }
            _audioSource.Play();
        }

        public void OnDestroy()
        {
            if (_audioSource != null)
            {
                if (_audioSource.isPlaying && (_audioSource.clip == _currentClip))
                {
                    _audioSource.Stop();
                }
                if (_restoreOriginalClip) _audioSource.clip = _originalClip;
                DialogueManager.UnloadAsset(_currentClip);
            }
        }

    }

}