using System.Collections.Generic;

using UnityEditor;
using UnityEditor.UIElements;

using UnityEngine;
using UnityEngine.Audio;
using UnityEngine.UIElements;

namespace Prototype.Editor
{
	public class AudioMixerWindow : EditorWindow
	{
		[MenuItem("Tools/Audio Mixer")]
		static void Init()
		{
			GetWindow<AudioMixerWindow>().titleContent = new("Audio Mixer");
		}

		AudioMixerGroup audioMixerGroup;

		List<SoundEffect> soundEffects;

		readonly List<(SoundEffect soundEffect, VisualElement element)> soundEffectTracks = new();

		void OnEnable()
		{
			audioMixerGroup = null;

			soundEffects = null;

			RefreshLayout();
		}

		void RefreshLayout()
		{
			var root = AssetDatabase.LoadAssetAtPath<VisualTreeAsset>(
				AssetDatabase.GUIDToAssetPath(
					AssetDatabase.FindAssets(
						$"t:{nameof(VisualTreeAsset)} {nameof(AudioMixerWindow)}"
					)[0]
				)
			).Instantiate();

			rootVisualElement.Clear();
			rootVisualElement.Add(root);

			root.StretchToParentSize();

			root.Q<ObjectField>().RegisterValueChangedCallback(x =>
			{
				audioMixerGroup = x.newValue as AudioMixerGroup;
				RefreshTracksVisibility();
			});
		}

		void OnInspectorUpdate()
		{
			var refreshTracksVisibility = false;

			if (soundEffects is null)
			{
				soundEffects = new();

				foreach (var guid in AssetDatabase.FindAssets($"t:{nameof(SoundEffect)}"))
				{
					soundEffects.Add(
						AssetDatabase.LoadAssetAtPath<SoundEffect>(
							AssetDatabase.GUIDToAssetPath(guid)
						)
					);
				}

				RefreshSoundEffectTracks();
				refreshTracksVisibility = true;
			}

			if (refreshTracksVisibility)
				RefreshTracksVisibility();
		}

		void RefreshSoundEffectTracks()
		{
			soundEffectTracks.Clear();

			if (soundEffects is not null)
			{
				foreach (var soundEffect in soundEffects)
				{
					var track = new VisualElement();
					track.AddToClassList("track");
					var applyButton = new Button(soundEffect.ApplyVolumeMultiplierFactor)
					{
						text = "Apply"
					};
					applyButton.AddToClassList("accent");
					track.Add(applyButton);
					track.Add(
						new AudioMixerSliderGUI
						{
							@object = soundEffect,
							propertyPath = "volumeMultiplierFactor",
							valueRange = new Vector2(0, 2),
							defaultValue = 1
						}
					);
					track.Add(
						new Label(
							soundEffect.name
								.Replace(" (Sound Effect)", "")
								.Replace(" - BGM", "")
								.Replace(" - SFX", "")
						)
					);
					track.Add(
						new Button(() => Selection.activeObject = soundEffect)
						{
							text = "Select"
						}
					);
					soundEffectTracks.Add((soundEffect, track));
				}
			}
		}

		void RefreshTracksVisibility()
		{
			var content = rootVisualElement.Q<ScrollView>().contentContainer;
			content.Clear();

			foreach (var (soundEffect, track) in soundEffectTracks)
			{
				if (audioMixerGroup &&
					audioMixerGroup != soundEffect.audioMixerGroup)
				{
					continue;
				}
				content.Add(track);
			}
		}
	}
}