using UnityEngine;
using Lean.Common;

namespace Lean.Touch
{
    /// <summary>This component can be added alongside the <b>LeanTouch</b> component to add simulated multi touch controls using the mouse and keyboard.</summary>
    [ExecuteInEditMode]
	[DisallowMultipleComponent]
	[RequireComponent(typeof(LeanTouch))]
	[HelpURL(LeanTouch.HelpUrlPrefix + "LeanTouchSimulator")]
	[AddComponentMenu(LeanTouch.ComponentPathPrefix + "Touch Simulator")]
    public class LeanTouchSimulator : MonoBehaviour
    {
        /// <summary>This allows you to set which key is required to simulate multi key twisting.</summary>
		public KeyCode PinchTwistKey { set { pinchTwistKey = value; } get { return pinchTwistKey; } } [SerializeField] private KeyCode pinchTwistKey = KeyCode.LeftControl;

		/// <summary>This allows you to set which key is required to change the pivot point of the pinch twist gesture.</summary>
		public KeyCode MovePivotKey { set { movePivotKey = value; } get { return movePivotKey; } } [SerializeField] private KeyCode movePivotKey = KeyCode.LeftAlt;

		/// <summary>This allows you to set which key is required to simulate multi key dragging.</summary>
		public KeyCode MultiDragKey { set { multiDragKey = value; } get { return multiDragKey; } } [SerializeField] private KeyCode multiDragKey = KeyCode.LeftAlt;

		/// <summary>This allows you to set which texture will be used to show the simulated fingers.</summary>
		public Texture2D FingerTexture { set { fingerTexture = value; } get { return fingerTexture; } } [SerializeField] private Texture2D fingerTexture;

		// The current pivot (0,0 = bottom left, 1,1 = top right)
		private Vector2 pivot = new Vector2(0.5f, 0.5f);

		[System.NonSerialized]
		private LeanTouch cachedTouch;

#if UNITY_EDITOR
		protected virtual void Reset()
		{
			// Set the finger texture?
			if (FingerTexture == null)
			{
				var guids = UnityEditor.AssetDatabase.FindAssets("FingerVisualization t:texture2d");

				if (guids.Length > 0)
				{
					var path = UnityEditor.AssetDatabase.GUIDToAssetPath(guids[0]);

					FingerTexture = UnityEditor.AssetDatabase.LoadMainAssetAtPath(path) as Texture2D;
				}
			}
		}
#endif

		protected virtual void OnEnable()
		{
			cachedTouch = GetComponent<LeanTouch>();

			cachedTouch.OnSimulateFingers += HandleSimulateFingers;
		}

		protected virtual void OnDisable()
		{
			cachedTouch.OnSimulateFingers -= HandleSimulateFingers;
		}

		protected virtual void OnGUI()
		{
			// Show simulated multi fingers?
			if (FingerTexture != null)
			{
				var count = 0;

				foreach (var finger in LeanTouch.Fingers)
				{
					if (finger.Index < 0 && finger.Index != LeanTouch.HOVER_FINGER_INDEX)
					{
						count += 1;
					}
				}

				if (count > 1)
				{
					foreach (var finger in LeanTouch.Fingers)
					{
						// Simulated fingers have a negative index
						if (finger.Index < 0)
						{
							var screenPosition = finger.ScreenPosition;
							var screenRect     = new Rect(0, 0, FingerTexture.width, FingerTexture.height);

							screenRect.center = new Vector2(screenPosition.x, Screen.height - screenPosition.y);

							GUI.DrawTexture(screenRect, FingerTexture);
						}
					}
				}
			}
		}

		private void HandleSimulateFingers()
		{
			// Simulate pinch & twist?
			if (LeanInput.GetMouseExists() == true && LeanInput.GetKeyboardExists() == true)
			{
				var mousePosition = LeanInput.GetMousePosition();
				var mouseSet      = false;
				var mouseUp       = false;

				for (var i = 0; i < 5; i++)
				{
					mouseSet |= LeanInput.GetMousePressed(i);
					mouseUp  |= LeanInput.GetMouseUp(i);
				}

				if (mouseSet == true || mouseUp == true)
				{
					if (LeanInput.GetPressed(MovePivotKey) == true)
					{
						pivot.x = mousePosition.x / Screen.width;
						pivot.y = mousePosition.y / Screen.height;
					}

					if (LeanInput.GetPressed(PinchTwistKey) == true)
					{
						var center = new Vector2(Screen.width * pivot.x, Screen.height * pivot.y);

						cachedTouch.AddFinger(-2, center - (mousePosition - center), 1.0f, mouseSet);
					}
					// Simulate multi drag?
					else if (LeanInput.GetPressed(MultiDragKey) == true)
					{
						cachedTouch.AddFinger(-2, mousePosition, 1.0f, mouseSet);
					}
				}
			}
		}
    }
}

#if UNITY_EDITOR
namespace Lean.Touch.Editor
{
	using TARGET = LeanTouchSimulator;

	[UnityEditor.CanEditMultipleObjects]
	[UnityEditor.CustomEditor(typeof(TARGET))]
	public class LeanTouchSimulator_Editor : LeanEditor
	{
		static LeanTouchSimulator_Editor()
		{
			LeanTouch_Editor.OnExtendInspector += HandleExtendInspector;
		}

		protected override void OnInspector()
		{
			TARGET tgt; TARGET[] tgts; GetTargets(out tgt, out tgts);

			Draw("pinchTwistKey", "This allows you to set which key is required to simulate multi key twisting.");
			Draw("movePivotKey", "This allows you to set which key is required to change the pivot point of the pinch twist gesture.");
			Draw("multiDragKey", "This allows you to set which key is required to simulate multi key dragging.");
			Draw("fingerTexture", "This allows you to set which texture will be used to show the simulated fingers.");
		}

		private static void HandleExtendInspector(LeanTouch touch)
		{
			if (touch.GetComponent<LeanTouchSimulator>() == null)
			{
				if (GUILayout.Button("Add Simulator") == true)
				{
					UnityEditor.Undo.AddComponent<LeanTouchSimulator>(touch.gameObject);
				}
			}
		}
	}
}
#endif