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

[InitializeOnLoad]
public class MultiTransformClipboard {

    const string ComponentName = "Transform";

    static MultiTransformClipboard()
    {
       EditorApplication.playmodeStateChanged += PlayModeState;
       lastGameMode = EditorApplication.isPlaying;
    }

    static void PlayModeState ()
    {
        if (EditorApplication.isPlaying && !lastGameMode) {
            Clipboard.Clear();
        }
        lastGameMode = EditorApplication.isPlaying;
    }

    private struct TransformClipboard {
        public Vector3?      position;
        public Quaternion?   rotation;
        public Vector3?      scale;
    }

    private static bool lastGameMode = false;
    private static Dictionary<int, TransformClipboard> Clipboard = new Dictionary<int, TransformClipboard>();

    [MenuItem("CONTEXT/"+ComponentName+"/+Copy", true)] static bool AddToCopyQueue() {
        return EditorApplication.isPlaying && ! Clipboard.ContainsKey(Selection.activeGameObject.GetInstanceID());
    }

    [MenuItem("CONTEXT/"+ComponentName+"/+Copy")]
    static void AddToCopyQueueFunc() {
        var tc = new TransformClipboard();
        tc.position = Selection.activeTransform.localPosition;
        tc.rotation = Selection.activeTransform.localRotation;
        tc.scale = Selection.activeTransform.localScale;
        Clipboard.Add(Selection.activeGameObject.GetInstanceID(), tc);
    }

    [MenuItem("CONTEXT/"+ComponentName+"/-Copy", true)]
    static bool RemoveFromCopyQueue() { return EditorApplication.isPlaying  && Clipboard.ContainsKey(Selection.activeGameObject.GetInstanceID()); }

    [MenuItem("CONTEXT/"+ComponentName+"/-Copy")]
    static void RemoveFromCopyQueueFunc() { Clipboard.Remove(Selection.activeGameObject.GetInstanceID()); }

    [MenuItem("CONTEXT/"+ComponentName+"/Paste", true)]
    static bool PasteQueue() { return ! EditorApplication.isPlaying  && Clipboard.ContainsKey(Selection.activeGameObject.GetInstanceID()); }

    [MenuItem("CONTEXT/"+ComponentName+"/Paste")] static void PasteQueueFunc() {
        var tc = Clipboard[Selection.activeGameObject.GetInstanceID()];

        Selection.activeTransform.localPosition = tc.position ?? Selection.activeTransform.localPosition;
        Selection.activeTransform.localRotation = tc.rotation ?? Selection.activeTransform.localRotation;
        Selection.activeTransform.localScale = tc.scale ?? Selection.activeTransform.localScale;
    }

}