using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using UnityEditor;
using UnityEditor.ProjectWindowCallback;
using UnityEngine;
using XNode;
using Object = UnityEngine.Object;

namespace XNodeEditor
{
    /// <summary> A set of editor-only utilities and extensions for xNode </summary>
    public static class NodeEditorUtilities
    {
        /// <summary>C#'s Script Icon [The one MonoBhevaiour Scripts have].</summary>
        private static readonly Texture2D
            scriptIcon = EditorGUIUtility.IconContent("cs Script Icon").image as Texture2D;

        /// Saves Attribute from Type+Field for faster lookup. Resets on recompiles.
        private static readonly Dictionary<Type, Dictionary<string, Dictionary<Type, Attribute>>> typeAttributes =
            new Dictionary<Type, Dictionary<string, Dictionary<Type, Attribute>>>();

        /// Saves ordered PropertyAttribute from Type+Field for faster lookup. Resets on recompiles.
        private static readonly Dictionary<Type, Dictionary<string, List<PropertyAttribute>>>
            typeOrderedPropertyAttributes = new Dictionary<Type, Dictionary<string, List<PropertyAttribute>>>();

        public static bool GetAttrib<T>(Type classType, out T attribOut) where T : Attribute
        {
            object[] attribs = classType.GetCustomAttributes(typeof(T), false);
            return GetAttrib(attribs, out attribOut);
        }

        public static bool GetAttrib<T>(object[] attribs, out T attribOut) where T : Attribute
        {
            for (int i = 0; i < attribs.Length; i++)
            {
                if (attribs[i] is T)
                {
                    attribOut = attribs[i] as T;
                    return true;
                }
            }

            attribOut = null;
            return false;
        }

        public static bool GetAttrib<T>(Type classType, string fieldName, out T attribOut) where T : Attribute
        {
            // If we can't find field in the first run, it's probably a private field in a base class.
            FieldInfo field = classType.GetFieldInfo(fieldName);
            // This shouldn't happen. Ever.
            if (field == null)
            {
                Debug.LogWarning("Field " + fieldName + " couldnt be found");
                attribOut = null;
                return false;
            }

            object[] attribs = field.GetCustomAttributes(typeof(T), true);
            return GetAttrib(attribs, out attribOut);
        }

        public static bool HasAttrib<T>(object[] attribs) where T : Attribute
        {
            for (int i = 0; i < attribs.Length; i++)
            {
                if (attribs[i].GetType() == typeof(T))
                {
                    return true;
                }
            }

            return false;
        }

        public static bool GetCachedAttrib<T>(Type classType, string fieldName, out T attribOut) where T : Attribute
        {
            Dictionary<string, Dictionary<Type, Attribute>> typeFields;
            if (!typeAttributes.TryGetValue(classType, out typeFields))
            {
                typeFields = new Dictionary<string, Dictionary<Type, Attribute>>();
                typeAttributes.Add(classType, typeFields);
            }

            Dictionary<Type, Attribute> typeTypes;
            if (!typeFields.TryGetValue(fieldName, out typeTypes))
            {
                typeTypes = new Dictionary<Type, Attribute>();
                typeFields.Add(fieldName, typeTypes);
            }

            Attribute attr;
            if (!typeTypes.TryGetValue(typeof(T), out attr))
            {
                if (GetAttrib(classType, fieldName, out attribOut))
                {
                    typeTypes.Add(typeof(T), attribOut);
                    return true;
                }

                typeTypes.Add(typeof(T), null);
            }

            if (attr == null)
            {
                attribOut = null;
                return false;
            }

            attribOut = attr as T;
            return true;
        }

        public static List<PropertyAttribute> GetCachedPropertyAttribs(Type classType, string fieldName)
        {
            Dictionary<string, List<PropertyAttribute>> typeFields;
            if (!typeOrderedPropertyAttributes.TryGetValue(classType, out typeFields))
            {
                typeFields = new Dictionary<string, List<PropertyAttribute>>();
                typeOrderedPropertyAttributes.Add(classType, typeFields);
            }

            List<PropertyAttribute> typeAttributes;
            if (!typeFields.TryGetValue(fieldName, out typeAttributes))
            {
                FieldInfo field = classType.GetFieldInfo(fieldName);
                object[] attribs = field.GetCustomAttributes(typeof(PropertyAttribute), true);
                typeAttributes = attribs.Cast<PropertyAttribute>().Reverse().ToList(); //Unity draws them in reverse
                typeFields.Add(fieldName, typeAttributes);
            }

            return typeAttributes;
        }

        public static bool IsMac()
        {
#if UNITY_2017_1_OR_NEWER
            return SystemInfo.operatingSystemFamily == OperatingSystemFamily.MacOSX;
#else
            return SystemInfo.operatingSystem.StartsWith("Mac");
#endif
        }

        /// <summary> Returns true if this can be casted to <see cref="Type" /></summary>
        public static bool IsCastableTo(this Type from, Type to)
        {
            if (to.IsAssignableFrom(from))
            {
                return true;
            }

            var methods = from.GetMethods(BindingFlags.Public | BindingFlags.Static)
                .Where(
                    m => m.ReturnType == to &&
                         (m.Name == "op_Implicit" ||
                          m.Name == "op_Explicit")
                );
            return methods.Count() > 0;
        }

        /// <summary>
        ///     Looking for ports with value Type compatible with a given type.
        /// </summary>
        /// <param name="nodeType">Node to search</param>
        /// <param name="compatibleType">Type to find compatiblities</param>
        /// <param name="direction"></param>
        /// <returns>True if NodeType has some port with value type compatible</returns>
        public static bool HasCompatiblePortType(Type nodeType, Type compatibleType,
            NodePort.IO direction = NodePort.IO.Input)
        {
            Type findType = typeof(Node.InputAttribute);
            if (direction == NodePort.IO.Output)
            {
                findType = typeof(Node.OutputAttribute);
            }

            //Get All fields from node type and we go filter only field with portAttribute.
            //This way is possible to know the values of the all ports and if have some with compatible value tue
            foreach (FieldInfo f in NodeDataCache.GetNodeFields(nodeType))
            {
                object portAttribute = f.GetCustomAttributes(findType, false).FirstOrDefault();
                if (portAttribute != null)
                {
                    if (IsCastableTo(f.FieldType, compatibleType))
                    {
                        return true;
                    }
                }
            }

            return false;
        }

        /// <summary>
        ///     Filter only node types that contains some port value type compatible with an given type
        /// </summary>
        /// <param name="nodeTypes">List with all nodes type to filter</param>
        /// <param name="compatibleType">Compatible Type to Filter</param>
        /// <returns>Return Only Node Types with ports compatible, or an empty list</returns>
        public static List<Type> GetCompatibleNodesTypes(Type[] nodeTypes, Type compatibleType,
            NodePort.IO direction = NodePort.IO.Input)
        {
            //Result List
            var filteredTypes = new List<Type>();

            //Return empty list
            if (nodeTypes == null)
            {
                return filteredTypes;
            }

            if (compatibleType == null)
            {
                return filteredTypes;
            }

            //Find compatiblity
            foreach (Type findType in nodeTypes)
            {
                if (HasCompatiblePortType(findType, compatibleType, direction))
                {
                    filteredTypes.Add(findType);
                }
            }

            return filteredTypes;
        }


        /// <summary> Return a prettiefied type name. </summary>
        public static string PrettyName(this Type type)
        {
            if (type == null)
            {
                return "null";
            }

            if (type == typeof(object))
            {
                return "object";
            }

            if (type == typeof(float))
            {
                return "float";
            }

            if (type == typeof(int))
            {
                return "int";
            }

            if (type == typeof(long))
            {
                return "long";
            }

            if (type == typeof(double))
            {
                return "double";
            }

            if (type == typeof(string))
            {
                return "string";
            }

            if (type == typeof(bool))
            {
                return "bool";
            }

            if (type.IsGenericType)
            {
                string s = "";
                Type genericType = type.GetGenericTypeDefinition();
                if (genericType == typeof(List<>))
                {
                    s = "List";
                }
                else
                {
                    s = type.GetGenericTypeDefinition().ToString();
                }

                var types = type.GetGenericArguments();
                string[] stypes = new string[types.Length];
                for (int i = 0; i < types.Length; i++)
                {
                    stypes[i] = types[i].PrettyName();
                }

                return s + "<" + string.Join(", ", stypes) + ">";
            }

            if (type.IsArray)
            {
                string rank = "";
                for (int i = 1; i < type.GetArrayRank(); i++)
                {
                    rank += ",";
                }

                Type elementType = type.GetElementType();
                if (!elementType.IsArray)
                {
                    return elementType.PrettyName() + "[" + rank + "]";
                }

                {
                    string s = elementType.PrettyName();
                    int i = s.IndexOf('[');
                    return s.Substring(0, i) + "[" + rank + "]" + s.Substring(i);
                }
            }

            return type.ToString();
        }

        /// <summary> Returns the default name for the node type. </summary>
        public static string NodeDefaultName(Type type)
        {
            string typeName = type.Name;
            // Automatically remove redundant 'Node' postfix
            if (typeName.EndsWith("Node"))
            {
                typeName = typeName.Substring(0, typeName.LastIndexOf("Node"));
            }

            typeName = ObjectNames.NicifyVariableName(typeName);
            return typeName;
        }

        /// <summary> Returns the default creation path for the node type. </summary>
        public static string NodeDefaultPath(Type type)
        {
            string typePath = type.ToString().Replace('.', '/');
            // Automatically remove redundant 'Node' postfix
            if (typePath.EndsWith("Node"))
            {
                typePath = typePath.Substring(0, typePath.LastIndexOf("Node"));
            }

            typePath = ObjectNames.NicifyVariableName(typePath);
            return typePath;
        }

        /// <summary>Creates a new C# Class.</summary>
        [MenuItem("Assets/Create/xNode/Node C# Script", false, 89)]
        private static void CreateNode()
        {
            string[] guids = AssetDatabase.FindAssets("xNode_NodeTemplate.cs");
            if (guids.Length == 0)
            {
                Debug.LogWarning("xNode_NodeTemplate.cs.txt not found in asset database");
                return;
            }

            string path = AssetDatabase.GUIDToAssetPath(guids[0]);
            CreateFromTemplate(
                "NewNode.cs",
                path
            );
        }

        /// <summary>Creates a new C# Class.</summary>
        [MenuItem("Assets/Create/xNode/NodeGraph C# Script", false, 89)]
        private static void CreateGraph()
        {
            string[] guids = AssetDatabase.FindAssets("xNode_NodeGraphTemplate.cs");
            if (guids.Length == 0)
            {
                Debug.LogWarning("xNode_NodeGraphTemplate.cs.txt not found in asset database");
                return;
            }

            string path = AssetDatabase.GUIDToAssetPath(guids[0]);
            CreateFromTemplate(
                "NewNodeGraph.cs",
                path
            );
        }

        public static void CreateFromTemplate(string initialName, string templatePath)
        {
            ProjectWindowUtil.StartNameEditingIfProjectWindowExists(
                0,
                ScriptableObject.CreateInstance<DoCreateCodeFile>(),
                initialName,
                scriptIcon,
                templatePath
            );
        }

        /// Inherits from EndNameAction, must override EndNameAction.Action
        public class DoCreateCodeFile : EndNameEditAction
        {
            public override void Action(int instanceId, string pathName, string resourceFile)
            {
                Object o = CreateScript(pathName, resourceFile);
                ProjectWindowUtil.ShowCreatedAsset(o);
            }
        }

        /// <summary>Creates Script from Template's path.</summary>
        internal static Object CreateScript(string pathName, string templatePath)
        {
            string className = Path.GetFileNameWithoutExtension(pathName).Replace(" ", string.Empty);
            string templateText = string.Empty;

            UTF8Encoding encoding = new UTF8Encoding(true, false);

            if (File.Exists(templatePath))
            {
                /// Read procedures.
                StreamReader reader = new StreamReader(templatePath);
                templateText = reader.ReadToEnd();
                reader.Close();

                templateText = templateText.Replace("#SCRIPTNAME#", className);
                templateText = templateText.Replace("#NOTRIM#", string.Empty);
                /// You can replace as many tags you make on your templates, just repeat Replace function
                /// e.g.:
                /// templateText = templateText.Replace("#NEWTAG#", "MyText");

                /// Write procedures.

                StreamWriter writer = new StreamWriter(Path.GetFullPath(pathName), false, encoding);
                writer.Write(templateText);
                writer.Close();

                AssetDatabase.ImportAsset(pathName);
                return AssetDatabase.LoadAssetAtPath(pathName, typeof(Object));
            }

            Debug.LogError(string.Format("The template file was not found: {0}", templatePath));
            return null;
        }
    }
}