using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEngine;
using UnityExplorer.UI;
using UnityExplorer.UI.Shared;

namespace UnityExplorer.Inspectors.Reflection
{
    public class CacheMember : CacheObjectBase
    {
        public MemberInfo MemInfo { get; set; }
        public Type DeclaringType { get; set; }
        public object DeclaringInstance { get; set; }

        public virtual bool IsStatic { get; private set; }

        public override bool HasParameters => m_arguments != null && m_arguments.Length > 0;
        public override bool IsMember => true;

        public string RichTextName => m_richTextName ?? GetRichTextName();
        private string m_richTextName;

        public override bool CanWrite => m_canWrite ?? GetCanWrite();
        private bool? m_canWrite;

        public string ReflectionException { get; set; }

        public bool m_evaluated = false;
        public bool m_isEvaluating;
        public ParameterInfo[] m_arguments = new ParameterInfo[0];
        public string[] m_argumentInput = new string[0];

        public CacheMember(MemberInfo memberInfo, object declaringInstance)
        {
            MemInfo = memberInfo;
            DeclaringType = memberInfo.DeclaringType;
            DeclaringInstance = declaringInstance;
        }

        //public virtual void InitMember(MemberInfo member, object declaringInstance)
        //{
        //    MemInfo = member;
        //    DeclaringInstance = declaringInstance;
        //    DeclaringType = member.DeclaringType;
        //}

        public override void UpdateValue()
        {
            base.UpdateValue();
        }

        public override void SetValue()
        {
            // ...
        }

        public object[] ParseArguments()
        {
            if (m_arguments.Length < 1)
            {
                return new object[0];
            }

            var parsedArgs = new List<object>();
            for (int i = 0; i < m_arguments.Length; i++)
            {
                var input = m_argumentInput[i];
                var type = m_arguments[i].ParameterType;

                if (type.IsByRef)
                {
                    type = type.GetElementType();
                }

                if (!string.IsNullOrEmpty(input))
                {
                    if (type == typeof(string))
                    {
                        parsedArgs.Add(input);
                        continue;
                    }
                    else
                    {
                        try
                        {
                            var arg = type.GetMethod("Parse", new Type[] { typeof(string) })
                                          .Invoke(null, new object[] { input });

                            parsedArgs.Add(arg);
                            continue;
                        }
                        catch
                        {
                            ExplorerCore.Log($"Argument #{i} '{m_arguments[i].Name}' ({type.Name}), could not parse input '{input}'.");
                        }
                    }
                }

                // No input, see if there is a default value.
                if (HasDefaultValue(m_arguments[i]))
                {
                    parsedArgs.Add(m_arguments[i].DefaultValue);
                    continue;
                }

                // Try add a null arg I guess
                parsedArgs.Add(null);
            }

            return parsedArgs.ToArray();
        }

        public static bool HasDefaultValue(ParameterInfo arg) => arg.DefaultValue != DBNull.Value;

        //public void DrawArgsInput()
        //{
        //    for (int i = 0; i < this.m_arguments.Length; i++)
        //    {
        //        var name = this.m_arguments[i].Name;
        //        var input = this.m_argumentInput[i];
        //        var type = this.m_arguments[i].ParameterType.Name;

        //        var label = $"<color={SyntaxColors.Class_Instance}>{type}</color> ";
        //        label += $"<color={SyntaxColors.Local}>{name}</color>";
        //        if (HasDefaultValue(this.m_arguments[i]))
        //        {
        //            label = $"<i>[{label} = {this.m_arguments[i].DefaultValue ?? "null"}]</i>";
        //        }

                
        //    }
        //}

        private bool GetCanWrite()
        {
            if (MemInfo is FieldInfo fi)
                m_canWrite = !(fi.IsLiteral && !fi.IsInitOnly);
            else if (MemInfo is PropertyInfo pi)
                m_canWrite = pi.CanWrite;
            else
                m_canWrite = false;

            return (bool)m_canWrite;
        }

        private string GetRichTextName()
        {
            string memberColor = "";
            bool isStatic = false;

            if (MemInfo is FieldInfo fi)
            {
                if (fi.IsStatic)
                {
                    isStatic = true;
                    memberColor = SyntaxColors.Field_Static;
                }
                else
                    memberColor = SyntaxColors.Field_Instance;
            }
            else if (MemInfo is MethodInfo mi)
            {
                if (mi.IsStatic)
                {
                    isStatic = true;
                    memberColor = SyntaxColors.Method_Static;
                }
                else
                    memberColor = SyntaxColors.Method_Instance;
            }
            else if (MemInfo is PropertyInfo pi)
            {
                if (pi.GetAccessors()[0].IsStatic)
                {
                    isStatic = true;
                    memberColor = SyntaxColors.Prop_Static;
                }
                else
                    memberColor = SyntaxColors.Prop_Instance;
            }

            string classColor;
            if (MemInfo.DeclaringType.IsValueType)
            {
                classColor = SyntaxColors.StructGreen;
            }
            else if (MemInfo.DeclaringType.IsAbstract && MemInfo.DeclaringType.IsSealed)
            {
                classColor = SyntaxColors.Class_Static;
            }
            else
            {
                classColor = SyntaxColors.Class_Instance;
            }

            m_richTextName = $"<color={classColor}>{MemInfo.DeclaringType.Name}</color>.";
            if (isStatic) m_richTextName += "<i>";
            m_richTextName += $"<color={memberColor}>{MemInfo.Name}</color>";
            if (isStatic) m_richTextName += "</i>";

            // generic method args
            if (this is CacheMethod cm && cm.GenericArgs.Length > 0)
            {
                m_richTextName += "<";

                var args = "";
                for (int i = 0; i < cm.GenericArgs.Length; i++)
                {
                    if (args != "") args += ", ";
                    args += $"<color={SyntaxColors.StructGreen}>{cm.GenericArgs[i].Name}</color>";
                }
                m_richTextName += args;

                m_richTextName += ">";
            }

            return m_richTextName;
        }
    }
}