Config

/* Format example
Master {
    ClientConnection {
        ListenIP = 0.0.0.0
        ListenPort = 25000
        Backlog = 32
        MaxInactiveTime1 = 600.0
        MaxInactiveTime2 = 900.0
        }

    LoginServerConnection {
        IP = 127.0.0.1
        Port = 26000
        }

    DB {
        Data Source = example.net
        Port = 3306
        Database = example_db
        User Id = userid
        Password = pwd
        }
}
*/

public class ConfigObject
    {
        protected ConfigObject()
        {
            Name = "<root>";
            Parent = null;
        }
        public ConfigObject(string name, ConfigObject parent)
        {
            Name = name;
            Parent = parent;
        }
        private Dictionary<string, ConfigObject> Objects { get; } = new Dictionary<string, ConfigObject>();
        private Dictionary<string, string> Data { get; } = new Dictionary<string, string>();
        public string Name { get; }
        public ConfigObject Parent { get; }

        public IEnumerable<ConfigObject> AllObjects => Objects.Values;
        public IEnumerable<string> AllObjectNames => Objects.Keys;
        public bool ContainsObject(string name) => Objects.ContainsKey(name);
        public ConfigObject GetObject(string name)
        {
            ConfigObject o;
            return Objects.TryGetValue(name, out o) ? o : null;
        }
        public ConfigObject AddNewObject(string name)
        {
            var o = new ConfigObject(name, this);
            Objects[name] = o;
            return o;
        }
        public ConfigObject GetOrCreateObject(string name)
        {
            return GetObject(name) ?? AddNewObject(name);
        }
        public bool RemoveObject(string name)
        {
            return Objects.Remove(name);
        }
        public void RemoveAllObjects() => Objects.Clear();


        public IEnumerable<string> AllFields => Data.Values;
        public IEnumerable<string> AllFieldNames => Data.Keys;
        public bool ContainsField(string name) => Data.ContainsKey(name);
        public string GetStringField(string name, string defaultValue = null)
        {
            string v;
            return Data.TryGetValue(name, out v) ? v : defaultValue;
        }
        public long GetIntField(string name, long defaultValue = 0)
        {
            var svalue = GetStringField(name);
            if (string.IsNullOrWhiteSpace(svalue))
                return defaultValue;
            long value;
            if (long.TryParse(svalue, out value))
                return value;
            if (long.TryParse(svalue, NumberStyles.HexNumber, CultureInfo.CurrentCulture, out value))
                return value;
            return defaultValue;
        }
        public double GetFloatField(string name, double defaultValue = 0)
        {
            var svalue = GetStringField(name);
            if (string.IsNullOrWhiteSpace(svalue))
                return defaultValue;
            double value;
            return double.TryParse(svalue, out value) ? value : defaultValue;
        }
        public bool GetBoolField(string name, bool defaultValue = false)
        {
            var sv = GetStringField(name).ToLowerInvariant().Trim();
            switch (sv)
            {
                case "true":
                case "yes":
                case "y":
                case "t":
                    return true;
                case "false":
                case "no":
                case "n":
                case "f":
                    return false;
            }
            var iv = GetIntField(name, defaultValue ? 1 : 0);
            return iv != 0;
        }

        public void SetField(string name, object value)
        {
            Data[name] = value.ToString();
        }
        protected internal void SaveTo(StreamWriter w)
        {
            w.WriteLine(Name + " {");

            foreach (var name in AllObjectNames)
            {
                GetObject(name).SaveTo(w);
            }
            w.WriteLine();
            foreach (var name in AllFieldNames)
            {
                w.WriteLine($"{name} = {GetStringField(name)}");
            }

            w.WriteLine("}");
        }

        public override string ToString()
        {
            var o = this;
            var s = Name;
            o = o.Parent;
            while (o?.Parent != null)
            {
                s = $"{o.Name}." + s;
                o = o.Parent;
            }
            return s;
        }

        public ConfigObject ResolveObject(string name)
        {
            var id = name.IndexOf(".", StringComparison.Ordinal);
            if (id < 0)
                return GetObject(name.Trim());

            var obj = GetObject(name.Substring(0, id).Trim());
            return obj?.ResolveObject(name.Substring(id + 1).Trim());
        }
        public ConfigObject ResolveOrCreateObject(string name)
        {
            var id = name.IndexOf(".", StringComparison.Ordinal);
            if (id < 0)
                return GetOrCreateObject(name.Trim());

            var obj = GetOrCreateObject(name.Substring(0, id).Trim());
            return obj.ResolveOrCreateObject(name.Substring(id + 1).Trim());
        }
        public object Resolve(string name)
        {
            var id = name.IndexOf(".", StringComparison.Ordinal);
            if (id < 0)
                return (object) GetObject(name.Trim()) ?? GetStringField(name.Trim());

            var obj = GetObject(name.Substring(0, id).Trim());
            return obj?.Resolve(name.Substring(id + 1).Trim());
        }
    }

public class Config : ConfigObject
    {
        public Config(StreamReader r)
        {
            var stack = new Stack<ConfigObject>();
            ConfigObject currentObj = this;
            while (!r.EndOfStream)
            {
                var str = r.ReadLine();
                if (string.IsNullOrWhiteSpace(str) || str.Trim().StartsWith("//"))
                    continue;
                str = str.Trim();
                if (str.EndsWith("{"))
                {
                    stack.Push(currentObj);
                    var path = str.Substring(0, str.Length-1).Trim();
                    currentObj = currentObj.ResolveOrCreateObject(path);
                    continue;
                }
                if (str.StartsWith("}"))
                {
                    currentObj = stack.Any() ? stack.Pop() : this;
                    continue;
                }

                var id = str.IndexOf("=", StringComparison.Ordinal);
                if (id < 0)
                    continue;
                var key = str.Substring(0, id).Trim();
                var value = str.Substring(id + 1).Trim();
                var keyPath = key.Split('.');
                var obj = currentObj;
                for (int i = 0; i < keyPath.Length-1; i++)
                {
                    var name = keyPath[i].Trim();
                    if (string.IsNullOrWhiteSpace(str))
                        continue;
                    obj = obj.GetOrCreateObject(name);
                }
                obj.SetField(keyPath.Last(), value);
            }
        }
        public void Save(StreamWriter w)
        {
            w.WriteLine("// Root fields");
            foreach (var name in AllFieldNames)
            {
                w.WriteLine($"{name} = {GetStringField(name)}");
            }
            foreach (var name in AllObjectNames)
            {
                w.WriteLine();
                GetObject(name).SaveTo(w);
            }
        }
    }