// JSON C# Class Generator
// http://www.xamasoft.com/json-class-generator

using Newtonsoft.Json.Linq;

namespace JsonCSharpClassGenerator;

internal static class JsonClassHelper
{

    public static T GetJToken<T>(JObject obj, string field) where T : JToken
    {
        JToken value;
        if (obj.TryGetValue(field, out value))
            return GetJToken<T>(value);
        else
            return null;
    }

    private static T GetJToken<T>(JToken token) where T : JToken
    {
        if (token == null)
            return null;
        if (token.Type == JTokenType.Null)
            return null;
        if (token.Type == JTokenType.Undefined)
            return null;
        return (T)token;
    }

    public static string ReadString(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            return null;
        return (string)value.Value;
    }

    public static bool ReadBoolean(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            throw new Newtonsoft.Json.JsonSerializationException();
        return Convert.ToBoolean(value.Value);

    }

    public static bool? ReadNullableBoolean(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            return null;
        return Convert.ToBoolean(value.Value);
    }

    public static int ReadInteger(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            throw new Newtonsoft.Json.JsonSerializationException();
        return Convert.ToInt32((long)value.Value);

    }

    public static int? ReadNullableInteger(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            return null;
        return Convert.ToInt32((long)value.Value);

    }

    public static long ReadLong(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            throw new Newtonsoft.Json.JsonSerializationException();
        return Convert.ToInt64(value.Value);

    }

    public static long? ReadNullableLong(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            return null;
        return Convert.ToInt64(value.Value);
    }

    public static double ReadFloat(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            throw new Newtonsoft.Json.JsonSerializationException();
        return Convert.ToDouble(value.Value);

    }

    public static double? ReadNullableFloat(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            return null;
        return Convert.ToDouble(value.Value);

    }

    public static DateTime ReadDate(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            throw new Newtonsoft.Json.JsonSerializationException();
        return Convert.ToDateTime(value.Value);

    }

    public static DateTime? ReadNullableDate(JToken token)
    {
        JValue value = GetJToken<JValue>(token);
        if (value == null)
            return null;
        return Convert.ToDateTime(value.Value);

    }

    public static object ReadObject(JToken token)
    {
        JToken value = GetJToken<JToken>(token);
        if (value == null)
            return null;
        if (value.Type == JTokenType.Object)
            return value;
        if (value.Type == JTokenType.Array)
            return ReadArray(value, ReadObject);

        if (value is JValue jvalue)
            return jvalue.Value;

        return value;
    }

    public static T ReadStronglyTypedObject<T>(JToken token) where T : class
    {
        JObject value = GetJToken<JObject>(token);
        if (value == null)
            return null;
        return (T)Activator.CreateInstance(typeof(T), new object[] { token });

    }

    public delegate T ValueReader<T>(JToken token);

    public static T[] ReadArray<T>(JToken token, ValueReader<T> reader)
    {
        JArray value = GetJToken<JArray>(token);
        if (value == null)
            return null;

        T[] array = new T[value.Count];
        for (int i = 0; i < array.Length; i++)
        {
            array[i] = reader(value[i]);
        }
        return array;

    }

    public static Dictionary<string, T> ReadDictionary<T>(JToken token)
    {
        JObject value = GetJToken<JObject>(token);
        if (value == null)
            return null;

        Dictionary<string, T> dict = new();

        return dict;
    }

    public static Array ReadArray<K>(JArray jArray, ValueReader<K> reader, Type type)
    {
        if (jArray == null)
            return null;

        Type elemType = type.GetElementType();

        Array array = Array.CreateInstance(elemType, jArray.Count);
        for (int i = 0; i < array.Length; i++)
        {
            if (elemType.IsArray)
            {
                array.SetValue(ReadArray(GetJToken<JArray>(jArray[i]), reader, elemType), i);
            }
            else
            {
                array.SetValue(reader(jArray[i]), i);
            }

        }
        return array;

    }
}