using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using StardewModdingAPI.Toolkit.Serialization;
using StardewModdingAPI.Utilities;

namespace StardewModdingAPI.Framework.Serialization
{
    /// <summary>Handles deserialization of <see cref="Keybind"/> and <see cref="KeybindList"/> models.</summary>
    internal class KeybindConverter : JsonConverter
    {
        /*********
        ** Accessors
        *********/
        /// <inheritdoc />
        public override bool CanRead { get; } = true;

        /// <inheritdoc />
        public override bool CanWrite { get; } = true;


        /*********
        ** Public methods
        *********/
        /// <summary>Get whether this instance can convert the specified object type.</summary>
        /// <param name="objectType">The object type.</param>
        public override bool CanConvert(Type objectType)
        {
            return
                typeof(Keybind).IsAssignableFrom(objectType)
                || typeof(KeybindList).IsAssignableFrom(objectType);
        }

        /// <summary>Reads the JSON representation of the object.</summary>
        /// <param name="reader">The JSON reader.</param>
        /// <param name="objectType">The object type.</param>
        /// <param name="existingValue">The object being read.</param>
        /// <param name="serializer">The calling serializer.</param>
        public override object ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
        {
            string path = reader.Path;

            switch (reader.TokenType)
            {
                case JsonToken.Null:
                    return objectType == typeof(Keybind)
                        ? new Keybind()
                        : new KeybindList();

                case JsonToken.String:
                    {
                        string? str = JToken.Load(reader).Value<string>();

                        if (str is null)
                            return new Keybind(Array.Empty<SButton>());

                        if (objectType == typeof(Keybind))
                        {
                            return Keybind.TryParse(str, out Keybind? parsed, out string[] errors)
                                ? parsed
                                : throw new SParseException($"Can't parse {nameof(Keybind)} from invalid value '{str}' (path: {path}).\n{string.Join("\n", errors)}");
                        }
                        else
                        {
                            return KeybindList.TryParse(str, out KeybindList? parsed, out string[] errors)
                                ? parsed
                                : throw new SParseException($"Can't parse {nameof(KeybindList)} from invalid value '{str}' (path: {path}).\n{string.Join("\n", errors)}");
                        }
                    }

                default:
                    throw new SParseException($"Can't parse {objectType} from unexpected {reader.TokenType} node (path: {reader.Path}).");
            }
        }

        /// <summary>Writes the JSON representation of the object.</summary>
        /// <param name="writer">The JSON writer.</param>
        /// <param name="value">The value.</param>
        /// <param name="serializer">The calling serializer.</param>
        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
        {
            writer.WriteValue(value?.ToString());
        }
    }
}