using System.Runtime.CompilerServices;
using Jint.Native;

namespace Jint.Runtime;

public static class Arguments
{
    public static JsCallArguments Empty => [];

    public static JsValue[] From(params JsValue[] o)
    {
        return o;
    }

    /// <summary>
    /// Returns the arguments at the provided position or Undefined if not present
    /// </summary>
    /// <param name="args"></param>
    /// <param name="index">The index of the parameter to return</param>
    /// <param name="undefinedValue">The value to return is the parameter is not provided</param>
    /// <returns></returns>
    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static JsValue At(this JsValue[] args, int index, JsValue undefinedValue)
    {
        return (uint) index < (uint) args.Length ? args[index] : undefinedValue;
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static JsValue At(this JsValue[] args, int index)
    {
        return At(args, index, JsValue.Undefined);
    }

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    public static JsCallArguments Skip(this JsValue[] args, int count)
    {
        var newLength = args.Length - count;
        if (newLength <= 0)
        {
            return [];
        }

        var array = new JsValue[newLength];
        Array.Copy(args, count, array, 0, newLength);
        return array;
    }
}