namespace QRScript.Extensions;

using System.Text;

/// <summary>
/// Provides extension methods for common string transformations and validations.
/// </summary>
public static class StringExtensions
{
    /// <summary>
    /// Encodes the current string instance to Base64 using Unicode encoding.
    /// </summary>
    /// <param name="input">The input string to encode.</param>
    /// <returns>A Base64-encoded version of the input string.</returns>
    /// <remarks>
    /// This uses Unicode (UTF-16) encoding, which is standard in .NET strings.
    /// </remarks>
    public static string ToBase64(this string input)
    {
        if (input is null)
            throw new ArgumentNullException(nameof(input));

        byte[] bytes = Encoding.Unicode.GetBytes(input);
        return Convert.ToBase64String(bytes);
    }

    /// <summary>
    /// Joins an array of strings into a single string separated by the system's newline.
    /// </summary>
    /// <param name="lines">Array of strings to join.</param>
    /// <returns>A single string composed of all input lines, separated by newlines.</returns>
    public static string JoinLines(this IEnumerable<string> lines)
    {
        if (lines is null)
            throw new ArgumentNullException(nameof(lines));

        return string.Join(Environment.NewLine, lines);
    }

    /// <summary>
    /// Determines whether the string exceeds the specified character length limit.
    /// </summary>
    /// <param name="text">The input string to evaluate.</param>
    /// <param name="limit">The maximum number of allowed characters.</param>
    /// <returns><c>true</c> if the string's length is greater than or equal to <paramref name="limit"/>; otherwise, <c>false</c>.</returns>
    public static bool ExceedsLengthLimit(this string text, int limit)
    {
        if (text is null)
            throw new ArgumentNullException(nameof(text));

        if (limit < 0)
            throw new ArgumentOutOfRangeException(nameof(limit), "Limit must be non-negative.");

        return text.Length >= limit;
    }
}