using Luna.Identity.Abstractions;

namespace Luna.Identity;

public class PairingCodeGenerator : IPairingCodeGenerator
{
    private const int TimeToLiveMinutes = 5;
    private static readonly char[] CodeAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789".ToCharArray();

    public PairingCode Generate(string channelType, string userId)
        => new(
            Code: GenerateCode(),
            ChannelType: channelType,
            UserId: userId,
            CreatedAt: DateTimeOffset.UtcNow,
            TimeToLive: TimeSpan.FromMinutes(TimeToLiveMinutes));

    private string GenerateCode()
        => new(Enumerable.Range(0, 6)
            .Select(_ => CodeAlphabet[Random.Shared.Next(CodeAlphabet.Length)])
            .ToArray());
}