using System.Net.Mail;
using System.Security.Cryptography;
using StalwartSimpleLoginMiddleware.Entities;
using StalwartSimpleLoginMiddleware.Models;

namespace StalwartSimpleLoginMiddleware.Utilities;

public class ApiKeyHelper
{
    public static string GenerateKey()
    {
        var key = new byte[64];
        using (var generator = RandomNumberGenerator.Create())
            generator.GetBytes(key);
        return Convert.ToBase64String(key);
    }

    public static DbApiKey CreateDbApiKey(ApiKey dbKey)
    {
        return new DbApiKey
        {
            Key = dbKey.Key,
            OwnerName = dbKey.OwnerEmail,
            Claims = ClaimsHelper.BuildClaims(dbKey)
        };
    }

    public static KeyMetadata CreateKeyMetadata(ApiKey dbKey)
    {
        return new KeyMetadata
        {
            Domain = GetEmailDomain(dbKey.OwnerEmail),
            Members = GetMembers(dbKey, false),
            ExternalMembers = GetMembers(dbKey, true)
        };
    }

    public static ICollection<string> GetMembers(ApiKey dbKey, bool isExternal)
    {
        var members = dbKey.Members.Where(m => m.IsExternal == isExternal)
            .Select(m => m.Email);

        if (!isExternal)
        {
            return members.Append(dbKey.OwnerEmail)
                .ToArray();
        }

        return members.ToArray();
    }

    public static string GetEmailDomain(string email)
    {
        if (string.IsNullOrEmpty(email))
        {
            throw new ArgumentException("Email cannot be null or empty.", nameof(email));
        }

        if (MailAddress.TryCreate(email, out var address))
        {
            return address.Host;
        }

        throw new ArgumentException($"Invalid email format: {email}", nameof(email));
    }
}