using Microsoft.AspNetCore.Mvc;
using System.Security.Cryptography;
using System.Text;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace MegghysAPI.Controllers
{
    public class DnsRecord
    {
        [JsonPropertyName("name")]
        public string Name { get; set; } = string.Empty;
        
        [JsonPropertyName("type")]
        public int Type { get; set; }
        
        [JsonPropertyName("TTL")]
        public int Ttl { get; set; }
        
        [JsonPropertyName("data")]
        public string Data { get; set; } = string.Empty;
    }

    public class DnsResponse
    {
        public class DnsQuestion
        {
            public string Name { get; set; }
            public int type { get; set; }
        }
        [JsonPropertyName("Status")]
        public int Status { get; set; }
        
        [JsonPropertyName("TC")]
        public bool Tc { get; set; }
        
        [JsonPropertyName("RD")]
        public bool Rd { get; set; }
        
        [JsonPropertyName("RA")]
        public bool Ra { get; set; }
        
        [JsonPropertyName("AD")]
        public bool Ad { get; set; }
        
        [JsonPropertyName("CD")]
        public bool Cd { get; set; }
        
        [JsonPropertyName("Question")]
        public DnsQuestion Question { get; set; }
        
        [JsonPropertyName("Answer")]
        public List<DnsRecord>? Answer { get; set; }
    }

    [Route("api/public")]
    [ApiController]
    public class PublicController : MControllerBase
    {
        private static readonly HttpClient _httpClient = new();

        private static string CalculateKey(string accountId, string akSecret, long timestamp, string qname, string akId)
        {
            var input = $"{accountId}{akSecret}{timestamp}{qname}{akId}";
            using var sha256 = SHA256.Create();
            var hashBytes = sha256.ComputeHash(Encoding.UTF8.GetBytes(input));
            return BitConverter.ToString(hashBytes).Replace("-", "").ToLower();
        }

        [HttpGet("resolve-dns")]
        public async Task<IActionResult> ResolveDns([FromQuery] string domain, [FromQuery] string recordType = "A")
        {
            try
            {
                var config = Config.Instance;
                var accountId = config.DnsResolverAccountId;
                var akId = config.DnsResolverAkId;
                var akSecret = config.DnsResolverAkSecret;
                var endpoint = config.DnsResolverEndpoint;

                if (string.IsNullOrEmpty(accountId) || string.IsNullOrEmpty(akId) || string.IsNullOrEmpty(akSecret) || string.IsNullOrEmpty(endpoint))
                {
                    return new BadRequestObjectResult("DNS解析配置不完整。");
                }

                var timestamp = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
                var key = CalculateKey(accountId, akSecret, timestamp, domain, akId);

                var url = $"{endpoint}?name={Uri.EscapeDataString(domain)}&type={recordType}&uid={accountId}&ak={akId}&key={key}&ts={timestamp}";

                Logs.Info($"正在向 {url} 发起DNS请求");

                var response = await _httpClient.GetAsync(url);
                response.EnsureSuccessStatusCode();

                var content = await response.Content.ReadAsStringAsync();
                var dnsResponse = JsonSerializer.Deserialize<DnsResponse>(content);

                return new OkObjectResult(dnsResponse);
            }
            catch (Exception ex)
            {
                Logs.Error($"解析DNS记录时出错: {ex.Message}");
                return new StatusCodeResult(500);
            }
        }
        [HttpGet("header")]
        public IActionResult Header(bool? order = false)
        {
            var headers = Request.Headers.Select(h => $"{h.Key}: {h.Value}");
            if (order == true)
            {
                headers = headers.OrderBy(h => h);
            }
            return Ok(string.Join(Environment.NewLine, headers));
        }
    }
}