using System;
using System.Net.Http;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using AcaMate.V1.Models;
using Version = System.Version;

public class ApnsPushService
{
    private readonly string _uri;
    private readonly string _p12Path;
    private readonly string _p12PWPath;
    private readonly string _apnsTopic;
    

    public ApnsPushService(string uri,string p12Path, string p12PWPath, string apnsTopic)
    {
        _uri = uri ?? throw new ArgumentNullException(nameof(uri));
        _p12Path = p12Path ?? throw new ArgumentNullException(nameof(p12Path));
        _p12PWPath = p12PWPath ?? throw new ArgumentNullException(nameof(p12PWPath));
        _apnsTopic = apnsTopic ?? throw new ArgumentNullException(nameof(apnsTopic));
    }

    public async Task<APIResult> SendPushNotificationAsync(string deviceToken, Payload payload)
    {
        
        // 존재 안하면 예외 던져 버리는거
        if (!File.Exists(_p12PWPath))
        {
            Console.WriteLine($"File not found: {_p12PWPath}");
            return new APIResult
            {
                Success = false ,
                Code = "003",
                Message = "서버 오류 : p12 PW 파일 확인 필요"
            };
        }
        
        var jsonPayload = JsonSerializer.Serialize(payload);
        
        var keys = JsonSerializer.Deserialize<Dictionary<string, string>>(File.ReadAllText(_p12PWPath));
        var p12Password = keys["Password"];

        try
        {
            var certificate = new X509Certificate2(_p12Path, p12Password);
            Console.WriteLine($"Certificate Subject: {certificate.Subject}");
            Console.WriteLine($"Certificate Issuer: {certificate.Issuer}");
        
            var handler = new HttpClientHandler();
            handler.ClientCertificates.Add(certificate);
            handler.SslProtocols = System.Security.Authentication.SslProtocols.Tls12;

            using var client = new HttpClient(handler)
            {
                BaseAddress = new Uri(_uri),
                Timeout = TimeSpan.FromSeconds(60)
            };

            var request = new HttpRequestMessage(HttpMethod.Post, $"/3/device/{deviceToken}")
            {
                Content = new StringContent(jsonPayload, Encoding.UTF8, "application/json"),
                Version = new Version(2, 0) // HTTP/2 사용
            };

            // 필수 헤더 추가
            request.Headers.Add("apns-topic", _apnsTopic);
            request.Headers.Add("apns-push-type", "alert");
            
            Console.WriteLine($"Send -> Payload: {jsonPayload}");

            var response = await client.SendAsync(request);
            
            if (response.IsSuccessStatusCode)
            {
                return new APIResult
                {
                    Success = true
                };
            }
            else
            {
                var errorContent = await response.Content.ReadAsStringAsync();
                return new APIResult
                {
                    Success = false,
                    Code = "003",
                    Message = $"APN 통신 실패 = {response.StatusCode} : {errorContent}"
                };
            }
        }
        catch (HttpRequestException httpEx)
        {
            Console.WriteLine($"HttpRequestException: {httpEx.Message}");
            return new APIResult
            { 
                Success = false,
                Code = "003",
                Message = $"통신 실패 : {httpEx.Message}"
            };
        }
        
        catch (CryptographicException ex)
        {
            return new APIResult
            { 
                Success = false,
                Code = "999",
                Message = $"오류 발생 : {ex.Message}"
            };
        }
        
        catch (Exception ex)
        {
            return new APIResult
            { 
                Success = false,
                Code = "999",
                Message = $"오류 발생 : {ex.Message}"
            };
        }
    }
}