using Ashi.MongoInterface.Service;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.RateLimiting;
using Microsoft.Extensions.Caching.Memory;
using Microsoft.Extensions.Options;
using MongoDB.Driver;
using Submission.Api.Dto;
using Submission.Api.Models;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace Submission.Api.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    public class SignController : ControllerBase
    {

        private readonly IMongoRepository<Author> _authorRepository;
        private readonly IMongoRepository<PetitionDetail> _detailRepository;
        private readonly IMongoRepository<Signature> _signatureRepository;
        private readonly IMemoryCache _cache;
        public readonly TurnstileService _turnstileService;

        public SignController(
            IMongoRepository<Author> authorRepository,
            IMongoRepository<PetitionDetail> detailRepository,
            IMongoRepository<Signature> signatureRepository,
            IMemoryCache cache, TurnstileService turnstileService)
        {
            _authorRepository = authorRepository;
            _detailRepository = detailRepository;
            _signatureRepository = signatureRepository;
            _cache = cache;
            _turnstileService = turnstileService;
        }

        [HttpPost("petition/{petition_id}", Name = "SignPetition")]
        [EnableRateLimiting("SignPetitionPolicy")]
        public async Task<IActionResult> SignDisHoe([FromRoute] Guid petition_id, [FromBody] WidgetsDto body)
        {
            var remoteip = HttpContext.Request.Headers["CF-Connecting-IP"].FirstOrDefault() ??
                   HttpContext.Request.Headers["X-Forwarded-For"].FirstOrDefault() ??
                   HttpContext.Connection.RemoteIpAddress?.ToString();

            if (body.turnstileToken == null)
                return BadRequest("Turnstile token is missing");

            Console.WriteLine("Token received: " + body.turnstileToken);

            var validation = await _turnstileService.ValidateTokenAsync(body.turnstileToken, remoteip);

            if (validation.Success)
            {
                //why??
                var cacheKey = $"petition_{petition_id}";

                var pet = await _detailRepository.FindByIdAsync(petition_id);

                if (pet == null)
                    return NotFound();

                //TODO : add svg validation 
                //fuck i still havent done this


                //check to see if the same person signed the petition already
                //if dupe send error saying user already signed 
                var dupe = await _signatureRepository.FindOneAsync(x => x.IdCard == body.IdCard);
                if (dupe != null)
                    return Problem("You already signed this petition");

                //add signature to the db
                await _signatureRepository.InsertOneAsync(new Signature
                {
                    IdCard = body.IdCard,
                    Name = body.Name,
                    Signature_SVG = body.Signature,
                    Timestamp = DateTime.Now,
                    PetitionId = petition_id
                });

                //update signature count 
                if (pet.SignatureCount == null)
                {
                    pet.SignatureCount = 0;
                }

                var count_update_filter = Builders<PetitionDetail>.Filter.Eq("_id", petition_id);
                var Countupdate = Builders<PetitionDetail>.Update.Inc("SignatureCount", 1);
                await _detailRepository.UpdateOneAsync(count_update_filter, Countupdate);

                _cache.Remove(cacheKey);

                return Ok("your signature has been submitted");
            }
            else
            {
                // Invalid token - reject submission
                // Make joining error codes null-safe to avoid ArgumentNullException
                var errorCodes = validation?.ErrorCodes;
                var errors = (errorCodes != null && errorCodes.Length > 0)
                    ? string.Join(", ", errorCodes)
                    : "unknown";
                return BadRequest($"Verification failed: {errors}");
            }
        }

        [HttpGet("petition/{petition_id}", Name = "GetPetition")]
        public async Task<IActionResult> GetDisHoe([FromRoute] Guid petition_id)
        {
            var cacheKey = $"petition_{petition_id}";

            // Try to get from cache
            if (_cache.TryGetValue(cacheKey, out PetitionDetailsDto cachedDto))
            {
                return Ok(cachedDto);
            }

            // Not in cache, fetch from database
            var pet = await _detailRepository.FindByIdAsync(petition_id);

            if (pet == null)
                return NotFound();

            var author = await _authorRepository.FindOneAsync(x => x.Id == pet.AuthorId);

            var dto = new PetitionDetailsDto
            {
                Id = petition_id,
                NameDhiv = pet.NameDhiv,
                StartDate = pet.StartDate,
                NameEng = pet.NameEng,
                PetitionBodyDhiv = pet.PetitionBodyDhiv,
                PetitionBodyEng = pet.PetitionBodyEng,

                AuthorDetails = new AuthorsDto
                {
                    Name = author.Name,
                    NID = author.NID,
                },

                SignatureCount = pet.SignatureCount
            };

            // Store in cache with 5 minute expiration
            var cacheOptions = new MemoryCacheEntryOptions()
                .SetAbsoluteExpiration(TimeSpan.FromHours(1));

            _cache.Set(cacheKey, dto, cacheOptions);

            return Ok(dto);
        }
    }


    #region Turnstile Service
    public class TurnstileSettings
    {
        public string SecretKey { get; set; } = string.Empty;
    }

    public class TurnstileService
    {
        private readonly HttpClient _httpClient;
        private readonly string _secretKey;
        private const string SiteverifyUrl = "https://challenges.cloudflare.com/turnstile/v0/siteverify";

        public TurnstileService(HttpClient httpClient, IOptions<TurnstileSettings> options)
        {
            _httpClient = httpClient;
            _secretKey = options?.Value?.SecretKey ?? throw new ArgumentNullException(nameof(options), "Turnstile:SecretKey must be configured in appsettings.json");
        }

        public async Task<TurnstileResponse> ValidateTokenAsync(string token, string remoteip = null)
        {
            var parameters = new Dictionary<string, string>
            {
                { "secret", _secretKey },
                { "response", token }
            };

            if (!string.IsNullOrEmpty(remoteip))
            {
                parameters.Add("remoteip", remoteip);
            }

            var postContent = new FormUrlEncodedContent(parameters);

            try
            {
                var response = await _httpClient.PostAsync(SiteverifyUrl, postContent);
                var stringContent = await response.Content.ReadAsStringAsync();

                Console.WriteLine("Turnstile response: " + stringContent);

                // deserialize with case-insensitive option; mapping for "error-codes" is handled by attribute on ErrorCodes
                var options = new JsonSerializerOptions { PropertyNameCaseInsensitive = true };
                return JsonSerializer.Deserialize<TurnstileResponse>(stringContent, options);
            }
            catch (Exception)
            {
                return new TurnstileResponse
                {
                    Success = false,
                    ErrorCodes = new[] { "internal-error" }
                };
            }
        }
    }

    public class TurnstileResponse
    {
        [JsonPropertyName("success")]
        public bool Success { get; set; }

        // Cloudflare returns "error-codes" (with a hyphen) — map it explicitly
        [JsonPropertyName("error-codes")]
        public string[] ErrorCodes { get; set; }

        [JsonPropertyName("challenge_ts")]
        public string ChallengeTs { get; set; }

        public string Hostname { get; set; }

        public string Action { get; set; }

        // "cdata" may be present
        public string Cdata { get; set; }

        // metadata is optional and can be an object
        public JsonElement? Metadata { get; set; }
    }
    #endregion
}