using Microsoft.AspNetCore.Mvc;
using System.Text;
using System.Text.Json;
using LittleShop.Services;
using LittleShop.Enums;

namespace LittleShop.Controllers;

[ApiController]
[Route("api/silverpay")]
public class SilverPayWebhookController : ControllerBase
{
    private readonly ICryptoPaymentService _cryptoPaymentService;
    private readonly ISilverPayService _silverPayService;
    private readonly IConfiguration _configuration;
    private readonly ILogger<SilverPayWebhookController> _logger;

    public SilverPayWebhookController(
        ICryptoPaymentService cryptoPaymentService,
        ISilverPayService silverPayService,
        IConfiguration configuration,
        ILogger<SilverPayWebhookController> logger)
    {
        _cryptoPaymentService = cryptoPaymentService;
        _silverPayService = silverPayService;
        _configuration = configuration;
        _logger = logger;
    }

    [HttpPost("webhook")]
    public async Task<IActionResult> ProcessWebhook()
    {
        try
        {
            // Read the raw request body
            using var reader = new StreamReader(Request.Body);
            var requestBody = await reader.ReadToEndAsync();

            // Get webhook signature from headers
            var signature = Request.Headers["X-SilverPay-Signature"].FirstOrDefault()
                        ?? Request.Headers["X-Webhook-Signature"].FirstOrDefault();

            if (string.IsNullOrEmpty(signature))
            {
                _logger.LogWarning("SilverPAY webhook received without signature");
                // For development, we might allow unsigned webhooks
                if (!_configuration.GetValue<bool>("SilverPay:AllowUnsignedWebhooks", false))
                {
                    return BadRequest("Missing webhook signature");
                }
            }
            else
            {
                // Validate webhook signature
                var isValid = await _silverPayService.ValidateWebhookAsync(requestBody, signature);
                if (!isValid)
                {
                    _logger.LogWarning("Invalid SilverPAY webhook signature");
                    return BadRequest("Invalid webhook signature");
                }
            }

            // Parse webhook data
            var webhookData = JsonSerializer.Deserialize<SilverPayWebhookData>(requestBody, new JsonSerializerOptions
            {
                PropertyNameCaseInsensitive = true,
                PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower
            });

            if (webhookData == null)
            {
                _logger.LogWarning("Unable to parse SilverPAY webhook data");
                return BadRequest("Invalid webhook data");
            }

            _logger.LogInformation("Processing SilverPAY webhook: OrderId={OrderId}, Status={Status}, TxHash={TxHash}, Confirmations={Confirmations}",
                webhookData.OrderId, webhookData.Status, webhookData.TxHash, webhookData.Confirmations);

            // Process the webhook based on status
            var success = await ProcessWebhookEvent(webhookData);

            if (!success)
            {
                return BadRequest("Failed to process webhook");
            }

            return Ok(new { status = "received", processed = true });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error processing SilverPAY webhook");
            return StatusCode(500, "Internal server error");
        }
    }

    [HttpPost("webhook/{provider}")]
    public async Task<IActionResult> ProcessProviderWebhook(string provider)
    {
        // This endpoint handles provider-specific webhooks from SilverPAY
        // (e.g., notifications from specific blockchain APIs)
        try
        {
            using var reader = new StreamReader(Request.Body);
            var requestBody = await reader.ReadToEndAsync();

            _logger.LogInformation("Received SilverPAY provider webhook from {Provider}", provider);
            _logger.LogDebug("Provider webhook payload: {Payload}", requestBody);

            // For now, just acknowledge receipt
            // The actual processing would depend on the provider's format
            return Ok(new { status = "received", provider });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error processing SilverPAY provider webhook from {Provider}", provider);
            return StatusCode(500, "Internal server error");
        }
    }

    private async Task<bool> ProcessWebhookEvent(SilverPayWebhookData webhookData)
    {
        try
        {
            // Map SilverPAY status to our payment status
            var paymentStatus = MapSilverPayStatus(webhookData.Status);

            if (!paymentStatus.HasValue)
            {
                _logger.LogInformation("Ignoring SilverPAY webhook status: {Status}", webhookData.Status);
                return true; // Not an error, just not a status we care about
            }

            // Process the payment update
            var success = await _cryptoPaymentService.ProcessSilverPayWebhookAsync(
                webhookData.OrderId,
                paymentStatus.Value,
                webhookData.Amount,
                webhookData.TxHash,
                webhookData.Confirmations);

            if (success)
            {
                _logger.LogInformation("Successfully processed SilverPAY webhook for order {OrderId} with status {Status}",
                    webhookData.OrderId, paymentStatus.Value);
            }
            else
            {
                _logger.LogWarning("Failed to process SilverPAY webhook for order {OrderId}", webhookData.OrderId);
            }

            return success;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error processing SilverPAY webhook event for order {OrderId}", webhookData.OrderId);
            return false;
        }
    }

    private static PaymentStatus? MapSilverPayStatus(string status)
    {
        return status?.ToLowerInvariant() switch
        {
            "pending" => PaymentStatus.Pending,
            "waiting" => PaymentStatus.Pending,
            "unconfirmed" => PaymentStatus.Processing,
            "confirming" => PaymentStatus.Processing,
            "partially_paid" => PaymentStatus.Processing,
            "paid" => PaymentStatus.Paid,
            "confirmed" => PaymentStatus.Completed,
            "completed" => PaymentStatus.Completed,
            "expired" => PaymentStatus.Expired,
            "failed" => PaymentStatus.Failed,
            "cancelled" => PaymentStatus.Failed,
            _ => null // Unknown status
        };
    }

    // Internal class for JSON deserialization
    private class SilverPayWebhookData
    {
        public string OrderId { get; set; } = string.Empty;
        public string ExternalId { get; set; } = string.Empty;
        public string Status { get; set; } = string.Empty;
        public string Address { get; set; } = string.Empty;
        public string? TxHash { get; set; }
        public decimal Amount { get; set; }
        public int Confirmations { get; set; }
        public int? BlockHeight { get; set; }
        public DateTime Timestamp { get; set; }
        public string? Currency { get; set; }
        public Dictionary<string, object>? PaymentDetails { get; set; }
    }
}