using Nuuru.Server.Services;

namespace Nuuru.Server.Middleware
{
    public class IpBanCheckMiddleware
    {
        private readonly RequestDelegate _next;
        private readonly ILogger<IpBanCheckMiddleware> _logger;

        private static readonly HashSet<string> MutatingMethods = new(StringComparer.OrdinalIgnoreCase)
        {
            "POST", "PUT", "DELETE", "PATCH"
        };

        public IpBanCheckMiddleware(RequestDelegate next, ILogger<IpBanCheckMiddleware> logger)
        {
            _next = next;
            _logger = logger;
        }

        public async Task InvokeAsync(HttpContext context, IIpBanService ipBanService)
        {
            // Only block mutating methods — reads always pass through
            if (!MutatingMethods.Contains(context.Request.Method))
            {
                await _next(context);
                return;
            }

            var ip = context.Connection.RemoteIpAddress?.ToString();
            if (string.IsNullOrEmpty(ip))
            {
                await _next(context);
                return;
            }

            var path = context.Request.Path.Value ?? string.Empty;
            if (path.StartsWith("/api/Moderation/ip-bans/mine", StringComparison.OrdinalIgnoreCase) ||
                path.StartsWith("/api/Moderation/ip-bans/appeals", StringComparison.OrdinalIgnoreCase))
            {
                await _next(context);
                return;
            }

            if (await ipBanService.IsIpBannedAsync(ip))
            {
                var ban = await ipBanService.GetActiveIpBanAsync(ip);
                _logger.LogWarning("IP-banned address {IpAddress} attempted {Method} {Path}",
                    ip, context.Request.Method, context.Request.Path);

                context.Response.StatusCode = StatusCodes.Status403Forbidden;
                context.Response.ContentType = "application/json";
                await context.Response.WriteAsJsonAsync(new
                {
                    error = "Your IP address is banned",
                    reason = ban?.Reason,
                    until = ban?.EndTime == DateTime.MaxValue ? (DateTime?)null : ban?.EndTime,
                    type = "ip_ban",
                    banId = ban?.Id
                });
                return;
            }

            await _next(context);
        }
    }
}