using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading.Tasks;
using LanDiscovery.Models;

namespace LanDiscovery.Services
{
    public class ExportService
    {
        public async Task ExportToCsvAsync(IEnumerable<DiscoveredDevice> devices, string filePath)
        {
            var sb = new StringBuilder();
            sb.AppendLine("IP Address,MAC Address,Vendor,Hostname,Type,Ping (ms),Status,First Seen,Last Seen");

            foreach (var device in devices)
            {
                sb.AppendLine($"{device.IpAddress},{device.MacAddress},{Escape(device.Vendor)},{Escape(device.Hostname)},{device.DeviceTypeHint},{device.PingMs},{(device.IsPingAlive ? "Online" : "Unknown")},{device.FirstSeen},{device.LastSeen}");
            }

            await File.WriteAllTextAsync(filePath, sb.ToString());
        }

        private string Escape(string? input)
        {
            if (string.IsNullOrEmpty(input)) return "";
            if (input.Contains(",") || input.Contains("\"") || input.Contains("\n"))
            {
                return $"\"{input.Replace("\"", "\"\"")}\"";
            }
            return input;
        }
    }
}