diff --git a/EpsonPrintService/ConfigurationLoader.cs b/EpsonPrintService/ConfigurationLoader.cs
new file mode 100644
index 0000000..f14356f
--- /dev/null
+++ b/EpsonPrintService/ConfigurationLoader.cs
@@ -0,0 +1,55 @@
+using Inspectron.Epson.PrintServer.ConfigurationSources;
+
+namespace EpsonPrintService;
+
+public record ConfigLoadResult(bool Success, EpsonPrintServiceConfiguration? Config, string? Error);
+
+public static class ConfigurationLoader
+{
+ public static ConfigLoadResult TryLoadFromBase64(string base64Content)
+ {
+ try
+ {
+ var decoded = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(base64Content.Trim()));
+ var parts = decoded.Split(';');
+ if (parts.Length != 3)
+ return new ConfigLoadResult(false, null, $"Invalid configuration format. Expected 'apiUrl;restaurantId;apiKey', got {parts.Length} parts.");
+
+ var config = new EpsonPrintServiceConfiguration
+ {
+ ApiUrl = parts[0],
+ RestaurantId = parts[1],
+ ApiKey = parts[2]
+ };
+
+ if (string.IsNullOrWhiteSpace(config.ApiUrl) || string.IsNullOrWhiteSpace(config.RestaurantId) || string.IsNullOrWhiteSpace(config.ApiKey))
+ return new ConfigLoadResult(false, null, "Configuration contains empty values.");
+
+ return new ConfigLoadResult(true, config, null);
+ }
+ catch (FormatException)
+ {
+ return new ConfigLoadResult(false, null, "Invalid base64 content.");
+ }
+ }
+
+ public static ConfigLoadResult TryLoadFromFile()
+ {
+ try
+ {
+ var configPath = ConfigurationPaths.GetConfigPath();
+ if (!File.Exists(configPath))
+ return new ConfigLoadResult(false, null, $"Configuration file not found: {configPath}");
+
+ var base64Line = File.ReadAllText(configPath).Trim();
+ if (string.IsNullOrWhiteSpace(base64Line))
+ return new ConfigLoadResult(false, null, "Configuration file is empty.");
+
+ return TryLoadFromBase64(base64Line);
+ }
+ catch (Exception ex)
+ {
+ return new ConfigLoadResult(false, null, $"Failed to read configuration: {ex.Message}");
+ }
+ }
+}
diff --git a/EpsonPrintService/HtmlPageBuilder.cs b/EpsonPrintService/HtmlPageBuilder.cs
new file mode 100644
index 0000000..614ad1c
--- /dev/null
+++ b/EpsonPrintService/HtmlPageBuilder.cs
@@ -0,0 +1,127 @@
+using Inspectron.Epson.PrintServer.ConfigurationSources;
+
+namespace EpsonPrintService;
+
+public static class HtmlPageBuilder
+{
+ public static string BuildConfigPage(
+ EpsonPrintServiceConfiguration? currentConfig,
+ bool printServerRunning,
+ UsbKeyResult? usbResult,
+ string? errorMessage = null)
+ {
+ var statusColor = printServerRunning ? "#2e7d32" : "#e65100";
+ var statusText = printServerRunning ? "Running" : "Not Configured";
+
+ return $@"
+
+
+
+
+Epson Print Server
+
+
+
+Epson Print Server
+
+
+
Status: {statusText}
+ {(currentConfig != null ? $@"
+
+
Restaurant ID: {Escape(currentConfig.RestaurantId)}
+
API URL: {Escape(currentConfig.ApiUrl ?? "(not set)")}
+
" : "")}
+
{Escape(errorMessage)}
" : "")}
+
+{BuildUsbSection(usbResult)}
+
+
+
+
+";
+ }
+
+ private static string BuildUsbSection(UsbKeyResult? usbResult)
+ {
+ if (usbResult == null)
+ return "";
+
+ if (usbResult.Error != null && !usbResult.Found)
+ return $@"{Escape(usbResult.Error)}
No USB drive with print_server_key.txt found. Insert a USB drive and press Refresh.
USB key found but invalid: {Escape(usbResult.Error)}
";
+
+ return $@"
+
+
+
USB Key Found
+
Restaurant ID: {Escape(usbResult.DecodedRestaurantId ?? "?")}
+
API URL: {Escape(usbResult.DecodedApiUrl ?? "?")}
+
+
+
Configuration Updated!
+
+
+
The configuration has been saved. The service will restart automatically.
+
+
+
Restaurant ID: {Escape(newConfig.RestaurantId)}
+
API URL: {Escape(newConfig.ApiUrl ?? "(not set)")}
+
+
This page will refresh in 5 seconds...
+
Not Found
";
+ }
+
+ var buffer = Encoding.UTF8.GetBytes(html);
+ response.ContentType = "text/html; charset=utf-8";
+ response.ContentLength64 = buffer.Length;
+ await response.OutputStream.WriteAsync(buffer);
+ response.Close();
+ }
+ catch (Exception ex)
+ {
+ Console.WriteLine($"HTTP error: {ex.Message}");
+ try { context.Response.Close(); } catch { }
+ }
+ }
+
+ private async Task BuildIndexPageAsync()
+ {
+ var usbResult = await UsbKeyScanner.ScanForKeyAsync();
+ return HtmlPageBuilder.BuildConfigPage(_getConfig(), _getIsRunning(), usbResult);
+ }
+
+ private async Task HandleUpdateKeyAsync()
+ {
+ var usbResult = await UsbKeyScanner.ScanForKeyAsync();
+
+ if (!usbResult.Found || usbResult.Base64Content == null)
+ {
+ return HtmlPageBuilder.BuildConfigPage(
+ _getConfig(), _getIsRunning(), usbResult,
+ errorMessage: "No valid USB key found. Please insert a USB drive and try again.");
+ }
+
+ // Validate again
+ var validation = ConfigurationLoader.TryLoadFromBase64(usbResult.Base64Content);
+ if (!validation.Success)
+ {
+ return HtmlPageBuilder.BuildConfigPage(
+ _getConfig(), _getIsRunning(), usbResult,
+ errorMessage: $"Key validation failed: {validation.Error}");
+ }
+
+ // Write config file
+ try
+ {
+ var configPath = ConfigurationPaths.GetConfigPath();
+ var configDir = Path.GetDirectoryName(configPath);
+ if (!string.IsNullOrEmpty(configDir) && !Directory.Exists(configDir))
+ Directory.CreateDirectory(configDir);
+
+ await File.WriteAllTextAsync(configPath, usbResult.Base64Content);
+ Console.WriteLine($"Configuration updated at {configPath}");
+ }
+ catch (Exception ex)
+ {
+ return HtmlPageBuilder.BuildConfigPage(
+ _getConfig(), _getIsRunning(), usbResult,
+ errorMessage: $"Failed to write configuration: {ex.Message}");
+ }
+
+ // Schedule exit so systemd restarts us with new config
+ _ = Task.Run(async () =>
+ {
+ await Task.Delay(500);
+ Console.WriteLine("Exiting for restart with new configuration...");
+ Environment.Exit(0);
+ });
+
+ return HtmlPageBuilder.BuildSuccessPage(validation.Config!);
+ }
+}
diff --git a/EpsonPrintService/UsbKeyScanner.cs b/EpsonPrintService/UsbKeyScanner.cs
new file mode 100644
index 0000000..2e38a2f
--- /dev/null
+++ b/EpsonPrintService/UsbKeyScanner.cs
@@ -0,0 +1,137 @@
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+using System.Text.Json;
+
+namespace EpsonPrintService;
+
+public record UsbKeyResult(bool Found, string? Base64Content, string? DecodedApiUrl, string? DecodedRestaurantId, string? Error);
+
+public static class UsbKeyScanner
+{
+ private const string KeyFileName = "print_server_key.txt";
+
+ public static async Task ScanForKeyAsync()
+ {
+ if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+ return new UsbKeyResult(false, null, null, null, "USB scanning is only supported on Linux.");
+
+ try
+ {
+ var lsblkJson = await RunCommandAsync("lsblk", "-J -o NAME,RM,MOUNTPOINT,TYPE");
+ if (lsblkJson == null)
+ return new UsbKeyResult(false, null, null, null, "Failed to run lsblk.");
+
+ var doc = JsonDocument.Parse(lsblkJson);
+ var devices = doc.RootElement.GetProperty("blockdevices");
+
+ foreach (var device in devices.EnumerateArray())
+ {
+ var result = await ScanDeviceAsync(device);
+ if (result != null)
+ return result;
+
+ // Check children (partitions)
+ if (device.TryGetProperty("children", out var children))
+ {
+ foreach (var child in children.EnumerateArray())
+ {
+ result = await ScanDeviceAsync(child);
+ if (result != null)
+ return result;
+ }
+ }
+ }
+
+ return new UsbKeyResult(false, null, null, null, null);
+ }
+ catch (Exception ex)
+ {
+ return new UsbKeyResult(false, null, null, null, $"USB scan failed: {ex.Message}");
+ }
+ }
+
+ private static async Task ScanDeviceAsync(JsonElement device)
+ {
+ var isRemovable = device.TryGetProperty("rm", out var rm) && (rm.ValueKind == JsonValueKind.True || (rm.ValueKind == JsonValueKind.Number && rm.GetInt32() == 1));
+ if (!isRemovable)
+ return null;
+
+ var type = device.TryGetProperty("type", out var t) ? t.GetString() : null;
+ if (type != "part")
+ return null;
+
+ var name = device.TryGetProperty("name", out var n) ? n.GetString() : null;
+ if (name == null)
+ return null;
+
+ var mountpoint = device.TryGetProperty("mountpoint", out var mp) && mp.ValueKind == JsonValueKind.String ? mp.GetString() : null;
+
+ if (!string.IsNullOrEmpty(mountpoint))
+ {
+ return CheckMountpoint(mountpoint);
+ }
+
+ // Try to mount and check
+ var tempMount = $"/tmp/usb_scan_{name}";
+ try
+ {
+ Directory.CreateDirectory(tempMount);
+ var mountResult = await RunCommandAsync("mount", $"-o ro /dev/{name} {tempMount}");
+ if (mountResult == null)
+ return null;
+
+ return CheckMountpoint(tempMount);
+ }
+ finally
+ {
+ try { await RunCommandAsync("umount", tempMount); } catch { }
+ try { Directory.Delete(tempMount); } catch { }
+ }
+ }
+
+ private static UsbKeyResult? CheckMountpoint(string mountpoint)
+ {
+ var keyPath = Path.Combine(mountpoint, KeyFileName);
+ if (!File.Exists(keyPath))
+ return null;
+
+ var content = File.ReadAllText(keyPath).Trim();
+ if (string.IsNullOrWhiteSpace(content))
+ return null;
+
+ var validation = ConfigurationLoader.TryLoadFromBase64(content);
+ if (!validation.Success)
+ return new UsbKeyResult(true, content, null, null, $"Key file found but invalid: {validation.Error}");
+
+ return new UsbKeyResult(true, content, validation.Config!.ApiUrl, validation.Config.RestaurantId, null);
+ }
+
+ private static async Task RunCommandAsync(string command, string arguments)
+ {
+ try
+ {
+ using var process = new Process
+ {
+ StartInfo = new ProcessStartInfo
+ {
+ FileName = command,
+ Arguments = arguments,
+ RedirectStandardOutput = true,
+ RedirectStandardError = true,
+ UseShellExecute = false,
+ CreateNoWindow = true
+ }
+ };
+
+ process.Start();
+ var output = await process.StandardOutput.ReadToEndAsync();
+ await process.WaitForExitAsync();
+
+ return process.ExitCode == 0 ? output : null;
+ }
+ catch
+ {
+ return null;
+ }
+ }
+}