fallback support

EpsonPrintService/Program.cs

@@ -54,6 +54,8 @@ kernel.Bind<EpsonPrintServiceConfiguration>().ToConstant(config);
 kernel.Bind<IPrinterFactory>().To<EpsonPrinterFactory>();
 
 kernel.Bind<IPrintJobSource, SignalRPrintJobSource>().To<SignalRPrintJobSource>().InSingletonScope();
+//kernel.Bind<IPrintJobSource>().To<HttpPollingPrintJobSource>().InSingletonScope();
+
 kernel.Bind<IPrintService>().To<Inspectron.Epson.PrintServer.PrintServices.EpsonPrintService>();
 kernel.Bind<ILogger>().ToMethod(ctx =>
 {
@@ -74,6 +76,7 @@ kernel.Bind<IDiscoveredPrintersReceiver>().To<JamesDiscoveredPrintersReceiver>()
 kernel.Bind<PrinterDiscoveryBackgroundTask>().ToSelf().InSingletonScope();
 kernel.Bind<HeartbeatBackgroundTask>().ToSelf().InSingletonScope();
 
+
 var printLoop = kernel.Get<PrintLoop>();
 var printServer = kernel.Get<PrintServer>();
 
@@ -81,7 +84,7 @@ var printServer = kernel.Get<PrintServer>();
  
 var discoveryTask = kernel.Get<PrinterDiscoveryBackgroundTask>();
 var heartbeatTask = kernel.Get<HeartbeatBackgroundTask>();
-
+var jobSourceTask = kernel.Get<IPrintJobSource>();
 //printServer.RegisterPrinter("10.0.20.12");
 
 
@@ -100,10 +103,13 @@ Console.CancelKeyPress += (sender, e) =>
 _ = discoveryTask.StartAsync(cts.Token);
 _ = heartbeatTask.StartAsync(cts.Token);
 
+
 // delay for a moment to allow discovery to find printers
 Console.WriteLine("Waiting for printer discovery...");
 await Task.Delay(3000);
 
+_ = jobSourceTask.StartAsync();
+
 await printLoop.StartAsync();
 
 try

Inspectron.Epson/EpsonPrinter.cs

@@ -12,7 +12,7 @@ namespace Inspectron.Epson;
 /// </summary>
 public class EpsonPrinter : IEpsonPrinter
 {
-    private readonly ILogger? _logger;
+    private readonly ILogger? _logger=null;
     private TcpClient? _tcpClient;
     private NetworkStream? _stream;
     private string? _printerIp;
@@ -29,9 +29,9 @@ public class EpsonPrinter : IEpsonPrinter
     /// Initialize a new instance of EpsonPrinter
     /// </summary>
     /// <param name="logger">Optional logger for diagnostic output</param>
-    public EpsonPrinter(ILogger? logger = null)
+    public EpsonPrinter(/*ILogger? logger = null*/)
     {
-        _logger = logger;
+        //_logger = logger;
         RegisterCodepages();
     }
 

Inspectron.Epson/PrintServer/IPrintJobSource.cs

@@ -4,5 +4,6 @@ namespace Inspectron.Epson.PrintServer;
 
 public interface IPrintJobSource
 {
+    Task StartAsync();
     Task<PrintJob> GetNextJobAsync(CancellationToken cancellationToken);
 }

Inspectron.Epson/PrintServer/JobSources/HttpPollingPrintJobSource.cs

@@ -0,0 +1,143 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Threading.Channels;
+using Inspectron.Epson.PrintServer.ConfigurationSources;
+using Inspectron.Epson.Queue;
+using Microsoft.Extensions.Logging;
+
+namespace Inspectron.Epson.PrintServer.JobSources;
+
+public class HttpPollingPrintJobSource : IPrintJobSource, IDisposable
+{
+    private readonly EpsonPrintServiceConfiguration _groupConfiguration;
+    private readonly ILogger _logger;
+    private readonly HttpClient _httpClient;
+    private readonly Channel<PrintJob> _printJobChannel = Channel.CreateUnbounded<PrintJob>();
+    private readonly CancellationTokenSource _pollingCts = new();
+    private readonly TimeSpan _pollingInterval;
+
+    public HttpPollingPrintJobSource(
+        EpsonPrintServiceConfiguration groupConfiguration,
+        ILogger logger
+)
+    {
+        _groupConfiguration = groupConfiguration;
+        _logger = logger;
+        _pollingInterval = TimeSpan.FromSeconds(3);
+
+        _httpClient = new HttpClient
+        {
+            BaseAddress = new Uri(groupConfiguration.ApiUrl?.TrimEnd('/') + "/")
+        };
+        _httpClient.DefaultRequestHeaders.Add("X-Printer-Server-Key", groupConfiguration.ApiKey);
+
+    }
+
+    private async Task StartPollingAsync(CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Starting HTTP polling for print jobs at {BaseUrl}", _httpClient.BaseAddress);
+
+        while (!cancellationToken.IsCancellationRequested)
+        {
+            try
+            {
+                await PollForJobsAsync(cancellationToken);
+            }
+            catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+            {
+                break;
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error polling for print jobs. Retrying in {Interval}...", _pollingInterval);
+            }
+
+            try
+            {
+                await Task.Delay(_pollingInterval, cancellationToken);
+            }
+            catch (OperationCanceledException)
+            {
+                break;
+            }
+        }
+
+        _logger.LogInformation("HTTP polling stopped.");
+    }
+
+    private async Task PollForJobsAsync(CancellationToken cancellationToken)
+    {
+        var requestUrl = $"/api/printerServer/jobs";
+
+        var response = await _httpClient.GetAsync(requestUrl, cancellationToken);
+
+        if (!response.IsSuccessStatusCode)
+        {
+            _logger.LogWarning("Failed to fetch jobs. Status: {StatusCode}", response.StatusCode);
+            return;
+        }
+
+        var jobs = await response.Content.ReadFromJsonAsync<List<PrintJobDto>>(cancellationToken: cancellationToken);
+
+        if (jobs == null || jobs.Count == 0)
+        {
+            return;
+        }
+
+        _logger.LogInformation("Received {Count} print job(s) from HTTP endpoint.", jobs.Count);
+
+        foreach (var job in jobs)
+        {
+            _logger.LogInformation("Queuing print job: {PrintJob}", JsonSerializer.Serialize(job));
+            _printJobChannel.Writer.TryWrite(new PrintJob
+            {
+                JobId = job.JobId,
+                IP = job.PrinterIp,
+                Document = new SignalRPrintJobSource.PrintJobFromSignalR
+                {
+                    JobId = job.JobId,
+                    PrinterIp = job.PrinterIp,
+                    LogoUrl = job.LogoUrl,
+                    ReceiptType = job.ReceiptType,
+                    Content = job.Content
+                }
+            });
+        }
+    }
+
+    public Task StartAsync()
+    {
+        return StartPollingAsync(_pollingCts.Token);
+    }
+
+    public async Task<PrintJob> GetNextJobAsync(CancellationToken cancellationToken)
+    {
+        return await _printJobChannel.Reader.ReadAsync(cancellationToken);
+    }
+
+    public void Dispose()
+    {
+        _pollingCts.Cancel();
+        _pollingCts.Dispose();
+        _httpClient.Dispose();
+    }
+
+    public class PrintJobDto
+    {
+        [JsonPropertyName("jobId")]
+        public string JobId { get; set; } = "";
+
+        [JsonPropertyName("printerIp")]
+        public string PrinterIp { get; set; } = "";
+
+        [JsonPropertyName("logoUrl")]
+        public string? LogoUrl { get; set; }
+
+        [JsonPropertyName("receiptType")]
+        public int ReceiptType { get; set; }
+
+        [JsonPropertyName("content")]
+        public string Content { get; set; } = "";
+    }
+}

Inspectron.Epson/PrintServer/JobSources/SignalRPrintJobSource.cs

@@ -34,7 +34,7 @@ public class SignalRPrintJobSource: IPrintJobSource
         _connection.Reconnected += OnReconnected;
         _connection.Closed += OnClosed;
 
-        _ = InitializeConnectionAsync();
+        
     }
 
     private async Task InitializeConnectionAsync()
@@ -106,6 +106,11 @@ public class SignalRPrintJobSource: IPrintJobSource
         });
     }
 
+    public Task StartAsync()
+    {
+        return InitializeConnectionAsync();
+    }
+
     public async Task<PrintJob> GetNextJobAsync(CancellationToken cancellationToken)
     {
         return await _printJobChannel.Reader.ReadAsync(cancellationToken);

Inspectron.Epson/PrintServer/JobSources/SingleJobSource.cs

@@ -11,6 +11,11 @@ public class SingleJobSource: IPrintJobSource
     }
 
     private Channel<PrintJob> _channel = Channel.CreateUnbounded<PrintJob>();
+    public Task StartAsync()
+    {
+        return Task.CompletedTask;
+    }
+
     public async Task<PrintJob> GetNextJobAsync(CancellationToken cancellationToken)
     {
         return await _channel.Reader.ReadAsync(cancellationToken);

JUNIOR_ENGINEER_TASKS.md

@@ -1,454 +0,0 @@
-# Junior Engineer Task List - Code Improvements
-
-This document contains actionable tasks derived from the code analysis in `plan.md`. Complete tasks in priority order. After each fix, run:
-```bash
-dotnet build Inspectron.Epson.slnx
-dotnet test EpsonTest/EpsonTest.csproj
-```
-
----
-
-## CRITICAL PRIORITY (Fix First)
-
-### Task 1: Move API Key to Environment Variable
-**File:** `EpsonPrintService/config.json:4`
-
-**Problem:** API key stored in plaintext - security risk.
-
-**Steps:**
-1. Remove `ApiKey` from `config.json`
-2. In `EpsonPrintService/Program.cs`, read from environment:
-```csharp
-var apiKey = Environment.GetEnvironmentVariable("EPSON_API_KEY")
-    ?? throw new InvalidOperationException("EPSON_API_KEY environment variable not set");
-```
-3. Update `EpsonPrintServiceConfiguration` class to accept apiKey via constructor or property
-4. Add to systemd service file `epson.service`:
-```ini
-[Service]
-Environment="EPSON_API_KEY=your-key-here"
-```
-5. Document the required environment variable in README
-
----
-
-### Task 2: Fix HttpClient Anti-Pattern
-**Files:**
-- `EpsonPrintService/HeartbeatBackgroundTask.cs:24`
-- `Inspectron.Epson/PrintServer/PrintServices/EpsonPrintService.cs:68`
-
-**Problem:** Creating new HttpClient per request causes socket exhaustion.
-
-**Steps:**
-1. In `HeartbeatBackgroundTask.cs`:
-   - Change constructor to accept `HttpClient` as parameter
-   - Remove `_httpClient = new HttpClient();` line
-   - Keep using `_httpClient` field
-
-2. In `Program.cs` where HeartbeatBackgroundTask is created:
-```csharp
-// Create ONE HttpClient instance for the app lifetime
-var httpClient = new HttpClient();
-var heartbeatTask = new HeartbeatBackgroundTask(httpClient, ...);
-```
-
-3. In `EpsonPrintService.cs:68`:
-   - Add `HttpClient _httpClient` field to class
-   - Inject via constructor
-   - Replace `using var httpClient = new HttpClient();` with `_httpClient`
-
----
-
-### Task 3: Add Graceful Shutdown
-**File:** `EpsonPrintService/Program.cs:51-82`
-
-**Problem:** PrintLoop and PrintServer never call StopAsync() - jobs lost on Ctrl+C.
-
-**Steps:**
-1. Store references to started services:
-```csharp
-var printLoop = kernel.Get<PrintLoop>();
-var printServer = kernel.Get<PrintServer>();
-```
-
-2. In the Console.CancelKeyPress handler (or before Environment.Exit):
-```csharp
-Console.CancelKeyPress += async (sender, e) =>
-{
-    e.Cancel = true; // Prevent immediate exit
-    Console.WriteLine("Shutting down gracefully...");
-
-    await printLoop.StopAsync();
-    await printServer.StopAsync();
-
-    cts.Cancel();
-};
-```
-
-3. Ensure `PrintLoop` and `PrintServer` have `StopAsync()` methods that properly clean up
-
----
-
-### Task 4: Add Null Check for PrinterId
-**File:** `Inspectron.Epson/PrintServer/PrintServices/EpsonPrintService.cs:35-44`
-
-**Problem:** `GetPrinterIdAsync()` can return null but `.Value` accessed without check.
-
-**Steps:**
-1. Find this code block:
-```csharp
-var printerId = await epsonPrinter.GetPrinterIdAsync();
-var printerAdapter = _wrapperPrinterFactory.CreatePrinterFromId(printerId.Value, ...);
-```
-
-2. Add null check:
-```csharp
-var printerId = await epsonPrinter.GetPrinterIdAsync();
-if (printerId == null || !printerId.HasValue)
-{
-    _logger.LogError("Failed to get printer ID from {PrinterIp}", printerIp);
-    return false;
-}
-var printerAdapter = _wrapperPrinterFactory.CreatePrinterFromId(printerId.Value, ...);
-```
-
----
-
-### Task 5: Fix Race Condition in PrintServer
-**File:** `Inspectron.Epson/Queue/PrintServer.cs:19-23`
-
-**Problem:** TOCTOU bug - two threads could create duplicate queues.
-
-**Steps:**
-1. Change dictionary type from `Dictionary<string, PrinterQueue>` to:
-```csharp
-private readonly ConcurrentDictionary<string, PrinterQueue> _printerQueues = new();
-```
-
-2. Replace this pattern:
-```csharp
-if (_printerQueues.ContainsKey(printerIp))
-    return;
-var queue = new PrinterQueue(...);
-_printerQueues[printerIp] = queue;
-```
-
-With atomic operation:
-```csharp
-var queue = _printerQueues.GetOrAdd(printerIp, ip =>
-{
-    var newQueue = new PrinterQueue(ip, _printService, _logger);
-    newQueue.StartAsync(); // Start the queue
-    Console.WriteLine($"Printer {ip} registered");
-    return newQueue;
-});
-```
-
-3. Add `using System.Collections.Concurrent;` at top of file
-
----
-
-## HIGH PRIORITY
-
-### Task 6: Add CancellationToken Support
-**File:** `Inspectron.Epson/EpsonPrinter.cs` - Lines 52, 96, 129, 205, 335, 408, etc.
-
-**Problem:** Async methods can't be cancelled by callers.
-
-**Steps:**
-1. Find all public async methods in EpsonPrinter.cs
-2. Add optional parameter to each:
-```csharp
-// Before:
-public async Task<bool> ConnectAsync(string host, int port = 9100)
-
-// After:
-public async Task<bool> ConnectAsync(string host, int port = 9100, CancellationToken cancellationToken = default)
-```
-
-3. Pass cancellationToken to internal async calls:
-```csharp
-await _stream.WriteAsync(data, cancellationToken);
-await _stream.ReadAsync(buffer, cancellationToken);
-```
-
-4. Update interface `IEpsonPrinter` if one exists
-
----
-
-### Task 7: Add Exception Handling to Fire-and-Forget Tasks
-**Files:**
-- `Inspectron.Epson/PrintServer/PrintLoop.cs:29`
-- `EpsonPrintService/Program.cs:71-72`
-
-**Problem:** Unobserved exceptions crash the process.
-
-**Steps:**
-1. In `PrintLoop.cs`, replace:
-```csharp
-_ = Task.Run(Loop);
-```
-With:
-```csharp
-_ = Task.Run(async () =>
-{
-    try
-    {
-        await Loop();
-    }
-    catch (Exception ex)
-    {
-        _logger.LogError(ex, "PrintLoop crashed unexpectedly");
-    }
-});
-```
-
-2. In `Program.cs`, replace:
-```csharp
-_ = discoveryTask.StartAsync(cts.Token);
-_ = heartbeatTask.StartAsync(cts.Token);
-```
-With:
-```csharp
-var discoveryRunning = Task.Run(async () =>
-{
-    try { await discoveryTask.StartAsync(cts.Token); }
-    catch (Exception ex) { Console.WriteLine($"Discovery error: {ex.Message}"); }
-});
-
-var heartbeatRunning = Task.Run(async () =>
-{
-    try { await heartbeatTask.StartAsync(cts.Token); }
-    catch (Exception ex) { Console.WriteLine($"Heartbeat error: {ex.Message}"); }
-});
-```
-
----
-
-### Task 8: Implement IDisposable for Resource Cleanup
-**Files:**
-- `EpsonPrintService/HeartbeatBackgroundTask.cs`
-- `Inspectron.Epson/Queue/PrinterQueue.cs:13-14`
-- `Inspectron.Epson/EpsonPrinter.cs:757-761`
-
-**Steps:**
-
-1. **HeartbeatBackgroundTask.cs** - Add IDisposable:
-```csharp
-public class HeartbeatBackgroundTask : IDisposable
-{
-    private bool _disposed;
-
-    public void Dispose()
-    {
-        if (_disposed) return;
-        _httpClient?.Dispose();
-        _disposed = true;
-    }
-}
-```
-
-2. **PrinterQueue.cs** - Add IDisposable:
-```csharp
-public class PrinterQueue : IDisposable
-{
-    private bool _disposed;
-
-    public void Dispose()
-    {
-        if (_disposed) return;
-        _semaphore?.Dispose();
-        _cts?.Dispose();
-        _disposed = true;
-    }
-}
-```
-
-3. **EpsonPrinter.cs** - Fix DisposeAsync:
-```csharp
-public async ValueTask DisposeAsync()
-{
-    Disconnect();
-    GC.SuppressFinalize(this);
-    await Task.CompletedTask;
-}
-```
-
----
-
-### Task 9: Replace .Wait() with await
-**File:** `Inspectron.Epson/Queue/PrintServer.cs:32`
-
-**Problem:** `.Wait()` can cause deadlocks.
-
-**Steps:**
-1. Find method containing:
-```csharp
-queue.StopAsync().Wait();
-```
-
-2. Make the method async:
-```csharp
-// Before:
-public void StopQueue(string printerIp)
-
-// After:
-public async Task StopQueueAsync(string printerIp)
-```
-
-3. Replace `.Wait()` with `await`:
-```csharp
-await queue.StopAsync();
-```
-
-4. Update all callers to use `await StopQueueAsync()`
-
----
-
-### Task 10: Add Configuration Validation at Startup
-**File:** `EpsonPrintService/Program.cs:20-21`
-
-**Problem:** No validation after deserializing config.
-
-**Steps:**
-1. After config deserialization, add validation:
-```csharp
-var config = JsonSerializer.Deserialize<EpsonPrintServiceConfiguration>(configJson);
-
-if (config == null)
-    throw new InvalidOperationException("Failed to parse config.json");
-
-if (string.IsNullOrEmpty(config.GroupId))
-    throw new InvalidOperationException("GroupId is required in config.json");
-
-if (string.IsNullOrEmpty(config.RestaurantId))
-    throw new InvalidOperationException("RestaurantId is required in config.json");
-
-if (config.PrinterConfigurations == null || config.PrinterConfigurations.Count == 0)
-    Console.WriteLine("Warning: No printer configurations found");
-```
-
----
-
-## MEDIUM PRIORITY
-
-### Task 11: Replace Console.WriteLine with ILogger
-**File:** `Inspectron.Epson/Queue/PrintServer.cs:25, 34, 64`
-
-Replace all `Console.WriteLine()` calls with proper logging:
-```csharp
-// Before:
-Console.WriteLine($"Printer {printerIp} registered");
-
-// After:
-_logger.LogInformation("Printer {PrinterIp} registered", printerIp);
-```
-
----
-
-### Task 12: Fix Logger Factory Singleton
-**File:** `EpsonPrintService/Program.cs:33-40`
-
-Create factory once:
-```csharp
-// Create once at startup
-using var loggerFactory = LoggerFactory.Create(builder =>
-{
-    builder.AddConsole();
-    builder.SetMinimumLevel(LogLevel.Debug);
-});
-
-// Bind as singleton for all injections
-kernel.Bind<ILoggerFactory>().ToConstant(loggerFactory);
-kernel.Bind(typeof(ILogger<>)).ToMethod(ctx =>
-    loggerFactory.CreateLogger(ctx.Request.Service.GetGenericArguments()[0]));
-```
-
----
-
-### Task 13: Extract Magic Numbers to Constants
-**File:** `Inspectron.Epson/Queue/PrinterQueue.cs:87-88`
-
-```csharp
-// Add at top of class:
-private const int MaxRetryCount = 3;
-
-// Replace:
-if (job.RetryCount >= 3)
-// With:
-if (job.RetryCount >= MaxRetryCount)
-```
-
----
-
-### Task 14: Fix Static Thread Safety
-**File:** `Inspectron.Epson/EpsonPrinter.cs:38-43`
-
-```csharp
-private static readonly object _initLock = new();
-private static bool _initialized;
-
-private static void RegisterCodepages()
-{
-    if (_initialized) return;
-
-    lock (_initLock)
-    {
-        if (_initialized) return; // Double-check pattern
-        Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
-        _initialized = true;
-    }
-}
-```
-
----
-
-## LOW PRIORITY
-
-### Task 15: Remove Commented-Out Code
-- `EpsonPrintService/Program.cs:27-28` - Delete old factory bindings
-- `Inspectron.Epson/PrintServer/Printers/TM-T30III.cs:25` - Delete dead code
-
-### Task 16: Resolve TODO Comments
-**File:** `Inspectron.Epson/Queue/PrintJob.cs:5`
-- Either change `IP` property to proper type or remove the TODO comment
-
-### Task 17: Remove Unused Serilog Packages
-**File:** `EpsonPrintService/EpsonPrintService.csproj:14-16`
-```bash
-dotnet remove EpsonPrintService/EpsonPrintService.csproj package Serilog
-dotnet remove EpsonPrintService/EpsonPrintService.csproj package Serilog.Extensions.Logging
-dotnet remove EpsonPrintService/EpsonPrintService.csproj package Serilog.Sinks.Console
-```
-
-### Task 18: Fix Inconsistent Logging Style
-Change string interpolation to structured logging:
-```csharp
-// Before:
-_logger.LogWarning($"Printer {printerIp} not found");
-
-// After:
-_logger.LogWarning("Printer {PrinterIp} not found", printerIp);
-```
-
----
-
-## Verification Checklist
-
-After completing all tasks:
-
-- [ ] `dotnet build Inspectron.Epson.slnx` - No errors
-- [ ] `dotnet test EpsonTest/EpsonTest.csproj` - All tests pass
-- [ ] Test printer connectivity manually
-- [ ] Verify systemd service starts/stops cleanly
-- [ ] Verify graceful shutdown with Ctrl+C
-- [ ] Check no Console.WriteLine in library code (only logging)
-
----
-
-## Questions?
-
-If you're unsure about any task:
-1. Read the original issue in `plan.md` for more context
-2. Look at existing patterns in the codebase
-3. Ask a senior engineer before making architectural changes

plan.md

@@ -1,262 +0,0 @@
-# Code Improvement Analysis: EpsonPrintService & Inspectron.Epson
-
-## Executive Summary
-
-Analysis of both projects revealed **50+ distinct issues** across security, reliability, performance, and maintainability. The most critical issues involve resource management, thread safety, and missing cancellation support.
-
----
-
-## Critical Issues (Fix Immediately)
-
-### 1. Security: Plaintext API Key
-**File:** `EpsonPrintService/config.json:4`
-```json
-"ApiKey": "Pd8X/VtXLWgl5Djy4ksjdHC3xboeoh5Jig3Qo4277GQ="
-```
-- API key stored in plaintext JSON file
-- **Fix:** Move to environment variables or secure configuration provider
-
-### 2. HttpClient Anti-Pattern (Socket Exhaustion Risk)
-**File:** `EpsonPrintService/HeartbeatBackgroundTask.cs:24`
-```csharp
-_httpClient = new HttpClient();  // Created per instance
-```
-**File:** `Inspectron.Epson/PrintServer/PrintServices/EpsonPrintService.cs:68`
-```csharp
-using var httpClient = new HttpClient();  // Created per request
-```
-- **Fix:** Inject singleton HttpClient or use IHttpClientFactory
-
-### 3. Missing Graceful Shutdown
-**File:** `EpsonPrintService/Program.cs:51-82`
-- `PrintLoop` and `PrintServer` never call `StopAsync()` on exit
-- Queued print jobs are lost on Ctrl+C
-- **Fix:** Store references and call shutdown methods before exiting
-
-### 4. NullReferenceException Risk
-**File:** `Inspectron.Epson/PrintServer/PrintServices/EpsonPrintService.cs:35-44`
-```csharp
-var printerId = await epsonPrinter.GetPrinterIdAsync();
-var printerAdapter = _wrapperPrinterFactory.CreatePrinterFromId(printerId.Value, ...);
-```
-- `GetPrinterIdAsync()` can return null but `.Value` is called without check
-- **Fix:** Add null check before accessing `.Value`
-
-### 5. Thread Safety: Race Condition in PrintServer
-**File:** `Inspectron.Epson/Queue/PrintServer.cs:19-23`
-```csharp
-if (_printerQueues.ContainsKey(printerIp))
-    return;
-var queue = new PrinterQueue(...);
-_printerQueues[printerIp] = queue;
-```
-- TOCTOU bug: two threads could create duplicate queues
-- **Fix:** Use `ConcurrentDictionary.GetOrAdd()` or `TryAdd()`
-
----
-
-## High Priority Issues
-
-### 6. Missing CancellationToken Support
-**File:** `Inspectron.Epson/EpsonPrinter.cs` - Lines 52, 96, 129, 205, 335, 408, etc.
-- Core async methods don't accept CancellationToken
-- Callers cannot cancel long-running operations
-- **Fix:** Add optional `CancellationToken cancellationToken = default` to all async methods
-
-### 7. Fire-and-Forget Tasks Without Exception Handling
-**File:** `Inspectron.Epson/PrintServer/PrintLoop.cs:29`
-```csharp
-_= Task.Run(Loop);  // No exception handling
-```
-**File:** `EpsonPrintService/Program.cs:71-72`
-```csharp
-_ = discoveryTask.StartAsync(cts.Token);
-_ = heartbeatTask.StartAsync(cts.Token);
-```
-- Unobserved exceptions will terminate the process
-- **Fix:** Use exception handler or track tasks for proper completion
-
-### 8. Resource Leaks (IDisposable Not Implemented)
-**File:** `EpsonPrintService/HeartbeatBackgroundTask.cs` - No IDisposable
-- HttpClient never disposed
-
-**File:** `Inspectron.Epson/Queue/PrinterQueue.cs:13-14`
-- SemaphoreSlim and CancellationTokenSource never disposed
-
-**File:** `Inspectron.Epson/EpsonPrinter.cs:757-761`
-```csharp
-public async ValueTask DisposeAsync()
-{
-    Disconnect();
-    await Task.CompletedTask;  // Missing GC.SuppressFinalize
-}
-```
-- **Fix:** Implement proper disposal pattern with try/finally
-
-### 9. Synchronous Wait in Async Context
-**File:** `Inspectron.Epson/Queue/PrintServer.cs:32`
-```csharp
-queue.StopAsync().Wait();  // Deadlock risk
-```
-- **Fix:** Use `await` or proper async pattern
-
-### 10. Configuration Not Validated at Startup
-**File:** `EpsonPrintService/Program.cs:20-21`
-```csharp
-var config = JsonSerializer.Deserialize<EpsonPrintServiceConfiguration>(...);
-// No null check or validation
-```
-- **Fix:** Validate all required fields immediately after deserialization
-
----
-
-## Medium Priority Issues
-
-### 11. Console.WriteLine in Library Code
-**File:** `Inspectron.Epson/Queue/PrintServer.cs:25, 34, 64`
-```csharp
-Console.WriteLine($"Printer {printerIp} registered");
-```
-- Library code should use ILogger only
-- **Fix:** Replace with `_logger.LogInformation()`
-
-### 12. Logger Factory Created Repeatedly
-**File:** `EpsonPrintService/Program.cs:33-40`
-- Creates new LoggerFactory for every ILogger injection
-- **Fix:** Create factory once and bind as singleton
-
-### 13. Magic Numbers Throughout
-**File:** `Inspectron.Epson/EpsonPrinter.cs:263, 273, 282, 327, 463`
-- Hard-coded ESC/POS bytes scattered in code
-- **Fix:** Move to `EpsonCommands` static class
-
-**File:** `Inspectron.Epson/Queue/PrinterQueue.cs:87-88`
-```csharp
-if (job.RetryCount >= 3)  // Magic number
-```
-- **Fix:** Extract to configurable constant
-
-### 14. SOLID Violations
-
-**SRP Violation - EpsonPrinter.cs (763 lines)**
-- Handles: connection, status, image processing, text printing, cutting
-- **Fix:** Split into smaller classes (ConnectionManager, StatusProvider, ImagePrinter)
-
-**SRP Violation - EpsonPrintServiceConfiguration**
-- Implements both `IPrinterConfigurationSource` AND `IAssignedPrinterRepository`
-- **Fix:** Separate into two classes
-
-### 15. Code Duplication
-
-**Image Conversion:**
-- `ConvertToRasterData()` and `ConvertToColumnFormat()` share 50%+ logic
-- **Fix:** Extract common image processing pipeline
-
-**Image Loading:**
-- Same file loading pattern repeated 4 times in EpsonPrinter.cs
-- **Fix:** Create private helper method
-
-### 16. Performance Issue in Image Conversion
-**File:** `Inspectron.Epson/EpsonImageConverter.cs:243-247`
-```csharp
-image.ProcessPixelRows(accessor => { ... });  // Called per pixel!
-```
-- O(n²) performance instead of O(n)
-- **Fix:** Call ProcessPixelRows once and cache accessor
-
-### 17. Missing Input Validation
-- `ConnectAsync()` doesn't validate IP format
-- `PrintTextAsync()` doesn't validate text encoding
-- `FeedLinesAsync()` doesn't validate line count > 0
-- **Fix:** Add guard clauses with ArgumentException
-
-### 18. Static State Thread Safety
-**File:** `Inspectron.Epson/EpsonPrinter.cs:38-43`
-```csharp
-private static bool _initialized;
-private static void RegisterCodepages()
-{
-    if (_initialized) return;  // No lock!
-    Encoding.RegisterProvider(...);
-    _initialized = true;
-}
-```
-- **Fix:** Use lock or `Interlocked.CompareExchange()`
-
----
-
-## Low Priority Issues
-
-### 19. Commented-Out Code
-- `EpsonPrintService/Program.cs:27-28` - Old factory bindings
-- `Inspectron.Epson/PrintServer/Printers/TM-T30III.cs:25` - Dead code
-- **Fix:** Remove or track in issue tracker
-
-### 20. TODO Comments Left in Code
-**File:** `Inspectron.Epson/Queue/PrintJob.cs:5`
-```csharp
-// todo: change to ip address
-public string IP { get; set; }
-```
-- **Fix:** Resolve or create proper issue
-
-### 21. Unused Serilog Dependencies
-**File:** `EpsonPrintService/EpsonPrintService.csproj:14-16`
-- Serilog packages referenced but not used
-- **Fix:** Remove unused packages
-
-### 22. Inconsistent Logging
-- String interpolation used instead of structured logging placeholders
-- Log levels inconsistent (LogWarning for config errors that should fail startup)
-- **Fix:** Use `LogWarning("Printer {PrinterId} not found", printerIp)` pattern
-
-### 23. API Design Inconsistencies
-- `PrintTextAsync()` vs `PrintTextAndCutAsync()` naming
-- 3 overloads of `PrintImageBitModeAsync()` and `LoadImageAsync()`
-- Interface doesn't match all implementation overloads
-- **Fix:** Rationalize method naming and signatures
-
----
-
-## Suggested Refactoring Projects
-
-### Project 1: Resource Management Overhaul
-- Implement IAsyncDisposable properly across all classes
-- Fix all HttpClient instantiation
-- Add proper cleanup on shutdown
-- **Scope:** ~10 files, ~200 lines changed
-
-### Project 2: Async Pattern Modernization
-- Add CancellationToken to all async methods
-- Fix fire-and-forget patterns
-- Replace synchronous waits
-- **Scope:** ~8 files, ~150 lines changed
-
-### Project 3: Thread Safety Fixes
-- Fix race conditions in PrintServer and PrinterQueue
-- Add proper locking for static initialization
-- **Scope:** ~4 files, ~50 lines changed
-
-### Project 4: Split EpsonPrinter Class
-- Extract ConnectionManager
-- Extract StatusProvider
-- Extract ImagePrinter
-- Keep EpsonPrinter as facade
-- **Scope:** ~5 new files, ~800 lines reorganized
-
-### Project 5: Configuration & DI Cleanup
-- Add configuration validation
-- Fix Logger factory singleton
-- Separate configuration concerns
-- Move secrets to environment variables
-- **Scope:** ~5 files, ~100 lines changed
-
----
-
-## Verification
-
-After implementing any changes:
-1. Build the solution: `dotnet build Inspectron.Epson.slnx`
-2. Run existing tests: `dotnet test EpsonTest/EpsonTest.csproj`
-3. Test printer connectivity manually with EpsonTest project
-4. Verify systemd service starts/stops cleanly