12. Application Data

Everything the application persists lives under the per-user AppData folder:

%LocalAppData%\BatchConvertToCHD\
├── logs\                          # Serilog rolling log files
│   └── BatchConvertToCHD-YYYYMMDD.log   (daily roll, 7 files retained)
└── screenshots\                   # F8 screenshots
    └── screenshot_yyyy-MM-dd_HH-mm-ss-fff.png

%LocalAppData% resolves to C:\Users\<user>\AppData\Local on a standard install.

12.1 Logs

Configured in App.xaml.cs ConfigureSerilog (:56–78).
File sink: %LocalAppData%\BatchConvertToCHD\logs\BatchConvertToCHD-.log, daily rolling (RollingInterval.Day), 7 files retained, minimum level Debug, invariant-culture timestamps {Timestamp:yyyy-MM-dd HH:mm:ss.fff} [{Level:u3}] {Message:lj}{NewLine}{Exception}.
Debug sink (visible in the Visual Studio debugger output) and the BugReportApiSink (warning+, see Bug Reporting System).
The in-app LogViewer shows the same messages (truncated at 100,000 characters, MaxLogLength); the AppData title-bar button opens %LocalAppData%\BatchConvertToCHD in Explorer.

12.2 Screenshots

Global hotkey F8 captures the foreground window (GDI BitBlt) and saves it as screenshot_yyyy-MM-dd_HH-mm-ss-fff.png under %LocalAppData%\BatchConvertToCHD\screenshots (folder created on demand — ScreenshotService.cs:97–104).
The saved path is logged in the app (“Screenshot saved: …”).

12.3 Temporary Directories

Temp directories are not under AppData — they live on the drive with the most free space:

Pattern: BatchConvertToCHD_Temp_<guid> on {drive}\BatchConvertToCHD_Temp\, or directly under the system temp when the preferred root isn’t usable (PathUtils.GetBestTempDirectory, see Utilities Reference).
Used for: archive extraction, CSO decompression, PBP/CCD cue generation, retry-via-temp-copy fallback, and cue work directories.
Cleanup: temp dirs are deleted after each file is processed; at startup, leftover BatchConvertToCHD_Temp_* folders from crashed sessions are removed (CleanupLeftoverTempDirectories, MainWindow.xaml.cs:304).

12.4 What Lives Next to the Executable

Item	Purpose
`BatchConvertToCHD.exe`	The application
`chdman.exe` / `chdman_arm64.exe`	MAME CHD tool (must stay next to the exe)
`7za.exe` / `7za_arm64.exe`	7-Zip fallback extractor
`CHDSharp.dll`, `WPF-UI` assemblies, etc.	Managed dependencies (copy-local)
`CCDSharp.dll`, `CSOSharp.dll`, `PBPSharp.dll`	In-house libraries

Legacy leftovers (logs, Resources, Screenshot folders; maxcso.exe, psxpackager.exe) are deleted automatically at startup by LegacyCleanupService (see Services Reference).

12.5 Network Endpoints

Endpoint	Purpose
`https://www.purelogiccode.com/bugreport/api/send-bug-report`	Bug reports (POST, `X-API-KEY` header)
`https://www.purelogiccode.com/ApplicationStats/stats`	Anonymous usage stats (POST, Bearer token)
`https://api.github.com/repos/drpetersonfernandes/BatchConvertToCHD/releases/latest`	Update checks (GET, User-Agent)

All HTTP traffic goes through the shared AppHttpClient singleton (TLS 1.2/1.3, see Services Reference).