Bulk File Renamer Utility

Anyone who has come back from a trip with 1,200 files named IMG_20250112_084211.jpg knows the pain: manual renaming is not an option, and the existing free renamers are either ad-ridden, Windows-only abandonware, or destructive without undo. This project builds a proper bulk renamer as a desktop application: load files or whole folders, stack rename rules (add prefix/suffix, sequential numbering with padding, find-and-replace, case conversion, EXIF/date insertion), and watch every new filename preview live as rules are edited. Before renaming, the engine checks for collisions and reserved names; during the run it writes a backup CSV mapping old names to new ones, so one click (or Ctrl+Z) restores everything. Saved templates capture whole rule stacks — "photo trip sort", "music library tidy" — as shareable JSON. The demo ships with a realistic photo-folder scenario so the preview, log and undo all work out of the box.

1. The user adds files or a folder (optionally including subfolders); the file list loads with sizes and current names.
2. Rules are added to the stack — e.g. prefix "Goa2025_", then 3-digit numbering, then strip "IMG_", then lowercase extensions.
3. The preview engine applies the rule stack to every filename in order and renders the before/after table live.
4. On Rename, a pre-flight pass checks for collisions, illegal characters and reserved names; conflicts are reported, not executed.
5. A backup CSV (old name → new name) is written, then files are renamed with per-file error handling.
6. The run log records timing, affected counts per rule and any skips; the Undo button (or Ctrl+Z) reverses the run from the backup.
7. The rule stack can be saved as a named JSON template and reapplied to any future folder in one click.

Tech stack:

• Desktop: Python with Tkinter/PyQt (or Electron + Node.js)
• File operations: OS-level rename with atomic per-file handling
• Preview engine: pure-function rule pipeline, testable without touching disk
• Templates: JSON rule-stack serialization
• Logging: timestamped run logs with CSV backup
• Packaging: PyInstaller / Electron Builder notes

• [Rule stacking] Combine prefix/suffix, sequential numbering with zero-padding, find-and-replace, case conversion and date-pattern rules in any order.
• [Live before/after preview] Every filename's new name updates instantly as rules are typed — nothing is renamed blind.
• [Conflict detection] Pre-flight check flags name collisions and reserved/illegal names before the run starts.
• [One-click undo] A backup CSV maps every old name to its new name; undo restores the originals exactly.
• [Rename log] Timestamped run log with per-rule affected counts, errors and skips, exportable as text.
• [Shareable templates] Save any rule stack as JSON, apply it in one click, share it with others.
• [Folder recursion] Include subfolders, filter by extension or name pattern, and select/deselect individual files.

• Complete desktop application source code
• Rule engine with live preview and conflict detection
• Undo system with backup CSV logging
• Template save/apply module with sample templates
• Packaging notes (installer build steps)
• Project report PDF (background, rule-engine design, safety design, methodology)
• PPT presentation for final review
• Viva Q&A preparation document (rule pipelines, filesystem safety, undo design)

• The demo's 1,248-files-in-6-seconds figure is a design target measured on the developer's machine class, not a guaranteed speed on all hardware.
• Undo covers renames performed by the app from its own backup CSV; files renamed or moved externally afterwards may not restore cleanly.
• EXIF-date rules depend on metadata actually present in the files; files without EXIF fall back to file dates.
• Network-drive and cloud-synced folders (OneDrive/Dropbox) can lock files mid-rename; the log reports these as skips.
• The demo UI is a desktop window; a web version of the renamer is future scope.