# Duplicate Finder

A self-hosted Docker web app that scans a photo/video library, detects duplicates using four methods, and lets you review them in a gallery UI. **No files are ever moved, renamed, or deleted** — all decisions are recorded in SQLite only.

## Quick start

```bash
# 1. Edit docker-compose.yml — set your photos volume path
# 2. Build and run
docker compose up -d --build
# 3. Open http://localhost:8765
# 4. Enter folder path in UI and click Scan
```

## Volume mounts

| Container path | Purpose |
|---|---|
| `/photos` | Your photo library — mounted **read-only** |
| `/data` | SQLite database persistence |

Edit `docker-compose.yml` to point these at your NAS paths.

## Detection methods

| Method | Color | Description |
|---|---|---|
| SHA-256 | Blue | Byte-identical files |
| Perceptual hash | Purple | Visually similar photos (hamming ≤ 10) |
| EXIF timestamp + device | Amber | Same camera, same moment |
| File size + dimensions | Gray | Same size and resolution (low confidence) |

## Scan modes

| Mode | Description |
|---|---|
| Incremental | Only re-hashes changed/new files. Prior decisions preserved. |
| New files only | Indexes newly added files. Existing decisions untouched. |
| Rebuild groups | Re-runs detection on existing index. No re-hashing. |
| Full reset | Wipes everything and scans from scratch. |

## Google Takeout

The scanner automatically detects Google Takeout folder structures and reads `.json` sidecar files to restore correct capture timestamps and original filenames. Takeout files are flagged in the UI.

## What "redundant" means

Marking a file redundant **only writes to the database**. Nothing is moved, renamed, or deleted. This tool produces a decision record only. A separate tool handles file actions.

## Tech stack

- Python 3.12, FastAPI, Uvicorn
- SQLite (stdlib `sqlite3`)
- Pillow, imagehash, pillow-heif
- Vanilla JS single-page frontend
- Docker / docker-compose