Tracks weekly grocery discounts at Mercator Hipermarket Rudnik (Supernova Ljubljana) and ranks the best deals by percentage off.

Live site: https://pikammmmm.github.io/lj-discounts/ (Rebuilds twice daily at 07:00 and 12:00 Europe/Ljubljana.)

Hits Mercator's online assortment API pinned to the Rudnik distribution center (HM LJUBLJANA RUDNIK, id=30) so the returned products match what's actually available at the store.

Download the latest lj-discounts-windows.zip, unzip, and double-click run-lj-discounts.cmd. The desktop app window opens, scrapes, and displays the report. lj-discounts-cli.exe is bundled for scheduled/headless use.

Grab download/lj-discounts.apk (also attached to every tagged release) and install it — you may need to enable Install unknown apps for your browser. The APK is a tiny WebView shell around the live site that runs fullscreen with no URL bar, so it always shows the freshest scrape without going through the Play Store.

To rebuild it locally (Debian/Ubuntu):

sudo apt-get install -y android-sdk-build-tools smali \
    default-jdk-headless zip curl
./android/build.sh   # writes download/lj-discounts.apk

The script fetches android-34.jar from a GitHub mirror on first run (cached under android/.cache/) since Debian doesn't ship a recent android-sdk-platform-* package.

The signing keystore at android/release.keystore is committed on purpose (password ljdiscounts) so anyone with the repo can sign updates that existing installs accept. Override KS_PASS / KEY_ALIAS env vars if you generate your own.

Install Python 3.12+, then double-click refresh.bat (or run .\refresh.ps1 from PowerShell). A .venv is created, dependencies are installed, and the app window opens.

python3 -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
python run.py --open

macOS users can double-click refresh.command.

python run.py [--html PATH] [--db PATH] [--top N] [--stale-days N] [--open|--no-open]

.
├── app.py                    # pywebview desktop shell
├── run.py                    # CLI entry point + HTML renderer
├── scrapers/
│   ├── mercator.py           # Mercator online API scraper
│   └── __init__.py
├── models.py                 # Offer dataclass
├── stores.py                 # physical-store label
├── weird.py                  # hot/suspicious deal flagging
├── categorize.py             # grocery vs non-grocery filter
├── assets/                   # app icon (ICO + PNG) + generator
├── manifest.json             # PWA manifest (served from gh-pages)
├── android/                  # WebView-wrapper APK source (smali + aapt2)
│   ├── AndroidManifest.xml
│   ├── smali/                # MainActivity.smali (Dalvik assembly)
│   ├── res/                  # icons, strings, theme
│   ├── release.keystore      # committed signing key (pass: ljdiscounts)
│   └── build.sh              # apt-only local build
├── download/lj-discounts.apk # latest signed APK (refreshed by android.yml)
├── windows/                  # Windows-only launchers bundled in the exe zip
├── refresh.{bat,ps1,command} # source-run launchers per platform
├── requirements.txt          # scrape-only deps (requests, beautifulsoup4)
├── requirements-windows.txt  # adds pywebview for the desktop app
└── .github/workflows/
    ├── scrape.yml            # daily scrape → gh-pages
    ├── windows.yml           # tag-triggered exe build + release
    └── android.yml           # tag-triggered APK build + release

1. Scrape (scheduled): scrape.yml runs python run.py on GitHub-hosted Ubuntu daily at 05:00 and 10:00 UTC (07:00 / 12:00 local).
2. Deploy: generated offers.html is copied to index.html, icons and manifest.json are staged, and the result is force-pushed to gh-pages.
3. Release (tag-triggered): pushing a v* tag runs windows.yml, which builds lj-discounts.exe (desktop) and lj-discounts-cli.exe, zips them with README and launcher, uploads as an artifact, and attaches the zip to the GitHub Release.
4. Android APK: android.yml runs ./android/build.sh on every push to main that touches android/** (also on tag pushes and via Run workflow). It installs Debian's android-sdk-build-tools and smali packages, fetches android-34.jar from a GitHub mirror so the APK targets a current Android API (Debian's newest platform jar is API 23, which Android 14 rejects), assembles MainActivity.smali, links resources with aapt2, signs with the committed keystore, commits the rebuilt download/lj-discounts.apk back to main ([skip ci]-tagged so it doesn't loop), and attaches it to tagged releases.

MIT © 2026 pikammmmm