Price Checker

Terminal application to monitor washing machine prices daily, track changes in a CSV table, and send a Telegram summary.

Requirements

• Go 1.22+
• Optional: Telegram bot token and chat ID for notifications

Usage

go run . --run-once

Use custom URLs:

go run . --urls "https://example.com/item1,https://example.com/item2" --run-once

Or provide a file with one URL per line:

go run . --urls-file urls.txt --run-once

Run continuously (default 24h interval):

go run .

Telegram configuration

Set the following environment variables to enable daily summaries:

export TELEGRAM_BOT_TOKEN="<bot_token>"
export TELEGRAM_CHAT_ID="<chat_id>"

Getting your Telegram bot token

1. Open Telegram and start a chat with @Botfather.
2. Send /newbot and follow the prompts to name your bot.
3. BotFather will return a token that looks like 123456789:ABCDEF.... Use this as TELEGRAM_BOT_TOKEN.

Getting your chat ID

1. Start a chat with your bot (send any message so the bot can see you).
2. Open the following URL in a browser, replacing <bot_token> with your token:
   https://api.telegram.org/bot<bot_token>/getUpdates
3. Look for "chat":{"id":...} in the JSON response. The numeric value is your TELEGRAM_CHAT_ID.
   • For a group chat, add the bot to the group, send a message, then call getUpdates again.

Data table

The application stores checks in prices.csv by default. Each run records:

• Timestamp
• URL
• Price and currency
• Delta from previous check
• Decrease flag

Notes

• The scraper looks for price metadata and JSON-LD data; if the site layout changes, update the selectors in main.go.