telegram2photoprism is a bot that downloads images and videos from a Telegram channel and uploads them to a PhotoPrism server. You can also add tags to your images and videos which is not possible to do using photoprism with WebDAV.

Telegram is a very convenient way to communicate with your family, and chats with family often include many important pictures. It is very convenient to upload these pictures to a private PhotoPrism server directly from the Telegram channel.

Another issue is that PhotoPrism's face detection is not ideal, so tags often need to be added to photos manually. In most photos, there are only a few specific people, so when a photo is uploaded, the desire is to choose them from predefined tags.

1. Open a session with BotFather
2. Enter /newbot
3. Enter name of the bot. For example: PhotoPrismSync
4. Enter a username for the bot.
5. Copy token in the safe place (it is needed for --telegram-access-token)
6. Enter /setprivacy
7. Select your bot and enter Disable. This allows the bot to see all messages in the chat where you added it.
8. Add your bot to the chat from which you want to download photos and upload them to the PhotoPrism server.
9. Open a session with BotFather again and enter /setjoingroups. Then, enter Disable so the bot cannot be added to any other groups.
10. Detect the chat ID of the chat from the previous step. You can do this, for example, using IDBot. The ID should look like: -4148908551. This is needed so that telegram2photoprism accepts only messages from the chat mentioned in step 8. (See --telegram-chat-id)

The default Telegram server https://api.telegram.org doesn't allow downloading files larger than 20MB from chats. If you only plan to use the bot for photos, this is okay. But if you want to upload videos larger than 20MB to the PhotoPrism server, you need to run the Telegram Bot API server in local mode. Follow the instructions here.

The local telegram bot api server should be specified using --telegram-bot-api-server

telegram2photoprism \
--telegram-access-token <TELEGRAM_ACCESS_TOKEN> \
--telegram-chat-id <TELEGRAM_CHAT_ID> \
--photoprism-url <PHOTOPRISM_URL> \
--photoprism-username <PHOTOPRISM_USERNAME> \
--photoprism-password <PHOTOPRISM_PASSWORD> 

If you want to use environment variables or specify tags, telegram bot api server then see next section.

This is my first project using the Rust language. There are likely pieces of code which can be improved. If you have any suggestions, please create a pull request or issue.

1. Support OAuth. PhotoPrism OAuth is not production ready - photoprism/photoprism#3943.
2. Add statistic base progress bar. The Telegram Bot API server does not provide information about file download progress (See tdlib/telegram-bot-api#37). The workaround is to take statistics for the last N downloads and tries to calculate an approximation.