Automatically register and recognize Telegram bot users

flowchart TD trig>"telegram message received"]:::trig s0[("look up user in records")]:::store s1["send personalized greeting"]:::task trig --> s0 gx{"× new or returning user"}:::gate s0 --> gx p00["register new user record"]:::task gx -->|"new user"| p00 p10["update existing record"]:::task gx -->|"returning user"| p10 jn{"○ record updated"}:::gate p00 --> jn p10 --> jn jn --> s1 out[/"user record updated and greeted"/]:::out pay{{"personalized recognition of every user"}}:::pay s1 --> out out --> pay classDef task fill:#e7f6fe,stroke:#34b8f0,color:#2c2a29 classDef svc fill:#f6f8fa,stroke:#7c8795,color:#2c2a29 classDef mi fill:#e7f6fe,stroke:#0079a8,color:#2c2a29,stroke-width:2px classDef human fill:#fff,stroke:#0079a8,color:#0079a8 classDef store fill:#f6f8fa,stroke:#0079a8,color:#2c2a29 classDef trig fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigtime fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigdata fill:#8ad4f5,stroke:#0079a8,color:#06314c,font-weight:bold classDef gate fill:#fff,stroke:#e8a23d,color:#6b4708,font-weight:bold classDef out fill:#1f9d6b,stroke:#167a53,color:#fff,font-weight:bold classDef pay fill:#06314c,stroke:#021f33,color:#fff