Schedule approved Facebook posts from a Google Sheets calendar

flowchart TD trig(["several times daily calendar check"]):::trigtime s0["filter approved posts for today"]:::task s1[["process each approved post"]]:::mi s2["publish post to facebook"]:::svc s3[("update sheet with result")]:::store trig --> s0 s0 -->|"one per posts approved for today"| s1 s2 --> s3 gx{"× does post have an image"}:::gate s1 --> gx p00["download image from drive"]:::task gx -->|"has image"| p00 p10["skip image download"]:::task gx -->|"no image"| p10 jn{"○ before publishing"}:::gate p00 --> jn p10 --> jn jn --> s2 out[/"posts published on schedule"/]:::out pay{{"no approved post missed or late"}}:::pay s3 --> 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