Function create_challenge

backend/app/main.py:277–333

(
    payload: ChallengeCreate,
    response: Response,
    participant=Cookie(default=None, alias=COOKIE_NAME),
)

@app.post("/api/challenges")
def create_challenge(
    payload: ChallengeCreate,
    response: Response,
    participant=Cookie(default=None, alias=COOKIE_NAME),
) -> dict:
    creator = get_or_create_participant(response, participant)
    challenge_id = new_id("ch")
    current = now_iso()
    ends_at = (datetime.now(UTC) + timedelta(hours=payload.duration_hours)).isoformat(
        timespec="seconds"
    )
    cells = generate_circle_cells(
        payload.center_lat,
        payload.center_lng,
        payload.radius_m,
        payload.h3_resolution,
    )
    if not cells:
        raise HTTPException(status_code=400, detail="No cells generated")

    with connect() as conn:
        conn.execute(
            """
            INSERT INTO challenges
              (id, name, description, place_name, center_lat, center_lng, radius_m,
               h3_resolution, status, starts_at, ends_at, created_by, created_at)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, 'active', ?, ?, ?, ?)
            """,
            (
                challenge_id,
                payload.name.strip(),
                payload.description.strip(),
                payload.place_name.strip(),
                payload.center_lat,
                payload.center_lng,
                payload.radius_m,
                payload.h3_resolution,
                current,
                ends_at,
                creator["id"],
                current,
            ),
        )
        conn.executemany(
            """
            INSERT INTO challenge_cells (challenge_id, cell_id, lat, lng)
            VALUES (?, ?, ?, ?)
            """,
            [
                (challenge_id, cell["cell_id"], cell["lat"], cell["lng"])
                for cell in cells
            ],
        )
        row = conn.execute(
            "SELECT * FROM challenges WHERE id = ?", (challenge_id,)
        ).fetchone()
        return {"challenge": public_challenge(conn, row)}