feat: new jumbotron page for dm hall screen

server/db/database.ts

@@ -65,6 +65,9 @@ export function createDatabaseWrapper(db: DatabaseInternal): DatabaseConnection
         getProblem(id: string): Promise<Problem | null> {
             return getProblem(db, id)
         },
+        getJumbotronProblem(): Promise<Problem | null> {
+            return getJumbotronProblem(db)
+        },
     }
 }
 
@@ -145,6 +148,18 @@ export const getProblem = (db: DatabaseInternal, id: string): Promise<Problem |
         return problem && !problem.deleted ? problem : null
     })
 
+export const getJumbotronProblem = (db: DatabaseInternal): Promise<Problem | null> =>
+    withDatabase(db, state => {
+        const mostRecentProblems = Object.values(state.problems)
+            .filter(p => !p.deleted)
+            .sort((p1, p2) => new Date(p2.createdAt).getTime() - new Date(p1.createdAt).getTime())
+            .slice(0, 3)
+
+        if (mostRecentProblems.length === 0) return null
+
+        return mostRecentProblems[Math.floor(Math.random() * mostRecentProblems.length)]
+    })
+
 export const getProblems = (db: DatabaseInternal): Promise<Problem[]> =>
     withDatabase(db, state => {
         return Object.values(state.problems).filter(p => !p.deleted)