assigner.clj

(defn all-duties-assigned? [apprentices duties-list]
  (loop [apprentices apprentices assigned-duties '()]
     (if (empty? apprentices) 
       (= (sort (remove nil? assigned-duties)) (sort (conj duties-list foreman-assignment))) 
       (let [apprentice (first apprentices) apprentices (rest apprentices)]
         (recur apprentices 
              (if-not (= (:assigned-to apprentice) nil) 
                  (conj assigned-duties (:assigned-to apprentice))
                  assigned-duties))))))

(defn all-apprentices-have-assignments? [apprentices]
  (loop [apprentices apprentices assigned-duties '()]
     (if (empty? apprentices )
       (every? identity assigned-duties)
       (let [apprentice (first apprentices) apprentices (rest apprentices)]
         (recur apprentices 
            (conj assigned-duties (:assigned-to apprentice)))))))

(defn assign-duty [apprentices assignments]
  (loop [duties-list (shuffle assignments)
        [a-map & more] (shuffle apprentices)
        acc []]
     (if a-map
       (let [duty (first duties-list) duties (rest duties-list)]
         (recur duties more 
              (if (and (in? (:duty-options a-map) duty) 
                       (= (:assigned-to a-map) nil)) 
                  (conj acc (assoc a-map :assigned-to duty))
                  (conj acc a-map))))
      acc)))

(defn assign-all-required-duties [apprentices duties]
  (let [orig-apprentices apprentices required-duties (required-duties duties)]
    (loop [apprentices apprentices] 
     (let [apprentices (assign-duty apprentices required-duties)]
     (if (all-duties-assigned? apprentices required-duties)
       apprentices
       (recur orig-apprentices))))))

(defn assign-all-remaining-apprentices [apprentices duties]
  (let [apprentices apprentices optional-duties (optional-duties duties)]
    (loop [apprentices apprentices]
    (let [apprentices (assign-duty apprentices optional-duties)] 
     (if (all-apprentices-have-assignments? apprentices)
       apprentices
       (recur apprentices))))))