diff --git a/src/2018/day07.lisp b/src/2018/day07.lisp
index 04648b9..d71ac47 100644
--- a/src/2018/day07.lisp
+++ b/src/2018/day07.lisp
@@ -1,5 +1,10 @@
 (defpackage :aoc/2018/07
-  (:use :cl :aoc :alexandria :queues))
+  (:use :cl :aoc :alexandria :queues)
+  (:export
+   #:sample-data
+   #:part1
+   #:step-time
+   ))
 (in-package :aoc/2018/07)
 
 (defparameter sample-input
@@ -37,14 +42,91 @@ Step F must be finished before step E can begin."))
 	   if (not (member p produced))
 	     collect p))))
 
+(defun available-steps (done dependencies)
+  (remove-if
+   (lambda (x) (member x done))
+   (append
+    (steps-without-dependencies dependencies)
+    (loop for dep in dependencies
+	  if (and
+	      (member (first dep) done)
+	      (prerequisites-availablep done (second dep) dependencies))
+	    collect (second dep)))))
+
+(defun next-step (done dependencies)
+  (let ((available (available-steps done dependencies)))
+    (first (sort available #'string-lessp))))
+
+(defun assembly-order (dependencies &optional (done '()))
+  (let ((next (next-step done dependencies)))
+    (if (not next)
+	(reverse done)
+	(assembly-order dependencies (push next done)))))
+
+(defun part1 (&optional (data input-data))
+  (format nil "~{~A~}" (assembly-order data)))
+
+;;; -------------------------------------------------------------------
+
+(defun step-time (step &optional (offset 60))
+  (+ offset (mod (char-code (character step)) 32)))
+
+(defun available-timed-steps (time done dependencies &optional (offset 60))
+  (map 'list
+       (lambda (s) (list (+ time (step-time s offset)) s))
+       (available-steps (map 'list #'second done) dependencies)))
+
+(defun timed-step-lessp (a b)
+  (cond
+    ((eq (first a) (first b)) (string-lessp (second a) (second b)))
+    (t (< (first a) (first b)))))
+
+(defun merge-timed-steps (steps add workers)
+  (let ((new-steps steps))
+    (loop for ev in (sort add #'timed-step-lessp)
+	  while (< (length new-steps) workers)
+	  if (not (member (second ev) (mapcar #'second new-steps)))
+	    do (setf new-steps (push ev new-steps)))
+    (sort new-steps #'timed-step-lessp)))
+
+(defun assembly-order-timed (dependencies &key (time 0) (done '()) (todo '()) (offset 60) (workers 5))
+
+  ;; done is a sorted list of (ts step) pairs
+  
+  (format t "todo: ~A with ~A at ~A~%" todo done time)
+  (cond
+    ((and (not done) (not todo))
+     (assembly-order-timed dependencies
+			   :time time
+			   :done done
+			   :todo (available-timed-steps time done dependencies offset)
+			   :offset offset
+			   :workers workers))
+    ((and done (not todo))
+     (progn
+       (format t "we're done : ~A~%" done)
+       done))
+    (t
+     (let* ((next-done (append done (remove-if (lambda (x) (< time (first x))) todo)))
+	    (next-todo (merge-timed-steps
+			(remove-if (lambda (x) (>= time (first x))) todo)
+			(available-timed-steps time next-done dependencies offset)
+			workers)))
+       (format t "next todo: ~A, done: ~A ~%" next-todo next-done)
+       (let* ((next-step (first next-todo))
+	      (nt (first next-step)))
+	 (format t "~A~%" next-todo)
+	 (assembly-order-timed
+	  dependencies
+	  :time nt
+	  :done next-done
+	  :todo next-todo
+	  :offset offset
+	  :workers workers))))))
 
 
-
-
-
-
-
-
-
+(defun part2 ()
+  (let ((finish (first (first (last (assembly-order-timed input-data))))))
+    (format nil "~A" finish)))
 
 
diff --git a/src/main.lisp b/src/main.lisp
index ee75f98..539c26d 100644
--- a/src/main.lisp
+++ b/src/main.lisp
@@ -3,6 +3,8 @@
   (:export
    #:split-lines
    #:test-input
+   #:submit-part1
+   #:submit-part2
    #:clear-data-cache))
 
 (in-package :aoc)
@@ -49,6 +51,22 @@
       (split-lines body))))
 
 
+(defun submit-answer (year day level answer)
+  (let ((url (format nil "~A/~D/day/~D/answer" *aoc-url* year day)))
+    (multiple-value-bind
+	  (body)
+	(dex:post url :cookie-jar *cookie-jar* :verbose t
+		      :content `(("level" . ,level)
+				 ("answer" . ,answer)
+				 ("submit" . "[Submit]")))
+      body)))
+
+(defun submit-part1 (year day answer)
+  (submit-answer year day "1" answer))
+
+(defun submit-part2 (year day answer)
+  (submit-answer year day "2" answer))
+
 (defvar *input-data-cache* (make-hash-table))
 
 (defun clear-data-cache ()
diff --git a/tests/2018/day07-test.lisp b/tests/2018/day07-test.lisp
new file mode 100644
index 0000000..2d5110b
--- /dev/null
+++ b/tests/2018/day07-test.lisp
@@ -0,0 +1,25 @@
+
+(defpackage :aoc/2018/07/tests
+  (:use :cl :aoc :aoc/tests :parachute :aoc/2018/07)
+  (:export
+   #:suite-2018-07
+   #:test-part1
+   #:test-step-size
+   ))
+
+(in-package :aoc/2018/07/tests)
+
+(define-test suite-2018-07
+					;:parent suite-2018
+  )
+
+
+(define-test test-part1
+  :parent suite-2018-07
+  (true (equal "CABDFE" (part1 sample-data))))
+
+(define-test test-step-size
+  :parent suite-2018-07
+  (true (equal 63 (step-time 'C)))
+  (true (equal 3 (step-time 'C 0)))
+  )