#lang racket

(require rackunit "main.rkt")

(define test-grid (grid (list
              (line (point 0 0) (point 0 1) 1)
              (line (point 0 1) (point 1 1) 0)
              (line (point 1 0) (point 1 1) 1)
              (line (point 0 0) (point 1 0) 0)
              (line (point 1 1) (point 2 1) 0)
              (line (point 2 0) (point 2 1) 1)
              (line (point 2 0) (point 3 0) 0)
              (line (point 3 3) (point 3 4) 0)
              (line (point 3 3) (point 4 3) 0)
              (line (point 4 3) (point 4 4) 0)
              (line (point 3 4) (point 4 4) 0)) 6 6))

(test-case
 "total-moves"
 (check-equal? (total-moves (grid '() 2 2)) 4)
 (check-equal? (total-moves (grid '() 4 5)) 31)
 (check-equal? (total-moves (grid '() 2 6)) 16))

(test-case
 "same-position?"
 (check-true (same-position? (line (point 0 0) (point 0 1) 1)
                             (line (point 0 0) (point 0 1) 0)))
 (check-true (same-position? (line (point 0 0) (point 0 1) 1)
                             (line (point 0 1) (point 0 0) 0)))
 (check-true (same-position? (line (point 0 2) (point 0 1) 0)
                             (line (point 0 2) (point 0 1) 0)))
 (check-false (same-position? (line (point 0 0) (point 0 1) 1)
                              (line (point 2 4) (point 0 3) 0))))

(test-case
 "valid-length?"
 (check-true (valid-length? (line (point 0 0) (point 0 1) 1)))
 (check-true (valid-length? (line (point 0 1) (point 0 0) 1)))
 (check-false (valid-length? (line (point 0 0) (point 1 1) 0)))
 (check-false (valid-length? (line (point 0 0) (point 0 2) 1)))
 (check-false (valid-length? (line (point 0 0) (point 0 2) 1))))

(test-case
 "boxes-for"
 (check-equal? (boxes-for (line (point 0 0) (point 0 1) 1) test-grid) (list (point 0 0)))
 (check-equal? (boxes-for (line (point 2 1) (point 2 2) 1) test-grid) (list (point 2 1) (point 1 1)))
 (check-equal? (boxes-for (line (point 0 0) (point 1 0) 1) test-grid) (list (point 0 0)))
 (check-equal? (boxes-for (line (point 1 1) (point 2 1) 1) test-grid)  (list (point 1 1) (point 1 0)))
 (check-equal? (boxes-for (line (point 0 5) (point 1 5) 1) test-grid) (list (point 0 4)))
 (check-equal? (boxes-for (line (point 5 0) (point 5 1) 0) test-grid) (list (point 4 0))))

(test-case
 "vertical?"
 (check-false (vertical? (line (point 2 0) (point 3 0) 0)))
 (check-true (vertical? (line (point 0 5) (point 0 6) 0))))

(test-case
 "horizontal?"
 (check-true (horizontal? (line (point 2 0) (point 3 0) 0)))
 (check-false (horizontal? (line (point 0 5) (point 0 6) 0))))

(test-case
 "box-in-grid?"
 (check-true (box-in-grid? test-grid (point 0 0)))
 (check-true (box-in-grid? test-grid (point 2 4)))
 (check-false (box-in-grid? test-grid (point 0 5)))
 (check-false (box-in-grid? test-grid (point 5 0)))
 (check-false (box-in-grid? test-grid (point -1 3))))

(test-case
 "completes-boxes"
 (define test-grid
   (grid (list
    (line (point 0 0) (point 0 1) 1)
    (line (point 0 1) (point 1 1) 0)
    (line (point 1 0) (point 1 1) 1)
    (line (point 0 2) (point 0 3) 1)
    (line (point 0 3) (point 1 3) 1)
    (line (point 0 2) (point 1 2) 1)
    (line (point 0 4) (point 0 5) 0)
    (line (point 0 4) (point 1 4) 1)
    (line (point 1 4) (point 1 5) 0)
    (line (point 3 0) (point 4 0) 0)
    (line (point 3 0) (point 3 1) 1)
    (line (point 4 0) (point 4 1) 0)
    (line (point 3 5) (point 4 5) 1)
    (line (point 3 4) (point 3 5) 0)
    (line (point 3 4) (point 4 4) 1)
    (line (point 4 5) (point 5 5) 1)
    (line (point 4 4) (point 5 4) 0)
    (line (point 5 4) (point 5 5) 1)) 6 6)) ; all possible unfinished boxes (plus an unfinished double)
 (check-equal? (completes-boxes test-grid (line (point 0 0) (point 1 0) 0)) 1)
 (check-equal? (completes-boxes test-grid (line (point 1 2) (point 1 3) 0)) 1)
 (check-equal? (completes-boxes test-grid (line (point 3 1) (point 4 1) 0)) 1)
 (check-equal? (completes-boxes test-grid (line (point 0 5) (point 1 5) 0)) 1)
 (check-equal? (completes-boxes test-grid (line (point 4 4) (point 4 5) 0)) 2)
 (check-equal? (completes-boxes test-grid (line (point 1 0) (point 2 0) 1)) 0))

(test-case
 "valid-move?"
 (define test-grid (grid (list
               (line (point 0 0) (point 0 1) 1)
               (line (point 0 1) (point 0 2) 0)
               (line (point 3 2) (point 3 3) 0)) 6 6))
 (check-false (valid-move? (line (point 0 0) (point 0 1) 1) test-grid))
 (check-true (valid-move? (line (point 0 2) (point 0 3) 0) test-grid))  ; not overwriting existing moves
 (check-false (valid-move? (line (point 0 2) (point 0 1) 1) test-grid)) ; moving forward
 (check-false (valid-move? (line (point 0 0) (point 0 2) 1) test-grid)) ; valid length check
 (check-false (valid-move? (line (point (+ (grid-width test-grid) 1) 0) (point 0 2) 1) test-grid))
 (check-false (valid-move? (line (point (+ (grid-width test-grid) 1) 0) (point 0 2) 1) test-grid))) ; out of bounds

(test-case
 "out-of-bounds?"
 (check-false (out-of-bounds? (point 0 0) test-grid))
 (check-false (out-of-bounds? (point 0 (- (grid-width test-grid) 1)) test-grid))
 (check-true (out-of-bounds? (point (grid-width test-grid) 0) test-grid))
 (check-true (out-of-bounds? (point -2 0) test-grid))
 (check-true (out-of-bounds? (point 0 -2) test-grid)))

(test-case
 "forwards?"
 (check-true (forwards? (line (point 0 0) (point 0 1) 1)))
 (check-true (forwards? (line (point 0 1) (point 1 1) 1)))
 (check-false (forwards? (line (point 1 1) (point 0 0) 0))))

(test-case
 "point+"
 (check-equal? (point+ (point 0 0) (point 1 2)) (point 1 2))
 (check-equal? (point+ (point 2 4) (point 5 0)) (point 7 4))
 (check-equal? (point+ (point 0 0) (point 0 0)) (point 0 0)))

(test-case
 "count-square"
  (check-equal? (count-square (point 0 0) test-grid) 4)
  (check-equal? (count-square (point 1 0) test-grid) 3)
  (check-equal? (count-square (point 2 0) test-grid) 2)
  (check-equal? (count-square (point 3 2) test-grid) 1)
  (check-equal? (count-square (point 0 4) test-grid) 0))

(test-case
 "append-move"
 (check-equal? (append-move test-grid (line (point 2 2) (point 2 3) 0)) (grid (append
                                                                               (grid-lines test-grid)
                                                                               (list (line (point 2 2) (point 2 3) 0)))
                                                                              (grid-width test-grid) (grid-height test-grid)))
 (check-equal? (append-move test-grid (line (point 0 0) (point 0 1) 0)) test-grid))


(test-case
 "valid-moves"
 (check-equal? (valid-moves test-grid) (list
 (line (point 0 1) (point 0 2) 1)
 (line (point 0 2) (point 1 2) 1)
 (line (point 0 2) (point 0 3) 1)
 (line (point 0 3) (point 1 3) 1)
 (line (point 0 3) (point 0 4) 1)
 (line (point 0 4) (point 1 4) 1)
 (line (point 0 4) (point 0 5) 1)
 (line (point 0 5) (point 1 5) 1)
 (line (point 1 0) (point 2 0) 1)
 (line (point 1 1) (point 1 2) 1)
 (line (point 1 2) (point 2 2) 1)
 (line (point 1 2) (point 1 3) 1)
 (line (point 1 3) (point 2 3) 1)
 (line (point 1 3) (point 1 4) 1)
 (line (point 1 4) (point 2 4) 1)
 (line (point 1 4) (point 1 5) 1)
 (line (point 1 5) (point 2 5) 1)
 (line (point 2 1) (point 3 1) 1)
 (line (point 2 1) (point 2 2) 1)
 (line (point 2 2) (point 3 2) 1)
 (line (point 2 2) (point 2 3) 1)
 (line (point 2 3) (point 3 3) 1)
 (line (point 2 3) (point 2 4) 1)
 (line (point 2 4) (point 3 4) 1)
 (line (point 2 4) (point 2 5) 1)
 (line (point 2 5) (point 3 5) 1)
 (line (point 3 0) (point 4 0) 1)
 (line (point 3 0) (point 3 1) 1)
 (line (point 3 1) (point 4 1) 1)
 (line (point 3 1) (point 3 2) 1)
 (line (point 3 2) (point 4 2) 1)
 (line (point 3 2) (point 3 3) 1)
 (line (point 3 4) (point 3 5) 1)
 (line (point 3 5) (point 4 5) 1)
 (line (point 4 0) (point 5 0) 1)
 (line (point 4 0) (point 4 1) 1)
 (line (point 4 1) (point 5 1) 1)
 (line (point 4 1) (point 4 2) 1)
 (line (point 4 2) (point 5 2) 1)
 (line (point 4 2) (point 4 3) 1)
 (line (point 4 3) (point 5 3) 1)
 (line (point 4 4) (point 5 4) 1)
 (line (point 4 4) (point 4 5) 1)
 (line (point 4 5) (point 5 5) 1)
 (line (point 5 0) (point 5 1) 1)
 (line (point 5 1) (point 5 2) 1)
 (line (point 5 2) (point 5 3) 1)
 (line (point 5 3) (point 5 4) 1)
 (line (point 5 4) (point 5 5) 1))))