#lang typed/racket

(provide degub)
(: degub (∀ (T) (→ T T)))
(define (degub x) (display "degub:") (displayln x) x)

;; ==== low/require-provide.rkt ====
(provide require/provide)

(define-syntax (require/provide stx)
  (syntax-case stx ()
    [(_ require-spec ...)
     #'(begin
         (require require-spec ...)
         (provide (all-from-out require-spec ...)))]))

(module+ test
  (require typed/rackunit)
  (module ma typed/racket
    (define require-provide-foo 7)
    (provide require-provide-foo))
  (module mb typed/racket
    (require (submod ".." ".."))
    (require/provide (submod ".." ma)))
  (require 'mb)
  (check-equal? require-provide-foo 7))

;; ==== low/define-syntax-parse.rkt ====
(require syntax/parse
         syntax/parse/define)

(provide define-syntax/parse
         λ/syntax-parse)

(begin-for-syntax
  (require (for-syntax racket/base
                       racket/stxparam)
           racket/stxparam)
  
  (provide stx)
  
  (define-syntax-parameter stx
    (lambda (stx)
      (raise-syntax-error (syntax-e stx) "Can only be used in define-syntax/parse"))))

(define-simple-macro (define-syntax/parse (name . args) . body)
  (define-syntax (name stx2)
    (syntax-parameterize ([stx (make-rename-transformer #'stx2)])
                         (syntax-parse stx2
                           [(_ . args) . body]))))

(define-simple-macro (λ/syntax-parse args . body)
  (λ (stx2)
    ;(syntax-parameterize ([stx (make-rename-transformer #'stx2)])
    (syntax-parse stx2
      [args . body])));)

;; If you include this as a file, you need to do:
;(begin-for-syntax (provide stx))
;; It's not provided by (all-from-out) :-(

;; ==== low/check-type-and-equal.rkt ====
(require ;"define-syntax-parse.rkt"
  (for-syntax syntax/parse
              syntax/parse/experimental/template)
  typed/rackunit)

(provide check-equal:?)

;; TODO: this won't expand types in the ann.

(define-syntax/parse
  (check-equal:? actual
                 (~optional (~seq (~datum :) type))
                 expected)
  (template (check-equal? (?? (ann actual type) actual) expected)))

;; ==== low/typed-fixnum.rkt ===

(provide fxxor)

;; For fxxor, used to compute hashes.
;; The type obtained just by writing (require racket/fixnum) is wrong, so we get a more precise one.
(require/typed racket/fixnum [(fxxor fxxor2) (→ Fixnum Fixnum Fixnum)])

(: fxxor (→ Fixnum * Fixnum))
(define (fxxor . args)
  (foldl fxxor2 0 args))

(module+ test
  (require typed/rackunit)
  (check-equal? (fxxor2 13206 23715) 28469)
  (check-equal? (fxxor 0) 0)
  (check-equal? (fxxor 13206) 13206)
  (check-equal? (fxxor 13206 23715 314576) 304101))

;; ==== Rest ====
(provide nameof
         first-value second-value third-value fourth-value fifth-value sixth-value seventh-value eighth-value ninth-value tenth-value
         (rename-out [compose ∘])
         stx-list
         stx-e
         stx-pair
         ;string-set!
         ;string-copy!
         ;string-fill!
         with-output-file
         in-tails
         in-heads
         in-split
         in-split*
         *in-split
         my-in-syntax
         indexof
         Syntax-Listof
         check-duplicate-identifiers)

(require (for-syntax syntax/parse syntax/parse/experimental/template))

(define-syntax-rule (nameof x) (begin x 'x))

(module+ test
  (require typed/rackunit)
  (let ((y 3))
    (check-equal? (nameof y) 'y)))

;(define (raise-multi-syntax-error name message exprs)
;(let ([e (exn:fail:syntax "message" (current-continuation-marks) (list #'aaa #'bbb))])
;  ((error-display-handler) (exn-message e) e))

(define-syntax-rule (λstx (param ...) body ...)
  (λ (param ...)
    (with-syntax ([param param] ...)
      body ...)))

(module+ test
  (require typed/rackunit)
  (check-equal? (syntax->datum ((λstx (foo bar) #'(foo bar)) #'a #'b))
                (syntax->datum #'(a b))))

(define-syntax-rule (define-value-getter name v ... last-v)
  (define-syntax-rule (name expr)
    (call-with-values (λ () expr) (λ (v ... last-v . rest) last-v))))

(define-value-getter first-value   v1)
(define-value-getter second-value  v1 v2)
(define-value-getter third-value   v1 v2 v3)
(define-value-getter fourth-value  v1 v2 v3 v4)
(define-value-getter fifth-value   v1 v2 v3 v4 v5)
(define-value-getter sixth-value   v1 v2 v3 v4 v5 v6)
(define-value-getter seventh-value v1 v2 v3 v4 v5 v6 v7)
(define-value-getter eighth-value  v1 v2 v3 v4 v5 v6 v7 v8)
(define-value-getter ninth-value   v1 v2 v3 v4 v5 v6 v7 v8 v9)
(define-value-getter tenth-value   v1 v2 v3 v4 v5 v6 v7 v8 v9 v10)

(module+ test
  (require typed/rackunit)
  (check-equal? (first-value   (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 1)
  (check-equal? (second-value  (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 2)
  (check-equal? (third-value   (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 3)
  (check-equal? (fourth-value  (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 4)
  (check-equal? (fifth-value   (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 5)
  (check-equal? (sixth-value   (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 6)
  (check-equal? (seventh-value (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 7)
  (check-equal? (eighth-value  (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 8)
  (check-equal? (ninth-value   (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 9)
  (check-equal? (tenth-value   (values 1 2 3 4 5 6 7 8 9 10 11 12 13 14)) 10))

(define-match-expander stx-list
  (lambda (stx)
    (syntax-case stx ()
      [(_ pat ...)
       #'(? syntax?
            (app syntax->list (list pat ...)))])))

(module+ test
  (require typed/rackunit)
  (check-equal? (match #'(1 2 3) [(stx-list a b c) (list (syntax-e c)
                                                         (syntax-e b)
                                                         (syntax-e a))])
                '(3 2 1))
  #;(check-equal? (match #`(1 . (2 3)) [(stx-list a b c) (list (syntax-e c)
                                                               (syntax-e b)
                                                               (syntax-e a))])
                  '(3 2 1)))

(define-match-expander stx-e
  (lambda (stx)
    (syntax-case stx ()
      [(_ pat)
       #'(? syntax?
            (app syntax-e pat))])))

(module+ test
  (require typed/rackunit)
  (check-equal? (match #'x [(stx-e s) s]) 'x)
  (check-equal? (match #'(x . y) [(stx-e (cons a b)) (cons (syntax-e b)
                                                           (syntax-e a))])
                '(y . x)))

(define-match-expander stx-pair
  (lambda (stx)
    (syntax-case stx ()
      [(_ pat-car pat-cdr)
       #'(? syntax?
            (app syntax-e (cons pat-car pat-cdr)))])))

(module+ test
  (require typed/rackunit)
  (check-equal? (match #'(x . y) [(stx-pair a b) (cons (syntax-e b)
                                                       (syntax-e a))])
                '(y . x))
  (check-equal? (match #'(x y z) [(stx-pair a b) (cons (map syntax->datum b)
                                                       (syntax->datum a))])
                '((y z) . x)))

(define-syntax (string-set! stx)
  (raise-syntax-error 'string-set! "Do not mutate strings." stx))
(define-syntax (string-copy! stx)
  (raise-syntax-error 'string-copy! "Do not mutate strings." stx))
(define-syntax (string-fill! stx)
  (raise-syntax-error 'string-fill! "Do not mutate strings." stx))

#|
(define-syntax (with-output-file stx)
  (syntax-parse stx
    [(_ filename:expr (~optional (~seq #:mode mode:expr)) (~optional (~seq #:exists exists:expr)) body ...)
     (template (with-output-to-file filename
                 (λ () body ...)
                 (?? (?@ #:mode mode))
                 (?? (?@ #:exists exists))))]))
|#

(define-syntax (with-output-file stx)
  (syntax-parse stx
    [(_ [var:id filename:expr] (~optional (~seq #:mode mode:expr)) (~optional (~seq #:exists exists:expr)) body ...)
     (template (call-with-output-file filename
                 (λ (var) body ...)
                 (?? (?@ #:mode mode))
                 (?? (?@ #:exists exists))))]))

(: in-tails (∀ (T) (→ (Listof T) (Listof (Pairof T (Listof T))))))
(define (in-tails l)
  (if (null? l)
      '()
      (cons l (in-tails (cdr l)))))

(module+ test
  (require typed/rackunit)
  (check-equal? (for/list : (Listof (Listof Number))
                  ([x : (Listof Number) (in-tails '(1 2 3 4 5))]) x)
                '((1 2 3 4 5) (2 3 4 5) (3 4 5) (4 5) (5)))
  (let ((l '(1 2 3 4 5)))
    (check-true (eq? (caddr (for/list : (Listof (Listof Number))
                              ([x : (Listof Number) (in-tails l)]) x))
                     (cddr l)))))

(: in-heads (∀ (T) (→ (Listof T) (Listof (Pairof T (Listof T))))))
(define (in-heads l)
  (: my-append1 (→ (Listof T) T (Pairof T (Listof T))))
  (define (my-append1 x y)
    (if (null? x)
        (list y)
        (cons (car x) (my-append1 (cdr x) y))))
  
  (define (on-heads/private [acc-head : (Listof T)] [l : (Listof T)])
    : (Listof (Pairof T (Listof T)))
    (if (null? l)
        '()
        (let ([new-head (my-append1 acc-head (car l))])
          (cons new-head (on-heads/private new-head (cdr l))))))
  (on-heads/private '() l))

(module+ test
  (require typed/rackunit)
  (check-equal? (for/list : (Listof (Listof Number))
                  ([x : (Listof Number) (in-heads '(1 2 3 4 5))]) x)
                '((1) (1 2) (1 2 3) (1 2 3 4) (1 2 3 4 5))))

;; Can't write the type of on-split, because typed/racket doesn't allow writing (Sequenceof A B), just (Sequenceof A).
;; in-parallel's type has access to the multi-valued version of Sequenceof, though, so we let typed/racket propagate the inferred type.
(define #:∀ (T) (in-split [l : (Listof T)])
  (in-parallel (sequence-append (in-value '()) (in-heads l))
               (sequence-append (in-tails l) (in-value '()))))

;; Same as in-split, but without the empty tail.
(define #:∀ (T) (in-split* [l : (Listof T)])
  (in-parallel (sequence-append (in-value '()) (in-heads l))
               (sequence-append (in-tails l))))

;; Same as in-split, but without the empty head.
(define #:∀ (T) (*in-split [l : (Listof T)])
  (in-parallel (in-heads l)
               (sequence-append (sequence-tail (in-tails l) 1) (in-value '()))))

(define #:∀ (T) (*in-split* [l : (Listof T)])
  (in-parallel (in-heads l)
               (sequence-tail (in-tails l) 1)))

(: indexof (∀ (A B) (→ A (Listof B) (→ A B Any) (U #f Integer))))
(define (indexof elt lst [compare equal?])
  (let rec ([lst lst] [index 0])
    (if (null? lst)
        #f
        (if (compare elt (car lst))
            index
            (rec (cdr lst) (+ index 1))))))

;; See also syntax-e, which does not flatten syntax pairs, and syntax->list, which isn't correctly typed (won't take #'(a . (b c d e))).
(define-type (Syntax-Listof T)
  (Rec R (Syntaxof (U Null
                      (Pairof T R)
                      (Listof T)))))

;; in-syntax is now provided by racket/sequence.
(: my-in-syntax (∀ (T) (→ (Syntax-Listof T)
                          (Listof T))))
(define (my-in-syntax stx)
  (let ((e (syntax-e stx)))
    (if (null? e)
        e
        (if (syntax? (cdr e))
            (cons (car e) (my-in-syntax (cdr e)))
            e))))

(define (test-in-syntax)
  (my-in-syntax #'((a . b) (c . d))) ; (ann `(,#'(a . b) ,#'(c . d)) (Listof (Syntaxof (U (Pairof (Syntaxof 'a) (Syntaxof 'b)) (Pairof (Syntaxof 'c) (Syntaxof 'c))))))
  (my-in-syntax #'(a . (b c d e)))   ; (ann `(,#'a ,#'b ,#'c ,#'d ,#'e) (Listof (Syntaxof (U 'a 'b 'c 'd))))
  (my-in-syntax #'()))               ; (ann '() (Listof (Syntaxof Nothing)))


(: check-duplicate-identifiers (→ (Syntaxof (Listof (Syntaxof Symbol)))
                                  Boolean))
(define (check-duplicate-identifiers ids)
  (if (check-duplicate-identifier (my-in-syntax ids)) #t #f))

(require syntax/parse/define)
(provide define-simple-macro)

(require racket/match)
(provide (all-from-out racket/match)
         (rename-out [match-lambda match-λ]
                     [match-lambda* match-λ*]
                     [match-lambda** match-λ**]))