#!/afs/cats.ucsc.edu/courses/cmps112-wm/usr/racket/bin/mzscheme -qr
;; $Id: sbi.scm,v 1.3 2016-09-23 18:23:20-07 - - $
;;
;; NAME
;;    sbi.scm - silly basic interpreter
;;
;; SYNOPSIS
;;    sbi.scm filename.sbir
;;
;; DESCRIPTION
;;    The file mentioned in argv[1] is read and assumed to be an SBIR
;;    program, which is the executed.  Currently it is only printed.
;;


;; here we create our tables
(define *label-table* (make-hash))
(define *variable-table* (make-hash))
(define *function-table* (make-hash))


;; here we fill the function table with the prelim. functions
;; I think we write somethin like this to uses functions
;; (printf "2 ^ 16 = ~s~n" ((symbol-get '^) 2.0 16.0))

;; I changed symbol-get and symbol-put to require the table
;; that their grabbing from so that way we could use them for
;; other hash tables :-)
(define (symbol-get table key)
        (hash-ref table key))

(define (symbol-put! table key value)
        (printf "~n~nputting ~s in table:~s  as ~s~n~n" key table value)
        (hash-set! table key value))

(for-each
    (lambda (pair)
            (symbol-put! *function-table* (car pair) (cadr pair)))
    `(

        (log10_2 0.301029995663981195213738894724493026768189881)
        (sqrt_2  1.414213562373095048801688724209698078569671875)
        (div     ,(lambda (x y) (floor (/ x y))))
        (log10   ,(lambda (x) (/ (log x) (log 10.0))))
        (mod     ,(lambda (x y) (- x (* (div x y) y))))
        (quot    ,(lambda (x y) (truncate (/ x y))))
        (rem     ,(lambda (x y) (- x (* (quot x y) y))))
        (+       ,+)
        (*       ,*)
        (-       ,-)
        (/       ,(lambda (x y) (/ x (+ y 0.0) )))
        (^       ,expt)
        (ceil    ,ceiling)
        (exp     ,exp)
        (floor   ,floor)
        (log     ,log) ;; add zero to x similarly to how we did /
        (sqrt    ,sqrt)
        (sin     ,sin)
        (cos 	 ,cos)
        (tan	 ,tan)
	    (atan	 ,atan)
     	(let	 , (lambda x (interpret-let x)))
        (print   , (lambda x (displayln x)));; (lambda x (apply displayln x)))

     ))
;; now we fill the variable table with the prelim values pi & e
(for-each
    (lambda (pair)
            (symbol-put! *variable-table* (car pair) (cadr pair)))
    `(

        (e       2.718281828459045235360287471352662497757247093)
        (pi      3.141592653589793238462643383279502884197169399)
))


;; here I create 'methods'
;; label table
(define (get-label program)
    (printf "get-label... ~s~n~n" program)
    (if (null? program) ;; if we passed in nothing
        #f
        (if (null? (cdr (car program))) ;; if just a line number
            (get-label (cdr program))
            (if (symbol? (cadr (car program)));; if we encounter a label
                (if (null? (cdr program)) ;; if there is nothing after label
                    (begin ;; nothing after label
                        (printf "~n ~n ~n ~n :) ~n") (symbol-put! *label-table* (cadr (car program)) (cdr (car program))) )
                    (begin ;; something after label
                        (symbol-put! *label-table* (cadr (car program)) (cons (caddr (car program)) (cdr program))) (get-label (cdr program))))
                (get-label (cdr program))))));; if we didn't encounter a label

(define (get-stmt line-list)
    (if (null? (cdr line-list))
        null
        (if (null? (cadr line-list))
            null
            (if (not (symbol? (cadr line-list)))
                (cadr line-list)
                null))))

;; goal find first smt on a line and evaluate the statement
(define (get-stmt line)
     (if (null? (cdr line))
        null
        (if (null? (cadr line))
            null
            (if (symbol? (cadr line)) ;; if a label
                (cddr line);; return the next item
                (cadr line))))) ;; otherwise return stmt vthis may be wrong

;; this method runs a single line of code
;; for this we first check if there is a label
;; or if there is a stmt
;; then we get the stmt and check the car of it
;; see if the cadr is equal to one of the six  key words
;; depending on which one we perform at action with the items
;; after the car
;; then look for next item on that list of line

;; if the cdr is null
;; - skip
;; now check if there is a label or no label



;; (begin (printf"statement not null "))  <---trash stmnt]
;; printf("The interpreter line was not null")))
;;(define (interpret-line line)
;;    (if (null? (  get-stmt line))
;;        null))

    ;;;;;;
;;        ())
;;    ( if (eq? (car (get-stmt line)) ("print"))
;;          (printf "~s~n" cadr (get-stmt line))
;;          ()) ;; do nothing, IDK IF U CAN DO THIS
;;    ( if) ;;  more if statements follow



(define *stderr* (current-error-port))

(define *run-file*
    (let-values
        (((dirpath basepath root?)
            (split-path (find-system-path 'run-file))))
        (path->string basepath))
)

(define (die list)
    (for-each (lambda (item) (display item *stderr*)) list)
    (newline *stderr*)
    (exit 1)
)

(define (usage-exit)
    (die `("Usage: " ,*run-file* " filename"))
)

(define (readlist-from-inputfile filename)
    (let ((inputfile (open-input-file filename)))
         (if (not (input-port? inputfile))
             (die `(,*run-file* ": " ,filename ": open failed"))
             (let ((program (read inputfile)))
                  (close-input-port inputfile)
                         program))))

(define (write-program-by-line filename program)
    (printf "==================================================~n")
    (printf "~a: ~s~n" *run-file* filename)
    (printf "==================================================~n")
    (printf "(~n")
    ;; this map function returns a list named 'program' which is the result of the procedure
    ;; (map (lambda (line) (printf "~s~n" line)) program) ;; this is where we print out each line
    ;; first pass grabbing labels
    ;; second pass interpret
    ;;(map (lambda (line) (get-stmt line)) program)
    ;;(map (lambda (line) ()))
    ;; (printf ")~n Output: ~n")

    (get-label program)
    (eval-stmt program)
 )


;; implementing LET statement
(define (interpret-let expr)
   (printf "let-interpretting.. ~s ~n" expr)
   (printf "car is ~s ~n" (car expr))
   (printf "cdr is ~s ~n" (cdr expr))

   (cond ((symbol? (car expr)) ;; if we are given a variable
	        (symbol-put! *variable-table* (car expr)  (eval-expr (cadr expr))))
         ((pair? (car expr)) ;; if we are given an array
                (vector-set! (symbol-get *variable-table* (car (car expr)))
                    (eval-expr(cadr (car expr))) (eval-expr(cadr expr))))                                         ;;(symbol-put! *variable-table* (car expr)  (eval-expr (cadr expr)))))
	     (else #f))
)

;; implementing DIM statement
(define (interpret-dim expr)
    ;; what do we put here? do we make a vector? a list?
    (printf "dim-interpretting.. ~s ~n" expr)
    (symbol-put! *variable-table* (car expr) (make-vector (cadr expr) [car expr]))
)

;; implementing GOTO statement
(define (interpret-goto expr)
    (printf "~ninterpretting-goto.. ~s ~n" expr)
    (printf "interpretting-goto.. ~s ~n" (symbol-get *label-table* expr))
    (eval-expr (symbol-get *label-table* expr))
)

(define (interpret-if expr)
    (if (eq? #t ((car (car expr)) (cadr (car expr))  (caddr (car expr))))
        (interpret-goto car (cddr expr))
        #f)
    )

(define (interpret-print expr) #f)

(define (interpret-input expr) #f)



(define (terminate-program)
    (exit))

(define (eval-stmt program)
    (printf "evaluating statement ~s~n" program)
    (cond ((null? (cdr program)) (exit));; stops infinite loop
          ((null? (cdr (car program)))
             (eval-stmt (cdr program)))
          ((symbol? (car (cdr (car program))))
             (begin ( printf" HI ~n~n~n")
             (cond ((eq? (car (cdr (car program))) 'if)
                        (interpret-if (cadr (cdr (car program)))))

                   ((eq? (car (cdr (car program))) 'goto)
                        (interpret-goto (cadr (cdr (car program)))))

                   ((eq? (car (cdr (car program))) 'let)
                        (interpret-let (cdr (cdr (car program)))))

                   ((eq? (car (cdr (car program))) 'dim)
                        (interpret-dim (cadr (cdr (car program)))))

                   ((eq? (car (cdr (car program))) 'print)
                        (interpret-print (cadr (cdr (car program)))))

                   ((eq? (car (cdr (car program))) 'input)
                        (interpret-input (cadr (cdr (car program)))))

                   (else (printf "error symbol undefined"))
                       )))
          (else (begin (printf "~n ~n ~s ~n ~n" (car (cdr (car program)))) (eval-stmt (cdr program))))))


(define (eval-expr expr)
   (printf "evaluating...~s ~n" expr)
   (cond ((number? expr) expr) ;; if its JUST a number
         ((hash-has-key? *variable-table* (car expr)) ;; if its JUST a variable
            (symbol-get *variable-table* (car expr)))
         ((pair? expr)
            (cond ((hash-has-key? *variable-table* (car expr)) ;; if its a memory operation
                       (vector-ref (symbol-get *variable-table* (car expr)) (eval-expr(cadr expr))))
                  ((hash-has-key? *function-table* (car expr)) ;; if its a function
                        (apply (symbol-get *function-table* (car expr)) (map eval-expr (cdr expr))))                                                        ;;(apply (hash-ref *function-table* (car expr)))
                  (else (map eval-expr (cdr expr))))) ;;IDK nested expr???
         (else expr))) ;; IDK string or something else??







(define (eval-expr2 expr)
   (printf "evaluating...~s ~n" expr)
   (cond ((number? expr) expr)
         ;;((null? (cdr expr)) terminate-program)
         ((symbol? expr)
            (if (hash-has-key? *variable-table* expr)
                (symbol-get *variable-table* expr)
                (hash-ref *function-table* expr #f)))
          ((pair? expr)
            (cond ((hash-has-key? *variable-table* (car expr))
                        (vector-ref (symbol-get *variable-table* (car expr)) (eval-expr(cadr expr))))
                  ((eq? (car expr) `let)
                        (interpret-let (cdr expr)))
                  ((eq? (car expr) `dim)
                        (interpret-dim (cadr expr)))
                  ((eq? (car expr) `goto)
                        (interpret-goto (cadr expr)))
                  ((hash-has-key? *function-table* (car expr))
                        (apply (symbol-get *function-table* (car expr)) (map eval-expr (cdr expr))))                                                        ;;(apply (hash-ref *function-table* (car expr)))
                  (else (map eval-expr (cdr expr)))))
         ((null? expr) #f)
         (else  expr))
)


(define (eval-expr2 expr)
   (printf "evaluating...~s ~n" expr)
   (cond ((number? expr) expr)
         ;;((null? (cdr expr)) terminate-program)
         ((symbol? expr)
            (if (hash-has-key? *variable-table* expr)
                (symbol-get *variable-table* expr)
                (hash-ref *function-table* expr #f)))
          ((pair? expr)
            (cond ((hash-has-key? *variable-table* (car expr))
                        (vector-ref (symbol-get *variable-table* (car expr)) (eval-expr(cadr expr))))
                  ((eq? (car expr) `let)
	 	                (interpret-let (cdr expr)))
                  ((eq? (car expr) `dim)
                        (interpret-dim (cadr expr)))
                  ((eq? (car expr) `goto)
                        (interpret-goto (cadr expr)))
	              ((hash-has-key? *function-table* (car expr))
                    	(apply (symbol-get *function-table* (car expr)) (map eval-expr (cdr expr))))                                                        ;;(apply (hash-ref *function-table* (car expr)))
                  (else (map eval-expr (cdr expr)))))
         ((null? expr) #f)
         (else  expr))
)


(define (main arglist)
    (if (or (null? arglist) (not (null? (cdr arglist))))
        (usage-exit)
        (let* ((sbprogfile (car arglist))
               (program (readlist-from-inputfile sbprogfile)))
              (write-program-by-line sbprogfile program))))

(main (vector->list (current-command-line-arguments)))