; assn10 - Recursive List
; CS340
; Nicholas Hershy

include Irvine32.inc
includelib Irvine32.lib

.386
;.model flat,stdcall
.stack 4096
ExitProcess proto,dwExitCode:dword

; '\r' comes before '\n' in txt file
CR EQU 0Dh
LF EQU 0Ah
NULL EQU 00h
COM EQU 2Ch ;comma
SPC EQU 20h
PER EQU 2Eh ;period/dot

.data

    ofilename BYTE "C:\Users\Nicholas Hershy\Desktop\asm_output.txt",0
    ifilename BYTE "C:\Users\Nicholas Hershy\Desktop\emply.dat",0
    err BYTE "Error: Unable to open input file",LF,NULL
    good BYTE "Input file opened successfully",LF,NULL
    fileHandle DWORD ? ;this is the file handle
    ifileHandle DWORD ?

    BUFFER_SIZE = 600
    buffer BYTE BUFFER_SIZE DUP (NULL)
    bytesRead BYTE ?
    temp DWORD ?

    Num1 DWORD 12
    Num2 DWORD 7
    Prod DWORD 0

    printNewLine BYTE LF,NULL

    ProductAry BYTE 5 dup (' ')

    numAry BYTE '1','2','3','4','5','6','7','8','9',NULL
    printNum BYTE 1 dup (' '),NULL


.code
main proc

    ;opens file and overwrite each time
    ;-------------------------------------------
    ;open outfile here - p.468 reference
    MOV edx, OFFSET ofilename
    call CreateOutputFile
    MOV fileHandle, eax
    ;-------------------------------------------

    ;opens inputfile p.163 reference
    ;---------------------------------------------------------
    LEA edx,ifilename
    CALL OpenInputFile
    .IF eax == INVALID_HANDLE_VALUE
        LEA esi,err
        CALL PrintToFile
    .ELSE
        MOV ifileHandle,eax
        LEA esi,good
        CALL PrintToFile
    .ENDIF
    ;----------------------------------------------------------

    call WriteWindowsMsg ;debug

    ;reads from input file and puts into buffer ary
    ;also finds bytesRead
    ;--------------------------------------------------------
    MOV edx,OFFSET buffer ; points to buffer
    MOV ecx,BUFFER_SIZE ; max bytes to read
    MOV eax,ifilehandle
    CALL ReadFromFile ; read the file
    MOV bytesRead,al
    ;---------------------------------------------------------

    PUSH OFFSET numAry
    CALL RecursivePrint

    LEA esi,printNewLine
    CALL PrintToFile

    PUSH OFFSET numAry
    CALL RecursivePrintRev

    invoke ExitProcess,0
main endp


;------------------------- itoa ------------------------------
;converts int to ascii
;condtion1: byte array must be blanked out first (Blankout proc)
;condition2: starts from end of the ary and moves backward...
;   point to one location after the end of ary as starting pos.
;param1: takes int (dword) variable into eax
;param2: takes 'BYTE x dup (?)' char array into esi
;--------------------------------------------------------------

itoa proc
    push ecx
    nextdigit: MOV edx,0
    MOV ebx, 10
    DIV ebx     ;divide eax by 10 chops off last digit?
    ADD dl, 30h     ;30h is zero?
    DEC esi
    MOV [esi], dl
    CMP eax, 0
    JNE nextdigit
    pop ecx
    ret

itoa endp

;---------------------------------atoi-----------------------------
;converts ary of ascii to int
;param1: takes byte array into esi
;returns result in eax
;condition: stops when does not find an ascii digit 0-9
;----------------------------------------------------------------

atoi proc

    MOV temp,10
    MOV ebx,0
    MOV eax,0
    nextDigit: MOV bl,[esi]
    CMP bl, '0'
    JL notADigit
    CMP bl,'9'
    JG notADigit
    ADD bl,-30h
    IMUL temp
    ADD eax, ebx
    INC esi
    JMP nextDigit
    notADigit: ret

atoi endp

;---------------------------PrintToFile-----------------------------
;prints ascii text to output file until NULL is hit
;param1: takes byte array into esi
;condition: must already have var called outfile open and set
;   to valid file handle
;------------------------------------------------------------------

PrintToFile proc

    push ecx
    nextchar: MOV dl, [esi]
    CMP dl, NULL
    JE exitloop
    MOV edx, esi
    MOV ecx,1
    MOV eax,fileHandle
    CALL WriteToFile
    INC esi
    JNE nextchar
    exitloop:
    pop ecx
    ret

PrintToFile endp

;------------------------- Blankout ---------------------------
;blanks out an array with spaces
;condition: must be a 'BYTE x dup (x)' of size x
;param1: takes 'BYTE x dup (x)' char array into esi
;--------------------------------------------------------------

Blankout proc

    PUSH ecx
    MOV ecx,0
    next: MOV dl, 20h
    MOV [esi], dl
    INC esi
    INC ecx
    cmp ecx,1 ;size of ary
    JNE next
    POP ecx
    ret

Blankout endp

;--------------------------RecursivePrint-------------------------
;prints out an array in order using recursion
;param1: beginning address of the array passed in on the stack
;----------------------------------------------------------------

RecursivePrint proc

    A EQU 8[ebp]
    MOV eax,0

    ;necessary
    PUSH ebp
    MOV ebp,esp

    MOV esi,A
    MOV edi,esi ;uses this to increment elements later
    MOV al,[esi]
    ;if (ary[x] = NULL)
    CMP al,NULL
    JE BC

    ;else print ary element
    LEA esi,printNum
    MOV [esi],al
    CALL PrintToFile

    ;move to the next element in the ary
    INC edi
    PUSH edi
    CALL RecursivePrint

    BC:
    MOV esp,ebp
    POP ebp
    ret ; don't think I need to return a num bc this is void function

RecursivePrint endp

;--------------------------RecursivePrintRev---------------------
;prints out an ary in reverse order using recursion
;param1: beginning element of ary passed in on the stack
;----------------------------------------------------------------

RecursivePrintRev proc

    MOV eax,0

    ;necessary
    PUSH ebp
    MOV ebp,esp

    MOV esi,A
    MOV edi,esi ;uses this to increment elements later
    MOV al,[esi]
    ;if (ary[x] = NULL)
    CMP al,NULL
    JE BC

    ;move to the next element in the ary
    INC edi
    PUSH edi
    CALL RecursivePrintRev

    ;else print ary element
    LEA esi,printNum
    MOV al,A
    MOV [esi],al
    CALL PrintToFile

    BC:
    MOV esp,ebp
    POP ebp
    ret ; don't think I need to return a num bc this is void function

RecursivePrintRev endp

end main