TITLE Array Sorting (Program4.asm)
;Author: Jared Hughes
;Email: hughesja@onid.oregonstate.edu
;Class#: CS271-400
;Program Assignment 4
;Due: 8/2/2015
;Description: This program will generate random numbers in a range
;			  display them to the user, sort them, and calculate the median.
;			  It will then display the sorted list in descending order.

INCLUDE Irvine32.inc

	MIN = 10
	MAX = 200
	LO = 100
	HI = 999

.data

	myName			BYTE 	"Array Sorting by Jared Hughes", 0
	explain			BYTE 	"This program will generate random numbers in a range (10-200).", 0
	explain2		BYTE	"It will display the array, sort it, calculate the median, and display it again.", 0
	getUserNum		BYTE	"How many numbers should be generated for the array? (10-200): ", 0
	errorM			BYTE	"ERROR: Out of allowable specified range.  Please enter again.", 0
	unsorted		BYTE	"The unsorted array: ", 0
	sorted			BYTE	"The sorted array in descending order: ", 0
	median			BYTE	"The median is ", 0
	spaces			BYTE	"   "
	ending			BYTE	"These results provided by J. Hughes.  Goodbye.", 0
	request			DWORD	?
	myArray			DWORD	MAX DUP(?)
	count 			DWORD	0
	medianValue		DWORD	?


.code

main PROC

	call Randomize					;set up seed for randomization

	call introduction
	push OFFSET request				;pushes the location of request onto stack to pass to getData
	call getData

	COMMENT @
	push OFFSET myArray
	push request
	call fillArray

	push OFFSET unsorted
	push OFFSET myArray
	push request
	call displayArray

	push OFFSET myArray
	push request
	call sortArray

	push OFFSET count
	push OFFSET medianValue
	push OFFSET myArray
	push request
	call medianArray

	push OFFSET sorted
	push OFFSET myArray
	push request
	call displayArray
	@
	call farewell

	exit
main ENDP

;-------------------------------------------------------------------
; introduction
;
;	Introduces the programmer to the user as well as explains the
;	details of the program.  Instructs user on how to proceed to
;	attain desired results.
;
;	Receives: NONE
;	Returns: NONE
;	Regs Changed: EDX
;-------------------------------------------------------------------
introduction PROC

	mov edx, OFFSET myName				;moves myName into the edx register
	call WriteString					;prints the string in the edx register to the console
	call CrLf							;newline (will not comment these last two lines out if they are repeated)
	mov edx, OFFSET explain
	call WriteString
	call CrLf
	mov edx, OFFSET explain2
	call WriteString
	call CrLf
	ret

introduction ENDP

;-------------------------------------------------------------------
; getData
;
;	gets the range chosen by the user to generate the array
;	validate the number is in the correct range specified.
;
;	Receives: reference parameter to 'request'
;	Returns: NONE, erases 8 bytes off stack
;	Regs Changed: EAX, EBX, EBP
;-------------------------------------------------------------------
getData PROC

	push ebp
	mov ebp, esp

getAgain:
	mov edx, OFFSET getUserNum
	call WriteString
	call ReadDec
	call CrLf
	mov [ebp+8], eax
	call validate
	mov eax, [ebp+8]
	mov ebx, 0
	cmp eax, ebx
	je getAgain								;if request is equal to (0) jump to getAgain-choice was out of range
	mov [ebp+8], eax
	pop ebp
	ret 4

getData ENDP

;-------------------------------------------------------------------
; validate
;
;	Validate user integer input is between 1 - 400.  Produce error
;	if number is outside range and prompt for new entry.
;
;	Receives: errorTest and request reference parameter
;	Returns: NONE
;	Registers Changed: EAX, EBP, EDX
;	Variables changed: by reference 'request' changed if out of range.
;-------------------------------------------------------------------
validate PROC

	push ebp
	mov ebp, esp
	mov eax, [ebp+16]
	cmp eax, MAX					;if higher than upper range move to error message and loop input
	jg errorMessage
	cmp eax, MIN					;same but if lower
	jl errorMessage
	jmp toRet						;if number within 10-200, move to return statement

errorMessage:
	mov edx, OFFSET errorM
	call WriteString
	call CrLf
	mov eax, 0						;set eax to zero, thus signal main proc to loop again
	mov [ebp+16], eax				;mov 0 into address request is located at

toRet:
	pop ebp
	ret
validate ENDP

;-------------------------------------------------------------------
; fillArray
;
;	generates a random number and fills the array to the user specified number
;	Receives: reference to array, count(value)
;	Returns: NONE
;	Regs Changed: EAX, ESI, ESP, EBP, EBX
;-------------------------------------------------------------------
fillArray PROC

	push ebp
	mov ebp, esp
	mov edi, [ebp+12]							;sets esi to start of array
	mov ecx, [ebp+8]							;set loop counter to quantity of numbers to generate

fill:
	mov eax, HI								;set up EAX with parameter for RandomRange
	sub eax, LO								;sets up range for available numbers to RandomRange
	inc eax
	call RandomRange
	add eax, LO								;gives a "random" number between 100-999
	mov [edi], eax
	add edi, 4
	loop fill

	pop ebp
	ret 8
fillArray ENDP

;-------------------------------------------------------------------
; displayArray
;
;	display array to the user through output
;	Receives: reference to array, request(value)
;	Returns: NONE
;	Regs Changed: EAX, ESI, ESP, EBP, EBX
;-------------------------------------------------------------------
displayArray PROC

	push ebp
	mov ebp, esp
	mov edx, [ebp+16]
	call WriteString
	call CrLf
	mov esi, [ebp+12]
	mov ecx, [ebp+8]
	mov ebx, 0

write:
	mov eax, [esi]					;set eax to current array location
	cmp ebx, 10						;compares line counter to line limit
	jne noNewLine					;if number printed to the screen less than 10 this line, jump
	mov ebx, 0						;if number printed is 10, reset counter to 0
	call CrLf						;moves print out of numbers to next line

noNewLine:
	call WriteDec
	mov edx, OFFSET spaces
	call WriteString
	inc ebx							;increment counter for number of composites per line
	add esi, 4						;mov esi to next array element
	loop write						;loop to display next array element

	pop ebp
	ret 12

displayArray ENDP

;-------------------------------------------------------------------
; sortArray
;
;	bubble sort array from largest to smallest number
;	Receives: reference to array, request(value)
;	Returns: NONE
;	Regs Changed: EAX, ESI, ESP, EBP, EBX
;-------------------------------------------------------------------
sortArray PROC

	push ebp
	mov ebp, esp
	mov ecx, [ebp+8]
	dec ecx
outer:
	push ecx
	mov esi, [ebp+12]
inner:
	mov eax, [esi]
	cmp [esi+4], eax
	jl loop3
	xchg eax, [esi+4]
	mov [esi], eax
loop3:
	add esi, 4
	loop inner

	pop ecx
	loop outer

	pop ebp
	ret 8

sortArray ENDP

;-------------------------------------------------------------------
; medianArray
;
;	calculate median from sorted array
;	Receives: reference myArray, value - request
;	Returns: none
;	Regs Changed: EAX, EBX, ESI, EBP
;	variables changed: median
;-------------------------------------------------------------------
medianArray PROC

	push ebp
	mov ebp, esp
	mov edx, 0
	mov eax, [ebp+8]
	mov esi, [ebp+12]
	mov ebx, 2
	div ebx
	cmp edx, 1
	jne center

center:

	ret

medianArray ENDP

;-------------------------------------------------------------------
; farewell
;
;	Statement to end the program and say goodbye to user;
;	Receives: NONE
;	Returns: NONE
;	Regs Changed: EDX
;-------------------------------------------------------------------
farewell PROC

	call CrLf						;say goodbye to user
	mov edx, OFFSET ending
	call WriteString
	call CrLf
	ret

farewell ENDP

END main