fproj.asm

%include "simple_io.inc"

global asm_main
extern rperm

section .data
	err1: db "First character is not 1 - 8", 10, 0
	err2: db "No comma", 10, 0
	err3: db "Third character is not 1 - 8", 10, 0
	err4: db "No need to swap a box with itself", 10, 0
	err5: db "Too many characters", 10, 0
	msg1: db "Enter a,b to swap", 10, 0
	msg2: db "Enter 0 to end: ", 0
	msg3: db "Box ", 0
	msg4: db " has been swapped with box ", 0
	msg5: db "Program terminated", 10, 0
section .bss
	array: resq 8
	buffer: resb 4
section .text

disp_seg:
	enter 0,0
	saveregs

	;r14 for element
	;r13 for level
	;r12 for left spacing
	;r15 for loop counting
	;bl for 1st printing char
	;cl for 2nd printing char

	mov r14, [rbp+24] ; element
	mov r13, [rbp+32] ; level
	dec r13 ; Offset

	;;;;;;;BASE Level;;;;;;;;;;

	cmp r13, qword 0
	jne NOTBASE

	mov r15, qword 0
	BASE_L_S:
	  cmp r15, qword 5
	  je BASE_L_E
	  mov al, ' '
	  call print_char
	  inc r15
	  jmp BASE_L_S

	BASE_L_E:

	mov rax, r14
	call print_int
	
	mov r15, qword 0
	BASE_R_S:
	  cmp r15, qword 4
	  je BASE_R_E
	  mov al, ' '
	  call print_char
	  inc r15
	  jmp BASE_R_S

	BASE_R_E:
	  jmp DONE

	NOTBASE:

	;;;;;;;;;;Left Spacing Amount;;;;;;;;;;

	mov r12, qword 2 ; Left spacing of rect
	cmp r14, qword 8
	je CHAR1
	cmp r14, qword 7
	je CHAR1
	inc r12 ; 3 spacing
	cmp r14, qword 6
	je CHAR1
	cmp r14, qword 5
	je CHAR1
	inc r12 ; 4 spacing
	cmp r14, qword 4
	je CHAR1
	cmp r14, qword 3
	je CHAR1
	inc r12 ; 5 spacing

	;;;;;;;;;;;1st Spacing Char;;;;;;;;;;;;;

	CHAR1:

	;;;;;;;;;;Level 1;;;;;;;;;;;;;;;;

	cmp qword r13, qword 1 ; level == 1
	jne NOT_L_1
	mov rbx, qword 0
	mov bl, '.'
	mov rcx, qword 0
	mov cl, '-'
	jmp PRINTING

	;;;;;;;;;;;Not Level 1;;;;;;;;;;;

	NOT_L_1:
	mov rbx, qword 0
	mov bl, ' '

	;;;;;;;Overhead Space;;;;;;;;
	
	cmp r14, r13 ; element < level
	jae CHAR2
	
	EMPTY_SPACE:  
	  mov r15, qword 0
	  EMPTY_SPACE_S:
	    cmp r15, qword 10
	    je DONE
	    mov al, ' '
	    call print_char
	    inc r15
	    jmp EMPTY_SPACE_S

	;;;;;2nd Spacing Char;;;;;;;;

	CHAR2:
	
	cmp r14, r13 ; element == level
	jne BLANK
	mov rcx, qword 0
	mov cl, '-'
	jmp PRINTING
	BLANK:
	mov rcx, qword 0
	mov cl, ' '

	;;;;;;;;;Printing;;;;;;;;;;

	PRINTING:

	;;;;;;;;;Left Spacing;;;;;

	LEFT:

	  mov r15, qword 0
	  LEFT_S:
	    cmp r15, r12 ; counter == left spacing
	    je LEFT_E
	    mov al, bl
	    call print_char
	    inc r15
	    jmp LEFT_S

	  LEFT_E:

	;;;;;;Rectangle Printing;;;;;;;

	  mov al, '+'
	  call print_char

	  cmp r14, qword 1 ; 1 has only 1 +
	  je RIGHT

	MIDDLE:
	  
	  mov r15, r14
	  sub r15, qword 2
	  
	  MID_S:
	    cmp r15, qword 0
	    jbe MID_E
	    mov al, cl
	    call print_char
	    dec r15
	    jmp MID_S

	  MID_E:
	    mov al, '+'
	    call print_char

	;;;;;;Right Spacing;;;;;;;;;;

	RIGHT:

	  mov r15, qword 10 ; Right spacing, 10 - element - left spacing
	  sub r15, r14
	  sub r15, r12
		
	  RIGHT_S:
	    cmp r15, qword 0
	    je RIGHT_E
	    mov al, bl
	    call print_char
	    dec r15
	    jmp RIGHT_S
	  
	  RIGHT_E:

	DONE:
	restoregs
	leave
	ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
display:
	enter 0,0
	saveregs

	;rbx for array
	;rcx for size
	;r15 for loop counting
	;r14 for level counter
	;r13 for array counter

	mov rbx, [rbp+24] ; array
	mov rcx, [rbp+32] ; size

	mov r14, rcx ; level counter
	inc r14 ; offset and include base level

	DISP_S: ; Display each line

          cmp r14, qword 0
          je DISP_E

	  mov r13, qword 0 ; array counter

	  LINE_S: ; Display the segment for each element
	    cmp r13, rcx ; array counter, size
	    je LINE_E
	    
	    push r14 ; level
	    push qword [rbx+r13*8] ; nth element in array
	    sub rsp, 8
	    call disp_seg
	    add rsp, 24
	    
	    inc r13 ; Updata array counter

	    jmp LINE_S

	  LINE_E:
	  
	  dec r14 ; Update level counter
	  call print_nl

	  jmp DISP_S
	
	DISP_E:
	  
	restoregs
	leave
	ret

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
asm_main:	
	enter 0,0
	saveregs

	mov	rdi, array ; Randomize array
	mov	rsi, qword 8
	call rperm

	LOOPING:

	push qword 8
	push array
	sub rsp, 8
	call display
	add rsp, 24

	;;;;;;;;Input;;;;;;;;

	mov rax, msg1
	call print_string
	mov rax, msg2
	call print_string

	mov r15, qword 0
	READ_S: ; Read until input buffer is empty
	  call read_char
	  cmp r15, qword 4 ; Only up to 4 characters matter for correct input
	  jae OVERFLOW
	  mov byte [buffer+r15], al

	  OVERFLOW:
	  inc r15
	  cmp al, byte 10
	  je READ_E
	  jmp READ_S

	READ_E:

	cmp byte [buffer], '0' ; Exit
	jne INPUT_SWAP
	cmp byte [buffer+1], byte 10
	je END
	jmp ERR5

	INPUT_SWAP: 

	cmp byte [buffer], '1' ; Checking
	jb ERR1
	cmp byte [buffer], '8'
	ja ERR1
	cmp byte [buffer+1], ','
	jne ERR2
	cmp byte [buffer+2], '1'
	jb ERR3
	cmp byte [buffer+2], '8'
	ja ERR3
	mov r15b, byte [buffer] ; Swapping the same box works but why bother?
	cmp r15b, byte [buffer+2]
	je ERR4
	cmp byte [buffer+3], byte 10 ; The enter key produces byte 10
	jne ERR5

	;;;;;;;Swap;;;;;;;

	mov rax, msg3
	call print_string
	mov al, byte [buffer]
	call print_char
	mov rax, msg4
	call print_string
	mov al, byte [buffer+2]
	call print_char
	call print_nl

	swap:

	mov r14, qword 0
	mov r14b, byte [buffer] ; Char to int
	sub r14, '0'
	mov r13, qword 0
	mov r13b, byte [buffer+2]
	sub r13, '0'

	mov r15, qword 0

	FIRST_S: ; Find 1st position
	  cmp r14, [array+r15*8]
	  je FIRST_E
	  inc r15
	  jmp FIRST_S

	FIRST_E:

	mov r14, r15 ; 1st position
	mov r15, qword 0

	SECOND_S: ; Find 2nd position
	  cmp r13, [array+r15*8]
	  je SECOND_E
	  inc r15
	  jmp SECOND_S

	SECOND_E:

	mov r13, r15 ; 2nd position

	mov r12, qword [array+r14*8] ; Swap 1st and 2nd using temp
	mov r15, qword [array+r13*8]
	mov qword [array+r14*8], r15
	mov qword [array+r13*8], r12

	jmp LOOPING

	ERR1:
	  mov rax, err1
	  call print_string
	  jmp LOOPING

	ERR2:
	  mov rax, err2
	  call print_string
	  jmp LOOPING

	ERR3:
	  mov rax, err3
	  call print_string
	  jmp LOOPING

	ERR4:
	  mov rax, err4
	  call print_string
	  jmp LOOPING

	ERR5:
	  mov rax, err5
	  call print_string
	  jmp LOOPING

	END:
	mov rax, msg5
	call print_string

	restoregs
	leave
	ret