.data
input: .asciiz "\nPrzed zamiana stalych:\n"
output: .asciiz "\nPo zamianie stalych:\n"
fin: .asciiz "text.txt"      # filename for input
fout:	.asciiz "after.c"
buffer: .space 4096
processingBuffer: .space 8192
.text

################################################ fileRead:

# Open file for reading

li   $v0, 13       # system call for open file
la   $a0, fin      # input file name
li   $a1, 0        # flag for reading
li   $a2, 0        # mode is ignored
syscall            # open a file
move $s0, $v0      # save the file descriptor

# reading from file just opened

li   $v0, 14       # system call for reading from file
move $a0, $s0      # file descriptor
la   $a1, buffer   # address of buffer from which to read
li   $a2,  4096  # hardcoded buffer length
syscall            # read from file
 # Close the file
li   $v0, 16       # system call for close file
move $a0, $s0      # file descriptor to close
syscall            # close file


la      $a0, input     #calling opening prompt
li      $v0, 4
syscall

la      $a0, buffer     #calling opening prompt
li      $v0, 4
syscall

li	$t0, 0
la	$t7, processingBuffer
li	$t8, 0
li	$t9, 'x'

checkChar:
lb	$t1, buffer($t0)
beqz	$t1, finish
blt	$t1, '0', copy
bgt	$t1, '9', copy

digitFound:
la	$t2, ($t0)

checkForHexOrOct:
addi	$t2, $t2, 1
lb	$t3, buffer($t2)
beq	$t3, 'h', toHex
beq	$t3, 'q', toOct
blt	$t3, '0', endOfNumber
bgt	$t3, '9', endOfNumber
j	checkForHexOrOct

toHex:
sb	$t9, ($t7)
addi	$t7, $t7, 1
sb	$t8, ($t7)
addi	$t7, $t7, 1

copyHexNumber:
sb	$t1, ($t7)
addi	$t0, $t0, 1
addi	$t7, $t7, 1
lb	$t1, buffer($t0)
bne	$t1, $t3, copyHexNumber
j	checkChar

toOct:
sb	$t8, ($t7)
addi	$t7, $t7, 1

copyOctNumber:
sb	$t1, ($t7)
addi	$t7, $t7, 1
addi	$t0, $t0, 1
lb	$t1, buffer($t0)
bne	$t1, $t3, copyOctNumber
j	checkChar

endOfNumber:
sb	$t1, ($t7)
addi	$t0, $t0, 1
addi	$t7, $t7, 1
lb	$t1, buffer($t0)
bgt	$t1, $t3, checkChar
j endOfNumber

copy:
sb	$t1, ($t2)
addi	$t2, $t2, 1
addi	$t0, $t0, 1
j	checkChar

finish:
la      $a0, output    #calling opening prompt
li      $v0, 4
syscall
li	$v0, 4
la	$a0, processingBuffer
syscall