.data
str:    .asciiz "\n Please enter the number of items you are purchasing (should be less than or equal to 20): "
str1:   .asciiz "\n Sorry too many items to purchase! Please enter number of items you are purchasing"
str2:   .asciiz "\n Please enter the price of item "
str3:   .asciiz "\n Please enter the number of coupons that you want to use. "
str4:   .asciiz "\n Please enter the number of coupons that you want to use.It has to equal the same amount of items"
str5:   .asciiz "\n Please enter the amount of coupon "
str6:   .asciiz "\n This coupon is not acceptable"
str7:   .asciiz "\n Your total charge is: $"
str8:   .asciiz "\n Thank you for shopping with us."
str9:   .asciiz ":\t"
str11:  .asciiz"\n Has to be greater than 0"
str10: .asciiz"sum of coupon:"
priArr: .word 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
couArr: .word 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
   .text

main:       li $t1, 20
           li $t2, 1
           li $t3, 0
           li $t5, 10
           la $s0, priArr
           la $s1, couArr

           li $v0, 4
           la $a0, str
           syscall

           li $v0, 5
           syscall

           add $s3, $0, $v0      #moving user input to $s3

           bgt $s3, $t1, error1 # checking if the number of items is less than 20
           blt $s3,$t3,error4 # checking if less than 0

	    add $a1, $s3, $0        # moving number of items to $a1

           jal FillPriceArray      #jumps to subroutine to fill array with prices
#--------------------------------------------------------------------------------------

           add $s2, $0, $v1        #adds price sum to s2


           la $s0, priArr

           li $v0, 4           #asks for how many coupons
           la $a0, str3
           syscall

           li $v0, 5           #loads integer into $v0
           syscall

           bgt $v0, $s3, error2        #if input >= limit, go to error
           blt $v0,$s3,error2
           add $t4, $v0, 0         #adds input to t4

           add $a3, $t4, $0        #adds input to a3

           jal FillCouponArray     #jumps to subroutine to fill array with coupon

           add $s5, $v1, $0        #adds coupon input to s5

           sub $t7, $s2, $s5       #subtracts price sum and coupons and puts it into t7
           li $v0, 4           #prints output
           la $a0, str7
           syscall

           li $v0, 1           #prints dollar amount
           add $a0, $t7, $0
           syscall


exit:       li $v0, 10
           syscall
#-----------------------------------------------------------------------------------
FillPriceArray:
             li $t0, 10           #adds limit($a1) to $t0
              li $t1, 1            #adds counter to $t1
              li $t2, 0            #adds loop counter to $t2
              add $t3, $a1, $0     #adds input to t3

read:
       beq $t3, $t2, end

           li $v0, 4           #asks for price of item
           la $a0, str2
           syscall

           li $v0, 1           #prints counter
           add $a0, $t1, $0
           syscall

           li $v0, 4           #prints colon and tab
           la $a0, str9
           syscall

           li $v0, 5           #loads integer into $v0
           syscall

	    blt $v0,$t2,error6

           sw $v0, 0($s0)          #stores the integer into array1

           add $t1, $t1, 1         #adds 1 to counter
           add $t2, $t2, 1         #adds 1 to loop counter
           add $s0, $s0, 4         #increments array
           add $t4, $t4, $v0       #adds number to sum

           j read

       end:

       add $v1, $t4, $0
           jr $ra

#-----------------------------------------------------------------------------------
FillCouponArray:    li $t0, 10          #adds 10 into t0
                   li $t1, 1           #adds counter to $t1
                   li $t2, 0           #adds loop counter to $t2
                   add $t4, $a3, $0        #adds coupon input to t4

       read1:  beq $t4, $t2, end1      #beg of loop

           lw $v0, 0($s0)          #stores word from price array into $v0 // might have to move outside loop

           add $t5, $0, $v0        #stores price into $t5

           li $v0, 4           #outputs please enter amount of coupon
           la $a0, str5
           syscall

           li $v0, 1           #prints counter
           add $a0, $t1, $0
           syscall

           li $v0, 4           #prints colon and tab
           la $a0, str9
           syscall

           li $v0, 5           #loads integer into $v0
           syscall

           blt $v0,$t2,error5

	    add $t3, $v0, $0        #adds input to t3

           bgt $t3, $t0, error3        #if input is > 10

           bge $t3, $t5, error3        #if input is >= price number

           sw $t3, 0($s1)          #stores the integer into array1

           add $t6, $t6, $v0       #adds number to sum

      increment:
                   add $t1, $t1, 1
                   add $t2, $t2, 1
                   add $s0, $s0, 4         #increments array
                   add $s1, $s1, 4         #increments array 2

                   j read1

       end1:   add $v1, $t6, $0        #adds coupon sum to v2

	         jr $ra                  #returns back to addresss



#-----------------------------------------------------------------------------------
error1:     li $v0, 4           #outputs too many items to purchase
           la $a0, str1
           syscall

           j main
#-----------------------------------------------------------------------------------
error2:     li $v0, 4           #outputs too many coupons
           la $a0, str4
           syscall

           jr $ra
#-----------------------------------------------------------------------------------
error3:     li $v0, 4           #outputs coupon is not acceptable
           la $a0, str6
           syscall

           sw $0, 0($s1)

	    j increment
#-----------------------------------------------------------------------------------
error4:

li $v0, 4
la $a0, str11
syscall

j main
#-----------------------------------------------------------------------------------
error5:
li $v0, 4
la $a0, str11
syscall

j read1
#-----------------------------------------------------------------------------------
error6:
li $v0, 4
la $a0, str11
syscall

j read