.data
KBBuffer: .skip 512
strPrompt: .asciz "Enter a string:\n"
nL: .asciz "\n"


lengthOutputPrompt: .asciz "1. Length of \'"
lengthOutputPrompt2: .asciz "\' is: "
lengthOutput: .skip 12


// Test variables
// endsWith
endsWithTestOutput: .asciz "10. Does \'"
endsWithTestOutput1: .asciz "\' end with \'"
endsWithTestOutput2: .asciz "\' ? "
endsWithTestSuccess: .asciz "yes"
endsWithTestFail:    .asciz "no"
endsWithTest: .asciz "in the hat."

// indexOf subroutines
indexOf_1Output:  .asciz "11. The index of the first occurence of \'g' in \'green eggs and ham\' is: "
indexOf_2Output:  .asciz "12. The index of the first occurence of \'g' starting from index 9 in \'green eggs and ham\' is: "
indexOf_3Output:  .asciz "13. The index of the first occurence of \'eggs`' in \'green eggs and ham\' is: "
indexOf_3Str: .asciz "eggs"

// lastIndexOf subroutines
lastIndexOf_1Output:  .asciz "14. The index of the last occurence of \'g\' in \'green eggs and ham\' is: "
lastIndexOf_2Output:  .asciz "15. The index of the last occurence of \'g\' starting from index 9 in \'green eggs and ham\' is: "
lastIndexOf_3Output:  .asciz "16. The index of the last occurence of \'eggs\' in \'green eggs and ham\' is: "

//replace
replace_Output: .asciz "17. Replace all occurences of \'C\' in str1 with \'B\': "

// upper/lower case
toLowerCase_Output: .asciz "18. Str1 toLowerCase: "
toUpperCase_Output: .asciz "19. Str1 toUpperCase: "

// concat
concat_Output: .asciz "20. Str1 + \' \' + Str2: "
strSpace: .asciz " "

@@@@ CODE @@
    .text
    .global _start
    .extern malloc
_start:

@@@@@@ GET FIRST INPUT @@@@@@
getFirstInput:
  ldr R1,=strPrompt
    bl putstring

    ldr R1, =KBBuffer
    mov R2, #512
    bl getstring  // R0 = number of characters read from keyboard
    add R0, R0, #1 // R0 = R0 + 1 ( for null terminator )
    bl malloc   // R0 = address of memory reserved
    mov R6, R0      // R6 = R0 (address of memory reserved)
    ldr R1, =KBBuffer
getFirstInput_Loop:
    ldrb R5, [R1], #1 // R5 = byte of *R1, R1++
    cmp R5, #0    // check for null
    strb R5, [R0], #1 // *R0 = R5, R0++
    bne getFirstInput_Loop
  ldr R1,=nL
    bl putstring

@@@@@@ GET SECOND INPUT @@@@@@
getSecondInput:
    ldr R1,=strPrompt
    bl putstring

    ldr R1, =KBBuffer
    mov R2, #512
    bl getstring  // R0 = number of characters read from keyboard
    add R0, R0, #1 // R0 = R0 + 1 ( for null terminator )
    bl malloc       // R0 = address of memory reserved
    mov R7, R0      // R7 = R0 (address of second input string)
    ldr R1, =KBBuffer
getSecondInput_Loop:
    ldrb R5, [R1], #1 // R5 = byte of *R1, R1++
    cmp R5, #0          // check for null
    strb R5, [R0], #1 // *R0 = R5, R0++
    bne getSecondInput_Loop // Keep looping until null terminator
    ldr R1,=nL
    bl putstring

    @@@@@@ GET THIRD INPUT @@@@@@
    getThirdInput:
        ldr R1,=strPrompt
        bl putstring

        ldr R1, =KBBuffer
        mov R2, #512
        bl getstring  // R0 = number of characters read from keyboard
        add R0, R0, #1 // R0 = R0 + 1 ( for null terminator )
        bl malloc       // R0 = address of memory reserved
        mov R8, R0      // R7 = R0 (address of second input string)
        ldr R1, =KBBuffer
    getThirdInput_Loop:
        ldrb R5, [R1], #1 // R5 = byte of *R1, R1++
        cmp R5, #0          // check for null
        strb R5, [R0], #1 // *R0 = R5, R0++
        bne getThirdInput_Loop // Keep looping until null terminator
        ldr R1,=nL
        bl putstring


    @@@@@@@@@ BEGIN TESTS @@@@@@@@@
    // Remember:
        //
        // R6 = &str1,
    // R7 = &str2,
    // R8 = &str3

    @@@ #1: Output length of str1, str2, and str3
    ldr R1,=lengthOutputPrompt
    bl putstring // output "Length of "

    mov R1, R6
    bl putstring     // output str1 to console
    bl length       // R0 = length(str1)

    ldr R1,=lengthOutput
    bl intasc32  // lengthOutput = asciz(length(str1))

    ldr R1,=lengthOutputPrompt2 // " is: "
    bl putstring // Outputs " is: " to console

    ldr R1,=lengthOutput // R1 <- &lengthOutput
    bl putstring // Outputs length of str1 to console
    ldr R1,=nL
    bl putstring

    @@ #1: Output length of str2
    ldr R1,=lengthOutputPrompt
    bl putstring // output "Length of "

    mov R1, R7
    bl putstring     // output str2 to console
    bl length       // R0 = length(str2)

    ldr R1,=lengthOutput
    bl intasc32  // lengthOutput = asciz(length(str2))

    ldr R1,=lengthOutputPrompt2 // " is: "
    bl putstring // Outputs " is: " to console

    ldr R1,=lengthOutput // R1 <- &lengthOutput
    bl putstring // Outputs length of str2 to console
    ldr R1,=nL
    bl putstring

    @@ Output length of str3
    ldr R1,=lengthOutputPrompt
    bl putstring // output "Length of "

    mov R1, R8
    bl putstring     // output str3 to console
    bl length       // R0 = length(str3)

    ldr R1,=lengthOutput
    bl intasc32  // lengthOutput = asciz(length(str3))

    ldr R1,=lengthOutputPrompt2 // " is: "
    bl putstring // Outputs " is: " to console

    ldr R1,=lengthOutput // R1 <- &lengthOutput
    bl putstring // Outputs length of str3 to console
    ldr R1,=nL
    bl putstring


    @@@@ #10: endsWith(s1, "in the hat")
    ldr R1,=endsWithTestOutput
    bl putstring //Outputs "Does '" to console
    mov R1, R6
    bl putstring // outputs str1 to console
    ldr R1,=endsWithTestOutput1
    bl putstring // Outputs "' end with '" to console
    ldr R1,=endsWithTest
    bl putstring // Outputs "in the hat" to console
    ldr R1,=endsWithTestOutput2
    bl putstring // Outputs "' ? "

    mov R1, R6 // R1 = &str1
    ldr R2,=endsWithTest
    bl endsWith // R0 should be true (1)
    cmp R0, #1
    beq endsWith_Success
    bne endsWith_Fail
endsWith_Success:
    ldr R1,=endsWithTestSuccess
    bl putstring
    b endsWith_Test_End
endsWith_Fail:
    ldr R1,=endsWithTestFail
    bl putstring
endsWith_Test_End:
    ldr R1,=nL
    bl putstring


    @@@@ #11: indexOf_1(s2, 'g') // output should be 7
    ldr R1,=indexOf_1Output
    bl putstring
    mov R1, R7 // R1 = &str2
    mov R2, #'g' // R2 = ascii('g')
    bl indexOf_1 // R0 = first occurence of 'g' in str2

    ldr R1,=lengthOutput // R1 <= &lengthOutput
    bl intasc32                  // R0 = ascii(indexOf_1(str2))
    bl putstring                 // Output ascii(indexOf_1(str2))
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline


    @@@@ #12: indexOf_2(s2, 'g', 9) // output should be -1
    ldr R1,=indexOf_2Output
    bl putstring
    mov R1, R7   // R1 = &str2
    mov R2, #'g' // R2 = ascii('g')
    mov R3, #9   // Index to start from
    bl indexOf_2 // R0 = first occurence of 'g' in str2

    ldr R1,=lengthOutput // R1 <= &lengthOutput
    bl intasc32                  // R0 <= ascii(indexOf_1(str2))
    bl putstring                 // Output ascii(indexOf_1(str2))
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline



    @@@@ #13: indexOf_3(s2, "eggs") // output should be 6
    ldr R1,=indexOf_3Output
    bl putstring
    mov R1, R7                          // R1 = &str2
    ldr R2, =indexOf_3Str   // R2 = asciz('egg')
    bl indexOf_3                      // R0 = first occurence of 'eggs' in str2

    ldr R1,=lengthOutput // R1 <= &lengthOutput
    bl intasc32                  // R0 <= ascii(indexOf_1(str2))
    bl putstring                 // Output ascii(indexOf_1(str2))
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline

    @@@@ #14: lastIndexOf_1(s2, 'g') // output should be 8
    ldr R1,=lastIndexOf_1Output
    bl putstring
    mov R1, R7                          // R1 = &str2
    mov R2,#'g'                         // R2 = 'g'
    bl lastIndexOf_1                      // R0 = last occurence of 'g' in str2

    ldr R1,=lengthOutput // R1 <= &lengthOutput
    bl intasc32                  // R0 <= ascii(indexOf_1(str2))
    bl putstring                 // Output ascii(indexOf_1(str2))
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline

    @@@@ #15: lastIndexOf_2(s2, 'g', 9) // output should be -1
    ldr R1,=lastIndexOf_2Output
    bl putstring
    mov R1, R7                              // R1 = &str2
    mov R2, #'g'                            // R2 = 'g'
    mov R3, #9                              // Index to start searching from
    bl lastIndexOf_2                    // R0 = last occurence of 'g' in str2

    ldr R1,=lengthOutput // R1 <= &lengthOutput
    bl intasc32                  // R0 <= ascii(indexOf_1(str2))
    bl putstring                 // Output ascii(indexOf_1(str2))
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline

    @@@@ #16: lastIndexOf_3(s2, "egg") // output should be 6
    ldr R1,=lastIndexOf_3Output
    bl putstring
    mov R1, R7                              // R1 = &str2
    ldr R2, =indexOf_3Str
    bl lastIndexOf_3                    // R0 = last occurence of 'eggs' in str2

    ldr R1,=lengthOutput // R1 <= &lengthOutput
    bl intasc32                  // R0 <= ascii(indexOf_1(str2))
    bl putstring                 // Output ascii(indexOf_1(str2))
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline


    @@@@ #17: replace(s1, 'C', 'B') // output should be &("Bat in the hat.")
    ldr R1,=replace_Output
    bl putstring
    mov R1, R6                              // R1 = &str1
    mov R2, #'C'                            // R2 = ascii "C"
    mov R3, #'B'                            // R3 = ascii "B"
    bl replace                              // replaces all occurences of 'C' with 'B' in s1

    mov R1, R0 // move returned string address into R1 for output
    bl putstring
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline


    @@@@ #18: toLowerCase(s1) // Output should be "bat in the hat."
    ldr R1,=toLowerCase_Output
    bl putstring
    mov R1, R6                              // R1 = &str1
    bl toLowerCase                    // Converts str1 into all lowercase

    mov R1, R0                  // move returned string into R1 for output
    bl putstring
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline


    @@@@ #19: toUpperCase(s1) // Output should be "BAT IN THE HAT."
    ldr R1,=toUpperCase_Output
    bl putstring
    mov R1, R6                              // R1 = &str1
    bl toUpperCase                    // Converts str1 into all lowercase

    mov R1, R0                  // move returned string into R1 for output
    bl putstring
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline

    @@@@ #20: concat(s1, " ") // Output should be "BAT IN THE HAT."
    ldr R1,=concat_Output
    bl putstring

    mov R1, R6                              // R1 = &str1
    ldr R2, =strSpace                   // R2 = &(" ")
    bl concat                     // Concatenate Str1 with a space
    mov R1, R0
    mov R2, R7          // R2 = &str2
    bl concat                     // Concatenate str1 + str2

    mov R1, R0                  // move returned string into R1 for output
    bl putstring
    ldr R1,=nL                   // R1 <= &nL
    bl putstring                 // Output newline


@ End driver program
end:
  mov r0, #0 @ Exit status code set to 0
  mov r7, #1 @ Service command code (1), will terminate this program
  svc 0      @ Issue Linux command to terminate program
  .end