%import textio
%import syslib

; Note: this code is compatible with C64 and CX16.

diskio {


    sub directory(ubyte drivenumber) -> ubyte {
        ; -- Shows the directory contents of disk drive 8-11 (provide as argument). Returns success flag.

        c64.SETNAM(1, "$")
        c64.SETLFS(1, drivenumber, 0)
        void c64.OPEN()          ; open 1,8,0,"$"
        if_cs
            goto io_error
        void c64.CHKIN(1)        ; use #1 as input channel
        if_cs
            goto io_error

        repeat 4 {
            void c64.CHRIN()     ; skip the 4 prologue bytes
        }

        ; while not key pressed / EOF encountered, read data.
        ubyte status = c64.READST()
        while not status {
            ubyte low = c64.CHRIN()
            ubyte high = c64.CHRIN()
            txt.print_uw(mkword(high, low))
            txt.chrout(' ')
            ubyte @zp char
            do {
                char = c64.CHRIN()
                txt.chrout(char)
            } until char==0
            txt.chrout('\n')
            void c64.CHRIN()     ; skip 2 bytes
            void c64.CHRIN()
            status = c64.READST()
            void c64.STOP()
            if_nz
                break
        }

io_error:
        status = c64.READST()
        c64.CLRCHN()        ; restore default i/o devices
        c64.CLOSE(1)

        if status and status != 64 {            ; 64=end of file
            txt.print("\ni/o error, status: ")
            txt.print_ub(status)
            txt.chrout('\n')
            return false
        }

        return true
    }


    ; TODO make a listfiles() call that accepts a callback routine to process the file entries.  This avoids the need to allocate and pass all those buffers.

    sub listfiles(ubyte drivenumber, uword pattern, ubyte suffixmatch,
                  uword namesarray, uword blocksarray, uword namesbuffer, ubyte maxnum) -> ubyte {
        ; -- returns a list of files in the directory matching the given prefix or suffix (optional)
        ;    their blocksizes will be put into the blocksarray
        ;    pointers to their names will be put into the namesarray
        ;    The namesbuffer should be at least 17 * maxnum and both arrays should be at least maxnum size as well.
        if maxnum==0  return 0

        ubyte num_files = 0
        ubyte pattern_size = 0
        if pattern!=0
            pattern_size = strlen(pattern)

        c64.SETNAM(1, "$")
        c64.SETLFS(1, drivenumber, 0)
        void c64.OPEN()          ; open 1,8,0,"$"
        if_cs
            goto close_end
        void c64.CHKIN(1)        ; use #1 as input channel
        if_cs
            goto close_end

        repeat 4 {
            void c64.CHRIN()     ; skip the 4 prologue bytes
        }

        ubyte disk_name = true
        uword last_filename_ptr = namesbuffer

        while not c64.READST() {
            @(blocksarray) = c64.CHRIN()
            @(blocksarray+1) = c64.CHRIN()

            ; read until the filename starts after the first "
            while c64.CHRIN()!='\"'  {
                if c64.READST()
                    goto close_end
            }

            ; append the filename to the buffer
            repeat {
                ubyte char = c64.CHRIN()
                if char==0
                    break
                ; if_z
                ;    break              ; TODO fix generated code for this jump
                if char=='\"'
                    break
                @(namesbuffer) = char
                namesbuffer++
            }

            if disk_name
                namesbuffer = last_filename_ptr
            else {
                @(namesbuffer) = 0
                namesbuffer++
                ubyte matches = true
                if pattern_size {
                    ; do filename matching
                    if suffixmatch
                        rightstr(last_filename_ptr, filename, pattern_size)
                    else
                        leftstr(last_filename_ptr, filename, pattern_size)
                    matches = strcmp(filename, pattern)==0
                }
                if matches {
                    ; enter the details into the arrays and increment
                    num_files++
                    @(namesarray) = lsb(last_filename_ptr)
                    @(namesarray+1) = msb(last_filename_ptr)
                    last_filename_ptr = namesbuffer
                    namesarray += 2
                    blocksarray += 2
                    if num_files>=maxnum
                        goto close_end
                } else {
                    ; no match, reset buffer to overwrite previous
                    namesbuffer = last_filename_ptr
                }
            }

            ; read the rest of the entry until the end
            do {
                ubyte char2 = c64.CHRIN()
                char2++              ; TODO fix condition test problem with ldx
            } until char2==1

            void c64.CHRIN()     ; skip 2 bytes
            void c64.CHRIN()
            disk_name = false
        }

close_end:
        c64.CLRCHN()        ; restore default i/o devices
        c64.CLOSE(1)
        return num_files
    }

    sub status(ubyte drivenumber) {
        ; -- display the disk drive's current status message
        c64.SETNAM(0, filename)
        c64.SETLFS(15, drivenumber, 15)
        void c64.OPEN()          ; open 15,8,15
        if_cs
            goto io_error
        void c64.CHKIN(15)        ; use #15 as input channel
        if_cs
            goto io_error

        while not c64.READST()
            txt.chrout(c64.CHRIN())

io_error:
        c64.CLRCHN()        ; restore default i/o devices
        c64.CLOSE(15)
    }


    sub save(ubyte drivenumber, uword filenameptr, uword address, uword size) -> ubyte {
        c64.SETNAM(strlen(filenameptr), filenameptr)
        c64.SETLFS(1, drivenumber, 0)
        uword end_address = address + size

        %asm {{
            lda  address
            sta  P8ZP_SCRATCH_W1
            lda  address+1
            sta  P8ZP_SCRATCH_W1+1
            stx  P8ZP_SCRATCH_REG
            lda  #<P8ZP_SCRATCH_W1
            ldx  end_address
            ldy  end_address+1
            jsr  c64.SAVE
            php
            ldx  P8ZP_SCRATCH_REG
            plp
        }}

        ubyte result=0
        if_cc
            result = c64.READST()==0

        c64.CLRCHN()
        c64.CLOSE(1)

        return result
    }

    sub load(ubyte drivenumber, uword filenameptr, uword address_override) -> uword {
        c64.SETNAM(strlen(filenameptr), filenameptr)
        ubyte secondary = 1
        uword end_of_load = 0
        if address_override
            secondary = 0
        c64.SETLFS(1, drivenumber, secondary)
        %asm {{
            stx  P8ZP_SCRATCH_REG
            lda  #0
            ldx  address_override
            ldy  address_override+1
            jsr  c64.LOAD
            bcs  +
            stx  end_of_load
            sty  end_of_load+1
+           ldx  P8ZP_SCRATCH_REG
        }}

        c64.CLRCHN()
        c64.CLOSE(1)

        if end_of_load
            return end_of_load - address_override

        return 0
    }


    str filename = "0:??????????????????????????????????????"

    sub delete(ubyte drivenumber, uword filenameptr) {
        ; -- delete a file on the drive
        ubyte flen = strlen(filenameptr)
        filename[0] = 's'
        filename[1] = ':'
        memcopy(filenameptr, &filename+2, flen+1)
        c64.SETNAM(flen+2, filename)
        c64.SETLFS(1, drivenumber, 15)
        void c64.OPEN()
        c64.CLRCHN()
        c64.CLOSE(1)
    }

    sub rename(ubyte drivenumber, uword oldfileptr, uword newfileptr) {
        ; -- rename a file on the drive
        ubyte flen_old = strlen(oldfileptr)
        ubyte flen_new = strlen(newfileptr)
        filename[0] = 'r'
        filename[1] = ':'
        memcopy(newfileptr, &filename+2, flen_new)
        filename[flen_new+2] = '='
        memcopy(oldfileptr, &filename+3+flen_new, flen_old+1)
        c64.SETNAM(3+flen_new+flen_old, filename)
        c64.SETLFS(1, drivenumber, 15)
        void c64.OPEN()
        c64.CLRCHN()
        c64.CLOSE(1)
    }
}