;==============================================

#define  Cn2_Setup          $4209
#define  Cn2_Clear_SendBuf  $420C
#define  Cn2_Clear_RecBuf   $420F
#define Cn2_Setdown         $4212
#define Cn2_GetK            $4221
#define SWord               $87FF
#define Rword               $86F8
#define Sdat                $8801
#define Rdat                $86FA
#define rvarlength          $9872+176   ; put at the end of appbackupscreen right after iambians variable only because idk what he is doing there so best safe then sorry
dbfCn2BASICSend:            ;INCOMPLETE
;Check arguments
; order is
; ID
; Data
; ID is any real variable preferably theta for simplicities sake
; Data can be a string of a list. gonna have to parse the vat for just the type and put a 1/0 in for type
; after thats parsed its a simple copy of the real to the ip part
; the size is copied from the data pointer
; for lists its (multx9)+1
; for strings its length+1

;   Order of stuff
; Check for pending frame if one quit early (send status code?)
; Set up buffers
; set up sizes
; mark pending
; set ans to 1 if frame was set to 0 if not
; quit
 ld a,(sword+1) ; load a with the frame pending flag byte
 bit 7,a             ; if the msb is set we have a frame
 jp z,QUITBAD
 ; Assumign theta for The real var removing from wiki now
 ld hl,IDRealName
 rst 20h
 bcall(chkfindsym)
 jr c,QUITBAD
 xor a
 cp b
 jr nz,QUITBAD
 inc de \ inc de ; Load to the actual data we want not the realvar info
 ex de,hl
 ld de,$87fa
 ld bc,5
 ldir


 ld hl,sc1
 rst 20h
 bcall(chkfindsym)
 jr c,QUITBAD
 xor a
 cp b
 jr nz,QUITBAD
 ex de,hl
 and 1fh
 cp 4
 jr z,SString
 cp 1
 jr z,SList
 jr BadQuit
SString:      ;Set (frame) to 0 ; Also get size from list and +3 to it for frame length
 ld a,0
 ld de,sdat    ; overwrite vat pointer (lol who uses those) with sdat
 ld (de),a     ; load first byte of frame with 1
 inc de
 ld c,(hl)
 inc hl
 ld b,(hl)
 dec hl
 push bc
  inc bc
  inc bc
  inc bc
  ld (sword),bc
 pop bc
 ldir
 ld a,0
 bcall(_setxxop1)
 set 7,(sword+1)
 ret
SList:        ; Set (frame) to 1
 ld a,1
 ld de,sdat    ; overwrite vat pointer (lol who uses those) with sdat
 ld (de),a     ; load first byte of frame with 1
 inc de
 ld c,(hl)  ; dont need the whole thing as this can not be over 28
  ld a,c
  cp 29
  jr nc,QUITBAD   ; quit if over 28
  add a,a
  add a,a
  add a,a
  add a,c
  ld c,a
  ld b,0
  inc a
  inc a
  push bc
   inc a
   ld (sword),a
  pop bc
 ; hl = var data
 ; bc = length of var.
 ; de = cn2 buffer
 ldir
 ld a,0
 bcall(_setxxop1)
 set 7,(sword+1)
 ret
dbfCn2BASICGet:             ;INCOMPLETE
; Check to see if there is a frame.
; if there is parse the frame and write out
; id gets copied into the String
; List gets copied into the list


; we are sending raw variable data in the frames
; So if it is a list add it to a list if it is a string add it to a string
; MAKE SURE WE HAVE ENOUGH Ram for this

;Order of routine.
;   Check for pending frame  [x]
;   MTROC ID string8
;   Copy ID over
;   Check Data Type
;   MTROC Appropriate variable  (LCn2,Str9)
;   Copy Data over
;   Clear Frame Pending
;   Ret
; set ans to 0 if frame was recieved

 ld a,(rword+1) ; load a with the incoming flag byte
 bit 7,a             ; if the msb is set we have a frame
 jp z,QUITBAD               ; if its not quit
 ld hl,IDrealName
 ld a,1                  ;delete and create theta.
 ld (RVarLength),a
 call DeleteAndCreate
 push de                ; save data pointer so we can write the id to it later
  ld a,(rdat)          ; load a with frame id
  or a    ;if 0 we have a string if one we have a list.
  jp nz,ldlist          ; if list div length by nine
  ld a,(Rword)
  sub 1                 ; if string calculate length
  ld (RVarLength),a
  ld hl,DataStringName
  jr Copydata
;kinda just shoved this here. Makes following it a pain but do I really care?
; nothing traverses here it all jumps over it. Woo dead space
QUITBAD:
 ;returns 1 if we failed. reusable routine.
 ld a,1
 bcall(_setxxop1)
 ret
ldlist:
  ld a,(rword)
  dec a
  ld b,0
Div9Loop:
  inc b
  sub 9
  jr z,Div9Done
  jr nc,div9loop
Div9Done:
  ld a,b
  ld (RVarLEngth),a
  ld hl,DataListName


CopyData:
  Call DeleteAndCreate
  ;get data length -1 -> bc
  ld a,(rword)      ; get length from frame and store into bc
  dec a
  ld c,a
  ld b,0
  ld hl,(rdat+1)    ; load hl with pointer to frame+1 for variable data
  ldir
 pop de
;here i handle the real this should be rather easy
;we are interested in just the first 5 values in the mantessa
; the mantessa is de+2
; so lets initialise our variable
 ld hl,$0080     ;standard exponent and no negative? i think we will see
 inc de \ inc de
;Now the next 5 bytes are our id.
 ld bc,5
 ld hl,($86F3)   ; recieve id
 ldir
;theta now has the user id in it
 ld hl,RWord+1
 res 7,(hl)
 ; aknowledge we got a frame and quit
 ld a,0
 bcall(_setxxop1)
 ret
 ;according to iambian and some of kerms code this is supposed to return the value of op1 in ans �\(�_o)/�
 ; jp XlibEndNoOut
DeleteAndCreate
;expects pointer to variable name in hl
;destroys all
;returns pointer to variable data in de
 push hl
  rst 20h  ;load op1 with variable name
  bcall(_chkfindsym)
  jr c,create
  ld hl,op1             ; I belive i need to do this for delvararc.
  bcall(_DelVarArc)   ;delete if since it exists
Create:
 pop hl
 ld a,(hl)
 ld hl,(RVarLength)
 bcall(_createvar)
 ret





DataStringName:
 .db strngOBJ,tVarStrng,tstr9,$0
IDRealName:
 .db $0,tTheta,$0,$0
DataListName:
 .db $01,tVarLst,tC,tN,t2,$0

dbfCn2BASICStop:                ;Main Functions Complete
 ld a,(nargs)
 cp 2
 jp nz,xLIBEndNoOut
 ld A,(var1)
 cp 1
 jr nz,{@}    ; If enabled, skip over enabling
 call enablecn2
 jr {2@}
@:
 call disablecn2
@:
 jp xLIBEndNoOut
EnableCn2:
;Disable APD Setup Cn2.2 Hook TiOs intterupt.
 di
 bcall(4C84h)            ;Disable APD  ( DO we even use ti83+.inc???
 call Cn2_Setup
 ld hl,0038
 ld (Cn2_Hook_Pre),HL   ; Hopefully chain The tios intterupt before the calcnet intterupt.
                          ; Personally wondering if this should be at the end of the calcnet intterupt.
                          ; only because of how the tios intterupt is unpredicable in length.
                          ; Do we really have to worry about that?? According to kerm I do not

 set 3,(iy+33h)           ; ignoreBPlink
 res 4,(iy+33h)           ; BPLinkOn      Disable link Assist for sure
 res 0,(iy+3Eh)           ;                Disables Silent linking supposedly
 ld a,%00000001
 out (08),a               ;Disable link assist via ports want as much cushion as possible here.
 ei
 jp xLIBEndNoOut

DisableCn2:
 di
 call Cn2_Setdown
 res 3,(iy+33h)           ; ignoreBPlink
 set 4,(iy+33h)           ; BPLinkOn      Enable Silent linking and link assist
 set 0,(iy+3Eh)
 ld a,0
 out (08),a               ; Reenable link assist disable intterupts
 bcall($4C87)              ; Enable Apd again
 ei
 jp xLibEndNoOut