; E06-S01: interface value ABI fixture in x128.
;
; Runs under CR=$0E. It checks:
;   - the four-byte value is little-endian: object low/high then table
;     low/high;
;   - null conversion writes four zero bytes and ignores the table pointer;
;   - a non-null object with no table is IF_ERR_TABLE with a zero table half;
;   - copying preserves all four bytes and never reads through a null pointer;
;   - slot lookup reads table[slot*2] in declaration slot order;
;   - the four-byte result area IF_RESULT carries all four bytes, and a failed
;     store leaves the previous result intact;
;   - four interface bytes pushed right-to-left arrive at FP+2..FP+5.
;
; MB_DATA flags 0..5 report the six phases.

.setcpu "6502"
.include "../../src/common/c128.inc"
.include "../../src/common/mailbox.inc"
.include "../../src/common/print.inc"
.include "../../src/common/frames.inc"
.include "../../src/common/interfaces.inc"

.import pr_char, pr_cr, pr_text
.import frame_init, frame_enter, frame_leave, frame_push_byte, frame_discard
.import if_conv, if_copy, if_is_null, if_slot, if_ret_store, if_ret_load
.import if_error
.importzp if_obj, if_tab, if_dst, if_src

.macro TEXT src, len
        lda #<src
        ldx #>src
        ldy #len
        jsr pr_text
.endmacro

.macro PHASE n
        lda #n
        sta MB_CODE
        lda #$00
        sta MB_CODE+1
.endmacro

.macro POINT var
        lda #<var
        sta tptr
        lda #>var
        sta tptr+1
.endmacro

.macro SETDST var
        lda #<var
        sta if_dst
        lda #>var
        sta if_dst+1
.endmacro

.macro SETSRC var
        lda #<var
        sta if_src
        lda #>var
        sta if_src+1
.endmacro

.macro EXPECT v0, v1, v2, v3
        lda #v0
        sta e0
        lda #v1
        sta e1
        lda #v2
        sta e2
        lda #v3
        sta e3
.endmacro

.macro FAIL_CS
        bcc :+
        jmp @fail
:
.endmacro

.macro FAIL_CC
        bcs :+
        jmp @fail
:
.endmacro

.macro FAIL_NE
        beq :+
        jmp @fail
:
.endmacro

.segment "LOADADDR"
        .word $1C01

.segment "EXEHDR"
        .word basic_end
        .word 10
        .byte $9E
        .byte "7181"
        .byte $00
basic_end:
        .word $0000

.segment "MAILBOX"
        .res MB_SIZE

.segment "ZEROPAGE"
tptr:   .res 2

.segment "STARTUP"
.export test_entry, test_end
test_entry:
        php
        sei
        ldx #MB_SIZE - 1
        lda #$00
@clr:   sta MB_BASE,x
        dex
        bpl @clr
        lda #MB_MAGIC0_VALUE
        sta MB_MAGIC0
        lda #MB_MAGIC1_VALUE
        sta MB_MAGIC1
        lda #MB_PROD_PROGRAM
        sta MB_PRODUCER
        lda #MB_ST_RUNNING
        sta MB_STATUS
        lda #$00
        sta MB_CODE
        sta MB_CODE+1

        lda MMU_CR
        sta saved_cr
        lda #CR_RAM0_KERNAL
        sta MMU_CR
        lda #PR_CLEAR
        jsr pr_char
        TEXT title, 22
        jsr pr_cr

        ; 1: little-endian layout of object and table pointers.
        PHASE 1
        lda #$34
        sta if_obj
        lda #$12
        sta if_obj+1
        lda #$78
        sta if_tab
        lda #$56
        sta if_tab+1
        SETDST val_a
        jsr if_conv
        FAIL_CS
        lda if_error
        FAIL_NE
        POINT val_a
        EXPECT $34, $12, $78, $56
        jsr cmp_val
        FAIL_CS
        lda #$01
        sta MB_DATA+0

        ; 2: canonical null and invalid conversion.
        PHASE 2
        lda #$00
        sta if_obj
        sta if_obj+1
        lda #$78
        sta if_tab
        lda #$56
        sta if_tab+1
        SETDST val_b
        jsr if_conv
        FAIL_CS
        lda if_error
        FAIL_NE
        POINT val_b
        EXPECT $00, $00, $00, $00
        jsr cmp_val
        FAIL_CS

        lda #<val_b
        ldx #>val_b
        jsr if_is_null
        FAIL_CC
        lda #<val_a
        ldx #>val_a
        jsr if_is_null
        FAIL_CS

        lda #$34
        sta if_obj
        lda #$12
        sta if_obj+1
        lda #$00
        sta if_tab
        sta if_tab+1
        SETDST val_c
        jsr if_conv
        FAIL_CC
        lda if_error
        cmp #IF_ERR_TABLE
        FAIL_NE
        POINT val_c
        EXPECT $34, $12, $00, $00
        jsr cmp_val
        FAIL_CS

        lda #$00
        ldx #$00
        jsr if_is_null
        FAIL_CC
        lda #$01
        sta MB_DATA+1

        ; 3: copying preserves every byte and rejects a null source pointer.
        PHASE 3
        SETSRC val_a
        SETDST val_d
        jsr if_copy
        FAIL_CS
        POINT val_d
        EXPECT $34, $12, $78, $56
        jsr cmp_val
        FAIL_CS
        POINT val_a
        EXPECT $34, $12, $78, $56
        jsr cmp_val
        FAIL_CS

        SETSRC val_b
        SETDST val_e
        jsr if_copy
        FAIL_CS
        POINT val_e
        EXPECT $00, $00, $00, $00
        jsr cmp_val
        FAIL_CS

        lda #$00
        sta if_src
        sta if_src+1
        SETDST val_e
        jsr if_copy
        FAIL_CC
        lda if_error
        cmp #IF_ERR_NULL
        FAIL_NE
        POINT val_e
        EXPECT $00, $00, $00, $00
        jsr cmp_val
        FAIL_CS
        lda #$01
        sta MB_DATA+2

        ; 4: slot order and the two refusal cases.
        PHASE 4
        lda #$34
        sta if_obj
        lda #$12
        sta if_obj+1
        lda #<slot_tab
        sta if_tab
        lda #>slot_tab
        sta if_tab+1
        SETDST val_f
        jsr if_conv
        FAIL_CS

        lda #<val_f
        ldx #>val_f
        ldy #0
        jsr if_slot
        FAIL_CS
        cmp #$EF
        FAIL_NE
        cpx #$BE
        FAIL_NE

        lda #<val_f
        ldx #>val_f
        ldy #1
        jsr if_slot
        FAIL_CS
        cmp #$FE
        FAIL_NE
        cpx #$CA
        FAIL_NE

        lda #<val_b
        ldx #>val_b
        ldy #0
        jsr if_slot
        FAIL_CC
        lda if_error
        cmp #IF_ERR_NULL
        FAIL_NE

        lda #<val_c
        ldx #>val_c
        ldy #0
        jsr if_slot
        FAIL_CC
        lda if_error
        cmp #IF_ERR_TABLE
        FAIL_NE
        lda #$01
        sta MB_DATA+3

        ; 5: four-byte result area.
        PHASE 5
        lda #<val_a
        ldx #>val_a
        jsr if_ret_store
        FAIL_CS
        POINT IF_RESULT
        EXPECT $34, $12, $78, $56
        jsr cmp_val
        FAIL_CS

        lda #<val_g
        ldx #>val_g
        jsr if_ret_load
        FAIL_CS
        POINT val_g
        EXPECT $34, $12, $78, $56
        jsr cmp_val
        FAIL_CS

        lda #<val_b
        ldx #>val_b
        jsr if_ret_store
        FAIL_CS
        lda #<val_h
        ldx #>val_h
        jsr if_ret_load
        FAIL_CS
        POINT val_h
        EXPECT $00, $00, $00, $00
        jsr cmp_val
        FAIL_CS

        lda #<val_a
        ldx #>val_a
        jsr if_ret_store
        FAIL_CS
        lda #$00
        ldx #$00
        jsr if_ret_store
        FAIL_CC
        lda if_error
        cmp #IF_ERR_NULL
        FAIL_NE
        POINT IF_RESULT
        EXPECT $34, $12, $78, $56
        jsr cmp_val
        FAIL_CS
        lda #$01
        sta MB_DATA+4

        ; 6: an interface argument pushed right-to-left lands object-first.
        PHASE 6
        jsr frame_init
        lda FRAME_SP
        sta saved_sp
        lda FRAME_SP+1
        sta saved_sp+1

        lda #$56
        jsr frame_push_byte
        FAIL_CS
        lda #$78
        jsr frame_push_byte
        FAIL_CS
        lda #$12
        jsr frame_push_byte
        FAIL_CS
        lda #$34
        jsr frame_push_byte
        FAIL_CS

        jsr take_iface
        FAIL_CS
        lda #IF_VALUE_SIZE
        ldx #$00
        jsr frame_discard
        lda FRAME_SP
        cmp saved_sp
        FAIL_NE
        lda FRAME_SP+1
        cmp saved_sp+1
        FAIL_NE
        lda #$01
        sta MB_DATA+5

        TEXT iface_ok, 12
        jsr pr_cr
        lda #MB_ST_PASS
        sta MB_STATUS
        lda #$00
        sta MB_CODE
        sta MB_CODE+1
        jmp @restore

@fail:
        lda #MB_ST_FAIL
        sta MB_STATUS
        TEXT iface_fail, 14
        jsr pr_cr
@restore:
        lda saved_cr
        sta MMU_CR
        plp
        rts

; Reads the four argument bytes at FP+2..FP+5: object $1234, table $5678.
take_iface:
        lda #$00
        ldx #$00
        jsr frame_enter
        bcs @bad
        ldy #2
        lda (FRAME_FP),y
        cmp #$34
        bne @bad
        iny
        lda (FRAME_FP),y
        cmp #$12
        bne @bad
        iny
        lda (FRAME_FP),y
        cmp #$78
        bne @bad
        iny
        lda (FRAME_FP),y
        cmp #$56
        bne @bad
        jsr frame_leave
        clc
        rts
@bad:   sec
        rts

; C=1 when the four bytes at tptr differ from e0..e3.
cmp_val:
        ldy #$00
        lda (tptr),y
        cmp e0
        bne @no
        iny
        lda (tptr),y
        cmp e1
        bne @no
        iny
        lda (tptr),y
        cmp e2
        bne @no
        iny
        lda (tptr),y
        cmp e3
        bne @no
        clc
        rts
@no:    sec
        rts

.segment "DATA"
slot_tab:
        .word $BEEF
        .word $CAFE
.assert * - slot_tab = 2 * IF_SLOT_SIZE, error, "slot table size"

.segment "RODATA"
title:          .byte "NOVA128 INTERFACE ABI"
iface_ok:       .byte "INTERFACE OK"
iface_fail:     .byte "INTERFACE FAIL"

.segment "BSS"
saved_cr:       .res 1
saved_sp:       .res 2
e0:             .res 1
e1:             .res 1
e2:             .res 1
e3:             .res 1
val_a:          .res IF_VALUE_SIZE
val_b:          .res IF_VALUE_SIZE
val_c:          .res IF_VALUE_SIZE
val_d:          .res IF_VALUE_SIZE
val_e:          .res IF_VALUE_SIZE
val_f:          .res IF_VALUE_SIZE
val_g:          .res IF_VALUE_SIZE
val_h:          .res IF_VALUE_SIZE
test_end: