# E01-S03: build the C128 KERNAL wrapper probe and its test disk.
[CmdletBinding()]
param()

$ErrorActionPreference = "Stop"
$project = Split-Path $PSScriptRoot -Parent
$build = Join-Path $project "build"
$source = Join-Path $project "src\platform\kernal-probe.s"
$config = Join-Path $project "cfg\kernal-probe-c128.cfg"
$object = Join-Path $build "kernal-probe.o"
$program = Join-Path $build "kernal-probe.prg"
$map = Join-Path $build "kernal-probe.map"
$labels = Join-Path $build "kernal-probe.lbl"
$debug = Join-Path $build "kernal-probe.dbg"
$listing = Join-Path $build "kernal-probe.lst"

$ca65 = (Get-Command ca65 -ErrorAction Stop).Source
$ld65 = (Get-Command ld65 -ErrorAction Stop).Source
New-Item -ItemType Directory -Force -Path $build | Out-Null

foreach ($path in @($object, $program, $map, $labels, $debug, $listing)) {
    if (Test-Path -LiteralPath $path) { Remove-Item -LiteralPath $path -Force }
}

& $ca65 --cpu 6502 --debug-info -l $listing -o $object $source
if ($LASTEXITCODE -ne 0) { throw "ca65 failed with exit code $LASTEXITCODE" }
& $ld65 -C $config -o $program -m $map -Ln $labels --dbgfile $debug $object
if ($LASTEXITCODE -ne 0) { throw "ld65 failed with exit code $LASTEXITCODE" }

$bytes = [IO.File]::ReadAllBytes($program)
if ($bytes.Length -lt 16) { throw "kernal-probe.prg is unexpectedly short" }
if ($bytes[0] -ne 0x01 -or $bytes[1] -ne 0x1C) {
    throw "kernal-probe.prg load address is not `$1C01"
}
$expectedHeader = [byte[]](0x0B,0x1C,0x0A,0x00,0x9E,0x37,0x31,0x38,0x31,0x00,0x00,0x00)
for ($i = 0; $i -lt $expectedHeader.Length; $i++) {
    if ($bytes[$i + 2] -ne $expectedHeader[$i]) {
        throw ("BASIC header differs at file offset {0}" -f ($i + 2))
    }
}

# The last loaded byte must remain below $2000, the end of the selected 8K
# bottom-common window. File bytes after the two-byte load address begin $1C01.
$lastAddress = 0x1C01 + ($bytes.Length - 2) - 1
if ($lastAddress -ge 0x2000) {
    throw ("probe ends at `${0:X4}, outside bottom common RAM" -f $lastAddress)
}

$labelText = Get-Content -Raw -LiteralPath $labels
foreach ($name in @(
    'kprobe_entry','kprobe_done','kprobe_result','kprobe_complete',
    'kprobe_state_result','kprobe_fail_a','kprobe_fail_p','kprobe_fail_st',
    'kprobe_status_buf','kprobe_code_end','kcall')) {
    if ($labelText -notmatch ("(?im)^al\s+[0-9a-f]+\s+\." + [regex]::Escape($name) + "\s*$")) {
        throw "missing exported linker label $name"
    }
}

# The drive-8 success path needs a real disk: a fresh D64 holding only the
# probe, so autostart loads it through true drive emulation.
$c1541 = "C:\Program Files\GTK3VICE-3.10-win64\bin\c1541.exe"
if (-not (Test-Path -LiteralPath $c1541)) { throw "c1541.exe not found at $c1541" }
$disk = Join-Path $build "kernal-probe.d64"
if (Test-Path -LiteralPath $disk) { Remove-Item -LiteralPath $disk -Force }
& $c1541 -format "kprobe,kp" d64 $disk -write $program "kernal-probe" | Out-Null
if ($LASTEXITCODE -ne 0 -or -not (Test-Path -LiteralPath $disk)) {
    throw "c1541 could not create $disk"
}

Write-Host ("built {0} ({1} bytes, ends `${2:X4})" -f $program, $bytes.Length, $lastAddress)
Write-Host ("disk  {0}" -f $disk)
Write-Host ("map   {0}" -f $map)
Write-Host ("labels {0}" -f $labels)