# build-ml.ps1 - assemble vml.s with cc65 and generate vml.c, the Power C unit
# that carries the machine code as a byte array plus its C wrappers.
#
#   powershell -NoProfile -File build-ml.ps1
#
# Run it whenever vml.s or vmlwrap.c changes, then build.ps1 as usual.
# vml.c is generated: edit vml.s (the code) or vmlwrap.c (the C side).
#
# The code is assembled for $C000. At start-up mlinit() calls highmem($C000) so
# Power C keeps below it, and copies the array up there. Entry addresses come
# from ld65's label file and are written into vml.c as #defines.

$ErrorActionPreference = "Stop"
$here = $PSScriptRoot

$ca65 = (Get-Command ca65 -ErrorAction SilentlyContinue).Source
if (-not $ca65) { throw "ca65 not found on PATH (cc65 bin folder)" }
$ld65 = Join-Path (Split-Path $ca65) "ld65.exe"

$tmp = Join-Path $env:TEMP "vml-build"
New-Item -ItemType Directory -Force -Path $tmp | Out-Null
$cfg = Join-Path $tmp "vml.cfg"
@"
MEMORY { M: start = `$C000, size = `$0400, file = "%O"; }
SEGMENTS { CODE: load = M, type = ro; }
"@ | Set-Content $cfg -Encoding ascii

$obj = Join-Path $tmp "vml.o"
$lbl = Join-Path $tmp "vml.lbl"
$out = Join-Path $here "vml.bin"
& $ca65 (Join-Path $here "vml.s") -o $obj
if ($LASTEXITCODE) { throw "ca65 failed" }
& $ld65 -C $cfg -o $out -Ln $lbl $obj
if ($LASTEXITCODE) { throw "ld65 failed" }

# entry points: "al 00C000 .scrn"
$defs = @()
foreach ($ln in (Get-Content $lbl)) {
    if ($ln -match '^al\s+([0-9A-Fa-f]+)\s+\.(scrn|row|bmove|ladj|kpop)$') {
        $defs += ("#define ML{0} 0x{1}" -f $matches[2].ToUpper(), $matches[1].Substring(2).ToLower())
    }
}
if ($defs.Count -ne 5) { throw "expected 5 entry labels in $lbl, got $($defs.Count)" }

$b = [IO.File]::ReadAllBytes($out)
$rows = @()
for ($i = 0; $i -lt $b.Length; $i += 12) {
    $n = [Math]::Min(12, $b.Length - $i)
    $rows += "    " + (($b[$i..($i + $n - 1)] | ForEach-Object { "$_" }) -join ", ")
}
$arr = $rows -join ",`n"
$wrap = Get-Content (Join-Path $here "vmlwrap.c") -Raw

@"
/* vml.c - GENERATED by build-ml.ps1 from vml.s and vmlwrap.c. Do not edit.
 *
 * The machine code helpers as a byte array. mlinit() copies them to `$C000.
 */

$($defs -join "`n")
#define MLSIZE $($b.Length)

char mlcode[$($b.Length)] = {
$arr
};

$wrap
"@ | Set-Content (Join-Path $here "vml.c") -Encoding ascii

Write-Host ("vml.bin {0} bytes -> vml.c  ({1})" -f $b.Length, ($defs -join '; '))