# Shared helpers for Nova128 build and x128 verification scripts.
#   Import-Module (Join-Path $PSScriptRoot "lib\Nova128Test.psm1") -Force

$script:ViceBin = "C:\Program Files\GTK3VICE-3.10-win64\bin"

function Get-ViceTool([string]$Name) {
    $path = Join-Path $script:ViceBin "$Name.exe"
    if (-not (Test-Path -LiteralPath $path)) { throw "$Name.exe not found at $path" }
    return $path
}

# Assemble each source and link them with an ld65 config.
# Returns @{ Program; Map; Labels }.
function Invoke-Nova128Link {
    param(
        [Parameter(Mandatory)][string]$Name,
        [Parameter(Mandatory)][string[]]$Sources,
        [Parameter(Mandatory)][string]$Config,
        [Parameter(Mandatory)][string]$BuildDir,
        [string[]]$Defines = @()
    )
    $ca65 = (Get-Command ca65 -ErrorAction Stop).Source
    $ld65 = (Get-Command ld65 -ErrorAction Stop).Source
    New-Item -ItemType Directory -Force -Path $BuildDir | Out-Null
    $out = @{
        Program = Join-Path $BuildDir "$Name.prg"
        Map = Join-Path $BuildDir "$Name.map"
        Labels = Join-Path $BuildDir "$Name.lbl"
    }
    foreach ($path in $out.Values) {
        if (Test-Path -LiteralPath $path) { Remove-Item -LiteralPath $path -Force }
    }
    $defineArgs = @()
    foreach ($d in $Defines) { $defineArgs += @("-D", $d) }
    $objects = @()
    foreach ($source in $Sources) {
        $object = Join-Path $BuildDir ("$Name-" + [IO.Path]::GetFileNameWithoutExtension($source) + ".o")
        & $ca65 --cpu 6502 @defineArgs -o $object $source
        if ($LASTEXITCODE -ne 0) { throw "ca65 failed on $source" }
        $objects += $object
    }
    $linkOutput = & $ld65 -C $Config -o $out.Program -m $out.Map -Ln $out.Labels @objects 2>&1
    if ($LASTEXITCODE -ne 0) { throw ("ld65 failed:`n" + ($linkOutput | Out-String)) }
    return $out
}

function Get-Nova128Label {
    param([Parameter(Mandatory)][string]$Labels, [Parameter(Mandatory)][string]$Name)
    $text = Get-Content -Raw -LiteralPath $Labels
    $m = [regex]::Match($text, "(?im)^al\s+([0-9a-f]+)\s+\." + [regex]::Escape($Name) + "\s*$")
    if (-not $m.Success) { throw "label $Name not found in $Labels" }
    return [Convert]::ToInt32($m.Groups[1].Value, 16)
}

# ASCII text -> PETSCII SEQ bytes, using the same rules as Vim and
# prepare-disk.ps1: a-z -> $41-$5A, A-Z -> $C1-$DA, CRLF/LF -> $0D.
function ConvertTo-Nova128Petscii {
    param([Parameter(Mandatory)][AllowEmptyString()][string]$Text)
    $bytes = [Text.Encoding]::ASCII.GetBytes($Text)
    $out = New-Object System.Collections.Generic.List[byte]
    for ($i = 0; $i -lt $bytes.Length; $i++) {
        $v = $bytes[$i]
        if ($v -eq 13) {
            if ($i + 1 -lt $bytes.Length -and $bytes[$i + 1] -eq 10) { continue }
            $out.Add(13); continue
        }
        if ($v -eq 10) { $out.Add(13); continue }
        if ($v -ge 0x61 -and $v -le 0x7A) { $out.Add([byte]($v - 0x20)); continue }
        if ($v -ge 0x41 -and $v -le 0x5A) { $out.Add([byte]($v + 0x80)); continue }
        $out.Add($v)
    }
    return ,$out.ToArray()
}

# Create a fresh disk image and write files to it.
# $Files: ordered list of @{ Name = "decls.n8"; Path = host file; Type = "seq"|"prg" }
function New-Nova128Disk {
    param(
        [Parameter(Mandatory)][string]$Path,
        [Parameter(Mandatory)][object[]]$Files,
        [ValidateSet("d64", "d81")][string]$Type = "d81",
        [string]$Label = "nova128,n8"
    )
    $c1541 = Get-ViceTool "c1541"
    if (Test-Path -LiteralPath $Path) { Remove-Item -LiteralPath $Path -Force }
    $c1541Args = @("-format", $Label, $Type, $Path)
    foreach ($f in $Files) {
        $suffix = if ($f.Type -eq "seq") { ",s" } else { "" }
        $c1541Args += @("-write", $f.Path, ($f.Name + $suffix))
    }
    $output = & $c1541 @c1541Args 2>&1
    if ($LASTEXITCODE -ne 0 -or -not (Test-Path -LiteralPath $Path)) {
        throw ("c1541 failed:`n" + ($output | Out-String))
    }
    $listing = (& $c1541 -attach $Path -list 2>&1) | Out-String
    foreach ($f in $Files) {
        if ($listing -notmatch ('"' + [regex]::Escape($f.Name) + '"\s+' + $f.Type)) {
            throw "$($f.Name) ($($f.Type)) missing from $Path"
        }
    }
}

# Start x128 with a remote monitor. Returns a session object.
function Start-Nova128X128 {
    param(
        [Parameter(Mandatory)][string]$Autostart,
        [int]$Port = 6530,
        [string]$Drive8Image,
        [string]$Drive8Type = "1581",
        [string]$Screenshot,
        [string]$Keys = "",
        [int]$KeyDelay = 4000
    )
    $x128 = Get-ViceTool "x128"
    $argList = @()
    if ($Drive8Image) {
        $argList += @("-drive8type", $Drive8Type, "-drive8truedrive", "-8", ('"' + $Drive8Image + '"'))
    }
    $argList += @("-autostart", ('"' + $Autostart + '"'), "-autostart-warp", "-warp",
        "-sounddev", "dummy", "-remotemonitor",
        "-remotemonitoraddress", "ip4://127.0.0.1:$Port")
    if ($Keys) {
        $argList += @("-keybuf", ('"' + $Keys + '"'), "-keybuf-delay", "$KeyDelay")
    }
    if ($Screenshot) {
        if (Test-Path -LiteralPath $Screenshot) { Remove-Item -LiteralPath $Screenshot -Force }
        $argList += @("-exitscreenshotvicii", ('"' + $Screenshot + '"'))
    }
    $psi = [Diagnostics.ProcessStartInfo]::new()
    $psi.FileName = $x128
    $psi.Arguments = $argList -join ' '
    $psi.UseShellExecute = $true
    $psi.WindowStyle = [Diagnostics.ProcessWindowStyle]::Hidden
    $process = [Diagnostics.Process]::Start($psi)

    $client = $null
    $deadline = [DateTime]::UtcNow.AddSeconds(10)
    while ([DateTime]::UtcNow -lt $deadline) {
        if ($process.HasExited) { throw "x128 exited before the remote monitor connected" }
        try {
            $client = [Net.Sockets.TcpClient]::new()
            $client.Connect("127.0.0.1", $Port)
            break
        } catch {
            if ($client) { $client.Dispose(); $client = $null }
            Start-Sleep -Milliseconds 200
        }
    }
    if (-not $client) { $process.Kill(); throw "could not connect to the VICE remote monitor" }
    $stream = $client.GetStream()
    $writer = [IO.StreamWriter]::new($stream, [Text.Encoding]::ASCII, 1024, $true)
    $writer.NewLine = "`n"
    $writer.AutoFlush = $true
    return [pscustomobject]@{ Process = $process; Client = $client; Stream = $stream; Writer = $writer }
}

function Invoke-Nova128Monitor {
    param([Parameter(Mandatory)]$Session, [Parameter(Mandatory)][string]$Command,
        [int]$TimeoutMs = 5000)
    $Session.Writer.WriteLine($Command)
    $buffer = New-Object byte[] 65536
    $text = ""
    # Every monitor reply ends with a prompt such as "(C:$1c0d) ".
    $deadline = [DateTime]::UtcNow.AddMilliseconds($TimeoutMs)
    while ([DateTime]::UtcNow -lt $deadline) {
        if ($Session.Stream.DataAvailable) {
            $n = $Session.Stream.Read($buffer, 0, $buffer.Length)
            if ($n -le 0) { break }
            $text += [Text.Encoding]::ASCII.GetString($buffer, 0, $n)
            if ($text -match '\(C:\$[0-9a-f]{4}\)\s*$') { break }
        } else {
            Start-Sleep -Milliseconds 50
        }
    }
    return $text
}

# Read memory through the monitor. Returns byte[] (length = Count).
# Reads RAM bank 0 by default, not the CPU's current view: after a program
# returns to BASIC, $4000-$BFFF shows BASIC ROM in the CPU view.
function Read-Nova128Memory {
    param([Parameter(Mandatory)]$Session, [int]$Address, [int]$Count, [string]$Bank = "ram")
    Invoke-Nova128Monitor $Session "bank $Bank" | Out-Null
    $timeout = 5000 + 2 * $Count                   # large dumps print slowly
    $text = Invoke-Nova128Monitor $Session ("m `${0:X4} `${1:X4}" -f $Address, ($Address + $Count - 1)) -TimeoutMs $timeout
    $memory = @{}
    foreach ($row in [regex]::Matches($text, "(?i)C:([0-9a-f]{4})((?:[ ]{1,2}[0-9a-f]{2}){1,16})")) {
        $a = [Convert]::ToInt32($row.Groups[1].Value, 16)
        foreach ($hex in ($row.Groups[2].Value.Trim() -split '\s+')) {
            $memory[$a] = [Convert]::ToByte($hex, 16); $a++
        }
    }
    $bytes = New-Object byte[] $Count
    for ($i = 0; $i -lt $Count; $i++) {
        if (-not $memory.ContainsKey($Address + $i)) {
            throw ("monitor did not return `${0:X4}; response: {1}" -f ($Address + $i), $text)
        }
        $bytes[$i] = $memory[$Address + $i]
    }
    return ,$bytes
}

# Poll the test mailbox ($1BF0) until it reports PASS or FAIL. Returns its
# 16 bytes. Resumes emulation between polls.
function Wait-Nova128Mailbox {
    param([Parameter(Mandatory)]$Session, [int]$TimeoutSeconds = 60)
    $deadline = [DateTime]::UtcNow.AddSeconds($TimeoutSeconds)
    while ($true) {
        Start-Sleep -Seconds 1
        $mb = Read-Nova128Memory $Session 0x1BF0 16
        if ($mb[0] -eq 0x4E -and $mb[1] -eq 0x38 -and ($mb[3] -eq 0xA5 -or $mb[3] -eq 0xFA)) {
            return ,$mb
        }
        if ([DateTime]::UtcNow -ge $deadline) {
            $state = if ($mb[0] -eq 0x4E) { "status `$" + $mb[3].ToString("X2") } else { "never initialized" }
            throw "mailbox did not finish within $TimeoutSeconds s ($state)"
        }
        Invoke-Nova128Monitor $Session "x" | Out-Null
    }
}

# Let the program finish printing, then quit x128 (writes any exit screenshot).
function Stop-Nova128X128 {
    param([Parameter(Mandatory)]$Session, [int]$SettleSeconds = 2)
    try {
        if ($SettleSeconds -gt 0) {
            Invoke-Nova128Monitor $Session "x" | Out-Null
            Start-Sleep -Seconds $SettleSeconds
            Invoke-Nova128Monitor $Session "m 0000 0000" | Out-Null
        }
        $Session.Writer.WriteLine("quit")
        $Session.Writer.Dispose()
        $Session.Client.Dispose()
        if (-not $Session.Process.WaitForExit(10000)) { throw "x128 did not exit" }
    } finally {
        if (-not $Session.Process.HasExited) { $Session.Process.Kill(); $Session.Process.WaitForExit() }
    }
}

Export-ModuleMember -Function Get-ViceTool, Invoke-Nova128Link, Get-Nova128Label,
    ConvertTo-Nova128Petscii, New-Nova128Disk, Start-Nova128X128, Invoke-Nova128Monitor,
    Read-Nova128Memory, Wait-Nova128Mailbox, Stop-Nova128X128