# E07-S01: create a disposable Nova128 development D81 from the Vim work disk.
[CmdletBinding()]
param(
    [string]$SourceImage = "",
    [string]$OutputImage = "",
    [string]$C1541Path = "",
    [string]$CompilerPrg = "",
    [string]$ProbePrg = "",
    [string]$ExamplesDirectory = "",
    [switch]$RequireCompiler
)

$ErrorActionPreference = "Stop"

$project = Split-Path $PSScriptRoot -Parent
$repository = Split-Path $project -Parent
$build = Join-Path $project "build"

if ($SourceImage -eq "") {
    $SourceImage = Join-Path $repository "vim\work.d81"
}
if ($OutputImage -eq "") {
    $OutputImage = Join-Path $build "newlang-dev.d81"
}
if ($C1541Path -eq "") {
    $C1541Path = "C:\Program Files\GTK3VICE-3.10-win64\bin\c1541.exe"
}
if ($CompilerPrg -eq "") {
    $CompilerPrg = Join-Path $build "n128c.prg"
}
if ($ProbePrg -eq "") {
    $ProbePrg = Join-Path $build "minimal.prg"
}
if ($ExamplesDirectory -eq "") {
    $ExamplesDirectory = Join-Path $project "examples"
}

$SourceImage = [IO.Path]::GetFullPath($SourceImage)
$OutputImage = [IO.Path]::GetFullPath($OutputImage)
$C1541Path = [IO.Path]::GetFullPath($C1541Path)
$CompilerPrg = [IO.Path]::GetFullPath($CompilerPrg)
$ProbePrg = [IO.Path]::GetFullPath($ProbePrg)
$ExamplesDirectory = [IO.Path]::GetFullPath($ExamplesDirectory)

if (-not (Test-Path -LiteralPath $SourceImage -PathType Leaf)) {
    throw "source D81 not found: $SourceImage"
}
if (-not (Test-Path -LiteralPath $C1541Path -PathType Leaf)) {
    throw "c1541 tool not found: $C1541Path"
}
if ([IO.Path]::GetExtension($OutputImage) -ine ".d81") {
    throw "output image must use the .d81 extension: $OutputImage"
}
if ([string]::Equals($SourceImage, $OutputImage,
        [StringComparison]::OrdinalIgnoreCase)) {
    throw "output image must not be the source D81"
}

$sourceHashBefore = (Get-FileHash -LiteralPath $SourceImage -Algorithm SHA256).Hash
$outputDirectory = Split-Path $OutputImage -Parent
New-Item -ItemType Directory -Force -Path $outputDirectory | Out-Null

# Only the exact generated output is removed. The source image and its folder
# are never used as deletion targets.
if (Test-Path -LiteralPath $OutputImage) {
    Remove-Item -LiteralPath $OutputImage -Force
}
Copy-Item -LiteralPath $SourceImage -Destination $OutputImage

$staging = Join-Path $build "disk-staging"
New-Item -ItemType Directory -Force -Path $staging | Out-Null
$injected = New-Object System.Collections.Generic.List[string]

function Get-DiskDirectory {
    $listing = (& $C1541Path $OutputImage -list 2>&1) -join "`n"
    if ($LASTEXITCODE -ne 0) {
        throw "c1541 could not list the copied D81:`n$listing"
    }
    return $listing
}

function Add-DiskFile {
    param(
        [Parameter(Mandatory = $true)][string]$HostPath,
        [Parameter(Mandatory = $true)][string]$DiskName,
        [Parameter(Mandatory = $true)][ValidateSet("prg", "seq")][string]$Type
    )

    if (-not (Test-Path -LiteralPath $HostPath -PathType Leaf)) {
        throw "artifact disappeared before injection: $HostPath"
    }
    $destination = if ($Type -eq "seq") { "$DiskName,s" } else { $DiskName }
    $writeOutput = (& $C1541Path $OutputImage -write $HostPath $destination 2>&1) -join "`n"
    if ($LASTEXITCODE -ne 0) {
        throw "c1541 failed to inject '$DiskName':`n$writeOutput"
    }

    $listing = Get-DiskDirectory
    $pattern = '(?im)"' + [regex]::Escape($DiskName) + '"\s+' + $Type + '\s*$'
    if ($listing -notmatch $pattern) {
        throw "c1541 reported success but '$DiskName' ($Type) is absent from the D81"
    }
    $injected.Add("$DiskName ($Type)")
}

function ConvertTo-PetsciiSeq {
    param(
        [Parameter(Mandatory = $true)][string]$InputPath,
        [Parameter(Mandatory = $true)][string]$OutputPath
    )

    $bytes = [IO.File]::ReadAllBytes($InputPath)
    $start = 0
    if ($bytes.Length -ge 3 -and $bytes[0] -eq 0xEF -and
        $bytes[1] -eq 0xBB -and $bytes[2] -eq 0xBF) {
        $start = 3
    }

    $converted = New-Object System.Collections.Generic.List[byte]
    for ($i = $start; $i -lt $bytes.Length; $i++) {
        $value = $bytes[$i]
        if ($value -eq 13) {
            if ($i + 1 -lt $bytes.Length -and $bytes[$i + 1] -eq 10) {
                continue
            }
            $converted.Add([byte]13)
            continue
        }
        if ($value -eq 10) {
            $converted.Add([byte]13)
            continue
        }
        if ($value -gt 0x7F) {
            throw "example source is not ASCII/UTF-8 text: $InputPath at byte $i"
        }
        if ($value -ge 0x61 -and $value -le 0x7A) {
            $converted.Add([byte]($value - 0x20))
            continue
        }
        if ($value -ge 0x41 -and $value -le 0x5A) {
            $converted.Add([byte]($value + 0x80))
            continue
        }
        $converted.Add([byte]$value)
    }
    [IO.File]::WriteAllBytes($OutputPath, $converted.ToArray())
}

if (Test-Path -LiteralPath $CompilerPrg -PathType Leaf) {
    Add-DiskFile -HostPath $CompilerPrg -DiskName "n128c" -Type prg
} elseif ($RequireCompiler) {
    throw "required Nova128 compiler PRG not found: $CompilerPrg"
} else {
    Write-Warning "Nova128 compiler is not built yet; skipped $CompilerPrg"
}

if (Test-Path -LiteralPath $ProbePrg -PathType Leaf) {
    Add-DiskFile -HostPath $ProbePrg -DiskName "n128probe" -Type prg
} else {
    Write-Warning "optional native C128 probe is absent; skipped $ProbePrg"
}

if (Test-Path -LiteralPath $ExamplesDirectory -PathType Container) {
    $examples = @(Get-ChildItem -LiteralPath $ExamplesDirectory -Filter "*.n8" -File |
        Sort-Object Name)
    foreach ($example in $examples) {
        if ($example.BaseName.Length -gt 12) {
            throw "example base name exceeds the 12-character source profile: $($example.Name)"
        }
        $diskName = $example.BaseName.ToLowerInvariant() + ".n8"
        $petscii = Join-Path $staging ($example.BaseName + ".pet")
        ConvertTo-PetsciiSeq -InputPath $example.FullName -OutputPath $petscii
        Add-DiskFile -HostPath $petscii -DiskName $diskName -Type seq
    }
    if ($examples.Count -eq 0) {
        Write-Warning "examples directory contains no .n8 files: $ExamplesDirectory"
    }
} else {
    Write-Warning "examples directory does not exist yet; skipped $ExamplesDirectory"
}

$sourceHashAfter = (Get-FileHash -LiteralPath $SourceImage -Algorithm SHA256).Hash
if ($sourceHashAfter -ne $sourceHashBefore) {
    throw "source D81 changed while preparing the disposable image"
}

# A final listing proves the resulting image is readable after all writes.
$null = Get-DiskDirectory
$outputHash = (Get-FileHash -LiteralPath $OutputImage -Algorithm SHA256).Hash

Write-Host "prepared disposable D81: $OutputImage"
Write-Host "source SHA-256 unchanged: $sourceHashAfter"
if ($injected.Count -eq 0) {
    Write-Host "injected: no optional Nova128 artifacts are built yet"
} else {
    Write-Host ("injected: " + ($injected -join ", "))
}

[pscustomobject]@{
    SourceImage = $SourceImage
    OutputImage = $OutputImage
    SourceHash = $sourceHashAfter
    OutputHash = $outputHash
    Injected = @($injected)
}