<#
.SYNOPSIS
    Grokkit Windows installer (PowerShell)
.DESCRIPTION
    Downloads, verifies checksum, extracts, and installs grokkit.exe.
    Mirrors the hardened grokkit-install.sh exactly.
#>

$ErrorActionPreference = 'Stop'

$VERSION = $env:VERSION
if (-not $VERSION) {
    Write-Error "❌ VERSION environment variable not set. Example: `$env:VERSION='0.3.3'; ./grokkit-install.ps1"
    exit 1
}

# Strip leading 'v' if present
$VERSION = $VERSION.TrimStart('v')

$GITEA_BASE = "https://repos.gmgauthier.com/gmgauthier/grokkit"

# Platform detection (Windows only supports amd64 for now; arm64 ready for future)
$ARCH = "amd64"
if ($env:PROCESSOR_ARCHITECTURE -like "*ARM*") {
    $ARCH = "arm64"
}

$ASSET = "grokkit-windows-${ARCH}-v${VERSION}.tar.gz"

Write-Host "Installing grokkit ${VERSION} for windows/${ARCH}..."

$TempDir = Join-Path ([System.IO.Path]::GetTempPath()) ([System.Guid]::NewGuid().ToString())
New-Item -ItemType Directory -Path $TempDir | Out-Null
try {
    Push-Location $TempDir

    # Download asset + checksums
    Write-Host "Downloading ${ASSET}..."
    Invoke-WebRequest -Uri "${GITEA_BASE}/releases/download/v${VERSION}/${ASSET}" -OutFile "asset.tar.gz"

    Write-Host "Downloading checksums.txt..."
    Invoke-WebRequest -Uri "${GITEA_BASE}/releases/download/v${VERSION}/checksums.txt" -OutFile "checksums.txt"

    # Robust checksum verification
    Write-Host "Verifying checksum..."
    $ChecksumContent = Get-Content "checksums.txt" -Raw
    $HashLine = $ChecksumContent -split "`n" | Where-Object { $_ -match $ASSET }
    if ($HashLine) {
        $ExpectedHash = ($HashLine -split '\s+')[0]
        $ActualHash = (Get-FileHash "asset.tar.gz" -Algorithm SHA256).Hash.ToLower()
        if ($ActualHash -ne $ExpectedHash) {
            Write-Error "❌ Checksum mismatch for ${ASSET}!"
            exit 1
        }
        Write-Host "✅ Checksum verified successfully"
    }
    else {
        Write-Warning "⚠️  No checksum entry found for ${ASSET} – continuing without verification"
    }

    # Extract (modern Windows has tar.exe)
    Write-Host "Extracting asset..."
    tar -xzf "asset.tar.gz"

    # The binary inside is named grokkit-windows-amd64.exe (per release workflow)
    $BinaryName = "grokkit-windows-${ARCH}.exe"

    # Install
    $InstallDir = Join-Path $env:USERPROFILE ".local\bin"
    New-Item -ItemType Directory -Path $InstallDir -Force | Out-Null
    Move-Item $BinaryName "${InstallDir}\grokkit.exe" -Force
    Write-Host "✅ grokkit ${VERSION} installed to ${InstallDir}\grokkit.exe"

    Write-Host "Add to PATH if needed: `$env:PATH += `";${InstallDir}`""
    & "${InstallDir}\grokkit.exe" version
}
finally {
    Pop-Location
    Remove-Item -Recurse -Force $TempDir -ErrorAction SilentlyContinue
}