#Requires -Version 5.1
<#
.SYNOPSIS
    Configures VMware shared folder entries in the CI template VMX for build cache sharing.

.DESCRIPTION
    Adds two shared folder mappings to the template VM's .vmx file:
      nuget-cache  host: F:\CI\Cache\NuGet  guest: \\vmware-host\Shared Folders\nuget-cache
      pip-cache    host: F:\CI\Cache\pip    guest: \\vmware-host\Shared Folders\pip-cache

    These UNC paths are used by Invoke-RemoteBuild.ps1 -UseSharedCache to redirect
    dotnet's NuGet package store and pip's download cache to persistent host-side
    directories, avoiding repeat downloads across builds.

    The script is idempotent: existing sharedFolder.* lines are removed before
    the new block is written. A .bak copy of the original VMX is kept alongside it.

    Prerequisites:
      - Template VM must NOT be running when this script runs.
      - VMware Tools (HGFS driver) must be installed in the template guest.
      - Run once; all subsequent linked clones inherit the shared folder config.

    After running: use Invoke-RemoteBuild.ps1 -UseSharedCache on builds that
    target VMs cloned from this updated template.

.PARAMETER TemplatePath
    Full path to the template VM's .vmx file.
    Default: F:\CI\Templates\WinBuild\CI-WinBuild.vmx

.PARAMETER NuGetCacheDir
    Host-side path for the NuGet package cache directory.
    Default: F:\CI\Cache\NuGet

.PARAMETER PipCacheDir
    Host-side path for the pip download cache directory.
    Default: F:\CI\Cache\pip

.EXAMPLE
    # Configure template (run from elevated PowerShell — template must be stopped)
    .\Set-TemplateSharedFolders.ps1

    # Preview changes without modifying files
    .\Set-TemplateSharedFolders.ps1 -WhatIf
#>
[CmdletBinding(SupportsShouldProcess)]
param(
    [string] $TemplatePath  = 'F:\CI\Templates\WinBuild\CI-WinBuild.vmx',
    [string] $NuGetCacheDir = 'F:\CI\Cache\NuGet',
    [string] $PipCacheDir   = 'F:\CI\Cache\pip'
)

Set-StrictMode -Version Latest
$ErrorActionPreference = 'Stop'

if (-not (Test-Path $TemplatePath -PathType Leaf)) {
    throw "Template VMX not found: $TemplatePath"
}

# ── Step 1: Ensure host cache directories exist ───────────────────────────────
foreach ($dir in @($NuGetCacheDir, $PipCacheDir)) {
    if (-not (Test-Path $dir)) {
        if ($PSCmdlet.ShouldProcess($dir, 'Create host cache directory')) {
            New-Item -ItemType Directory -Path $dir -Force | Out-Null
            Write-Host "[SharedFolders] Created host cache dir: $dir"
        }
    } else {
        Write-Host "[SharedFolders] Host cache dir exists: $dir"
    }
}

# ── Step 2: Read VMX, strip existing sharedFolder + HGFS lines ───────────────
$lines    = [System.IO.File]::ReadAllLines($TemplatePath, [System.Text.Encoding]::UTF8)
$stripped = $lines | Where-Object {
    $_ -notmatch '^sharedFolder' -and
    $_ -notmatch '^isolation\.tools\.hgfs\.disable'
}

# ── Step 3: Build replacement sharedFolder block ──────────────────────────────
# VMX hostPath requires double-escaped backslashes
$nugetEsc = $NuGetCacheDir.Replace('\', '\\')
$pipEsc   = $PipCacheDir.Replace('\', '\\')

$sharedBlock = @(
    'sharedFolder.maxNum = "2"'
    'sharedFolder0.present = "TRUE"'
    'sharedFolder0.enabled = "TRUE"'
    'sharedFolder0.readAccess = "TRUE"'
    'sharedFolder0.writeAccess = "TRUE"'
    "sharedFolder0.hostPath = `"$nugetEsc`""
    'sharedFolder0.guestName = "nuget-cache"'
    'sharedFolder0.expiration = "never"'
    'sharedFolder1.present = "TRUE"'
    'sharedFolder1.enabled = "TRUE"'
    'sharedFolder1.readAccess = "TRUE"'
    'sharedFolder1.writeAccess = "TRUE"'
    "sharedFolder1.hostPath = `"$pipEsc`""
    'sharedFolder1.guestName = "pip-cache"'
    'sharedFolder1.expiration = "never"'
    'isolation.tools.hgfs.disable = "FALSE"'
)

$newLines = @($stripped) + $sharedBlock

# ── Step 4: Backup and write VMX ─────────────────────────────────────────────
if ($PSCmdlet.ShouldProcess($TemplatePath, 'Write updated VMX with shared folder entries')) {
    $backupPath = "$TemplatePath.bak"
    Copy-Item $TemplatePath $backupPath -Force
    Write-Host "[SharedFolders] Original backed up: $backupPath"

    [System.IO.File]::WriteAllLines($TemplatePath, $newLines, [System.Text.Encoding]::UTF8)

    Write-Host "[SharedFolders] VMX updated: $TemplatePath"
    Write-Host "[SharedFolders] Mappings:"
    Write-Host "  nuget-cache  $NuGetCacheDir  ->  \\vmware-host\Shared Folders\nuget-cache"
    Write-Host "  pip-cache    $PipCacheDir    ->  \\vmware-host\Shared Folders\pip-cache"
    Write-Host "[SharedFolders] Next: run Invoke-RemoteBuild.ps1 -UseSharedCache to activate."
}