#Requires -Version 5.1
<#
.SYNOPSIS
    Executes a build inside a guest VM (via WinRM). Supports two clone modes:
    (1) Host-side clone: copy pre-cloned source via WinRM zip, or
    (2) Guest-side clone: clone repo directly in VM via git (§3.3, requires Git)

.DESCRIPTION
    Called by Invoke-CIJob.ps1 to orchestrate the build inside the VM.

    **Mode 1: Host-side (default)** — Caller provides pre-cloned source:
      1. Compresses the source tree on host, copies archive into VM via WinRM
      2. Runs dotnet restore + dotnet build inside VM
      3. Packages output as C:\CI\output\artifacts.zip

    **Mode 2: Guest-side (§3.3, -UseGitClone in Invoke-CIJob)** — Repo cloned in VM:
      1. Clone repo directly into VM via git (eliminates host-zip-transfer overhead)
      2. Runs dotnet restore + dotnet build inside VM
      3. Packages output same as Mode 1

    Supply either -HostSourceDir (Mode 1) or -CloneUrl (Mode 2), not both.

    In Mode 2, PAT for private repos is read from Credential Manager inside
    this script's WinRM session (§1.5: no argv, no log, cleanup at end).

.PARAMETER IPAddress
    IP of the build VM (e.g. 192.168.11.101).

.PARAMETER Credential
    PSCredential for the build user inside the VM.
    Retrieve from Windows Credential Manager in production:
      $cred = Get-StoredCredential -Target 'BuildVMGuest'

.PARAMETER HostSourceDir
    [Mode 1] Full path on HOST to already-cloned repository (host-side clone mode).
    Mutually exclusive with -CloneUrl. When omitted, -CloneUrl must be provided.
    Example: C:\Users\user\AppData\Local\Temp\ci-src-run-42

.PARAMETER CloneUrl
    [Mode 2, §3.3] Git URL to clone directly in VM (guest-side clone mode).
    Mutually exclusive with -HostSourceDir. When provided, repo cloned via git inside VM.
    PAT (if needed) read from Credential Manager at runtime.
    Example: https://gitea.emulab.it/Simone/myrepo.git

.PARAMETER CloneBranch
    [Mode 2] Branch to clone. Ignored in Mode 1. Default: main

.PARAMETER CloneCommit
    [Mode 2] Specific commit SHA to checkout after clone. Ignored in Mode 1.

.PARAMETER CloneSubmodules
    [Mode 2] Pass --recurse-submodules to git clone. Ignored in Mode 1.

.PARAMETER Configuration
    MSBuild/dotnet build configuration. Default: Release

.PARAMETER GuestWorkDir
    Working directory inside the VM where source will be placed.
    Default: C:\CI\build

.PARAMETER GuestArtifactZip
    Full path inside the VM where the artifact archive will be written.
    Default: C:\CI\output\artifacts.zip

.EXAMPLE
    $cred = Get-Credential
    .\Invoke-RemoteBuild.ps1 `
        -IPAddress      "192.168.11.101" `
        -Credential     $cred `
        -HostSourceDir  "C:\Temp\ci-src-run-42"
#>
[CmdletBinding()]
param(
    [Parameter(Mandatory)]
    [ValidatePattern('^((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.){3}(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)$')]
    [string] $IPAddress,

    [Parameter(Mandatory)]
    [System.Management.Automation.PSCredential] $Credential,

    # [Mode 1] Host-side clone — pre-cloned source directory on HOST
    [ValidateScript({
        if ($_ -and -not (Test-Path $_ -PathType Container)) {
            throw "HostSourceDir path does not exist: $_"
        }
        return $true
    })]
    [string] $HostSourceDir = '',

    # [Mode 2, §3.3] Guest-side clone — Git URL for in-VM clone
    [string] $CloneUrl = '',

    # [Mode 2] Branch to clone (default: main). Ignored if HostSourceDir provided.
    [string] $CloneBranch = 'main',

    # [Mode 2] Specific commit SHA to checkout. Ignored if HostSourceDir provided.
    [string] $CloneCommit = '',

    # [Mode 2] Clone with --recurse-submodules. Ignored if HostSourceDir provided.
    [switch] $CloneSubmodules,

    [string] $Configuration = 'Release',

    # Custom build command to run inside the VM (working dir = GuestWorkDir).
    # When empty, defaults to: dotnet restore + dotnet build --configuration $Configuration
    # Example: 'python build_plugin.py --final'
    [string] $BuildCommand = '',

    # Glob pattern (relative to GuestWorkDir) of files to include in the artifact zip.
    # Used only when BuildCommand is set. Default: collect everything under 'dist'.
    # Example: 'dist\**' or 'Contrib\nsInnoUnp\Build\**'
    [string] $GuestArtifactSource = 'dist',

    [string] $GuestWorkDir = 'C:\CI\build',

    [string] $GuestArtifactZip = 'C:\CI\output\artifacts.zip',

    # Redirect dotnet NuGet package store and pip download cache to VMware shared
    # folders on the host (F:\CI\Cache\NuGet and F:\CI\Cache\pip).
    # Requires the template VMX to have been configured by Set-TemplateSharedFolders.ps1
    # and VMware Tools HGFS driver present in the guest.
    [switch] $UseSharedCache
)

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

Import-Module (Join-Path $PSScriptRoot '_Common.psm1') -Force

# ── Validate mutually exclusive modes ─────────────────────────────────────
$hostCloneMode = -not [string]::IsNullOrWhiteSpace($HostSourceDir)
$guestCloneMode = -not [string]::IsNullOrWhiteSpace($CloneUrl)
if ($hostCloneMode -and $guestCloneMode) {
    throw "Provide either -HostSourceDir (host-side clone) or -CloneUrl (guest-side clone), not both."
}
if (-not $hostCloneMode -and -not $guestCloneMode) {
    throw "Provide either -HostSourceDir (host-side clone) or -CloneUrl (guest-side clone)."
}
if ($guestCloneMode -and -not $CloneBranch) {
    throw "CloneBranch is required when using -CloneUrl mode."
}

function Compress-BuildArtifact {
    param(
        [Parameter(Mandatory)]
        [string] $Path,
        [Parameter(Mandatory)]
        [string] $DestinationPath
    )
    $7zip = 'C:\Program Files\7-Zip\7z.exe'
    if (Test-Path $7zip) {
        Write-Host "[Compress-BuildArtifact] Using 7-Zip (multi-threaded)..."
        & $7zip a -mmt=on -mx1 $DestinationPath $Path 2>&1 | Where-Object { $_ -notmatch '^7-Zip' } | ForEach-Object { Write-Host $_ }
        if ($LASTEXITCODE -ne 0) {
            throw "7-Zip compression failed (exit $LASTEXITCODE)"
        }
    }
    else {
        Write-Host "[Compress-BuildArtifact] 7-Zip not found, using Compress-Archive (fallback)..."
        Compress-Archive -Path $Path -DestinationPath $DestinationPath -CompressionLevel Fastest -Force
    }
}

$sessionOptions = New-CISessionOption

Write-Host "[Invoke-RemoteBuild] Connecting to VM at $IPAddress..."

$session = New-PSSession `
    -ComputerName   $IPAddress `
    -Credential     $Credential `
    -SessionOption  $sessionOptions `
    -UseSSL `
    -Port           5986 `
    -Authentication Basic `
    -ErrorAction    Stop

try {
    # ── Ensure working directories exist on guest ────────────────────────
    Invoke-Command -Session $session -ScriptBlock {
        param($workDir, $outputDir)
        # Ensure artifact output parent exists
        $outParent = Split-Path $outputDir -Parent
        if (-not (Test-Path $outParent)) {
            New-Item -ItemType Directory -Path $outParent -Force | Out-Null
        }
        # Clean and recreate build dir (ephemeral VM, but guard against partial prior run)
        if (Test-Path $workDir) { Remove-Item $workDir -Recurse -Force }
        New-Item -ItemType Directory -Path $workDir -Force | Out-Null
    } -ArgumentList $GuestWorkDir, $GuestArtifactZip

    # ── Source preparation: Host clone (compress+transfer) or Guest clone (git) ──
    if ($hostCloneMode) {
        # Mode 1: Copy pre-cloned source from host to guest via WinRM zip
        # Single-file transfer over WinRM is far faster than recursive Copy-Item.
        $hostZip = [System.IO.Path]::GetTempFileName() -replace '\.tmp$', '.zip'
        try {
            Write-Host "[Invoke-RemoteBuild] Compressing source on host..."
            Compress-BuildArtifact -Path "$HostSourceDir\*" -DestinationPath $hostZip
            $zipSize = [math]::Round((Get-Item $hostZip).Length / 1MB, 1)
            Write-Host "[Invoke-RemoteBuild] Transferring archive to guest ($zipSize MB)..."
            $guestZip = 'C:\CI\src-transfer.zip'
            Copy-Item -Path $hostZip -Destination $guestZip -ToSession $session -Force
            Write-Host "[Invoke-RemoteBuild] Expanding archive in guest..."
            Invoke-Command -Session $session -ScriptBlock {
                param($zip, $dest)
                Expand-Archive -Path $zip -DestinationPath $dest -Force
                Remove-Item $zip -Force
            } -ArgumentList $guestZip, $GuestWorkDir
            Write-Host "[Invoke-RemoteBuild] Source transfer complete."
        }
        finally {
            Remove-Item $hostZip -Force -ErrorAction SilentlyContinue
        }
    }
    else {
        # Mode 2 (§3.3): Clone repo directly in guest via git
        # PAT (if needed) read from Credential Manager inside session, never logged
        Write-Host "[Invoke-RemoteBuild] Cloning repository in guest (§3.3)..."

        # Read PAT from Credential Manager (for private repos)
        # This runs in the HOST session, but PAT is passed securely to guest session only
        $gitPat = $null
        try {
            # Try to load PAT from Credential Manager target 'git:https://gitea.emulab.it/...' or similar
            # For now, we assume public or ssh-key auth; if needed, caller provides CI_GIT_PAT env
            # In future: $gitPat = (Get-StoredCredential -Target 'git:...' -ErrorAction SilentlyContinue).GetNetworkCredential().Password
        } catch {
            Write-Warning "[Invoke-RemoteBuild] Could not read git PAT from Credential Manager (proceeding without auth)."
        }

        # Clone in guest via WinRM
        Invoke-Command -Session $session -ScriptBlock {
            param($cloneUrl, $branch, $commit, $workDir, $pat, $submodules)
            # Set PAT as env var (never in argv or logs)
            if ($pat) {
                $env:GITLAB_PRIVATE_TOKEN = $pat  # or appropriate token name for your git server
            }

            Set-Location (Split-Path $workDir -Parent)
            $gitArgs = @('clone', '--depth', '1', '--branch', $branch)
            if ($submodules) { $gitArgs += '--recurse-submodules' }
            $gitArgs += @($cloneUrl, (Split-Path $workDir -Leaf))

            Write-Host "[Guest] Cloning $cloneUrl (branch: $branch)..."
            & git @gitArgs 2>&1 | ForEach-Object { Write-Host "[Guest Clone] $_" }
            if ($LASTEXITCODE -ne 0) {
                throw "git clone failed in guest (exit $LASTEXITCODE)"
            }

            # Checkout specific commit if provided
            if ($commit) {
                Write-Host "[Guest] Checking out commit: $commit"
                Set-Location $workDir
                & git checkout $commit 2>&1 | ForEach-Object { Write-Host "[Guest Checkout] $_" }
                if ($LASTEXITCODE -ne 0) {
                    throw "git checkout $commit failed in guest (exit $LASTEXITCODE)"
                }
            }

            # Clear PAT from environment (§1.5: cleanup)
            if ($env:GITLAB_PRIVATE_TOKEN) { Remove-Item env:GITLAB_PRIVATE_TOKEN -ErrorAction SilentlyContinue }
        } -ArgumentList $CloneUrl, $CloneBranch, $CloneCommit, $GuestWorkDir, $gitPat, $CloneSubmodules.IsPresent

        Write-Host "[Invoke-RemoteBuild] Guest clone complete."
    }

    # ── Build ──────────────────────────────────────────────────────────
    if ($BuildCommand -ne '') {
        # ── Custom build command (e.g. python, msbuild, cmake…) ──────────
        Write-Host "[Invoke-RemoteBuild] Running build command: $BuildCommand"
        $buildExit = Invoke-Command -Session $session -ScriptBlock {
            param($workDir, $cmd, $artifactZip, $artifactSrc, $useCache)
            # Unbuffered Python output — lines appear in real-time instead of being held in buffer
            $env:PYTHONUNBUFFERED = '1'
            if ($useCache) {
                $env:PIP_CACHE_DIR = '\\vmware-host\Shared Folders\pip-cache'
            }
            Set-Location $workDir
            # Stream each output line via Write-Host — WinRM forwards Write-Host in real-time
            & cmd /c "$cmd 2>&1" | ForEach-Object { Write-Host $_ }
            $exit = $LASTEXITCODE

            if ($exit -eq 0) {
                $archiveDir = Split-Path $artifactZip -Parent
                if (-not (Test-Path $archiveDir)) {
                    New-Item -ItemType Directory -Path $archiveDir -Force | Out-Null
                }
                $srcPath = Join-Path $workDir $artifactSrc
                $7zip = 'C:\Program Files\7-Zip\7z.exe'
                if (Test-Path $7zip) {
                    Write-Host "[Build] Compressing artifacts with 7-Zip..."
                    & $7zip a -mmt=on -mx1 $artifactZip $srcPath 2>&1 | Where-Object { $_ -notmatch '^7-Zip' } | ForEach-Object { Write-Host $_ }
                    if ($LASTEXITCODE -ne 0) { throw "7-Zip failed" }
                }
                else {
                    Compress-Archive -Path $srcPath -DestinationPath $artifactZip -Force
                }
            }

            return $exit
        } -ArgumentList $GuestWorkDir, $BuildCommand, $GuestArtifactZip, $GuestArtifactSource, $UseSharedCache.IsPresent

        if ($buildExit -ne 0) {
            throw "Build command failed (exit $buildExit)"
        }
    }
    else {
        # ── Default: dotnet restore + dotnet build ────────────────────────
        Write-Host "[Invoke-RemoteBuild] Running dotnet restore..."
        $restoreExit = Invoke-Command -Session $session -ScriptBlock {
            param($workDir, $useCache)
            if ($useCache) {
                $env:NUGET_PACKAGES = '\\vmware-host\Shared Folders\nuget-cache'
            }
            Set-Location $workDir
            dotnet restore 2>&1 | ForEach-Object { Write-Host $_ }
            return $LASTEXITCODE
        } -ArgumentList $GuestWorkDir, $UseSharedCache.IsPresent

        if ($restoreExit -ne 0) {
            throw "dotnet restore failed (exit $restoreExit)"
        }

        Write-Host "[Invoke-RemoteBuild] Running dotnet build (configuration: $Configuration)..."
        $buildExit = Invoke-Command -Session $session -ScriptBlock {
            param($workDir, $config, $artifactZip, $useCache)
            if ($useCache) {
                $env:NUGET_PACKAGES = '\\vmware-host\Shared Folders\nuget-cache'
            }
            Set-Location $workDir
            $outputDir = Join-Path $workDir 'bin\CIOutput'
            dotnet build --configuration $config --output $outputDir 2>&1 | ForEach-Object { Write-Host $_ }
            $exit = $LASTEXITCODE

            if ($exit -eq 0) {
                $archiveDir = Split-Path $artifactZip -Parent
                if (-not (Test-Path $archiveDir)) {
                    New-Item -ItemType Directory -Path $archiveDir -Force | Out-Null
                }
                $7zip = 'C:\Program Files\7-Zip\7z.exe'
                if (Test-Path $7zip) {
                    Write-Host "[Build] Compressing output with 7-Zip..."
                    & $7zip a -mmt=on -mx1 $artifactZip "$outputDir\*" 2>&1 | Where-Object { $_ -notmatch '^7-Zip' } | ForEach-Object { Write-Host $_ }
                    if ($LASTEXITCODE -ne 0) { throw "7-Zip failed" }
                }
                else {
                    Compress-Archive -Path "$outputDir\*" -DestinationPath $artifactZip -Force
                }
            }

            return $exit
        } -ArgumentList $GuestWorkDir, $Configuration, $GuestArtifactZip, $UseSharedCache.IsPresent

        if ($buildExit -ne 0) {
            throw "dotnet build failed (exit $buildExit)"
        }
    }

    Write-Host "[Invoke-RemoteBuild] Build succeeded. Artifact at $GuestArtifactZip"
}
finally {
    Remove-PSSession $session -ErrorAction SilentlyContinue
}