<#
  Runs ON the IIS server (invoked over SSH by scripts\deploy-iis.ps1). Not meant to be run
  by hand except for troubleshooting a stuck deploy.

  - Stops the site/app pool
  - Wipes RemoteDir and re-extracts the release zip into it (safe: the DB and error log
    live outside RemoteDir, at DbPath/ErrorLogDir, so a full wipe never touches them)
  - Points IIS at RemoteDir\public
  - Ensures the app pool identity has modify rights on the persistent data folder
  - Runs pending migrations (32-bit cscript - ACE OLEDB is x86-only)
  - Restarts the site/app pool
#>

param(
  [Parameter(Mandatory = $true)][string]$ZipPath,
  [Parameter(Mandatory = $true)][string]$RemoteDir,
  [Parameter(Mandatory = $true)][string]$SiteName,
  [Parameter(Mandatory = $true)][string]$AppPool,
  [Parameter(Mandatory = $true)][string]$DbPath,
  [string]$AdminSiteName = '',
  [string]$AdminAppPool = '',
  [switch]$RunMigrations = $true
)

$ErrorActionPreference = 'Stop'
Import-Module WebAdministration

# Stop-WebAppPool only requests a stop - the w3wp.exe worker process can keep running for a
# few seconds afterwards (finishing in-flight requests), still holding the site's files open.
# Wait for the pool to actually report Stopped, then force-kill any worker process that's
# still lingering past the timeout so the wipe below doesn't hit "Access is denied".
function Wait-AppPoolFullyStopped {
  param([string]$PoolName, [int]$TimeoutSec = 30)

  if([string]::IsNullOrWhiteSpace($PoolName)){ return }

  $deadline = (Get-Date).AddSeconds($TimeoutSec)
  while((Get-Date) -lt $deadline){
    if((Get-WebAppPoolState -Name $PoolName -ErrorAction SilentlyContinue).Value -eq 'Stopped'){
      return
    }
    Start-Sleep -Milliseconds 500
  }

  Write-Host "App pool $PoolName did not report Stopped within ${TimeoutSec}s - killing any lingering worker process"
  Get-CimInstance Win32_Process -Filter "Name = 'w3wp.exe'" -ErrorAction SilentlyContinue |
    Where-Object { $_.CommandLine -like ('*' + $PoolName + '*') } |
    ForEach-Object {
      try { Stop-Process -Id $_.ProcessId -Force -ErrorAction SilentlyContinue } catch { }
    }
}

# Wipes are attempted a few times with a short pause - file handles (IIS or AV scanning
# the just-stopped worker process's files) can take a moment to release even after the
# worker process itself is confirmed gone.
function Remove-DirectoryContentsWithRetry {
  param([string]$Path, [int]$MaxAttempts = 5, [int]$DelayMs = 2000)

  for($attempt = 1; $attempt -le $MaxAttempts; $attempt++){
    $failure = $null
    try {
      Remove-Item -Recurse -Force $Path -ErrorAction Stop
      return
    } catch {
      $failure = $_
      if($attempt -lt $MaxAttempts){
        Write-Host "Wipe attempt $attempt failed (files still locked?) - retrying in $($DelayMs)ms"
        Start-Sleep -Milliseconds $DelayMs
      }
    }
  }
  throw $failure
}

if(!(Get-Website -Name $SiteName -ErrorAction SilentlyContinue)){
  throw "IIS site '$SiteName' does not exist yet. Create the site and app pool once manually (or via a one-time setup script) before running this deploy."
}
if(!(Test-Path ('IIS:\AppPools\' + $AppPool))){
  throw "App pool '$AppPool' does not exist yet. Create it once manually before running this deploy."
}

Write-Host "Stopping IIS site $SiteName and app pool $AppPool"
try { Stop-Website -Name $SiteName } catch { }
try { Stop-WebAppPool -Name $AppPool } catch { }
Wait-AppPoolFullyStopped -PoolName $AppPool

# The admin site's physical path may already point inside RemoteDir (e.g. RemoteDir\public-admin)
# from a previous deploy - if it's left running, IIS holds those files open and the wipe below
# fails with "Access is denied". Stop it up front, alongside the public site, not after.
if(![string]::IsNullOrWhiteSpace($AdminSiteName) -and (Get-Website -Name $AdminSiteName -ErrorAction SilentlyContinue)){
  Write-Host "Stopping IIS admin site $AdminSiteName"
  try { Stop-Website -Name $AdminSiteName } catch { }
  if(![string]::IsNullOrWhiteSpace($AdminAppPool)){
    try { Stop-WebAppPool -Name $AdminAppPool } catch { }
    Wait-AppPoolFullyStopped -PoolName $AdminAppPool
  }
}

if(Test-Path $RemoteDir){
  Write-Host "Wiping $RemoteDir"
  Remove-DirectoryContentsWithRetry -Path (Join-Path $RemoteDir '*')
} else {
  New-Item -ItemType Directory -Force -Path $RemoteDir | Out-Null
}

Write-Host "Extracting $ZipPath -> $RemoteDir"
Expand-Archive -Path $ZipPath -DestinationPath $RemoteDir -Force
Remove-Item $ZipPath -ErrorAction SilentlyContinue

$publicDir = Join-Path $RemoteDir 'public'
if(!(Test-Path $publicDir)){
  throw "No public\ folder in the extracted release - deploy aborted, site left stopped for inspection."
}

# Persistent data folder (DB + error log) - lives outside RemoteDir so it survives the wipe
# above. Create it and grant the app pool identity modify rights.
$dataDir = Split-Path $DbPath -Parent
if(!(Test-Path $dataDir)){
  New-Item -ItemType Directory -Force -Path $dataDir | Out-Null
}
$logDir = Join-Path $dataDir 'logs'
if(!(Test-Path $logDir)){
  New-Item -ItemType Directory -Force -Path $logDir | Out-Null
}
icacls $dataDir /grant ("IIS AppPool\" + $AppPool + ":(OI)(CI)(M)") /T | Out-Null

Set-ItemProperty ('IIS:\Sites\' + $SiteName) -Name physicalPath -Value $publicDir
Set-ItemProperty ('IIS:\Sites\' + $SiteName) -Name applicationPool -Value $AppPool

# This server has the 64-bit Access Database Engine (ACE OLEDB) installed, unlike the local
# dev machine, which needs the 32-bit one - so the app pool stays 64-bit here.
Set-ItemProperty ('IIS:\AppPools\' + $AppPool) -Name enable32BitAppOnWin64 -Value $false

# --- Admin site ---
$adminPublicDir = Join-Path $RemoteDir 'public-admin'
if(![string]::IsNullOrWhiteSpace($AdminSiteName) -and (Test-Path $adminPublicDir)){
  if(!(Get-Website -Name $AdminSiteName -ErrorAction SilentlyContinue)){
    throw "IIS admin site '$AdminSiteName' does not exist yet. Create the site and app pool once manually before running this deploy."
  }
  Write-Host "Configuring admin site $AdminSiteName"
  if(![string]::IsNullOrWhiteSpace($AdminAppPool)){
    Set-ItemProperty ('IIS:\Sites\' + $AdminSiteName) -Name applicationPool -Value $AdminAppPool
    Set-ItemProperty ('IIS:\AppPools\' + $AdminAppPool) -Name enable32BitAppOnWin64 -Value $false
    icacls $dataDir /grant ("IIS AppPool\" + $AdminAppPool + ":(OI)(CI)(M)") /T | Out-Null
  }
  Set-ItemProperty ('IIS:\Sites\' + $AdminSiteName) -Name physicalPath -Value $adminPublicDir
}

if($RunMigrations){
  Write-Host 'Running pending migrations'
  Push-Location $RemoteDir
  try {
    & cscript.exe //nologo scripts\runMigrations.vbs up
    if($LASTEXITCODE -ne 0){ throw 'runMigrations.vbs up failed - see output above' }
  } finally {
    Pop-Location
  }
}

Write-Host "Starting IIS site $SiteName and app pool $AppPool"
if((Get-WebAppPoolState -Name $AppPool).Value -eq 'Started'){
  Restart-WebAppPool -Name $AppPool
} else {
  Start-WebAppPool -Name $AppPool
}
Start-Website $SiteName

if(![string]::IsNullOrWhiteSpace($AdminSiteName)){
  if(![string]::IsNullOrWhiteSpace($AdminAppPool)){
    if((Get-WebAppPoolState -Name $AdminAppPool).Value -eq 'Started'){
      Restart-WebAppPool -Name $AdminAppPool
    } else {
      Start-WebAppPool -Name $AdminAppPool
    }
  }
  Start-Website $AdminSiteName
}

Write-Host 'Remote apply complete.'