<#
.SYNOPSIS
  Rock-solid cold backup of an Open Dental server: stop MySQL/MariaDB, copy the
  entire data directory and the A-to-Z (OpenDentImages) folder, then restart the
  service. Guarantees the service is restarted even if the copy fails.

.DESCRIPTION
  The only fully consistent, engine-agnostic file backup of a MySQL/MariaDB
  database is a COLD copy: the service is cleanly stopped (which flushes InnoDB),
  the data directory is copied, then the service is restarted. This works for
  both MyISAM and InnoDB, unlike a hot file copy or Open Dental's built-in Backup
  tool (which cannot restore InnoDB).

  Two correctness points this script gets right:
    - It copies the ENTIRE data directory, not just the `opendental` subfolder.
      InnoDB's shared tablespace and redo logs (ibdata1, ib_logfile*) live at the
      datadir root; copying only `opendental` yields an unrestorable backup.
    - The service is stopped and VERIFIED stopped before any copy begins. A copy
      of a running InnoDB datadir is corrupt. If the service will not stop, the
      script aborts without copying.

  The service restart runs in a finally block, so an interrupted or failed copy
  never leaves the practice's database down.

  This is the primary "gold" backup. Pair it with an off-hours mysqldump for a
  portable logical copy and with off-site/immutable retention — see
  od-db-backup.md.

.NOTES
  Run ON THE DATABASE SERVER, elevated, when no one is using Open Dental:
      irm https://gitea.ivangodwin.com/ops/rb/raw/branch/main/scripts/od-db-backup.ps1 | iex

  Because `irm | iex` runs in the caller's session: no param() block (prompts via
  Read-Host), and #Requires is not enforced (admin is checked manually).

  Causes DOWNTIME for the duration of the copy — Open Dental is unavailable on
  every workstation while the service is stopped. Run it off-hours.

  PUBLIC REPO: no client specifics hard-coded. All paths are auto-detected or
  prompted at run time.
#>

$ErrorActionPreference = 'Stop'

# --- Admin check (do not rely on #Requires under iex) ---
$isAdmin = ([Security.Principal.WindowsPrincipal] `
    [Security.Principal.WindowsIdentity]::GetCurrent()
  ).IsInRole([Security.Principal.WindowsBuiltinRole]::Administrator)
if (-not $isAdmin) {
    Write-Warning 'This script needs an elevated PowerShell session. Re-run as Administrator.'
    return
}

Write-Host '== Open Dental: cold database + images backup ==' -ForegroundColor Cyan
Write-Host 'Run this ON THE DB SERVER, off-hours. It stops MySQL/MariaDB (downtime).' -ForegroundColor Yellow
Write-Host ''

# --- 1. Resolve the MySQL/MariaDB service ---
$dbServices = @(Get-Service | Where-Object { $_.Name -match 'mysql|mariadb' -or $_.DisplayName -match 'mysql|mariadb' })
if ($dbServices.Count -eq 1) {
    $svcName = $dbServices[0].Name
    Write-Host "Detected database service: $svcName ($($dbServices[0].DisplayName)) [$($dbServices[0].Status)]" -ForegroundColor Green
    if ((Read-Host "Use this service? (Y/n)") -eq 'n') { $svcName = $null }
}
elseif ($dbServices.Count -gt 1) {
    Write-Host 'Multiple database services found:' -ForegroundColor Yellow
    $dbServices | ForEach-Object { Write-Host "  - $($_.Name)  ($($_.DisplayName))  [$($_.Status)]" }
    $svcName = $null
}
else {
    Write-Warning 'No service matching mysql/mariadb found. Enter the name manually.'
    $svcName = $null
}
if (-not $svcName) {
    $svcName = Read-Host 'MySQL/MariaDB service name (e.g. MySQL, MySQL57, MariaDB)'
}
$svc = Get-Service -Name $svcName   # throws if it doesn't exist

# --- 2. Resolve the data directory (copy the WHOLE dir, not just opendental) ---
$dataGuesses = @('C:\mysql\data', 'C:\Program Files\MySQL\MySQL Server*\data',
                 'C:\ProgramData\MySQL\MySQL Server*\Data', 'C:\Program Files\MariaDB*\data') |
    ForEach-Object { Get-Item $_ -ErrorAction SilentlyContinue } |
    Where-Object { $_ } | Select-Object -ExpandProperty FullName
$dataDir = $dataGuesses | Where-Object { Test-Path (Join-Path $_ 'opendental') } | Select-Object -First 1
if ($dataDir) {
    Write-Host "Detected data directory: $dataDir" -ForegroundColor Green
    if ((Read-Host "Use this data directory? (Y/n)") -eq 'n') { $dataDir = $null }
}
if (-not $dataDir) {
    $dataDir = Read-Host 'MySQL data directory (the folder CONTAINING the opendental subfolder, e.g. C:\mysql\data)'
}
if (-not (Test-Path (Join-Path $dataDir 'opendental'))) {
    Write-Warning "No 'opendental' subfolder under: $dataDir"
    if ((Read-Host 'Continue anyway? (y/N)') -ne 'y') { return }
}

# --- 3. Resolve the A-to-Z / OpenDentImages folder (optional) ---
$imgGuess = @('C:\OpenDentImages', 'D:\OpenDentImages') | Where-Object { Test-Path $_ } | Select-Object -First 1
$imgDir = Read-Host "OpenDentImages (A-to-Z) folder [blank to skip]$(if($imgGuess){" (detected: $imgGuess)"})"
if (-not $imgDir -and $imgGuess) { $imgDir = $imgGuess }
if ($imgDir -and -not (Test-Path $imgDir)) {
    Write-Warning "Images path not found: $imgDir — it will be skipped."
    $imgDir = $null
}

# --- 4. Backup destination ---
$destRoot = Read-Host 'Backup destination root (external/second disk or UNC path, e.g. E:\OD-Backups)'
if (-not (Test-Path $destRoot)) {
    if ((Read-Host "Destination does not exist. Create it? (Y/n)") -eq 'n') { return }
    New-Item -ItemType Directory -Path $destRoot -Force | Out-Null
}
$stamp     = Get-Date -Format 'yyyyMMdd-HHmmss'
$backupDir = Join-Path $destRoot "od-backup-$stamp"

# --- 5. Size / free-space sanity check ---
function Get-DirSizeGB($path) {
    try {
        $bytes = (Get-ChildItem -LiteralPath $path -Recurse -Force -File -ErrorAction SilentlyContinue |
                  Measure-Object -Property Length -Sum).Sum
        [math]::Round(($bytes / 1GB), 2)
    } catch { $null }
}
Write-Host 'Measuring source size (may take a moment for large image folders)...'
$dataGB = Get-DirSizeGB $dataDir
$imgGB  = if ($imgDir) { Get-DirSizeGB $imgDir } else { 0 }
$needGB = [math]::Round(($dataGB + $imgGB), 2)
try {
    $destQualifier = (Split-Path -Qualifier $backupDir)
    $freeGB = [math]::Round(((Get-PSDrive ($destQualifier.TrimEnd(':'))).Free / 1GB), 2)
} catch { $freeGB = $null }

Write-Host ''
Write-Host 'Plan:' -ForegroundColor Cyan
Write-Host "  Service to cycle : $svcName [$($svc.Status)]"
Write-Host "  Data directory   : $dataDir   (~$dataGB GB)"
Write-Host "  Images folder    : $(if($imgDir){"$imgDir   (~$imgGB GB)"}else{'(skipped)'})"
Write-Host "  Destination      : $backupDir"
Write-Host "  Approx needed    : ~$needGB GB$(if($freeGB){"   (free at dest: $freeGB GB)"})"
if ($freeGB -and $needGB -gt $freeGB) {
    Write-Warning 'Destination may not have enough free space for this backup.'
}
Write-Host ''
Write-Host 'This STOPS the database (Open Dental goes down on all workstations) for the copy.' -ForegroundColor Yellow
if ((Read-Host 'Proceed? (y/N)') -ne 'y') { Write-Host 'Aborted. No changes made.'; return }

New-Item -ItemType Directory -Path $backupDir -Force | Out-Null
$logPath = Join-Path $backupDir 'backup.log'
function Log($msg) {
    $line = "$(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')  $msg"
    Write-Host $line
    Add-Content -LiteralPath $logPath -Value $line
}

# robocopy: /E all subdirs incl empty, /COPY:DAT+/DCOPY:DAT data/attrs/timestamps,
# /R:2 /W:5 short retries, /NFL /NDL /NP quieter. Exit code >= 8 = failure.
function Copy-Tree($src, $dst, $label) {
    Log "Copying $label : $src  ->  $dst"
    robocopy $src $dst /E /COPY:DAT /DCOPY:DAT /R:2 /W:5 /NFL /NDL /NP /NJH /NJS | Out-Null
    $code = $LASTEXITCODE
    Log "robocopy ($label) exit code $code"
    if ($code -ge 8) { throw "robocopy failed copying $label (exit $code)." }
}

$wasRunning = ($svc.Status -eq 'Running')
$ok = $false
try {
    # --- 6. Stop the service and VERIFY it stopped before copying ---
    if ($svc.Status -ne 'Stopped') {
        Log "Stopping service $svcName ..."
        Stop-Service -Name $svcName -Force
        $svc.WaitForStatus('Stopped', [TimeSpan]::FromSeconds(120))  # throws on timeout
    }
    (Get-Service -Name $svcName).Refresh()
    if ((Get-Service -Name $svcName).Status -ne 'Stopped') {
        throw "Service $svcName did not reach Stopped — aborting before copy."
    }
    Log "Service $svcName confirmed Stopped. Beginning cold copy."

    # --- 7. Copy the whole data directory, then images ---
    Copy-Tree $dataDir (Join-Path $backupDir 'data') 'data directory'
    if ($imgDir) { Copy-Tree $imgDir (Join-Path $backupDir 'OpenDentImages') 'OpenDentImages' }

    $ok = $true
    Log 'Cold copy completed successfully.'
}
catch {
    Log "ERROR: $($_.Exception.Message)"
    Write-Warning "Backup failed: $($_.Exception.Message)"
}
finally {
    # --- 8. ALWAYS restart the service if it was running (never leave DB down) ---
    if ($wasRunning) {
        try {
            Log "Restarting service $svcName ..."
            Start-Service -Name $svcName
            (Get-Service -Name $svcName).WaitForStatus('Running', [TimeSpan]::FromSeconds(120))
            Log "Service $svcName is Running again."
        }
        catch {
            Write-Warning "CRITICAL: could not restart $svcName. Start it manually NOW: Start-Service $svcName"
            Log "CRITICAL: restart failed: $($_.Exception.Message)"
        }
    }
    else {
        Log "Service was not running at start; left as-found (Stopped)."
    }
}

# --- 9. Capture recovery aids: FreeDentalConfig.xml + version stamps (best-effort) ---
# The Open Dental program is NOT backed up (reinstall the matching version on
# restore). But grabbing the connection config and recording the exact versions
# makes a restore fast and version-correct. Best-effort: never fails the backup.
if ($ok) {
    $odInstall = @(${env:ProgramFiles(x86)}, $env:ProgramFiles) | Where-Object { $_ } |
        ForEach-Object { Join-Path $_ 'Open Dental' } |
        Where-Object { Test-Path $_ } | Select-Object -First 1
    $odVersion = 'unknown'
    if ($odInstall) {
        $cfg = Join-Path $odInstall 'FreeDentalConfig.xml'
        if (Test-Path $cfg) {
            try { Copy-Item -LiteralPath $cfg -Destination (Join-Path $backupDir 'FreeDentalConfig.xml') -Force
                  Log 'Captured FreeDentalConfig.xml (connection/AtoZ config).' }
            catch { Log "Could not copy FreeDentalConfig.xml: $($_.Exception.Message)" }
        }
        $exe = Join-Path $odInstall 'OpenDental.exe'
        if (Test-Path $exe) { try { $odVersion = (Get-Item $exe).VersionInfo.FileVersion } catch {} }
    }
    # DB engine version from the service's backing executable
    $dbVersion = 'unknown'
    try {
        $imgPath = (Get-CimInstance Win32_Service -Filter "Name='$svcName'" -ErrorAction Stop).PathName
        $exePath = ([regex]::Match($imgPath, '([A-Za-z]:\\[^"]*?\.exe)')).Groups[1].Value
        if ($exePath -and (Test-Path $exePath)) { $dbVersion = (Get-Item $exePath).VersionInfo.ProductVersion }
    } catch {}
}

# --- 10. Write a manifest and report ---
if ($ok) {
    $manifest = @"
Open Dental cold backup
  Created           : $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')
  Host              : $env:COMPUTERNAME
  Service           : $svcName
  Open Dental ver   : $odVersion   (reinstall THIS version to restore)
  DB engine ver     : $dbVersion   (restore onto a matching MySQL/MariaDB)
  Data directory    : $dataDir  (~$dataGB GB)
  Images folder     : $(if($imgDir){"$imgDir  (~$imgGB GB)"}else{'(skipped)'})
  FreeDentalConfig  : $(if($odInstall -and (Test-Path (Join-Path $backupDir 'FreeDentalConfig.xml'))){'captured'}else{'(not found)'})
  Backup folder     : $backupDir
  Method            : cold copy (service stopped + verified), whole data dir incl InnoDB shared tablespace/logs
"@
    Set-Content -LiteralPath (Join-Path $backupDir 'MANIFEST.txt') -Value $manifest
    Write-Host ''
    Write-Host "Backup complete: $backupDir" -ForegroundColor Green
    Write-Host "Open Dental $odVersion / DB $dbVersion — reinstall matching versions to restore." -ForegroundColor Green
    Write-Host 'Next: copy this folder OFF-SITE, and TEST-RESTORE it periodically on an isolated machine.' -ForegroundColor Green
    Write-Host 'Never restore over a live production database.' -ForegroundColor Yellow
}
else {
    Write-Warning "Backup did NOT complete. See log: $logPath"
    Write-Warning "Confirm the database service is running: Get-Service $svcName"
}