# ===== Logging ===============================================================
$logFile = ".\term_export_Log-$(Get-Date -Format "yyyyMMdd-HHmm").csv"
function Log-Message {
    param (
        [string]$Message,
        [string]$Status = "Info"
    )
    switch ($Status) {
        "Success" { $color = "Green" }
        "Info"    { $color = "Blue" }
        "Error"   { $color = "Red" }
        default   { $color = "White" }
    }
    Write-Host -ForegroundColor $color "$Status => $Message"
    $logEntry = [PSCustomObject]@{
        Timestamp = (Get-Date).ToString("yyyy-MM-dd HH:mm:ss")
        Message   = $Message
        Status    = $Status
    }
    # Ensure log file exists and append
    if (-not (Test-Path $logFile)) {
        $logEntry | Export-Csv -Path $logFile -NoTypeInformation
    } else {
        $logEntry | Export-Csv -Path $logFile -Append -NoTypeInformation
    }
}

# ===== Config ================================================================
$clientId = "xxxxxxx"

# Term store groups to export
$groups = @("Document Management Tags - PROD")

# Output path
$invocation     = (Get-Variable MyInvocation).Value
$directoryPath  = Split-Path $invocation.MyCommand.Path
$currentTime    = (Get-Date).ToString("yyyyMMddHHmmss")

# Create output folder if missing
$outputFolder   = Join-Path $directoryPath "output_files"
if (-not (Test-Path $outputFolder)) { New-Item -Path $outputFolder -ItemType Directory | Out-Null }

# Final CSV file path
$FilePath       = Join-Path $outputFolder ("TermStoreReport-" + $currentTime + ".csv")

# ===== Helpers ===============================================================


# Use Get-PnPTermLabel to retrieve synonyms (non-default labels)
function Get-Synonyms {
  param(
      [Guid]$TermId,
      [string]$TermName
  )
  try {
      $labels = Get-PnPTermLabel -Lcid 1033 -Term $TermId -ErrorAction Stop
      $labels = $labels | where-object{$_.Value -ne $TermName}
      # Return a comma-separated unique string
      return $labels.Value -join ","
  } catch {
      Log-Message -Message "Get-PnPTermLabel failed for TermId $TermId : $($_.Exception.Message)" -Status "Error"
      return ""
  }
}

# ===== Export ================================================================

# Split a semicolon-delimited path and return cleaned segments
function Split-PathSegments {
  param(
      [Parameter(Mandatory)]
      [string]$PathString
  )
  # Split on ';', trim whitespace, remove empty segments
  $segments = $PathString -split ';' |
      ForEach-Object { $_.Trim() } |
      Where-Object { $_ -ne "" }

  return ,$segments  # return as array
}

# Return the numeric level (count of segments after cleaning)
function Get-PathLevel {
  param(
      [Parameter(Mandatory)]
      [string]$PathString
  )
  $segments = Split-PathSegments -PathString $PathString
  return $segments.Count
}

# Pad/clip segments to exactly 7 levels for CSV columns
function Get-Levels1to7 {
  param(
      [Parameter(Mandatory)]
      [string]$PathString,
      [int]$MaxLevels = 7
  )
  $segments = Split-PathSegments -PathString $PathString

  # Pad with blanks and clip to MaxLevels
  $padded = @($segments + @("", "", "", "", "", "", ""))[0..($MaxLevels-1)]
  return   ,$padded
}

# Example row builder when you have a semicolon path string
$rows = New-Object System.Collections.Generic.List[object]
function Add-RowFromPath {
  param(
      [string]$TermSetName,
      [string]$TermSetDescription,
      [string]$PathString,
      [string]$AvailableForTagging,
      [string]$TermDescription,
      [string]$Synonyms
  )

  $levels = Get-Levels1to7 -PathString $PathString
  
  $Rows.Add([PSCustomObject]@{
      "Term Set Name"         = $TermSetName
      "Term Set Description"  = $TermSetDescription
      "Available for Tagging" = $AvailableForTagging
      "Term Description"      = $TermDescription
      "Level 1 Term"          = $levels[0]
      "Level 2 Term"          = $levels[1]
      "Level 3 Term"          = $levels[2]
      "Level 4 Term"          = $levels[3]
      "Level 5 Term"          = $levels[4]
      "Level 6 Term"          = $levels[5]
      "Level 7 Term"          = $levels[6]
      "Synonyms"              = $Synonyms
  })
}

function Process-Term {
param(
  [object]$Term,
  [string]$TermSetName,
  [string]$TermSetDescription
)
  $available = [string]$Term.IsAvailableForTagging -replace 'True','TRUE' -replace 'False','FALSE'
  $termDesc  = $Term.Description
  $synonyms  = Get-Synonyms -TermId $Term.Id -TermName $Term.Name
  $PathOfTerm = $Term.PathOfTerm
  Add-RowFromPath -TermSetName $TermSetName -TermSetDescription $TermSetDescription -PathString $PathOfTerm -AvailableForTagging $available -TermDescription $termDesc -Synonyms $synonyms -Rows $rows
}
function ExportTerms {
    try {
        # If groups were not specified, enumerate all groups
        if ($groups.Length -eq 0) {
            $groups = @(Get-PnPTermGroup | ForEach-Object { $_.Name })
        }

        foreach ($termGroupName in $groups) {
            try {
                Log-Message -Message "Exporting terms from group: $termGroupName" -Status "Info"
                # Load term sets in the group
                $termGroupObj = Get-PnPTermGroup -Identity $termGroupName -Includes TermSets
                foreach ($termSet in $termGroupObj.TermSets) {
                    # Ensure Terms collection loaded
                    $termSetTerms = Get-PnPTerm -TermSet $termSet.Id -TermGroup $termGroupName -IncludeChildTerms -Recursive
                    $tsName     = $termSet.Name
                    $tsDesc     = $termSet.Description

                    # Level 1 terms (root terms under the term set)
                    foreach ($lvl1 in $termSetTerms) {
                        # If the level 1 term has children, output each level bases on path of term
                        if ($lvl1.Terms -and $lvl1.Terms.Count -gt 0) {
                            foreach ($lvl2 in $lvl1.Terms) {
                              Process-Term -Term $lvl2 -TermSetName $tsName -TermSetDescription $tsDesc
                              if ($lvl2.Terms -and $lvl2.Terms.Count -gt 0) {
                                foreach($lvl3 in $lvl2.Terms)
                                {
                                  Process-Term -Term $lvl3 -TermSetName $tsName -TermSetDescription $tsDesc 
                                  if ($lvl3.Terms -and $lvl3.Terms.Count -gt 0) {
                                  foreach($lvl4 in $lvl3.Terms)
                                  {
                                    Process-Term -Term $lvl4 -TermSetName $tsName -TermSetDescription $tsDesc
                                    if ($lvl4.Terms -and $lvl4.Terms.Count -gt 0) {
                                    foreach($lvl5 in $lvl4.Terms)
                                    {
                                      Process-Term -Term $lvl5 -TermSetName $tsName -TermSetDescription $tsDesc
                                      if ($lvl5.Terms -and $lvl5.Terms.Count -gt 0) {
                                      foreach($lvl6 in $lvl5.Terms)
                                      {
                                      Process-Term -Term $lvl6 -TermSetName $tsName -TermSetDescription $tsDesc
                                      }
                                    }
                                  }
                                  }
                                }
                                }
                              }
                              }
                            }
                        }
                        else {
                          Process-Term -Term $lvl1 -TermSetName $tsName -TermSetDescription $tsDesc
                        }
                    }
                }
            }
            catch {
                Log-Message -Message "Error in group '$termGroupName': $($_.Exception.Message)" -Status "Error"
            }
        }

        # Write the CSV once (safer than repeating Add-Content)
        $rows | Export-Csv -Path $FilePath -NoTypeInformation
        Log-Message -Message "Export complete. File: $FilePath" -Status "Success"
    }
    catch {
        Log-Message -Message "Unhandled error: $($_.Exception.Message)" -Status "Error"
    }
}

# ===== Connect, Run, Disconnect =============================================
Connect-PnPOnline -Url "https://contoso.sharepoint.com/" -ClientId $clientId
Log-Message -Message "Connected to SharePoint" -Status "Info"

ExportTerms

Disconnect-PnPOnline
Log-Message -Message "Disconnected" -Status "Info"