<#
.SYNOPSIS
  Export ODBC DSNs, registry keys, and driver inventory.
  Generate migration package + report with vendor download links.

.DESCRIPTION
  This script:
  - Exports ODBC System/User DSNs
  - Exports registry keys for ODBC.INI
  - Lists all installed ODBC drivers and Add/Remove Program entries
  - Matches known ODBC drivers to official vendor download URLs
  - Searches for local EXE/MSI installers
  - Generates CSV + Markdown reports
  - Compresses all output into a single ZIP archive

  Run as Administrator on the source PC.
#>

# ===========================
# CONFIGURATION
# ===========================
$BaseDir   = "C:\ODBC_Migration"
$ExportDir = Join-Path $BaseDir "export"
$ZipFile   = Join-Path $BaseDir "ODBC_Backup.zip"
$LogFile   = Join-Path $BaseDir "export_log.txt"

# Optional: Add local folders to search for installers
$InstallerHuntPaths = @(
  "$env:USERPROFILE\Downloads",
  "C:\Installers",
  "C:\Drivers",
  "$env:PUBLIC\Downloads"
) | Where-Object { Test-Path $_ }

# ===========================
# PREP
# ===========================
New-Item -ItemType Directory -Path $ExportDir -Force | Out-Null
Start-Transcript -Path $LogFile -Append
Write-Host "Starting ODBC migration export..." -ForegroundColor Cyan

# ===========================
# STEP 1: EXPORT BASELINE DATA
# ===========================
Write-Host "Exporting ODBC driver list..."
$drivers = Get-OdbcDriver | Select-Object Name, Platform, Version, Attribute
$driversCsv = Join-Path $ExportDir "odbc_drivers.csv"
$drivers | Export-Csv -Path $driversCsv -NoTypeInformation -Encoding UTF8

Write-Host "Exporting DSNs..."
$dsnsXml = Join-Path $ExportDir "odbc_dsns.xml"
Get-OdbcDsn | Export-Clixml $dsnsXml

Write-Host "Exporting registry keys..."
reg export "HKLM\SOFTWARE\ODBC\ODBC.INI" (Join-Path $ExportDir "ODBC_System.reg") /y | Out-Null
reg export "HKCU\Software\ODBC\ODBC.INI" (Join-Path $ExportDir "ODBC_User.reg") /y | Out-Null
$WowKey = "HKLM\SOFTWARE\WOW6432Node\ODBC\ODBC.INI"
if (Test-Path "Registry::$WowKey") {
  reg export $WowKey (Join-Path $ExportDir "ODBC_System32.reg") /y | Out-Null
  Write-Host "Exported 32-bit ODBC keys."
}

# ===========================
# STEP 2: ENUMERATE INSTALLED PRODUCTS
# ===========================
Write-Host "Enumerating Add/Remove Programs entries..."
function Get-UninstallEntries {
  $roots = @(
    "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall",
    "HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall",
    "HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall"
  )
  foreach ($r in $roots) {
    if (Test-Path $r) {
      Get-ChildItem $r | ForEach-Object { Get-ItemProperty $_.PsPath }
    }
  }
}
$uninst = Get-UninstallEntries | Select-Object `
  DisplayName, DisplayVersion, Publisher, InstallLocation, UninstallString, ModifyPath, QuietUninstallString

# Tokenizer helper
function Normalize([string]$s) {
  if (-not $s) { return "" }
  return (($s -replace '[^a-zA-Z0-9]+', ' ') -as [string]).Trim().ToLowerInvariant()
}

# Map ODBC drivers -> installed programs
Write-Host "Mapping ODBC drivers to installed programs..."
$map = foreach ($d in $drivers) {
  $nameNorm = Normalize $d.Name
  $candidates = $uninst | Where-Object {
    $_.DisplayName -and (Normalize $_.DisplayName) -match ($nameNorm -replace '\s+','.*')
  }

  if (-not $candidates -and $d.Name -match 'oracle|mysql|postgres|sql\s*server|mariadb|sqlite|snowflake|teradata|ibm|db2|progress|sybase|firebird|hana|vertica|redshift') {
    $kw = ($matches[0])
    $candidates = $uninst | Where-Object { $_.DisplayName -match $kw }
  }

  [PSCustomObject]@{
    OdbcDriverName  = $d.Name
    Platform        = $d.Platform
    DriverVersion   = $d.Version
    ProductName     = ($candidates | Select-Object -First 1 -ExpandProperty DisplayName)
    ProductVersion  = ($candidates | Select-Object -First 1 -ExpandProperty DisplayVersion)
    Publisher       = ($candidates | Select-Object -First 1 -ExpandProperty Publisher)
    InstallLocation = ($candidates | Select-Object -First 1 -ExpandProperty InstallLocation)
    UninstallString = ($candidates | Select-Object -First 1 -ExpandProperty UninstallString)
  }
}

# ===========================
# STEP 3: ADD KNOWN VENDOR LINKS
# ===========================
Write-Host "Attaching known vendor download links..."

$vendorLinks = @{
  # --- Microsoft ---
  'odbc driver 18 for sql server' = 'https://learn.microsoft.com/sql/connect/odbc/download-odbc-driver-for-sql-server'
  'odbc driver 17 for sql server' = 'https://learn.microsoft.com/sql/connect/odbc/download-odbc-driver-for-sql-server'
  'sql server native client'      = 'https://learn.microsoft.com/sql/relational-databases/native-client/applications/installing-sql-server-native-client'
  'microsoft access driver'       = 'https://www.microsoft.com/download/details.aspx?id=54920'
  'microsoft excel driver'        = 'https://www.microsoft.com/download/details.aspx?id=54920'
  'microsoft text driver'         = 'https://www.microsoft.com/download/details.aspx?id=54920'
  'microsoft dbase driver'        = 'https://www.microsoft.com/download/details.aspx?id=54920'
  'microsoft odbc for oracle'     = 'https://learn.microsoft.com/sql/odbc/microsoft/odbc-driver-for-oracle'

  # --- Oracle ---
  'oracle odbc driver'            = 'https://www.oracle.com/database/technologies/releasenote-odbc-ic.html'
  'oracle in oraclient'           = 'https://www.oracle.com/database/technologies/releasenote-odbc-ic.html'

  # --- MySQL / MariaDB ---
  'mysql odbc'                    = 'https://dev.mysql.com/downloads/connector/odbc/'
  'mariadb odbc'                  = 'https://mariadb.com/products/connectors/odbc/'

  # --- PostgreSQL ---
  'postgresql odbc'               = 'https://odbc.postgresql.org/'
  'psqlodbc'                      = 'https://odbc.postgresql.org/'

  # --- SQLite ---
  'sqlite odbc'                   = 'https://www.ch-werner.de/sqliteodbc/'

  # --- IBM / Informix ---
  'ibm db2 odbc'                  = 'https://www.ibm.com/support/pages/db2-clients'
  'informix odbc'                 = 'https://www.ibm.com/support/pages/informix-odbc-driver'

  # --- Snowflake ---
  'snowflake odbc'                = 'https://developers.snowflake.com/odbc/'

  # --- Teradata ---
  'teradata odbc'                 = 'https://downloads.teradata.com/connectivity/odbc-driver'

  # --- Progress / OpenEdge ---
  'progress openedge odbc'        = 'https://www.progress.com/odbc/openedge'
  'openedge odbc'                 = 'https://www.progress.com/odbc/openedge'

  # --- SAP HANA ---
  'sap hana odbc'                 = 'https://tools.hana.ondemand.com/#hanatools'

  # --- Amazon Redshift ---
  'redshift odbc'                 = 'https://docs.aws.amazon.com/redshift/latest/mgmt/configure-odbc-connection.html'

  # --- Vertica ---
  'vertica odbc'                  = 'https://www.vertica.com/download/vertica/client-drivers/'

  # --- Firebird ---
  'firebird odbc'                 = 'https://firebirdsql.org/en/odbc-driver/'

  # --- Generic fallback ---
  'generic odbc driver'           = 'https://www.microsoft.com/en-us/sql/connect/odbc/'
}

foreach ($item in $map) {
  $norm = Normalize $item.OdbcDriverName
  $found = $false
  foreach ($key in $vendorLinks.Keys) {
    if ($norm -like "*$key*") {
      $item | Add-Member -NotePropertyName "DownloadURL" -NotePropertyValue $vendorLinks[$key]
      $found = $true
      break
    }
  }
  if (-not $found) {
    $item | Add-Member -NotePropertyName "DownloadURL" -NotePropertyValue "Search manually"
  }
}

# ===========================
# STEP 4: FIND LOCAL INSTALLER FILES
# ===========================
Write-Host "Scanning for local installers..."
$searchTerms = ($map.OdbcDriverName | Sort-Object -Unique)
$installerHits = @()
foreach ($p in $InstallerHuntPaths) {
  Get-ChildItem -Path $p -Recurse -ErrorAction SilentlyContinue -Include *.msi,*.exe |
    ForEach-Object {
      $fileNorm = Normalize $_.Name
      foreach ($term in $searchTerms) {
        $t = Normalize $term
        if ($fileNorm -match ($t -replace '\s+','.*')) {
          $installerHits += [PSCustomObject]@{
            Term        = $term
            FileName    = $_.Name
            FullPath    = $_.FullName
            SizeMB      = [math]::Round($_.Length/1MB,2)
            LastWrite   = $_.LastWriteTime
            SearchRoot  = $p
          }
          break
        }
      }
    }
}

# ===========================
# STEP 5: REPORT OUTPUT
# ===========================
$mapCsv = Join-Path $ExportDir "odbc_driver_product_map.csv"
$map    | Export-Csv -Path $mapCsv -NoTypeInformation -Encoding UTF8
$hitsCsv = Join-Path $ExportDir "odbc_installer_hits.csv"
$installerHits | Export-Csv -Path $hitsCsv -NoTypeInformation -Encoding UTF8

$reportMd = Join-Path $ExportDir "ODBC_Migration_Report.md"
@"
# ODBC Migration Report

**Generated:** $(Get-Date -Format "yyyy-MM-dd HH:mm:ss")
**Machine:**   $env:COMPUTERNAME

## Summary
- Drivers detected: $($drivers.Count)
- DSNs exported:    $((Get-OdbcDsn).Count)
- Installer hits:   $($installerHits.Count)

## Drivers & Product Mapping
| ODBC Driver | Platform | Version | Product | Publisher | Download Link |
|---|---:|---|---|---|---|
$(
  ($map | ForEach-Object {
    $dn = if ($_.OdbcDriverName) { $_.OdbcDriverName.Replace('|','-') } else { '' }
    $pf = $_.Platform
    $dv = $_.DriverVersion
    $pn = ($_.ProductName    -replace '\|','-')
    $pu = ($_.Publisher      -replace '\|','-')
    $dl = if ($_.DownloadURL -match '^https?') { "[Download]($($_.DownloadURL))" } else { $_.DownloadURL }
    "| $dn | $pf | $dv | $pn | $pu | $dl |"
  }) -join "`r`n"
)

## Likely Local Installer Files
| Matches Term | File | Size (MB) | Modified | Path |
|---|---|---:|---|---|
$(
  ($installerHits | Sort-Object Term,FileName | ForEach-Object {
    "| $($_.Term) | $($_.FileName) | $($_.SizeMB) | $($_.LastWrite.ToString('yyyy-MM-dd')) | $($_.FullPath) |"
  }) -join "`r`n"
)

## Next Steps
1. On the **target PC**, install matching ODBC driver packages using the links above or your local installers.
2. Then run **Restore-ODBC.ps1** to import DSNs and registry settings.
3. Verify DSNs in *ODBC Data Source Administrator* (both 32-bit and 64-bit).
"@ | Out-File -FilePath $reportMd -Encoding UTF8

# ===========================
# STEP 6: ZIP PACKAGE
# ===========================
if (Test-Path $ZipFile) { Remove-Item $ZipFile -Force }
Compress-Archive -Path "$ExportDir\*" -DestinationPath $ZipFile -Force

Write-Host "Export complete. ZIP created at: $ZipFile" -ForegroundColor Green
Stop-Transcript