#Requires -Version 5.1

<#
.SYNOPSIS
    Oracle connectivity and operations functions for ROA setup scripts.

.DESCRIPTION
    Provides functions for Oracle database connectivity, SQL*Plus execution,
    version detection, and Data Pump operations.

.NOTES
    File Name      : oracle-functions.ps1
    Prerequisite   : PowerShell 5.1 or higher, Oracle Client installed
    Copyright 2024 : ROMFAST
#>

# Source logging functions
. "$PSScriptRoot\logging-functions.ps1"

<#
.SYNOPSIS
    Get the listener host address.

.DESCRIPTION
    Auto-detects the host address from listener configuration.
    Returns the IP address the listener is bound to.

.PARAMETER OracleHome
    Oracle Home directory.

.OUTPUTS
    String. The host address (IP or hostname).

.EXAMPLE
    $host = Get-ListenerHost -OracleHome "C:\app\oracle\product\21c\dbhomeXE"
#>
function Get-ListenerHost {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome
    $lsnrctl = Join-Path $oraHome "bin\lsnrctl.exe"

    if (-not (Test-Path $lsnrctl)) {
        return "localhost"
    }

    try {
        # Set Oracle environment
        $env:ORACLE_HOME = $oraHome
        $env:PATH = "$oraHome\bin;$env:PATH"

        $output = & $lsnrctl status 2>&1 | Out-String

        # Parse HOST from listener output - look for TCP endpoint (not TCPS)
        # Format: (PROTOCOL=tcp)(HOST=10.0.20.130)(PORT=1521)
        # Use simple IP pattern to avoid regex escaping issues
        $tcpMatch = [regex]::Match($output, "PROTOCOL=tcp\).*?HOST=([0-9\.]+)")
        if ($tcpMatch.Success) {
            $listenerHost = $tcpMatch.Groups[1].Value

            # If listener is bound to 0.0.0.0, try to get actual IP
            if ($listenerHost -eq "0.0.0.0") {
                $ip = (Get-NetIPAddress -AddressFamily IPv4 |
                       Where-Object { $_.IPAddress -notmatch "^127\." -and $_.PrefixOrigin -ne "WellKnown" } |
                       Select-Object -First 1).IPAddress
                if ($ip) { return $ip }
                return "localhost"
            }

            # If it's a specific IP (not localhost), return it
            if ($listenerHost -notmatch "^127\." -and $listenerHost -ne "localhost") {
                return $listenerHost
            }
        }

        # Fallback: try any HOST= pattern
        $anyHostMatch = [regex]::Match($output, "HOST=([0-9\.]+)")
        if ($anyHostMatch.Success) {
            $listenerHost = $anyHostMatch.Groups[1].Value
            if ($listenerHost -notmatch "^127\." -and $listenerHost -ne "0.0.0.0") {
                return $listenerHost
            }
        }

        return "localhost"
    }
    catch {
        return "localhost"
    }
}

<#
.SYNOPSIS
    Find Oracle Home directory.

.DESCRIPTION
    Auto-detects Oracle Home from registry, environment variable, or common paths.

.PARAMETER OracleHome
    Optional explicit Oracle Home path. If not specified, auto-detects.

.OUTPUTS
    String. The Oracle Home path.

.EXAMPLE
    $oracleHome = Get-OracleHome
#>
function Get-OracleHome {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome
    )

    # If explicitly provided, validate and return
    if ($OracleHome) {
        if (Test-Path -Path "$OracleHome\bin\sqlplus.exe") {
            return $OracleHome
        }
        throw "Invalid Oracle Home: sqlplus.exe not found at $OracleHome\bin\sqlplus.exe"
    }

    # Try ORACLE_HOME environment variable
    if ($env:ORACLE_HOME -and (Test-Path -Path "$env:ORACLE_HOME\bin\sqlplus.exe")) {
        return $env:ORACLE_HOME
    }

    # Try registry for Oracle XE
    $regPaths = @(
        'HKLM:\SOFTWARE\Oracle\KEY_OraDB21Home1',
        'HKLM:\SOFTWARE\Oracle\KEY_OraDB18Home1',
        'HKLM:\SOFTWARE\Oracle\KEY_XE',
        'HKLM:\SOFTWARE\Wow6432Node\Oracle\KEY_OraDB21Home1',
        'HKLM:\SOFTWARE\Wow6432Node\Oracle\KEY_OraDB18Home1'
    )

    foreach ($regPath in $regPaths) {
        if (Test-Path -Path $regPath) {
            $oraHome = (Get-ItemProperty -Path $regPath -ErrorAction SilentlyContinue).ORACLE_HOME
            if ($oraHome -and (Test-Path -Path "$oraHome\bin\sqlplus.exe")) {
                return $oraHome
            }
        }
    }

    # Try common installation paths (including user-specific paths)
    $currentUser = $env:USERNAME
    $commonPaths = @(
        "C:\app\$currentUser\product\21c\dbhomeXE",
        "C:\app\$currentUser\product\21c\dbhome_1",
        "C:\app\$currentUser\product\18c\dbhomeXE",
        'C:\app\oracle\product\21c\dbhomeXE',
        'C:\app\oracle\product\21c\dbhome_1',
        'C:\app\oracle\product\18c\dbhomeXE',
        'C:\app\romfast\product\21c\dbhomeXE',
        'C:\app\romfast\product\21c\dbhome_1',
        'C:\oraclexe\app\oracle\product\11.2.0\server',
        "D:\app\$currentUser\product\21c\dbhomeXE",
        'D:\app\oracle\product\21c\dbhomeXE',
        'D:\app\oracle\product\18c\dbhomeXE'
    )

    foreach ($path in $commonPaths) {
        if (Test-Path -Path "$path\bin\sqlplus.exe") {
            return $path
        }
    }

    throw "Oracle Home not found. Please specify -OracleHome parameter or set ORACLE_HOME environment variable."
}

<#
.SYNOPSIS
    Get Oracle version information.

.DESCRIPTION
    Detects Oracle version (XE vs SE), edition, and whether it's a Container Database (CDB).

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Username
    Username for connection (default: SYSTEM).

.PARAMETER Password
    Password for connection.

.OUTPUTS
    PSCustomObject with Version, Edition, IsCDB, IsXE properties.

.EXAMPLE
    $version = Get-OracleVersion -ServiceName "XE" -Password "oracle"
#>
function Get-OracleVersion {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $false)]
        [string]$DbHost,

        [Parameter(Mandatory = $false)]
        [int]$Port = 1521,

        [Parameter(Mandatory = $false)]
        [string]$Username = "SYSTEM",

        [Parameter(Mandatory = $true)]
        [string]$Password
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome

    $sql = @"
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF
SELECT 'VERSION:' || version_full FROM v`$instance;
SELECT 'EDITION:' || edition FROM v`$instance;
SELECT 'CDB:' || CDB FROM v`$database;
EXIT;
"@

    $result = Invoke-SqlPlus -OracleHome $oraHome -ServiceName $ServiceName `
        -DbHost $DbHost -Port $Port `
        -Username $Username -Password $Password -SqlCommand $sql -Silent

    $versionInfo = [PSCustomObject]@{
        Version  = ""
        Edition  = ""
        IsCDB    = $false
        IsXE     = $false
        FullInfo = $result
    }

    foreach ($line in $result -split "`n") {
        if ($line -match "^VERSION:(.+)$") {
            $versionInfo.Version = $Matches[1].Trim()
        }
        elseif ($line -match "^EDITION:(.+)$") {
            $versionInfo.Edition = $Matches[1].Trim()
            $versionInfo.IsXE = $versionInfo.Edition -match "XE|Express"
        }
        elseif ($line -match "^CDB:(.+)$") {
            $versionInfo.IsCDB = $Matches[1].Trim() -eq "YES"
        }
    }

    return $versionInfo
}

<#
.SYNOPSIS
    Get the default service name based on Oracle configuration.

.DESCRIPTION
    Auto-detects the appropriate service name. Returns XEPDB1 for Oracle XE CDB,
    or ROA for traditional non-CDB installations.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER SystemPassword
    SYSTEM user password.

.OUTPUTS
    String. The service name.

.EXAMPLE
    $serviceName = Get-ServiceName -SystemPassword "oracle"
#>
function Get-ServiceName {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $false)]
        [string]$DbHost,

        [Parameter(Mandatory = $false)]
        [int]$Port = 1521,

        [Parameter(Mandatory = $true)]
        [string]$SystemPassword
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome

    # First try to connect to XE and check if it's CDB
    try {
        $version = Get-OracleVersion -OracleHome $oraHome -ServiceName "XE" `
            -DbHost $DbHost -Port $Port `
            -Password $SystemPassword -ErrorAction Stop

        if ($version.IsCDB) {
            # For CDB, use XEPDB1 (the default pluggable database)
            return "XEPDB1"
        }
        else {
            return "XE"
        }
    }
    catch {
        # Try ROA as service name
        try {
            $null = Test-OracleConnection -OracleHome $oraHome -ServiceName "ROA" `
                -DbHost $DbHost -Port $Port `
                -Username "SYSTEM" -Password $SystemPassword -ErrorAction Stop
            return "ROA"
        }
        catch {
            # Default to XEPDB1 for modern XE installations
            return "XEPDB1"
        }
    }
}

<#
.SYNOPSIS
    Test Oracle database connection.

.DESCRIPTION
    Attempts to connect to Oracle and verifies the connection is successful.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Username
    Username for connection.

.PARAMETER Password
    Password for connection.

.OUTPUTS
    Boolean. True if connection successful.

.EXAMPLE
    if (Test-OracleConnection -ServiceName "XEPDB1" -Username "SYSTEM" -Password "oracle") {
        Write-Host "Connected!"
    }
#>
function Test-OracleConnection {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $false)]
        [string]$DbHost,

        [Parameter(Mandatory = $false)]
        [int]$Port = 1521,

        [Parameter(Mandatory = $false)]
        [string]$Username = "SYSTEM",

        [Parameter(Mandatory = $true)]
        [string]$Password,

        [Parameter(Mandatory = $false)]
        [switch]$AsSysdba
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome

    $sql = "SELECT 'CONNECTED' FROM dual; EXIT;"

    try {
        $result = Invoke-SqlPlus -OracleHome $oraHome -ServiceName $ServiceName `
            -DbHost $DbHost -Port $Port `
            -Username $Username -Password $Password -SqlCommand $sql -AsSysdba:$AsSysdba -Silent

        return $result -match "CONNECTED"
    }
    catch {
        return $false
    }
}

<#
.SYNOPSIS
    Test if connected to a PDB or non-CDB.

.DESCRIPTION
    Checks the current container type to determine if connected to a PDB,
    the CDB root, or a non-CDB database.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Username
    Username for connection.

.PARAMETER Password
    Password for connection.

.OUTPUTS
    PSCustomObject with ContainerName, IsPDB, IsCDBRoot, IsNonCDB properties.

.EXAMPLE
    $containerInfo = Test-PDB -ServiceName "XEPDB1" -Password "oracle"
#>
function Test-PDB {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $false)]
        [string]$DbHost,

        [Parameter(Mandatory = $false)]
        [int]$Port = 1521,

        [Parameter(Mandatory = $false)]
        [string]$Username = "SYSTEM",

        [Parameter(Mandatory = $true)]
        [string]$Password
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome

    $sql = @"
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF
SELECT 'CONTAINER:' || SYS_CONTEXT('USERENV', 'CON_NAME') FROM dual;
SELECT 'CON_ID:' || SYS_CONTEXT('USERENV', 'CON_ID') FROM dual;
EXIT;
"@

    $result = Invoke-SqlPlus -OracleHome $oraHome -ServiceName $ServiceName `
        -DbHost $DbHost -Port $Port `
        -Username $Username -Password $Password -SqlCommand $sql -Silent

    $containerInfo = [PSCustomObject]@{
        ContainerName = ""
        ConId         = 0
        IsPDB         = $false
        IsCDBRoot     = $false
        IsNonCDB      = $false
    }

    foreach ($line in $result -split "`n") {
        if ($line -match "^CONTAINER:(.+)$") {
            $containerInfo.ContainerName = $Matches[1].Trim()
        }
        elseif ($line -match "^CON_ID:(.+)$") {
            $containerInfo.ConId = [int]$Matches[1].Trim()
        }
    }

    if ($containerInfo.ConId -eq 0) {
        $containerInfo.IsNonCDB = $true
    }
    elseif ($containerInfo.ConId -eq 1) {
        $containerInfo.IsCDBRoot = $true
    }
    else {
        $containerInfo.IsPDB = $true
    }

    return $containerInfo
}

<#
.SYNOPSIS
    Execute SQL via SQL*Plus.

.DESCRIPTION
    Runs a SQL command or file using SQL*Plus and returns the output.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Username
    Username for connection.

.PARAMETER Password
    Password for connection.

.PARAMETER SqlCommand
    SQL command(s) to execute.

.PARAMETER SqlFile
    Path to SQL file to execute.

.PARAMETER AsSysdba
    Connect as SYSDBA.

.PARAMETER Silent
    Suppress console output.

.OUTPUTS
    String. The SQL*Plus output.

.EXAMPLE
    Invoke-SqlPlus -ServiceName "XEPDB1" -Username "SYSTEM" -Password "oracle" -SqlCommand "SELECT * FROM dual;"

.EXAMPLE
    Invoke-SqlPlus -ServiceName "XEPDB1" -Username "SYS" -Password "oracle" -SqlFile "C:\scripts\setup.sql" -AsSysdba
#>
function Invoke-SqlPlus {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $false)]
        [string]$DbHost,

        [Parameter(Mandatory = $false)]
        [int]$Port = 1521,

        [Parameter(Mandatory = $false)]
        [string]$Username = "SYSTEM",

        [Parameter(Mandatory = $true)]
        [string]$Password,

        [Parameter(Mandatory = $false)]
        [string]$SqlCommand,

        [Parameter(Mandatory = $false)]
        [string]$SqlFile,

        [Parameter(Mandatory = $false)]
        [switch]$AsSysdba,

        [Parameter(Mandatory = $false)]
        [switch]$Silent
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome
    $sqlplus = Join-Path $oraHome "bin\sqlplus.exe"

    if (-not (Test-Path -Path $sqlplus)) {
        throw "SQL*Plus not found at: $sqlplus"
    }

    # Auto-detect host from listener if not provided
    if (-not $DbHost) {
        $DbHost = Get-ListenerHost -OracleHome $oraHome
    }

    # Build connection string (always use EZConnect format for reliability)
    $sysdba = if ($AsSysdba) { " as sysdba" } else { "" }
    $connString = "$Username/`"$Password`"@${DbHost}:${Port}/${ServiceName}$sysdba"

    $tempFile = $null

    try {
        if ($SqlFile) {
            # Execute SQL file
            if (-not (Test-Path -Path $SqlFile)) {
                throw "SQL file not found: $SqlFile"
            }

            $arguments = "-S `"$connString`" @`"$SqlFile`""
        }
        else {
            # Create temp file for SQL command
            $tempFile = [System.IO.Path]::GetTempFileName()
            $tempFile = [System.IO.Path]::ChangeExtension($tempFile, ".sql")
            Set-Content -Path $tempFile -Value $SqlCommand -Encoding ASCII

            $arguments = "-S `"$connString`" @`"$tempFile`""
        }

        # Set Oracle environment
        $env:ORACLE_HOME = $oraHome
        $env:PATH = "$oraHome\bin;$env:PATH"
        $env:NLS_LANG = "AMERICAN_AMERICA.AL32UTF8"

        # Execute SQL*Plus
        $processInfo = New-Object System.Diagnostics.ProcessStartInfo
        $processInfo.FileName = $sqlplus
        $processInfo.Arguments = "-S `"$connString`""
        $processInfo.RedirectStandardInput = $true
        $processInfo.RedirectStandardOutput = $true
        $processInfo.RedirectStandardError = $true
        $processInfo.UseShellExecute = $false
        $processInfo.CreateNoWindow = $true

        $process = New-Object System.Diagnostics.Process
        $process.StartInfo = $processInfo
        $process.Start() | Out-Null

        # Send SQL
        if ($SqlFile) {
            $process.StandardInput.WriteLine("@`"$SqlFile`"")
        }
        else {
            $process.StandardInput.WriteLine($SqlCommand)
        }
        $process.StandardInput.Close()

        $output = $process.StandardOutput.ReadToEnd()
        $errorOutput = $process.StandardError.ReadToEnd()
        $process.WaitForExit()

        if ($errorOutput) {
            $output += "`n$errorOutput"
        }

        # Check for Oracle errors
        if ($output -match "ORA-\d{5}:|SP2-\d{4}:") {
            if (-not $Silent) {
                Write-LogWarning "SQL*Plus returned errors:"
                Write-Host $output -ForegroundColor Yellow
            }
        }

        return $output
    }
    finally {
        if ($tempFile -and (Test-Path -Path $tempFile)) {
            Remove-Item -Path $tempFile -Force -ErrorAction SilentlyContinue
        }
    }
}

<#
.SYNOPSIS
    Create Oracle directory object for Data Pump.

.DESCRIPTION
    Creates a directory object in Oracle for Data Pump operations if it doesn't exist.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Password
    SYS or SYSTEM password.

.PARAMETER DirectoryName
    Oracle directory object name (default: DMPDIR).

.PARAMETER DirectoryPath
    File system path for the directory (default: C:\DMPDIR).

.EXAMPLE
    New-OracleDirectory -ServiceName "XEPDB1" -Password "oracle" -DirectoryPath "D:\Dumps"
#>
function New-OracleDirectory {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $true)]
        [string]$Password,

        [Parameter(Mandatory = $false)]
        [string]$DirectoryName = "DMPDIR",

        [Parameter(Mandatory = $false)]
        [string]$DirectoryPath = "C:\DMPDIR"
    )

    # Create physical directory if it doesn't exist
    if (-not (Test-Path -Path $DirectoryPath)) {
        New-Item -ItemType Directory -Path $DirectoryPath -Force | Out-Null
        Write-Log "Created directory: $DirectoryPath"
    }

    # Always drop and recreate directory to ensure correct path
    # This fixes Oracle XE issue where DMPDIR may point to wrong default location
    # Using DROP + CREATE instead of CREATE OR REPLACE for reliability
    $sql = @"
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF LINESIZE 500
-- Check current directory path
VARIABLE v_path VARCHAR2(500);
VARIABLE v_exists NUMBER;
BEGIN
    SELECT COUNT(*), MAX(directory_path) INTO :v_exists, :v_path
    FROM dba_directories WHERE directory_name = '$DirectoryName';
END;
/
PRINT v_path

-- Drop if exists with different path
BEGIN
    IF :v_exists > 0 AND UPPER(TRIM(:v_path)) != UPPER('$DirectoryPath') THEN
        EXECUTE IMMEDIATE 'DROP DIRECTORY $DirectoryName';
        DBMS_OUTPUT.PUT_LINE('DROPPED_DIFFERENT_PATH');
    ELSIF :v_exists > 0 THEN
        DBMS_OUTPUT.PUT_LINE('PATH_ALREADY_CORRECT');
    END IF;
EXCEPTION
    WHEN OTHERS THEN NULL;
END;
/

-- Create or replace directory
CREATE OR REPLACE DIRECTORY $DirectoryName AS '$DirectoryPath';
GRANT READ, WRITE ON DIRECTORY $DirectoryName TO PUBLIC;

-- Verify
SELECT 'VERIFIED:' || directory_path FROM dba_directories WHERE directory_name = '$DirectoryName';
EXIT;
"@

    $result = Invoke-SqlPlus -OracleHome $OracleHome -ServiceName $ServiceName `
        -Username "SYS" -Password $Password -SqlCommand $sql -AsSysdba -Silent

    # Check verification result
    if ($result -match "VERIFIED:(.+)") {
        $verifiedPath = $Matches[1].Trim()
        if ($verifiedPath.ToUpper() -eq $DirectoryPath.ToUpper()) {
            Write-Log "Oracle directory $DirectoryName created pointing to $DirectoryPath"
            return $true
        }
        else {
            Write-LogWarning "Directory path mismatch! Expected: $DirectoryPath, Got: $verifiedPath"
            return $false
        }
    }
    else {
        Write-LogWarning "Could not verify directory creation"
        Write-LogWarning "SQL output: $result"
        return $false
    }
}

<#
.SYNOPSIS
    Get the default datafile path based on Oracle installation.

.DESCRIPTION
    Determines the appropriate datafile location based on Oracle Home and version.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Password
    SYSTEM password.

.OUTPUTS
    String. The datafile directory path.

.EXAMPLE
    $datafilePath = Get-DatafilePath -ServiceName "XEPDB1" -Password "oracle"
#>
function Get-DatafilePath {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $true)]
        [string]$Password
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome

    # Query Oracle for default datafile location
    $sql = @"
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF LINESIZE 500
SELECT 'DATAFILE_PATH:' || SUBSTR(file_name, 1, INSTR(file_name, '\', -1))
FROM dba_data_files
WHERE tablespace_name = 'SYSTEM'
AND ROWNUM = 1;
EXIT;
"@

    $result = Invoke-SqlPlus -OracleHome $oraHome -ServiceName $ServiceName `
        -Username "SYSTEM" -Password $Password -SqlCommand $sql -Silent

    foreach ($line in $result -split "`n") {
        if ($line -match "^DATAFILE_PATH:(.+)$") {
            $path = $Matches[1].Trim()
            # Remove trailing backslash if present
            return $path.TrimEnd('\')
        }
    }

    # Fallback: derive path from ORACLE_HOME
    # Example: C:\app\romfast\product\21c\dbhomeXE -> C:\app\romfast\product\21c\oradata\XE\XEPDB1
    Write-LogWarning "Could not query datafile path from database, using fallback based on ORACLE_HOME"

    $version = Get-OracleVersion -OracleHome $oraHome -ServiceName $ServiceName -Password $Password

    # Try to derive oradata path from ORACLE_HOME
    # Pattern: <base>\product\<version>\dbhomeXE -> <base>\product\<version>\oradata\XE\<PDB>
    if ($oraHome -match "^(.+\\product\\[^\\]+)\\dbhome") {
        $baseOradata = "$($Matches[1])\oradata"
        if ($version.IsXE) {
            if ($version.Version -match "^21") {
                return "$baseOradata\XE\XEPDB1"
            }
            elseif ($version.Version -match "^18") {
                return "$baseOradata\XE"
            }
        }
        return $baseOradata
    }

    # Legacy fallback for non-standard installations
    # Extract base from ORACLE_HOME (e.g., C:\app\romfast from C:\app\romfast\product\21c\dbhomeXE)
    if ($oraHome -match "^([A-Z]:\\[^\\]+\\[^\\]+)\\") {
        $appBase = $Matches[1]
        if ($version.IsXE) {
            if ($version.Version -match "^21") {
                return "$appBase\oradata\XE\XEPDB1"
            }
            elseif ($version.Version -match "^18") {
                return "$appBase\oradata\XE"
            }
        }
        return "$appBase\oradata"
    }

    # Ultimate fallback - this should rarely be reached
    Write-LogWarning "Could not derive datafile path from ORACLE_HOME, using hardcoded default"
    return "C:\app\oracle\oradata"
}

<#
.SYNOPSIS
    Execute Data Pump import.

.DESCRIPTION
    Runs impdp with specified parameters.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Username
    Username for connection (default: SYSTEM).

.PARAMETER Password
    Password for connection.

.PARAMETER DumpFile
    Name of the dump file (in DMPDIR).

.PARAMETER LogFile
    Name of the log file.

.PARAMETER Schemas
    Schema(s) to import.

.PARAMETER RemapSchema
    Remap schema mapping (e.g., "OLD_SCHEMA:NEW_SCHEMA").

.PARAMETER DirectoryName
    Oracle directory object name (default: DMPDIR).

.PARAMETER TableExists
    Table exists action: SKIP, APPEND, TRUNCATE, REPLACE (default: REPLACE).

.PARAMETER AdditionalParams
    Additional impdp parameters.

.OUTPUTS
    PSCustomObject with Success, LogContent, ErrorMessage properties.

.EXAMPLE
    Invoke-DataPumpImport -ServiceName "XEPDB1" -Password "oracle" -DumpFile "CONTAFIN_ORACLE.dmp" -Schemas "CONTAFIN_ORACLE"
#>
function Invoke-DataPumpImport {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $false)]
        [string]$Username = "SYSTEM",

        [Parameter(Mandatory = $true)]
        [string]$Password,

        [Parameter(Mandatory = $true)]
        [string]$DumpFile,

        [Parameter(Mandatory = $false)]
        [string]$LogFile,

        [Parameter(Mandatory = $false)]
        [string[]]$Schemas,

        [Parameter(Mandatory = $false)]
        [string]$RemapSchema,

        [Parameter(Mandatory = $false)]
        [string]$DirectoryName = "DMPDIR",

        [Parameter(Mandatory = $false)]
        [ValidateSet('SKIP', 'APPEND', 'TRUNCATE', 'REPLACE')]
        [string]$TableExists = "REPLACE",

        [Parameter(Mandatory = $false)]
        [string]$AdditionalParams
    )

    $oraHome = Get-OracleHome -OracleHome $OracleHome
    $impdp = Join-Path $oraHome "bin\impdp.exe"

    if (-not (Test-Path -Path $impdp)) {
        throw "impdp not found at: $impdp"
    }

    # Build impdp command
    if (-not $LogFile) {
        $LogFile = [System.IO.Path]::GetFileNameWithoutExtension($DumpFile) + "_import.log"
    }

    $connString = "$Username/`"$Password`"@$ServiceName"

    $params = @(
        "`"$connString`"",
        "directory=$DirectoryName",
        "dumpfile=$DumpFile",
        "logfile=$LogFile",
        "table_exists_action=$TableExists"
    )

    if ($Schemas) {
        $params += "schemas=$($Schemas -join ',')"
    }

    if ($RemapSchema) {
        $params += "remap_schema=$RemapSchema"
    }

    if ($AdditionalParams) {
        $params += $AdditionalParams
    }

    $arguments = $params -join " "

    Write-Log "Executing: impdp $($params -join ' ' -replace $Password, '****')"

    # Set Oracle environment
    $env:ORACLE_HOME = $oraHome
    $env:PATH = "$oraHome\bin;$env:PATH"
    $env:NLS_LANG = "AMERICAN_AMERICA.AL32UTF8"

    # Execute impdp
    $process = Start-Process -FilePath $impdp -ArgumentList $arguments -Wait -NoNewWindow -PassThru `
        -RedirectStandardOutput "$env:TEMP\impdp_out.txt" -RedirectStandardError "$env:TEMP\impdp_err.txt"

    $stdout = Get-Content -Path "$env:TEMP\impdp_out.txt" -Raw -ErrorAction SilentlyContinue
    $stderr = Get-Content -Path "$env:TEMP\impdp_err.txt" -Raw -ErrorAction SilentlyContinue

    $result = [PSCustomObject]@{
        Success      = $process.ExitCode -eq 0
        ExitCode     = $process.ExitCode
        Output       = $stdout
        ErrorOutput  = $stderr
        LogFile      = $LogFile
    }

    # Clean up temp files
    Remove-Item -Path "$env:TEMP\impdp_out.txt" -Force -ErrorAction SilentlyContinue
    Remove-Item -Path "$env:TEMP\impdp_err.txt" -Force -ErrorAction SilentlyContinue

    return $result
}

<#
.SYNOPSIS
    Check if a user/schema exists in the database.

.DESCRIPTION
    Queries DBA_USERS to check if a user exists.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Password
    SYSTEM password.

.PARAMETER SchemaName
    Name of the schema/user to check.

.OUTPUTS
    Boolean. True if user exists.

.EXAMPLE
    if (Test-OracleUser -ServiceName "XEPDB1" -Password "oracle" -SchemaName "CONTAFIN_ORACLE") {
        Write-Host "User exists"
    }
#>
function Test-OracleUser {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $true)]
        [string]$Password,

        [Parameter(Mandatory = $true)]
        [string]$SchemaName
    )

    $sql = @"
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF
SELECT 'USER_EXISTS' FROM dba_users WHERE username = UPPER('$SchemaName');
EXIT;
"@

    $result = Invoke-SqlPlus -OracleHome $OracleHome -ServiceName $ServiceName `
        -Username "SYSTEM" -Password $Password -SqlCommand $sql -Silent

    return $result -match "USER_EXISTS"
}

<#
.SYNOPSIS
    Get object count for a schema.

.DESCRIPTION
    Counts objects in a schema grouped by type.

.PARAMETER OracleHome
    Oracle Home directory.

.PARAMETER ServiceName
    Database service name.

.PARAMETER Password
    SYSTEM password.

.PARAMETER SchemaName
    Name of the schema.

.OUTPUTS
    Hashtable with object types and counts.

.EXAMPLE
    $counts = Get-SchemaObjectCount -ServiceName "XEPDB1" -Password "oracle" -SchemaName "CONTAFIN_ORACLE"
#>
function Get-SchemaObjectCount {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory = $false)]
        [string]$OracleHome,

        [Parameter(Mandatory = $true)]
        [string]$ServiceName,

        [Parameter(Mandatory = $true)]
        [string]$Password,

        [Parameter(Mandatory = $true)]
        [string]$SchemaName
    )

    $sql = @"
SET PAGESIZE 1000 FEEDBACK OFF VERIFY OFF HEADING OFF ECHO OFF LINESIZE 200
SELECT object_type || ':' || COUNT(*)
FROM dba_objects
WHERE owner = UPPER('$SchemaName')
GROUP BY object_type
ORDER BY object_type;
SELECT 'TOTAL:' || COUNT(*) FROM dba_objects WHERE owner = UPPER('$SchemaName');
SELECT 'INVALID:' || COUNT(*) FROM dba_objects WHERE owner = UPPER('$SchemaName') AND status = 'INVALID';
EXIT;
"@

    $oraHome = Get-OracleHome -OracleHome $OracleHome

    $result = Invoke-SqlPlus -OracleHome $oraHome -ServiceName $ServiceName `
        -Username "SYSTEM" -Password $Password -SqlCommand $sql -Silent

    $counts = @{}

    # Parse result lines for object type counts
    $lines = $result -split "`r?`n"
    foreach ($line in $lines) {
        $trimmed = $line.Trim()
        if ($trimmed.Length -gt 0 -and $trimmed -match "^([A-Z][A-Z_ ]*):(\d+)$") {
            $key = $Matches[1].Trim()
            $value = [int]$Matches[2]
            $counts[$key] = $value
        }
    }

    return $counts
}

# Note: Functions are available when dot-sourced (. .\oracle-functions.ps1)
# Do NOT use Export-ModuleMember - it only works inside .psm1 modules