compression_module.ps1

<#
CompressionModule.ps1 - 7zip 壓縮與加密模組
Version: v0.2
功能說明: 提供系統備份檔案的壓縮、解壓縮、完整性檢查及壓縮檔資訊查詢功能，
          支援密碼加密保護，並集成統一日誌記錄機制。

版本歷史:
v0.1 - 初始版本，實現基本壓縮、解壓縮、測試及資訊查詢功能
v0.2 - 修復日誌呼叫機制，統一使用logging_module中的Add-LogEntry進行日誌記錄，
       移除直接Write-Host調用，增強日誌可跟蹤性與輸出靈活性
#>

function Compress-BackupFile {
    param(
        [string]$SourceFile,
        [string]$Password = $null,
        [string]$CompressionLevel = "9",
        [string]$OutputPath = $null
    )

    $result = @{
        Success = $false
        CompressedFile = $null
        Error = $null
        OriginalSize = 0
        CompressedSize = 0
        CompressionRatio = 0
    }

    try {
        # 檢查來源檔案是否存在
        if (-not (Test-Path $SourceFile)) {
            throw "來源檔案不存在: $SourceFile"
        }

        # 獲取 7zip 路徑
        $config = Get-AppConfig
        $sevenZipPath = $config.SevenZipPath

        if (-not (Test-Path $sevenZipPath)) {
            throw "找不到 7zip 執行檔: $sevenZipPath"
        }

        # 建立輸出檔案路徑
        if (-not $OutputPath) {
            $sourceDir = [System.IO.Path]::GetDirectoryName($SourceFile)
            $sourceBaseName = [System.IO.Path]::GetFileNameWithoutExtension($SourceFile)
            $OutputPath = Join-Path $sourceDir "$sourceBaseName.7z"
        }

        # 獲取原始檔案大小
        $originalFileInfo = Get-Item $SourceFile
        $result.OriginalSize = $originalFileInfo.Length

        Add-LogEntry -Message "開始壓縮檔案: $SourceFile" -Level INFO -ConsoleOutput -GUIOutput
        Add-LogEntry -Message "輸出檔案: $OutputPath" -Level INFO -ConsoleOutput -GUIOutput
        Add-LogEntry -Message "原始大小: $([math]::Round($result.OriginalSize / 1MB, 2)) MB" -Level INFO -ConsoleOutput -GUIOutput

        # 建立 7zip 參數
        $sevenZipArgs = @(
            "a"                    # 添加到壓縮檔
            "-t7z"                 # 7z 格式
            "-mx=$CompressionLevel" # 壓縮等級 (0-9)
            "-mmt=on"              # 多執行緒
            "-ms=on"               # 固態壓縮
            "-md=64m"              # 字典大小
            "-mfb=64"              # 快速位元組數
            "-y"                   # 全部回答 Yes
        )

        # 如果有密碼，加入加密選項
        if ($Password) {
            $sevenZipArgs += "-p$Password"     # 設定密碼
            $sevenZipArgs += "-mhe=on"         # 加密檔案標頭
            $sevenZipArgs += "-mx0"            # 對於加密檔案，先用較低壓縮等級測試
            Add-LogEntry -Message "已啟用密碼保護" -Level INFO -ConsoleOutput -GUIOutput
        }

        # 加入輸出檔案和來源檔案
        $sevenZipArgs += "`"$OutputPath`""
        $sevenZipArgs += "`"$SourceFile`""

        # 執行 7zip 壓縮
        Add-LogEntry -Message "執行壓縮指令..." -Level INFO -ConsoleOutput -GUIOutput
        $process = Start-Process -FilePath $sevenZipPath -ArgumentList $sevenZipArgs -Wait -PassThru -NoNewWindow -RedirectStandardOutput "$env:TEMP\7zip_output.log" -RedirectStandardError "$env:TEMP\7zip_error.log"

        # 檢查執行結果
        if ($process.ExitCode -eq 0) {
            # 驗證輸出檔案是否存在
            if (Test-Path $OutputPath) {
                $compressedFileInfo = Get-Item $OutputPath
                $result.CompressedSize = $compressedFileInfo.Length
                $result.CompressionRatio = [math]::Round((1 - ($result.CompressedSize / $result.OriginalSize)) * 100, 2)
                
                Add-LogEntry -Message "壓縮完成！" -Level INFO -ConsoleOutput -GUIOutput
                Add-LogEntry -Message "壓縮後大小: $([math]::Round($result.CompressedSize / 1MB, 2)) MB" -Level INFO -ConsoleOutput -GUIOutput
                Add-LogEntry -Message "壓縮率: $($result.CompressionRatio)%" -Level INFO -ConsoleOutput -GUIOutput

                $result.Success = $true
                $result.CompressedFile = $OutputPath

                # 驗證壓縮檔完整性
                $testResult = Test-CompressedFile -FilePath $OutputPath -Password $Password
                if (-not $testResult.Success) {
                    throw "壓縮檔完整性驗證失敗: $($testResult.Error)"
                }
                Add-LogEntry -Message "壓縮檔完整性驗證通過" -Level INFO -ConsoleOutput -GUIOutput

            } else {
                throw "壓縮檔案建立失敗，找不到輸出檔案"
            }
        } else {
            $errorOutput = Get-Content "$env:TEMP\7zip_error.log" -Raw -ErrorAction SilentlyContinue
            throw "7zip 壓縮失敗 (錯誤碼: $($process.ExitCode)): $errorOutput"
        }

    }
    catch {
        $result.Error = $_.Exception.Message
        Add-LogEntry -Message "壓縮失敗: $($_.Exception.Message)" -Level ERROR -ConsoleOutput -GUIOutput
    }
    finally {
        # 清理暫存檔案
        Remove-Item "$env:TEMP\7zip_output.log" -ErrorAction SilentlyContinue
        Remove-Item "$env:TEMP\7zip_error.log" -ErrorAction SilentlyContinue
    }

    return $result
}

function Decompress-BackupFile {
    param(
        [string]$CompressedFile,
        [string]$OutputPath,
        [string]$Password = $null
    )

    $result = @{
        Success = $false
        ExtractedFiles = @()
        Error = $null
    }

    try {
        # 檢查壓縮檔是否存在
        if (-not (Test-Path $CompressedFile)) {
            throw "壓縮檔不存在: $CompressedFile"
        }

        # 獲取 7zip 路徑
        $config = Get-AppConfig
        $sevenZipPath = $config.SevenZipPath

        if (-not (Test-Path $sevenZipPath)) {
            throw "找不到 7zip 執行檔: $sevenZipPath"
        }

        # 建立輸出目錄
        if (-not (Test-Path $OutputPath)) {
            New-Item -Path $OutputPath -ItemType Directory -Force | Out-Null
        }

        Add-LogEntry -Message "開始解壓縮檔案: $CompressedFile" -Level INFO -ConsoleOutput -GUIOutput
        Add-LogEntry -Message "輸出目錄: $OutputPath" -Level INFO -ConsoleOutput -GUIOutput

        # 建立 7zip 解壓縮參數
        $sevenZipArgs = @(
            "x"                    # 解壓縮保持目錄結構
            "`"$CompressedFile`""  # 來源壓縮檔
            "-o`"$OutputPath`""    # 輸出目錄
            "-y"                   # 全部回答 Yes
        )

        # 如果有密碼，加入密碼選項
        if ($Password) {
            $sevenZipArgs += "-p$Password"
            Add-LogEntry -Message "使用密碼解壓縮" -Level INFO -ConsoleOutput -GUIOutput
        }

        # 執行 7zip 解壓縮
        Add-LogEntry -Message "執行解壓縮指令..." -Level INFO -ConsoleOutput -GUIOutput
        $process = Start-Process -FilePath $sevenZipPath -ArgumentList $sevenZipArgs -Wait -PassThru -NoNewWindow -RedirectStandardOutput "$env:TEMP\7zip_extract_output.log" -RedirectStandardError "$env:TEMP\7zip_extract_error.log"

        # 檢查執行結果
        if ($process.ExitCode -eq 0) {
            # 列出解壓縮的檔案
            $extractedFiles = Get-ChildItem -Path $OutputPath -Recurse -File
            $result.ExtractedFiles = $extractedFiles.FullName
            
            Add-LogEntry -Message "解壓縮完成！" -Level INFO -ConsoleOutput -GUIOutput
            Add-LogEntry -Message "解壓縮了 $($extractedFiles.Count) 個檔案" -Level INFO -ConsoleOutput -GUIOutput

            $result.Success = $true
        } else {
            $errorOutput = Get-Content "$env:TEMP\7zip_extract_error.log" -Raw -ErrorAction SilentlyContinue
            throw "7zip 解壓縮失敗 (錯誤碼: $($process.ExitCode)): $errorOutput"
        }

    }
    catch {
        $result.Error = $_.Exception.Message
        Add-LogEntry -Message "解壓縮失敗: $($_.Exception.Message)" -Level ERROR -ConsoleOutput -GUIOutput
    }
    finally {
        # 清理暫存檔案
        Remove-Item "$env:TEMP\7zip_extract_output.log" -ErrorAction SilentlyContinue
        Remove-Item "$env:TEMP\7zip_extract_error.log" -ErrorAction SilentlyContinue
    }

    return $result
}

function Test-CompressedFile {
    param(
        [string]$FilePath,
        [string]$Password = $null
    )

    $result = @{
        Success = $false
        Error = $null
    }

    try {
        # 獲取 7zip 路徑
        $config = Get-AppConfig
        $sevenZipPath = $config.SevenZipPath

        if (-not (Test-Path $sevenZipPath)) {
            throw "找不到 7zip 執行檔: $sevenZipPath"
        }

        # 建立測試參數
        $sevenZipArgs = @(
            "t"                   # 測試壓縮檔
            "`"$FilePath`""       # 壓縮檔路徑
        )

        # 如果有密碼，加入密碼選項
        if ($Password) {
            $sevenZipArgs += "-p$Password"
        }

        # 執行測試
        $process = Start-Process -FilePath $sevenZipPath -ArgumentList $sevenZipArgs -Wait -PassThru -NoNewWindow -RedirectStandardOutput "$env:TEMP\7zip_test_output.log" -RedirectStandardError "$env:TEMP\7zip_test_error.log"

        if ($process.ExitCode -eq 0) {
            $result.Success = $true
        } else {
            $errorOutput = Get-Content "$env:TEMP\7zip_test_error.log" -Raw -ErrorAction SilentlyContinue
            $result.Error = "壓縮檔測試失敗 (錯誤碼: $($process.ExitCode)): $errorOutput"
        }

    }
    catch {
        $result.Error = $_.Exception.Message
    }
    finally {
        # 清理暫存檔案
        Remove-Item "$env:TEMP\7zip_test_output.log" -ErrorAction SilentlyContinue
        Remove-Item "$env:TEMP\7zip_test_error.log" -ErrorAction SilentlyContinue
    }

    return $result
}

function Get-CompressedFileInfo {
    param([string]$FilePath)

    $result = @{
        Success = $false
        Files = @()
        TotalSize = 0
        CompressedSize = 0
        Error = $null
    }

    try {
        # 獲取 7zip 路徑
        $config = Get-AppConfig
        $sevenZipPath = $config.SevenZipPath

        if (-not (Test-Path $sevenZipPath)) {
            throw "找不到 7zip 執行檔: $sevenZipPath"
        }

        # 列出壓縮檔內容
        $sevenZipArgs = @(
            "l"                   # 列出內容
            "`"$FilePath`""       # 壓縮檔路徑
        )

        $process = Start-Process -FilePath $sevenZipPath -ArgumentList $sevenZipArgs -Wait -PassThru -NoNewWindow -RedirectStandardOutput "$env:TEMP\7zip_list_output.log" -RedirectStandardError "$env:TEMP\7zip_list_error.log"

        if ($process.ExitCode -eq 0) {
            $output = Get-Content "$env:TEMP\7zip_list_output.log"
            # 解析輸出以提取檔案資訊
            # 這裡簡化處理，實際可能需要更複雜的解析
            $result.Success = $true
            $result.CompressedSize = (Get-Item $FilePath).Length
        } else {
            $errorOutput = Get-Content "$env:TEMP\7zip_list_error.log" -Raw -ErrorAction SilentlyContinue
            $result.Error = "無法取得壓縮檔資訊 (錯誤碼: $($process.ExitCode)): $errorOutput"
        }

    }
    catch {
        $result.Error = $_.Exception.Message
    }
    finally {
        # 清理暫存檔案
        Remove-Item "$env:TEMP\7zip_list_output.log" -ErrorAction SilentlyContinue
        Remove-Item "$env:TEMP\7zip_list_error.log" -ErrorAction SilentlyContinue
    }

    return $result
}

# 匯出函數
Export-ModuleMember -Function Compress-BackupFile, Decompress-BackupFile, Test-CompressedFile, Get-CompressedFileInfo