Summary

Add gro drive download command to download files from Google Drive, including exporting Google Workspace files to common formats.

Usage

# Download regular files (PDF, images, etc.)
gro drive download <file-id>
gro drive download <file-id> --output ./report.pdf

# Export Google Docs to different formats
gro drive download <file-id> --format pdf      # Document → PDF
gro drive download <file-id> --format docx     # Document → Word
gro drive download <file-id> --format md       # Document → Markdown
gro drive download <file-id> --format txt      # Document → Plain text

# Export Google Sheets
gro drive download <file-id> --format xlsx     # Spreadsheet → Excel
gro drive download <file-id> --format csv      # Spreadsheet → CSV

# Export Google Slides
gro drive download <file-id> --format pptx     # Presentation → PowerPoint
gro drive download <file-id> --format pdf      # Presentation → PDF

# Output to stdout
gro drive download <file-id> --stdout

Flags

Export Format Mapping

Google Documents

Google Spreadsheets

Google Presentations

Google Drawings

Implementation

Files to Create/Modify

• internal/cmd/drive/download.go - Download command implementation
• internal/cmd/drive/download_test.go - Unit tests
• internal/cmd/drive/drive.go - Register download subcommand
• internal/drive/files.go - Add DownloadFile() and ExportFile() methods

Logic Flow

func runDownload(cmd *cobra.Command, args []string) error {
    fileID := args[0]
    
    // Get file metadata first
    file, err := client.GetFile(fileID)
    
    // Determine if this is a Google Workspace file
    if isGoogleWorkspaceFile(file.MimeType) {
        // Must use Export API
        if format == "" {
            return fmt.Errorf("Google %s requires --format flag", getTypeName(file.MimeType))
        }
        exportMime := getExportMimeType(file.MimeType, format)
        data, err := client.ExportFile(fileID, exportMime)
    } else {
        // Regular file - use Get with alt=media
        data, err := client.DownloadFile(fileID)
    }
    
    // Write to file or stdout
    if stdout {
        os.Stdout.Write(data)
    } else {
        outputPath := determineOutputPath(file.Name, format, outputFlag)
        os.WriteFile(outputPath, data, 0644)
    }
}

API Calls

// Download regular file
resp, err := srv.Files.Get(fileID).Download()

// Export Google Workspace file
resp, err := srv.Files.Export(fileID, exportMimeType).Download()

Output

Downloading: Q4 Budget Report.docx
Format: Microsoft Word (docx)
Size: 245 KB
Saved to: ./Q4 Budget Report.docx

Error Handling

• Invalid file ID → "file not found: "
• Google Doc without --format → "Google Document requires --format flag (pdf, docx, txt, html, md)"
• Invalid format for file type → "format 'csv' not supported for Google Document"
• Permission denied → "access denied: you don't have permission to download this file"

Acceptance Criteria

• Downloads regular files (PDF, images, etc.)
• Exports Google Docs to PDF, DOCX, TXT, MD
• Exports Google Sheets to XLSX, CSV
• Exports Google Slides to PPTX, PDF
• Respects --output path
• --stdout writes to stdout
• Clear error when --format missing for Google files
• Clear error for invalid format
• make verify passes

Blocked By

• feat(drive): add Drive client foundation and parent command #61 (foundation)