From 9aba5e7902f2fdfe7e376508fb64d63e5bbb1ae4 Mon Sep 17 00:00:00 2001
From: Moto <glancer@gmail.com>
Date: Mon, 29 Sep 2025 22:45:20 -0500
Subject: [PATCH] Upload files to "cmd/gemreader"

---
 cmd/gemreader/main.go | 148 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 cmd/gemreader/main.go

diff --git a/cmd/gemreader/main.go b/cmd/gemreader/main.go
new file mode 100644
index 0000000..c76261b
--- /dev/null
+++ b/cmd/gemreader/main.go
@@ -0,0 +1,148 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gemreader/internal/config"
+	"gemreader/internal/tui"
+	"github.com/charmbracelet/bubbletea"
+	"github.com/spf13/cobra"
+)
+
+const (
+	MaxFileSize = 10 * 1024 * 1024 // 10MB limit
+)
+
+// validateFilePath ensures the file path is safe by resolving it relative to the current working directory
+func validateFilePath(inputPath string) (string, error) {
+	// Clean the path to remove any .. elements
+	cleanPath := filepath.Clean(inputPath)
+
+	// Get the current working directory
+	currentDir, err := os.Getwd()
+	if err != nil {
+		return "", err
+	}
+
+	// Join the current working directory with the clean path
+	absPath := filepath.Join(currentDir, cleanPath)
+
+	// Resolve the absolute path to remove any .. elements
+	resolvedPath, err := filepath.Abs(absPath)
+	if err != nil {
+		return "", err
+	}
+
+	// Ensure the resolved path is within the current directory
+	relPath, err := filepath.Rel(currentDir, resolvedPath)
+	if err != nil {
+		return "", err
+	}
+
+	// If the relative path starts with .. or is an absolute path, it's trying to go outside the current directory
+	if strings.HasPrefix(relPath, "..") || filepath.IsAbs(relPath) {
+		return "", fmt.Errorf("path traversal detected: %s", inputPath)
+	}
+
+	return resolvedPath, nil
+}
+
+// validateFile performs additional security checks on the file
+func validateFile(filePath string) error {
+	// Check file size to prevent loading extremely large files
+	fileInfo, err := os.Stat(filePath)
+	if err != nil {
+		return err
+	}
+
+	if fileInfo.Size() > MaxFileSize {
+		return fmt.Errorf("file size too large: %d bytes (max: %d bytes)", fileInfo.Size(), MaxFileSize)
+	}
+
+	// Check file extension to ensure it's a text/markdown file
+	ext := strings.ToLower(filepath.Ext(filePath))
+	if ext != ".md" && ext != ".markdown" && ext != ".txt" && ext != "" {
+		// If there's no extension, we'll allow it since some markdown files don't have extensions
+		// If there's an extension, it should be markdown-related or text
+		if ext != "" {
+			return fmt.Errorf("unsupported file type: %s (only .md, .markdown, .txt files are allowed)", ext)
+		}
+	}
+
+	return nil
+}
+
+var rootCmd = &cobra.Command{
+	Use:   "gemreader [file]",
+	Short: "A markdown viewer for your terminal.",
+	Args:  cobra.MaximumNArgs(1),  // Allow 0 or 1 arguments
+	Run: func(cmd *cobra.Command, args []string) {
+		// Load configuration
+		cfg, err := config.LoadConfig()
+		if err != nil {
+			fmt.Printf("could not load config: %v\n", err)
+			// Continue with default behavior if config loading fails
+			cfg = config.Config{Title: "GemReader", DefaultFile: ""} // default values
+		}
+
+		var filePath string
+		if len(args) > 0 {
+			// Use the provided file path from command line arguments
+			filePath = args[0]
+			// Validate the file path to prevent directory traversal attacks
+			securePath, err := validateFilePath(args[0])
+			if err != nil {
+				fmt.Printf("invalid file path: %v\n", err)
+				os.Exit(1)
+			}
+			filePath = securePath
+		} else if cfg.DefaultFile != "" {
+			// Use the default file from configuration
+			securePath, err := validateFilePath(cfg.DefaultFile)
+			if err != nil {
+				fmt.Printf("invalid default file path in config: %v\n", err)
+				os.Exit(1)
+			}
+			filePath = securePath
+		} else {
+			// No file provided and no default file configured
+			fmt.Println("No file provided and no default file configured. Please provide a file or set default_file in config.toml")
+			os.Exit(1)
+		}
+
+		// Perform additional security validation on the file
+		if err := validateFile(filePath); err != nil {
+			fmt.Printf("file validation failed: %v\n", err)
+			os.Exit(1)
+		}
+
+		content, err := os.ReadFile(filePath)
+		if err != nil {
+			fmt.Printf("could not read file: %v\n", err)
+			os.Exit(1)
+		}
+
+		// Pass raw content to TUI so it can generate TOC from the original markdown
+		m := tui.NewModel(string(content), cfg)
+
+		p := tea.NewProgram(m)
+		if err := p.Start(); err != nil {
+			fmt.Printf("Alas, there's been an error: %v\n", err)
+			os.Exit(1)
+		}
+	},
+}
+
+func Execute() {
+	if err := rootCmd.Execute(); err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+}
+
+func main() {
+	Execute()
+}
\ No newline at end of file