feat: Add replace command.

cmd/replace.go

@@ -4,6 +4,14 @@ Copyright © 2022 Jonathan Gao <[email protected]>
 package cmd
 
 import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
 	"github.com/spf13/cobra"
 )
 
@@ -20,24 +28,73 @@ var replaceCmd = &cobra.Command{
 		exitIfError(err)
 		onlyIn, err := cmd.Flags().GetString("only-in")
 		exitIfError(err)
-
-		if from != "" || to != "" {
+		fmt.Printf("from: %s, to: %s, in: %s\n", from, to, onlyIn)
+		if from != "" && to != "" {
 			if onlyIn != "" {
 				// replace in only in dir
-
+				matches, err := findFiles(onlyIn)
+				exitIfError(err)
+				for _, f := range matches {
+					e := replaceStringInFile(f, from, to)
+					if e != nil {
+						fmt.Fprintf(os.Stderr, "%s", e)
+					}
+				}
 			} else {
 				// replace in cwd
+				currentDir, err := os.Getwd()
+				exitIfError(err)
+				matches, err := findFiles(currentDir)
+				exitIfError(err)
+				for _, f := range matches {
+					e := replaceStringInFile(f, from, to)
+					if e != nil {
+						fmt.Fprintf(os.Stderr, "%s", e)
+					}
+				}
 			}
-		} else if to == "" || from != "" {
+		} else if to == "" && from != "" {
 			// replace to is empty, do search only
 			if onlyIn != "" {
 				// search in only in dir
+				matches, err := findFiles(onlyIn)
+				exitIfError(err)
+				for _, f := range matches {
+					e := findStringInFile(f, from)
+					if e != nil {
+						fmt.Fprintf(os.Stderr, "%s", e)
+					}
+				}
 			} else {
-				// search in cwd
+				// replace in cwd
+				currentDir, err := os.Getwd()
+				exitIfError(err)
+				matches, err := findFiles(currentDir)
+				exitIfError(err)
+				for _, f := range matches {
+					e := findStringInFile(f, from)
+					if e != nil {
+						fmt.Fprintf(os.Stderr, "%s", e)
+					}
+				}
 			}
 		} else {
-			// print help
-			cmd.Help()
+			// print files
+			if onlyIn != "" {
+				matches, err := findFiles(onlyIn)
+				exitIfError(err)
+				for _, f := range matches {
+					fmt.Println(f)
+				}
+			} else {
+				currentDir, err := os.Getwd()
+				exitIfError(err)
+				matches, err := findFiles(currentDir)
+				exitIfError(err)
+				for _, f := range matches {
+					fmt.Println(f)
+				}
+			}
 		}
 	},
 }
@@ -49,3 +106,127 @@ func init() {
 	replaceCmd.Flags().StringP("to", "t", "", "replace to")
 	replaceCmd.Flags().StringP("only-in", "d", "", "replace only in directory")
 }
+
+func replaceStringInFile(filePath string, oldString, newString string) error {
+	fmt.Printf("Start replace in file: %s\n", filePath)
+	// Open the file for reading and writing
+	file, err := os.OpenFile(filePath, os.O_RDWR, 0644)
+	if err != nil {
+		return fmt.Errorf("failed to open file: %w", err)
+	}
+	defer file.Close()
+
+	// Read the entire file content into a byte slice
+	data, err := io.ReadAll(file)
+	if err != nil {
+		return fmt.Errorf("failed to read file: %w", err)
+	}
+
+	// Replace occurrences of oldString with newString in the byte slice
+	newData := bytes.ReplaceAll(data, []byte(oldString), []byte(newString))
+
+	// Truncate the file to clear its contents
+	err = file.Truncate(0)
+	if err != nil {
+		return fmt.Errorf("failed to truncate file: %w", err)
+	}
+
+	// Seek to the beginning of the file
+	_, err = file.Seek(0, 0)
+	if err != nil {
+		return fmt.Errorf("failed to seek file: %w", err)
+	}
+
+	// Write the modified data back to the file
+	_, err = file.Write(newData)
+	if err != nil {
+		return fmt.Errorf("failed to write to file: %w", err)
+	}
+
+	return nil
+}
+
+func findStringInFile(filePath string, matchString string) error {
+	fmt.Printf("Start find in file: %s\n", filePath)
+
+	file, err := os.Open(filePath)
+	if err != nil {
+		return fmt.Errorf("failed to open file: %w", err)
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	lineNumber := 1
+
+	for scanner.Scan() {
+		line := scanner.Text()
+		if strings.Contains(line, matchString) {
+			fmt.Printf("Line %d: %s\n", lineNumber, line)
+		}
+		lineNumber++
+	}
+
+	if err := scanner.Err(); err != nil {
+		return fmt.Errorf("error scanning file: %w", err)
+	}
+
+	return nil
+}
+
+func findFiles(arg string) ([]string, error) {
+	var foundFiles []string
+
+	if !filepath.IsAbs(arg) {
+		currentDir, err := os.Getwd()
+		exitIfError(err)
+		arg = filepath.Join(currentDir, arg)
+	}
+
+	// Check if arg is a path with a pattern or just a directory path
+	if strings.ContainsRune(arg, '*') || strings.ContainsRune(arg, '?') {
+		// Treat arg as a path with a pattern
+		rootPath, pattern, err := parsePathPattern(arg)
+		if err != nil {
+			return nil, fmt.Errorf("invalid path or pattern: %w", err)
+		}
+		fmt.Printf("Warking in %s with pattern %s\n", rootPath, pattern)
+		err = filepath.Walk(rootPath, func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			if !info.IsDir() {
+				if matched, _ := filepath.Match(pattern, filepath.Base(path)); matched {
+					foundFiles = append(foundFiles, path)
+				}
+			}
+			return nil
+		})
+		return foundFiles, err
+	} else {
+		// Treat arg as a directory path
+		rootPath := arg
+		fmt.Printf("Warking in %s\n", rootPath)
+		err := filepath.Walk(rootPath, func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			if !info.IsDir() {
+				foundFiles = append(foundFiles, path)
+			}
+			return nil
+		})
+		return foundFiles, err
+	}
+}
+
+// Helper function to parse path and pattern from a combined argument
+func parsePathPattern(arg string) (string, string, error) {
+
+	lastSlash := strings.LastIndex(arg, string(filepath.Separator))
+	if lastSlash == -1 {
+		return arg, "", nil
+	}
+	rootPath := arg[:lastSlash]
+	pattern := arg[lastSlash+1:]
+	return rootPath, pattern, nil
+}