Adding the diffr base logic

Signed-off-by: Raj Babu Das <[email protected]>

.gitignore

@@ -0,0 +1 @@
+.idea

go.mod

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+module github.com/imrajdas/diffr
+
+go 1.20
+
+require (
+	github.com/pmezard/go-difflib v1.0.0
+	github.com/spf13/cobra v1.7.0
+)
+
+require (
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+)

go.sum

@@ -0,0 +1,12 @@
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/spf13/cobra v1.7.0 h1:hyqWnYt1ZQShIddO5kBpj3vu05/++x6tJ6dg8EC572I=
+github.com/spf13/cobra v1.7.0/go.mod h1:uLxZILRyS/50WlhOIKD7W6V5bgeIt+4sICxh6uRMrb0=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

main.go

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+package main
+
+import (
+	"github.com/imrajdas/diffr/pkg/cmd/root"
+)
+
+func main() {
+	root.Execute()
+}

pkg/cmd/root/root.go

@@ -0,0 +1,28 @@
+package root
+
+import (
+	"github.com/imrajdas/diffr/pkg/cmd/version"
+	"github.com/imrajdas/diffr/pkg/diffr"
+	"github.com/spf13/cobra"
+)
+
+var rootCmd = &cobra.Command{
+	Use:     "diffr [dir1] [dir2]",
+	Example: "diffr /path/to/dir1 /path/to/dir2",
+	Short:   "A web-based content difference analyzer",
+	Long:    `A web-based tool to compare content differences between two directories ` + "\n" + `Find more information at: https://github.com/imrajdas/diffr`,
+	Args:    cobra.ExactArgs(2),
+	Run:     diffr.RunWebServer,
+}
+
+func Execute() {
+	cobra.CheckErr(rootCmd.Execute())
+}
+
+func init() {
+	rootCmd.Flags().IntVarP(&diffr.Port, "port", "p", 8080, "Set the port for the web server to listen on, default is 8080")
+	rootCmd.Flags().StringVarP(&diffr.Address, "address", "a", "http://localhost", "Set the address for the web server to listen on, default is http://localhost")
+
+	rootCmd.CompletionOptions.DisableDefaultCmd = true
+	rootCmd.AddCommand(version.VersionCmd)
+}

pkg/cmd/version/version.go

@@ -0,0 +1,16 @@
+package version
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var VersionCmd = &cobra.Command{
+	Use:   "version",
+	Short: "Displays the version of diffr",
+	Long:  ``,
+	Run: func(cmd *cobra.Command, args []string) {
+		cmd.Printf("Diffr Version: %s", os.Getenv("VERSION"))
+	},
+}

pkg/diffr/config.go

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+package diffr
+
+var (
+	Port    int
+	Address string
+)

pkg/diffr/diff.go

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+package diffr
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/pmezard/go-difflib/difflib"
+)
+
+func compareFiles(file1, file2 string) (string, error) {
+	content1, err := ioutil.ReadFile(file1)
+	if err != nil {
+		return "", err
+	}
+
+	content2, err := ioutil.ReadFile(file2)
+	if err != nil {
+		return "", err
+	}
+
+	diff := difflib.UnifiedDiff{
+		A:        difflib.SplitLines(string(content1)),
+		B:        difflib.SplitLines(string(content2)),
+		FromFile: file1,
+		ToFile:   file2,
+		Context:  3,
+	}
+
+	diffs, err := difflib.GetUnifiedDiffString(diff)
+	if err != nil {
+		return "", err
+	}
+
+	return diffs, nil
+}
+
+func CompareDirectories(dir1, dir2 string, diffChan chan<- string, errorChan chan<- error, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	filepath.Walk(dir1, func(path1 string, info os.FileInfo, err error) error {
+		if err != nil {
+			errorChan <- fmt.Errorf("error accessing %s: %s", path1, err)
+			return nil
+		}
+
+		relPath, err := filepath.Rel(dir1, path1)
+		if err != nil {
+			errorChan <- fmt.Errorf("error getting relative path of %s: %s", path1, err)
+			return nil
+		}
+
+		path2 := filepath.Join(dir2, relPath)
+
+		if info.IsDir() {
+			return nil
+		}
+
+		if _, err := os.Stat(path2); err == nil {
+			diff, err := compareFiles(path1, path2)
+			if err != nil {
+				errorChan <- fmt.Errorf("error comparing files %s and %s: %s", path1, path2, err)
+				return nil
+			}
+
+			if diff != "" {
+				diffChan <- fmt.Sprintf("Differences in file: %s\n%s", relPath, diff)
+			}
+		} else if os.IsNotExist(err) {
+			diff, err := compareFiles(path1, "/dev/null")
+			if err != nil {
+				errorChan <- fmt.Errorf("error comparing files %s and /dev/null: %s", path1, err)
+				return nil
+			}
+
+			if diff != "" {
+				diffChan <- fmt.Sprintf("Differences in file: %s (present in %s but not in %s)\n%s", relPath, dir1, dir2, diff)
+			}
+		} else {
+			errorChan <- fmt.Errorf("error accessing %s: %s", path2, err)
+		}
+
+		return nil
+	})
+}

pkg/diffr/handler.go

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+package diffr
+
+import (
+	"fmt"
+	"html/template"
+	"net/http"
+	"os"
+	"os/exec"
+	"os/signal"
+	"runtime"
+	"sync"
+	"syscall"
+
+	"github.com/spf13/cobra"
+)
+
+var (
+	dir1 string
+	dir2 string
+)
+
+func openBrowser(url string) error {
+	var cmd *exec.Cmd
+
+	switch runtime.GOOS {
+	case "darwin":
+		cmd = exec.Command("open", url)
+	case "linux":
+		cmd = exec.Command("xdg-open", url)
+	case "windows":
+		cmd = exec.Command("cmd", "/c", "start", url)
+	default:
+		return fmt.Errorf("unsupported platform")
+	}
+
+	return cmd.Start()
+}
+
+func RunWebServer(cmd *cobra.Command, args []string) {
+	if len(args) != 2 {
+		fmt.Errorf("Error: Usage: \n diffr /path/to/dir1 /path/to/dir2")
+		return
+	}
+
+	dir1 = args[0]
+	dir2 = args[1]
+
+	serverURL := fmt.Sprintf("%s:%d", Address, Port)
+
+	http.HandleFunc("/", handler)
+	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
+
+	server := &http.Server{Addr: fmt.Sprintf(":%d", Port)}
+
+	// Channel to receive signals (e.g., interrupt or termination)
+	signalCh := make(chan os.Signal, 1)
+	signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM)
+
+	go func() {
+		fmt.Printf("Server started at %s\n", serverURL)
+		err := server.ListenAndServe()
+		if err != nil && err != http.ErrServerClosed {
+			fmt.Println("Error starting server:", err)
+			os.Exit(1)
+		}
+	}()
+
+	fmt.Println("Opening browser...")
+	err := openBrowser(serverURL)
+	if err != nil {
+		fmt.Println("Error opening browser:", err)
+	}
+
+	// Wait for a termination signal
+	<-signalCh
+
+	fmt.Println("Shutting down server...")
+	err = server.Shutdown(nil)
+	if err != nil {
+		fmt.Println("Error shutting down server:", err)
+	}
+}
+
+type PageData struct {
+	Title string
+	Diff  string
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	var (
+		wg        sync.WaitGroup
+		finalStr  = ""
+		diffChan  = make(chan string)
+		errorChan = make(chan error)
+	)
+
+	go func() {
+		for diff := range diffChan {
+			finalStr += diff
+		}
+	}()
+
+	go func() {
+		for err := range errorChan {
+			fmt.Printf("error: %v", err)
+		}
+	}()
+
+	wg.Add(1)
+	go CompareDirectories(dir1, dir2, diffChan, errorChan, &wg)
+	wg.Wait()
+
+	close(diffChan)
+	close(errorChan)
+
+	tmpl, err := template.ParseFiles("static/templates/template.html")
+	if err != nil {
+		fmt.Printf("error: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	data := PageData{
+		Title: "Diffr - A web-based content difference analyzer",
+		Diff:  finalStr,
+	}
+
+	// Execute the template with the data and write the output to the response writer
+	err = tmpl.Execute(w, data)
+	if err != nil {
+		fmt.Printf("error: %v", err)
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}

static/css/style.css

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+.navbar {
+    background-color: #010b18; /* Dark blue color */
+}
+.navbar-brand {
+    color: #fff;
+    font-weight: bold;
+}
+.github-star {
+    font-size: 24px;
+    color: #fff;
+    margin-right: 20px;
+}
+
+#myDiffElement {
+    margin-left: 10%;
+    margin-right: 10%;
+}

static/js/script.js

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+var diffString = document.getElementById("diff-data").getAttribute("data-diff");
+document.addEventListener('DOMContentLoaded', function () {
+    var targetElement = document.getElementById('myDiffElement');
+    var configuration = {
+        drawFileList: true,
+        fileListToggle: true,
+        fileListStartVisible: true,
+        fileContentToggle: true,
+        matching: 'lines',
+        outputFormat: 'side-by-side',
+        synchronisedScroll: true,
+        highlight: true,
+        highlightLanguages: true,
+        renderNothingWhenEmpty: false,
+    };
+    var diff2htmlUi = new Diff2HtmlUI(targetElement, diffString, configuration);
+    diff2htmlUi.draw();
+    diff2htmlUi.highlightCode();
+
+    // Dark mode toggle functionality
+    const darkModeToggle = document.getElementById('darkModeToggle');
+    const body = document.body;
+
+    darkModeToggle.addEventListener('click', () => {
+        body.classList.toggle('dark-mode');
+    });
+});