Create a command line tool and add file and server commands

Dockerfile

@@ -17,4 +17,4 @@ RUN go build -o app .
 EXPOSE 8080
 
 # Command to run the executable
-CMD ["./app"]
+CMD ["./app", "server"]

cmd/file.go

@@ -0,0 +1,48 @@
+/*
+Copyright © 2023 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/go-shiori/dom"
+	"github.com/omnivore-app/go-domdistiller/distiller"
+	"github.com/spf13/cobra"
+)
+
+// fileCmd represents the file command
+var fileCmd = &cobra.Command{
+	Use:   "file",
+	Short: "Extracts the main content from a file",
+	Run: func(cmd *cobra.Command, args []string) {
+		extractFromFile(cmd.Flag("input").Value.String(), cmd.Flag("output").Value.String())
+	},
+}
+
+func extractFromFile(inputPath string, outputPath string) {
+	// Apply distiller
+	result, err := distiller.ApplyForFile(inputPath, nil)
+	if err != nil {
+		panic(err)
+	}
+
+	// Print result
+	rawHTML := dom.OuterHTML(result.Node)
+
+	file, err := os.Create(outputPath)
+	if err != nil {
+		panic(err)
+	}
+	fmt.Fprint(file, rawHTML)
+}
+
+func init() {
+	rootCmd.AddCommand(fileCmd)
+
+	fileCmd.Flags().StringP("input", "i", "", "Path to the file to extract the main content from")
+	fileCmd.MarkFlagRequired("input")
+	fileCmd.Flags().StringP("output", "o", "", "Path to the file to write the extracted content to")
+	fileCmd.MarkFlagRequired("output")
+}

cmd/root.go

@@ -0,0 +1,19 @@
+package cmd
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+)
+
+var rootCmd = &cobra.Command{
+	Use:   "go-domdistiller",
+	Short: "go-domdistiller is a CLI tool for extracting the main content of a web page",
+}
+
+func Execute() {
+	err := rootCmd.Execute()
+	if err != nil {
+		os.Exit(1)
+	}
+}

cmd/server.go

@@ -0,0 +1,93 @@
+/*
+Copyright © 2023 NAME HERE <EMAIL ADDRESS>
+*/
+package cmd
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/go-shiori/dom"
+	"github.com/golang-jwt/jwt"
+	"github.com/omnivore-app/go-domdistiller/distiller"
+	"github.com/spf13/cobra"
+)
+
+// serverCmd represents the server command
+var serverCmd = &cobra.Command{
+	Use:   "server",
+	Short: "Starts a server that accepts HTML and returns the main content",
+	Run: func(cmd *cobra.Command, args []string) {
+		start()
+	},
+}
+
+func start() {
+	log.Print("starting server...")
+	http.HandleFunc("/", handler)
+
+	// Determine port for HTTP service.
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+		log.Printf("defaulting to port %s", port)
+	}
+
+	// Start HTTP server.
+	log.Printf("listening on port %s", port)
+	if err := http.ListenAndServe(":"+port, nil); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func handler(w http.ResponseWriter, r *http.Request) {
+	// decode JWT token and check if it's valid
+	token, err := jwt.Parse(r.Header.Get("Authorization"), func(token *jwt.Token) (interface{}, error) {
+		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
+		}
+		return []byte(os.Getenv("JWT_SECRET")), nil
+	})
+	if err != nil {
+		w.WriteHeader(http.StatusUnauthorized)
+		fmt.Fprint(w, "Unauthorized")
+		return
+	}
+	if !token.Valid {
+		w.WriteHeader(http.StatusUnauthorized)
+		fmt.Fprint(w, "Unauthorized")
+		return
+	}
+
+	// Parse request body
+	body, err := ioutil.ReadAll(r.Body)
+	if err != nil {
+		log.Println("Failed to read request body:", err)
+		w.WriteHeader(http.StatusBadRequest)
+		fmt.Fprint(w, "Failed to read request body")
+		return
+	}
+
+	// Apply distiller
+	result, err := distiller.ApplyForReader(strings.NewReader(string(body)), nil)
+	if err != nil {
+		fmt.Println("Failed to apply distiller:", err)
+		w.WriteHeader(http.StatusInternalServerError)
+		fmt.Fprint(w, "Failed to apply distiller")
+		return
+	}
+
+	// Print result
+	rawHTML := dom.OuterHTML(result.Node)
+	fmt.Fprint(w, rawHTML)
+}
+
+func init() {
+	rootCmd.AddCommand(serverCmd)
+
+	serverCmd.Flags().StringP("port", "p", "8080", "Port to listen on")
+}

main.go

@@ -1,74 +1,7 @@
 package main
 
-import (
-	"fmt"
-	"io/ioutil"
-	"log"
-	"net/http"
-	"os"
-	"strings"
-
-	"github.com/go-shiori/dom"
-	"github.com/omnivore-app/go-domdistiller/distiller"
-	"github.com/golang-jwt/jwt"
-)
+import "github.com/omnivore-app/go-domdistiller/cmd"
 
 func main() {
-	log.Print("starting server...")
-	http.HandleFunc("/", handler)
-
-	// Determine port for HTTP service.
-	port := os.Getenv("PORT")
-	if port == "" {
-		port = "8080"
-		log.Printf("defaulting to port %s", port)
-	}
-
-	// Start HTTP server.
-	log.Printf("listening on port %s", port)
-	if err := http.ListenAndServe(":"+port, nil); err != nil {
-		log.Fatal(err)
-	}
-}
-
-func handler(w http.ResponseWriter, r *http.Request) {
-	// decode JWT token and check if it's valid
-	token, err := jwt.Parse(r.Header.Get("Authorization"), func(token *jwt.Token) (interface{}, error) {
-		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
-			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
-		}
-		return []byte(os.Getenv("JWT_SECRET")), nil
-	})
-	if err != nil {
-		w.WriteHeader(http.StatusUnauthorized)
-		fmt.Fprint(w, "Unauthorized")
-		return
-	}
-	if !token.Valid {
-		w.WriteHeader(http.StatusUnauthorized)
-		fmt.Fprint(w, "Unauthorized")
-		return
-	}
-
-	// Parse request body
-	body, err := ioutil.ReadAll(r.Body)
-	if err != nil {
-		log.Println("Failed to read request body:", err)
-		w.WriteHeader(http.StatusBadRequest)
-		fmt.Fprint(w, "Failed to read request body")
-		return
-	}
-
-	// Apply distiller
-	result, err := distiller.ApplyForReader(strings.NewReader(string(body)), nil)
-	if err != nil {
-		fmt.Println("Failed to apply distiller:", err)
-		w.WriteHeader(http.StatusInternalServerError)
-		fmt.Fprint(w, "Failed to apply distiller")
-		return
-	}
-
-	// Print result
-	rawHTML := dom.OuterHTML(result.Node)
-	fmt.Fprint(w, rawHTML)
+	cmd.Execute()
 }