fix: use slog for logging

- Created a new slog logger for logging.
- Optionally enable verbose logging when generating the PDF document.

internal/cmd/create.go

@@ -4,7 +4,7 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"log"
+	"log/slog"
 	"os"
 	"time"
 
@@ -116,7 +116,7 @@ func (c *CreateCommand) Run() error {
 		return fmt.Errorf("unable to write the data to %s; %w", c.filename, err)
 	}
 
-	log.Printf("INFO: Successfully written the new CV to %s\n", file.Name())
+	slog.Info("CV successfully created", "filename", file.Name())
 
 	return nil
 }

internal/cmd/generate.go

@@ -5,7 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"log"
+	"log/slog"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -24,6 +24,7 @@ type GenerateCommand struct {
 	input             string
 	output            string
 	employmentHistory int
+	verbose           bool
 }
 
 func NewGenerateCommand() *GenerateCommand {
@@ -34,6 +35,7 @@ func NewGenerateCommand() *GenerateCommand {
 	gc.StringVar(&gc.input, "input", "", "specify the CV JSON file that you want to input to the builder.")
 	gc.StringVar(&gc.output, "output", "", "specify the name of the output CV file.")
 	gc.IntVar(&gc.employmentHistory, "employment-history", 10, "show employment history within these number of years.")
+	gc.BoolVar(&gc.verbose, "verbose", false, "set to true to enable verbose logging")
 
 	return &gc
 }
@@ -49,7 +51,7 @@ func (g *GenerateCommand) Run() error {
 	defer func() {
 		err := os.RemoveAll(tempDir)
 		if err != nil {
-			log.Printf("WARN: An error occurred when removing the temporary directory; %v", err)
+			slog.Warn(fmt.Sprintf("WARN: An error occurred when removing the temporary directory; %v", err))
 		}
 	}()
 
@@ -58,7 +60,7 @@ func (g *GenerateCommand) Run() error {
 		return fmt.Errorf("unable to create the tex file; %w", err)
 	}
 
-	if err := pdf(tempDir, texFile, g.output); err != nil {
+	if err := pdf(tempDir, texFile, g.output, g.verbose); err != nil {
 		return fmt.Errorf("unable to create the PDF file; %w", err)
 	}
 
@@ -67,6 +69,8 @@ func (g *GenerateCommand) Run() error {
 
 // tex generates the CV document as a Tex file.
 func tex(input, tempDir string, historyLimit time.Time) (string, error) {
+	slog.Info("Creating the Tex file.")
+
 	c, err := cv.NewCVFromFile(input)
 	if err != nil {
 		return "", fmt.Errorf("unable to create a new CV value from %s; %w", input, err)
@@ -97,19 +101,23 @@ func tex(input, tempDir string, historyLimit time.Time) (string, error) {
 		return "", fmt.Errorf("unable to execute the CV template. %w", err)
 	}
 
-	log.Printf("INFO: Tex file %s was successfully created.", output)
+	slog.Info("Tex file successfully created.", "filename", output)
 
 	return output, nil
 }
 
 // pdf generates the CV document as a PDF file from the tex file.
-func pdf(tempDir, texFile, output string) error {
+func pdf(tempDir, texFile, output string, verbose bool) error {
+	slog.Info("Creating the PDF document.")
+
 	pathArg := "--path=" + tempDir
 
 	command := exec.Command("mtxrun", pathArg, "--script", "context", texFile)
 
-	command.Stderr = os.Stderr
+	if verbose {
-	command.Stdout = os.Stdout
+		command.Stderr = os.Stderr
+		command.Stdout = os.Stdout
+	}
 
 	if err := command.Run(); err != nil {
 		return err
@@ -123,6 +131,8 @@ func pdf(tempDir, texFile, output string) error {
 		return err
 	}
 
+	slog.Info("PDF document successfully created.", "filename", output)
+
 	return nil
 }
 

main.go

@@ -1,7 +1,8 @@
 package main
 
 import (
-	"log"
+	"fmt"
+	"log/slog"
 	"os"
 
 	"codeflow.dananglin.me.uk/apollo/spruce/internal/cmd"
@@ -21,6 +22,14 @@ var (
 )
 
 func main() {
+	logOptions := slog.HandlerOptions{
+		AddSource: false,
+	}
+
+	logger := slog.New(slog.NewTextHandler(os.Stdout, &logOptions))
+
+	slog.SetDefault(logger)
+
 	commandMap := map[string]Runner{
 		"version": cmd.NewVersionCommand(
 			binaryVersion,
@@ -37,14 +46,17 @@ func main() {
 	runner, ok := commandMap[subcommand]
 
 	if !ok {
-		log.Fatalf("ERROR: unknown subcommand '%s'.", subcommand)
+		slog.Error("unknown subcommand", "subcommand", subcommand)
+		os.Exit(1)
 	}
 
 	if err := runner.Parse(os.Args[2:]); err != nil {
-		log.Fatalf("ERROR: unable to parse the command line flags; %v.", err)
+		slog.Error(fmt.Sprintf("unable to parse the command line flags; %v.", err))
+		os.Exit(1)
 	}
 
 	if err := runner.Run(); err != nil {
-		log.Fatalf("ERROR: unable to run '%s'; %v.", runner.Name(), err)
+		slog.Error(fmt.Sprintf("unable to run '%s'; %v.", runner.Name(), err))
+		os.Exit(1)
 	}
 }