added interactive setup of config.json

dbPrompt.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bufio"
 	"database/sql"
 	"embed"
 	"encoding/json"
@@ -52,17 +53,9 @@ var db *sql.DB
 var historyDir = "./history"
 
 func main() {
-	// Load configuration
-	file, err := os.Open("config.json")
+	config, err := loadOrCreateConfig("config.json")
 	if err != nil {
-		log.Fatalf("Failed to open config file: %v", err)
-	}
-	defer file.Close()
-
-	var config Config
-	decoder := json.NewDecoder(file)
-	if err := decoder.Decode(&config); err != nil {
-		log.Fatalf("Failed to decode config: %v", err)
+		log.Fatalf("Failed to load configuration: %v", err)
 	}
 
 	// Connect to the database
@@ -99,6 +92,124 @@ func main() {
 	}
 }
 
+func loadOrCreateConfig(path string) (Config, error) {
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		fmt.Printf("Configuration file %q was not found.\n", path)
+		fmt.Println("Please provide MySQL connection details to create it.")
+
+		cfg, promptErr := promptConfigFromConsole()
+		if promptErr != nil {
+			return Config{}, promptErr
+		}
+
+		data, marshalErr := json.MarshalIndent(cfg, "", "    ")
+		if marshalErr != nil {
+			return Config{}, fmt.Errorf("failed to serialize config: %w", marshalErr)
+		}
+
+		if writeErr := os.WriteFile(path, append(data, '\n'), 0600); writeErr != nil {
+			return Config{}, fmt.Errorf("failed to create %s: %w", path, writeErr)
+		}
+
+		fmt.Printf("Created %s successfully.\n", path)
+		return cfg, nil
+	} else if err != nil {
+		return Config{}, fmt.Errorf("failed to check config file: %w", err)
+	}
+
+	file, err := os.Open(path)
+	if err != nil {
+		return Config{}, fmt.Errorf("failed to open config file: %w", err)
+	}
+	defer file.Close()
+
+	var cfg Config
+	decoder := json.NewDecoder(file)
+	if err := decoder.Decode(&cfg); err != nil {
+		return Config{}, fmt.Errorf("failed to decode config: %w", err)
+	}
+
+	return cfg, nil
+}
+
+func promptConfigFromConsole() (Config, error) {
+	reader := bufio.NewReader(os.Stdin)
+
+	hostname, err := promptRequired(reader, "hostname")
+	if err != nil {
+		return Config{}, err
+	}
+
+	port, err := promptPort(reader, 3306)
+	if err != nil {
+		return Config{}, err
+	}
+
+	username, err := promptRequired(reader, "username")
+	if err != nil {
+		return Config{}, err
+	}
+
+	password, err := promptRequired(reader, "password")
+	if err != nil {
+		return Config{}, err
+	}
+
+	database, err := promptRequired(reader, "database")
+	if err != nil {
+		return Config{}, err
+	}
+
+	return Config{
+		Username: username,
+		Password: password,
+		Hostname: hostname,
+		Port:     port,
+		Database: database,
+	}, nil
+}
+
+func promptRequired(reader *bufio.Reader, field string) (string, error) {
+	for {
+		fmt.Printf("%s: ", field)
+		value, err := reader.ReadString('\n')
+		if err != nil {
+			return "", fmt.Errorf("failed to read %s: %w", field, err)
+		}
+
+		value = strings.TrimSpace(value)
+		if value == "" {
+			fmt.Printf("%s is required.\n", field)
+			continue
+		}
+
+		return value, nil
+	}
+}
+
+func promptPort(reader *bufio.Reader, defaultPort int) (int, error) {
+	for {
+		fmt.Printf("port [%d]: ", defaultPort)
+		value, err := reader.ReadString('\n')
+		if err != nil {
+			return 0, fmt.Errorf("failed to read port: %w", err)
+		}
+
+		value = strings.TrimSpace(value)
+		if value == "" {
+			return defaultPort, nil
+		}
+
+		port, atoiErr := strconv.Atoi(value)
+		if atoiErr != nil || port <= 0 || port > 65535 {
+			fmt.Println("Port must be a number between 1 and 65535.")
+			continue
+		}
+
+		return port, nil
+	}
+}
+
 func serveIndex(w http.ResponseWriter, r *http.Request) {
 	http.ServeFile(w, r, "index.html")
 }