feat(connection): add logic to validate and parse postgres and mysql …

…connections

pkg/connection/connection.go

@@ -4,18 +4,25 @@ import (
 	"errors"
 	"fmt"
 	"net/url"
+	"os"
+	"os/user"
 	"strings"
 
 	"github.com/danvergara/dblab/pkg/command"
 )
 
 var (
+	// ErrCantDetectUSer is the error used to notify that a default username is not found
+	// in the system to be used as database username.
+	ErrCantDetectUSer = errors.New("could not detect default username")
 	// ErrInvalidUPostgresRLFormat is the error used to notify that the postgres given url is not valid.
-	ErrInvalidUPostgresRLFormat = errors.New("Invalid URL. Valid format: postgres://user:password@host:port/db?sslmode=mode")
+	ErrInvalidUPostgresRLFormat = errors.New("invalid URL - Valid format: postgres://user:password@host:port/db?sslmode=mode")
 	// ErrInvalidUMySQLRLFormat is the error used to notify that the given mysql url is not valid.
-	ErrInvalidUMySQLRLFormat = errors.New("Invalid URL. Valid format: mysql://user:password@tcp(host:port)/db")
+	ErrInvalidUMySQLRLFormat = errors.New("invalid URL - valid format: mysql://user:password@tcp(host:port)/db")
 	// ErrInvalidURLFormat is used to notify the url is invalid.
 	ErrInvalidURLFormat = errors.New("invalid url")
+	// ErrInvalidDriver is used to notify that the provided driver is not supported.
+	ErrInvalidDriver = errors.New("invalid driver")
 )
 
 // BuildConnectionFromOpts return the connection uri string given the options passed by the uses.
@@ -31,6 +38,51 @@ func BuildConnectionFromOpts(opts command.Options) (string, error) {
 		}
 	}
 
+	if opts.User == "" {
+		u, err := currentUser()
+		if err == nil {
+			opts.User = u
+		}
+	}
+
+	switch opts.Driver {
+	case "postgres":
+		query := url.Values{}
+		if opts.SSL != "" {
+			query.Add("sslmode", opts.SSL)
+		} else {
+			if opts.Host == "localhost" || opts.Host == "127.0.0.1" {
+				query.Add("sslmode", "disable")
+			}
+		}
+
+		connDB := url.URL{
+			Scheme:   opts.Driver,
+			Host:     fmt.Sprintf("%v:%v", opts.Host, opts.Port),
+			User:     url.UserPassword(opts.User, opts.Pass),
+			Path:     fmt.Sprintf("/%s", opts.DBName),
+			RawQuery: query.Encode(),
+		}
+
+		return connDB.String(), nil
+	case "mysql":
+		return fmt.Sprintf("%s:%s@tcp(%s:%s)/%s", opts.User, opts.Pass, opts.Host, opts.Port, opts.DBName), nil
+	default:
+		return "", fmt.Errorf("%s: %w", opts.URL, ErrInvalidDriver)
+	}
+}
+
+func currentUser() (string, error) {
+	u, err := user.Current()
+	if err == nil {
+		return u.Username, nil
+	}
+
+	name := os.Getenv("USER")
+	if name != "" {
+		return name, nil
+	}
+
 	return "", nil
 }