add 'Validate' method to the 'Config'

pkg/config/config.go

@@ -1,9 +1,11 @@
 package config
 
 import (
+	"errors"
 	"fmt"
 	"net/url"
 	"os"
+	"slices"
 	"time"
 
 	"github.com/aykhans/dodo/pkg/types"
@@ -29,7 +31,10 @@ var Defaults = struct {
 	SkipVerify:     false,
 }
 
-var SupportedProxySchemes = []string{"http", "socks5", "socks5h"}
+var (
+	ValidProxySchemes      = []string{"http", "socks5", "socks5h"}
+	ValidRequestURLSchemes = []string{"http", "https"}
+)
 
 type IParser interface {
 	Parse() (*Config, error)
@@ -120,12 +125,73 @@ func (config *Config) SetDefaults() {
 	}
 }
 
+// Validate validates the config fields.
+// It can return the following errors:
+// - types.FieldValidationErrors
+func (config Config) Validate() error {
+	validationErrors := make([]types.FieldValidationError, 0)
+
+	if config.Method == nil {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Method", "", errors.New("method is required")))
+	}
+
+	if config.URL == nil {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("URL", "", errors.New("URL is required")))
+	} else if !slices.Contains(ValidRequestURLSchemes, config.URL.Scheme) {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("URL", config.URL.String(), fmt.Errorf("URL scheme must be one of: %v", ValidRequestURLSchemes)))
+	}
+
+	if config.DodosCount == nil {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Dodos Count", "", errors.New("dodos count is required")))
+	} else if *config.DodosCount == 0 {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Dodos Count", "0", errors.New("dodos count must be greater than 0")))
+	}
+
+	switch {
+	case config.RequestCount == nil && config.Duration == nil:
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Request Count / Duration", "", errors.New("either request count or duration must be specified")))
+	case (config.RequestCount != nil && config.Duration != nil) && (*config.RequestCount == 0 && *config.Duration == 0):
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Request Count / Duration", "0", errors.New("both request count and duration cannot be zero")))
+	case config.RequestCount != nil && config.Duration == nil && *config.RequestCount == 0:
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Request Count", "0", errors.New("request count must be greater than 0")))
+	case config.RequestCount == nil && config.Duration != nil && *config.Duration == 0:
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Duration", "0", errors.New("duration must be greater than 0")))
+	}
+
+	if config.Yes == nil {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Yes", "", errors.New("yes field is required")))
+	}
+
+	if config.SkipVerify == nil {
+		validationErrors = append(validationErrors, types.NewFieldValidationError("Skip Verify", "", errors.New("skip verify field is required")))
+	}
+
+	for i, proxy := range config.Proxies {
+		if !slices.Contains(ValidProxySchemes, proxy.Scheme) {
+			validationErrors = append(
+				validationErrors,
+				types.NewFieldValidationError(
+					fmt.Sprintf("Proxy[%d]", i),
+					proxy.String(),
+					fmt.Errorf("proxy scheme must be one of: %v", ValidProxySchemes),
+				),
+			)
+		}
+	}
+
+	if len(validationErrors) > 0 {
+		return types.NewFieldValidationErrors(validationErrors)
+	}
+
+	return nil
+}
+
 func ReadAllConfigs() *Config {
 	envParser := NewConfigENVParser("DODO")
 	envConfig, err := envParser.Parse()
 	_ = utils.HandleErrorOrDie(err,
 		utils.OnCustomError(func(err types.FieldParseErrors) error {
-			printValidationErrors("ENV", err.Errors...)
+			printParseErrors("ENV", err.Errors...)
 			fmt.Println()
 			os.Exit(1)
 			return nil
@@ -148,7 +214,7 @@ func ReadAllConfigs() *Config {
 		utils.OnCustomError(func(err types.FieldParseErrors) error {
 			cliParser.PrintHelp()
 			fmt.Println()
-			printValidationErrors("CLI", err.Errors...)
+			printParseErrors("CLI", err.Errors...)
 			os.Exit(1)
 			return nil
 		}),
@@ -169,7 +235,7 @@ func ReadAllConfigs() *Config {
 				return nil
 			}),
 			utils.OnCustomError(func(err types.FieldParseErrors) error {
-				printValidationErrors(fmt.Sprintf("CONFIG FILE '%s'", configFile.Path()), err.Errors...)
+				printParseErrors(fmt.Sprintf("CONFIG FILE '%s'", configFile.Path()), err.Errors...)
 				os.Exit(1)
 				return nil
 			}),
@@ -178,6 +244,23 @@ func ReadAllConfigs() *Config {
 		envConfig.Merge(fileConfig)
 	}
 
+	envConfig.SetDefaults()
+
+	err = envConfig.Validate()
+	_ = utils.HandleErrorOrDie(err,
+		utils.OnCustomError(func(err types.FieldValidationErrors) error {
+			for _, fieldErr := range err.Errors {
+				if fieldErr.Value == "" {
+					utils.PrintErr(text.FgYellow, "[VALIDATION] Field '%s': %v", fieldErr.Field, fieldErr.Err)
+				} else {
+					utils.PrintErr(text.FgYellow, "[VALIDATION] Field '%s' (%s): %v", fieldErr.Field, fieldErr.Value, fieldErr.Err)
+				}
+			}
+			os.Exit(1)
+			return nil
+		}),
+	)
+
 	return envConfig
 }
 
@@ -210,7 +293,7 @@ func parseConfigFile(configFile types.ConfigFile, maxDepth int) (*Config, error)
 	return fileConfig, nil
 }
 
-func printValidationErrors(parserName string, errors ...types.FieldParseError) {
+func printParseErrors(parserName string, errors ...types.FieldParseError) {
 	for _, fieldErr := range errors {
 		if fieldErr.Value == "" {
 			utils.PrintErr(text.FgYellow, "[%s] Field '%s': %v", parserName, fieldErr.Field, fieldErr.Err)