package validation

import "strings"

// FieldError represents a single field validation error
type FieldError struct {
	Field   string `json:"field"`            // Field name
	Tag     string `json:"tag"`              // Validation tag that failed
	Param   string `json:"param,omitempty"`  // Optional parameter (e.g., "100" for "max=100")
	Message string `json:"message"`          // Human-readable error message
}

// Error implements the error interface
func (e FieldError) Error() string {
	if e.Param != "" {
		return e.Field + ": " + e.Message + " (" + e.Tag + "=" + e.Param + ")"
	}
	return e.Field + ": " + e.Message
}

// ValidationErrors represents multiple field validation errors
type ValidationErrors []FieldError

// Error implements the error interface
func (ve ValidationErrors) Error() string {
	if len(ve) == 0 {
		return ""
	}

	var sb strings.Builder
	sb.WriteString("validation failed: ")
	for i, err := range ve {
		if i > 0 {
			sb.WriteString(", ")
		}
		sb.WriteString(err.Error())
	}
	return sb.String()
}

// HasErrors returns true if there are any validation errors
func (ve ValidationErrors) HasErrors() bool {
	return len(ve) > 0
}

// GetFieldError returns the first error for a specific field, or nil if none
func (ve ValidationErrors) GetFieldError(field string) *FieldError {
	for _, err := range ve {
		if err.Field == field {
			return &err
		}
	}
	return nil
}

// GetFieldErrors returns all errors for a specific field
func (ve ValidationErrors) GetFieldErrors(field string) []FieldError {
	var errors []FieldError
	for _, err := range ve {
		if err.Field == field {
			errors = append(errors, err)
		}
	}
	return errors
}