errors.go

package bertlv

import (
	"fmt"
	"reflect"
)

// DecodeError represents an error that occurred during BER-TLV decoding.
type DecodeError struct {
	Offset  int
	Field   string
	Type    reflect.Type
	Message string
}

// Error implements the error interface for DecodeError.
func (e *DecodeError) Error() string {
	if e.Field != "" {
		return fmt.Sprintf("bertlv: offset %d: cannot decode into field %s (type %s): %s",
			e.Offset, e.Field, e.Type, e.Message)
	}
	return fmt.Sprintf("bertlv: offset %d: %s", e.Offset, e.Message)
}

// EncodeError represents an error that occurred during BER-TLV encoding.
type EncodeError struct {
	Type    reflect.Type
	Field   string
	Message string
}

// Error implements the error interface for EncodeError.
func (e *EncodeError) Error() string {
	if e.Field != "" {
		return fmt.Sprintf("bertlv: cannot encode field %s (type %s): %s",
			e.Field, e.Type, e.Message)
	}
	if e.Type != nil {
		return fmt.Sprintf("bertlv: cannot encode type %s: %s", e.Type, e.Message)
	}
	return fmt.Sprintf("bertlv: encode error: %s", e.Message)
}

// UnmarshalTypeError describes a BER-TLV value that was
// not appropriate for a value of a specific Go type.
type UnmarshalTypeError struct {
	Value  string       // description of BER-TLV value
	Type   reflect.Type // type of Go value it could not be assigned to
	Offset int64        // error occurred after reading Offset bytes
	Struct string       // name of the struct type containing the field
	Field  string       // name of the field holding the Go value
}

// Error implements the error interface for UnmarshalTypeError.
func (e *UnmarshalTypeError) Error() string {
	if e.Struct != "" || e.Field != "" {
		return fmt.Sprintf("bertlv: cannot unmarshal %s into Go struct field %s.%s of type %s",
			e.Value, e.Struct, e.Field, e.Type.String())
	}
	return fmt.Sprintf("bertlv: cannot unmarshal %s into Go value of type %s",
		e.Value, e.Type.String())
}

// InvalidUnmarshalError describes an invalid argument passed to Unmarshal.
type InvalidUnmarshalError struct {
	Type reflect.Type
}

// Error implements the error interface for InvalidUnmarshalError.
func (e *InvalidUnmarshalError) Error() string {
	if e.Type == nil {
		return "bertlv: Unmarshal(nil)"
	}
	if e.Type.Kind() != reflect.Pointer {
		return "bertlv: Unmarshal(non-pointer " + e.Type.String() + ")"
	}
	return "bertlv: Unmarshal(nil " + e.Type.String() + ")"
}

// MissingRequiredFieldError describes that field that was marked as required wasn't encountered in the BER-TLV data.
type MissingRequiredFieldError struct {
	Field string
	Tag   TagInfo
}

// Error implements the error interface for MissingRequiredFieldError.
func (e *MissingRequiredFieldError) Error() string {
	return fmt.Sprintf("bertlv: missing required tag %s for field '%s'", e.Tag, e.Field)
}

// UnknownFieldError is returned when an unknown tag is encountered with DisallowUnknownFields.
type UnknownFieldError struct {
	Tag    TagInfo
	Offset int
}

// Error implements the error interface for UnknownFieldError.
func (e *UnknownFieldError) Error() string {
	return fmt.Sprintf("bertlv: unknown tag %s at offset %d", e.Tag.String(), e.Offset)
}