Refactor error handling

common/errors.go

@@ -0,0 +1,192 @@
+package common
+
+import (
+	"errors"
+	"fmt"
+)
+
+// CommonError represents a structured error type for the common package
+type CommonError struct {
+	Code    ErrorCode
+	Message string
+	Cause   error
+}
+
+// ErrorCode represents different types of errors
+type ErrorCode string
+
+const (
+	// Directory operation errors
+	ErrDirCreation ErrorCode = "DIRECTORY_CREATION_FAILED"
+	ErrDirAccess   ErrorCode = "DIRECTORY_ACCESS_FAILED"
+
+	// File operation errors
+	ErrFileNotFound ErrorCode = "FILE_NOT_FOUND"
+	ErrFileRead     ErrorCode = "FILE_READ_FAILED"
+	ErrFileWrite    ErrorCode = "FILE_WRITE_FAILED"
+	ErrFileCreate   ErrorCode = "FILE_CREATE_FAILED"
+
+	// Network operation errors
+	ErrNetworkRequest  ErrorCode = "NETWORK_REQUEST_FAILED"
+	ErrNetworkResponse ErrorCode = "NETWORK_RESPONSE_FAILED"
+
+	// Template and configuration errors
+	ErrTemplateLoad  ErrorCode = "TEMPLATE_LOAD_FAILED"
+	ErrTemplateParse ErrorCode = "TEMPLATE_PARSE_FAILED"
+	ErrConfigInvalid ErrorCode = "CONFIG_INVALID"
+
+	// Subscription errors
+	ErrSubscriptionLoad  ErrorCode = "SUBSCRIPTION_LOAD_FAILED"
+	ErrSubscriptionParse ErrorCode = "SUBSCRIPTION_PARSE_FAILED"
+
+	// Regex errors
+	ErrRegexCompile ErrorCode = "REGEX_COMPILE_FAILED"
+	ErrRegexInvalid ErrorCode = "REGEX_INVALID"
+
+	// Database errors
+	ErrDatabaseConnect ErrorCode = "DATABASE_CONNECTION_FAILED"
+	ErrDatabaseQuery   ErrorCode = "DATABASE_QUERY_FAILED"
+	ErrRecordNotFound  ErrorCode = "RECORD_NOT_FOUND"
+
+	// Validation errors
+	ErrValidation   ErrorCode = "VALIDATION_FAILED"
+	ErrInvalidInput ErrorCode = "INVALID_INPUT"
+)
+
+// Error returns the string representation of the error
+func (e *CommonError) Error() string {
+	if e.Cause != nil {
+		return fmt.Sprintf("[%s] %s: %v", e.Code, e.Message, e.Cause)
+	}
+	return fmt.Sprintf("[%s] %s", e.Code, e.Message)
+}
+
+// Unwrap returns the underlying error
+func (e *CommonError) Unwrap() error {
+	return e.Cause
+}
+
+// Is allows error comparison
+func (e *CommonError) Is(target error) bool {
+	if t, ok := target.(*CommonError); ok {
+		return e.Code == t.Code
+	}
+	return false
+}
+
+// NewError creates a new CommonError
+func NewError(code ErrorCode, message string, cause error) *CommonError {
+	return &CommonError{
+		Code:    code,
+		Message: message,
+		Cause:   cause,
+	}
+}
+
+// NewSimpleError creates a new CommonError without a cause
+func NewSimpleError(code ErrorCode, message string) *CommonError {
+	return &CommonError{
+		Code:    code,
+		Message: message,
+	}
+}
+
+// Convenience constructors for common error types
+
+// Directory errors
+func NewDirCreationError(dirPath string, cause error) *CommonError {
+	return NewError(ErrDirCreation, fmt.Sprintf("failed to create directory: %s", dirPath), cause)
+}
+
+func NewDirAccessError(dirPath string, cause error) *CommonError {
+	return NewError(ErrDirAccess, fmt.Sprintf("failed to access directory: %s", dirPath), cause)
+}
+
+// File errors
+func NewFileNotFoundError(filePath string) *CommonError {
+	return NewSimpleError(ErrFileNotFound, fmt.Sprintf("file not found: %s", filePath))
+}
+
+func NewFileReadError(filePath string, cause error) *CommonError {
+	return NewError(ErrFileRead, fmt.Sprintf("failed to read file: %s", filePath), cause)
+}
+
+func NewFileWriteError(filePath string, cause error) *CommonError {
+	return NewError(ErrFileWrite, fmt.Sprintf("failed to write file: %s", filePath), cause)
+}
+
+func NewFileCreateError(filePath string, cause error) *CommonError {
+	return NewError(ErrFileCreate, fmt.Sprintf("failed to create file: %s", filePath), cause)
+}
+
+// Network errors
+func NewNetworkRequestError(url string, cause error) *CommonError {
+	return NewError(ErrNetworkRequest, fmt.Sprintf("network request failed for URL: %s", url), cause)
+}
+
+func NewNetworkResponseError(message string, cause error) *CommonError {
+	return NewError(ErrNetworkResponse, message, cause)
+}
+
+// Template errors
+func NewTemplateLoadError(template string, cause error) *CommonError {
+	return NewError(ErrTemplateLoad, fmt.Sprintf("failed to load template: %s", template), cause)
+}
+
+func NewTemplateParseError(cause error) *CommonError {
+	return NewError(ErrTemplateParse, "failed to parse template", cause)
+}
+
+// Subscription errors
+func NewSubscriptionLoadError(url string, cause error) *CommonError {
+	return NewError(ErrSubscriptionLoad, fmt.Sprintf("failed to load subscription: %s", url), cause)
+}
+
+func NewSubscriptionParseError(cause error) *CommonError {
+	return NewError(ErrSubscriptionParse, "failed to parse subscription", cause)
+}
+
+// Regex errors
+func NewRegexCompileError(pattern string, cause error) *CommonError {
+	return NewError(ErrRegexCompile, fmt.Sprintf("failed to compile regex pattern: %s", pattern), cause)
+}
+
+func NewRegexInvalidError(paramName string, cause error) *CommonError {
+	return NewError(ErrRegexInvalid, fmt.Sprintf("invalid regex in parameter: %s", paramName), cause)
+}
+
+// Database errors
+func NewDatabaseConnectError(cause error) *CommonError {
+	return NewError(ErrDatabaseConnect, "failed to connect to database", cause)
+}
+
+func NewRecordNotFoundError(recordType string, id string) *CommonError {
+	return NewSimpleError(ErrRecordNotFound, fmt.Sprintf("%s not found: %s", recordType, id))
+}
+
+// Validation errors
+func NewValidationError(field string, message string) *CommonError {
+	return NewSimpleError(ErrValidation, fmt.Sprintf("validation failed for %s: %s", field, message))
+}
+
+func NewInvalidInputError(paramName string, value string) *CommonError {
+	return NewSimpleError(ErrInvalidInput, fmt.Sprintf("invalid input for parameter %s: %s", paramName, value))
+}
+
+// IsErrorCode checks if an error has a specific error code
+func IsErrorCode(err error, code ErrorCode) bool {
+	var commonErr *CommonError
+	if errors.As(err, &commonErr) {
+		return commonErr.Code == code
+	}
+	return false
+}
+
+// GetErrorCode extracts the error code from an error
+func GetErrorCode(err error) (ErrorCode, bool) {
+	var commonErr *CommonError
+	if errors.As(err, &commonErr) {
+		return commonErr.Code, true
+	}
+	return "", false
+}