feat: implement enhanced error handling and recovery system - Add custom error types with context and categories - Implement exponential backoff and circuit breaker patterns - Create comprehensive input validation framework - Add checkpoint system for progress preservation - Addresses issue #13

Author: JohanDevl

pkg/errors/types/codes.go

@@ -0,0 +1,128 @@
+package types
+
+// Error Categories and Codes as defined in issue #13
+
+// Network errors
+const (
+	ErrNetworkTimeout     = "NET_001"
+	ErrNetworkUnavailable = "NET_002"
+	ErrRateLimited        = "NET_003"
+	ErrConnectionRefused  = "NET_004"
+	ErrDNSResolution      = "NET_005"
+)
+
+// Authentication errors
+const (
+	ErrInvalidCredentials = "AUTH_001"
+	ErrTokenExpired       = "AUTH_002"
+	ErrUnauthorized       = "AUTH_003"
+	ErrForbidden          = "AUTH_004"
+	ErrAPIKeyMissing      = "AUTH_005"
+)
+
+// Validation errors
+const (
+	ErrInvalidConfig      = "VAL_001"
+	ErrInvalidInput       = "VAL_002"
+	ErrMissingRequired    = "VAL_003"
+	ErrInvalidFormat      = "VAL_004"
+	ErrOutOfRange         = "VAL_005"
+)
+
+// Operation errors
+const (
+	ErrExportFailed       = "OP_001"
+	ErrImportFailed       = "OP_002"
+	ErrFileSystem         = "OP_003"
+	ErrProcessingFailed   = "OP_004"
+	ErrOperationCanceled  = "OP_005"
+	ErrOperationFailed    = "OP_006"
+)
+
+// Data errors
+const (
+	ErrDataCorrupted      = "DATA_001"
+	ErrDataMissing        = "DATA_002"
+	ErrDataFormat         = "DATA_003"
+	ErrDataIntegrity      = "DATA_004"
+)
+
+// Configuration errors
+const (
+	ErrConfigMissing      = "CFG_001"
+	ErrConfigCorrupted    = "CFG_002"
+	ErrConfigPermissions  = "CFG_003"
+	ErrConfigSyntax       = "CFG_004"
+)
+
+// System errors
+const (
+	ErrSystemResource     = "SYS_001"
+	ErrSystemPermission   = "SYS_002"
+	ErrSystemDisk         = "SYS_003"
+	ErrSystemMemory       = "SYS_004"
+)
+
+// ErrorCategory represents error categories for classification
+type ErrorCategory string
+
+const (
+	CategoryNetwork       ErrorCategory = "network"
+	CategoryAuthentication ErrorCategory = "authentication"
+	CategoryValidation     ErrorCategory = "validation"
+	CategoryOperation      ErrorCategory = "operation"
+	CategoryData           ErrorCategory = "data"
+	CategoryConfiguration  ErrorCategory = "configuration"
+	CategorySystem         ErrorCategory = "system"
+)
+
+// GetErrorCategory returns the category for a given error code
+func GetErrorCategory(code string) ErrorCategory {
+	switch {
+	case code[:3] == "NET":
+		return CategoryNetwork
+	case code[:4] == "AUTH":
+		return CategoryAuthentication
+	case code[:3] == "VAL":
+		return CategoryValidation
+	case code[:2] == "OP":
+		return CategoryOperation
+	case code[:4] == "DATA":
+		return CategoryData
+	case code[:3] == "CFG":
+		return CategoryConfiguration
+	case code[:3] == "SYS":
+		return CategorySystem
+	default:
+		return CategoryOperation // default category
+	}
+}
+
+// IsRetryableError determines if an error should be retried
+func IsRetryableError(code string) bool {
+	retryableCodes := map[string]bool{
+		ErrNetworkTimeout:     true,
+		ErrNetworkUnavailable: true,
+		ErrRateLimited:        true,
+		ErrConnectionRefused:  true,
+		ErrTokenExpired:       true,
+		ErrSystemResource:     true,
+		ErrSystemDisk:         false, // Usually not retryable
+		ErrSystemMemory:       false, // Usually not retryable
+	}
+	
+	return retryableCodes[code]
+}
+
+// IsTemporaryError determines if an error is temporary
+func IsTemporaryError(code string) bool {
+	temporaryCodes := map[string]bool{
+		ErrNetworkTimeout:     true,
+		ErrNetworkUnavailable: true,
+		ErrRateLimited:        true,
+		ErrSystemResource:     true,
+		ErrTokenExpired:       true,
+	}
+	
+	return temporaryCodes[code]
+} 

pkg/errors/types/errors.go

@@ -0,0 +1,87 @@
+package types
+
+import (
+	"context"
+	"fmt"
+	"time"
+)
+
+// AppError represents the main error structure for the application
+type AppError struct {
+	Code     string       `json:"code"`
+	Message  string       `json:"message"`
+	Details  string       `json:"details,omitempty"`
+	Cause    error        `json:"-"`
+	Context  ErrorContext `json:"context,omitempty"`
+	Time     time.Time    `json:"timestamp"`
+}
+
+// ErrorContext provides additional context for errors
+type ErrorContext struct {
+	Operation   string            `json:"operation"`
+	RequestID   string            `json:"request_id,omitempty"`
+	UserID      string            `json:"user_id,omitempty"`
+	Metadata    map[string]string `json:"metadata,omitempty"`
+	StackTrace  string            `json:"stack_trace,omitempty"`
+}
+
+// Error implements the error interface
+func (e *AppError) Error() string {
+	if e.Cause != nil {
+		return fmt.Sprintf("%s: %s (caused by: %v)", e.Code, e.Message, e.Cause)
+	}
+	return fmt.Sprintf("%s: %s", e.Code, e.Message)
+}
+
+// Unwrap allows error unwrapping for errors.Is and errors.As
+func (e *AppError) Unwrap() error {
+	return e.Cause
+}
+
+// WithContext adds context to an error
+func (e *AppError) WithContext(ctx context.Context) *AppError {
+	if requestID := ctx.Value("request_id"); requestID != nil {
+		if id, ok := requestID.(string); ok {
+			e.Context.RequestID = id
+		}
+	}
+	if userID := ctx.Value("user_id"); userID != nil {
+		if id, ok := userID.(string); ok {
+			e.Context.UserID = id
+		}
+	}
+	return e
+}
+
+// WithMetadata adds metadata to the error context
+func (e *AppError) WithMetadata(key, value string) *AppError {
+	if e.Context.Metadata == nil {
+		e.Context.Metadata = make(map[string]string)
+	}
+	e.Context.Metadata[key] = value
+	return e
+}
+
+// NewAppError creates a new application error
+func NewAppError(code, message string, cause error) *AppError {
+	return &AppError{
+		Code:    code,
+		Message: message,
+		Cause:   cause,
+		Time:    time.Now(),
+		Context: ErrorContext{},
+	}
+}
+
+// NewAppErrorWithOperation creates a new application error with operation context
+func NewAppErrorWithOperation(code, message, operation string, cause error) *AppError {
+	return &AppError{
+		Code:    code,
+		Message: message,
+		Cause:   cause,
+		Time:    time.Now(),
+		Context: ErrorContext{
+			Operation: operation,
+		},
+	}
+}