errors.go

package vsax

import (
	"errors"
	"fmt"
)

// Sentinel errors for common cases. Typed errors below wrap these so callers
// can match with errors.Is as well as type-assert for extra detail.
var (
	ErrNotFound     = errors.New("resource not found")
	ErrUnauthorized = errors.New("unauthorized")
	ErrForbidden    = errors.New("forbidden")
	ErrBadRequest   = errors.New("bad request")
	ErrServer       = errors.New("server error")
)

// Error is the base API error carrying the HTTP status, server message, and
// kind (a short machine-readable type tag).
type Error struct {
	Code    int    // HTTP status code
	Message string // Meta.ErrorMessage from the response, or HTTP status text
	Kind    string // short tag: auth, forbidden, not_found, validation, server, api
}

func (e Error) Error() string {
	return fmt.Sprintf("vsax: %s (code: %d)", e.Message, e.Code)
}

// APIError represents an unclassified API error.
type APIError struct{ Base Error }

func (e *APIError) Error() string { return e.Base.Error() }
func (e *APIError) Unwrap() error { return ErrServer }

// AuthError represents a 401 response.
type AuthError struct{ Base Error }

func (e *AuthError) Error() string {
	if e.Base.Message != "" {
		return "vsax: authentication failed - " + e.Base.Message
	}
	return "vsax: authentication failed - invalid or expired token"
}
func (e *AuthError) Unwrap() error { return ErrUnauthorized }

// ForbiddenError represents a 403 response (authenticated but not permitted).
type ForbiddenError struct{ Base Error }

func (e *ForbiddenError) Error() string {
	if e.Base.Message != "" {
		return "vsax: forbidden - " + e.Base.Message
	}
	return "vsax: forbidden - insufficient permissions"
}
func (e *ForbiddenError) Unwrap() error { return ErrForbidden }

// NotFoundError represents a 404 response.
type NotFoundError struct {
	Base         Error
	ResourceType string
	ResourceID   string
}

func (e *NotFoundError) Error() string {
	if e.ResourceType != "" && e.ResourceID != "" {
		return fmt.Sprintf("vsax: %s %q not found", e.ResourceType, e.ResourceID)
	}
	if e.Base.Message != "" {
		return "vsax: not found - " + e.Base.Message
	}
	return "vsax: resource not found"
}
func (e *NotFoundError) Unwrap() error { return ErrNotFound }

// ValidationError represents a 400 response (bad request / validation failure).
type ValidationError struct{ Base Error }

func (e *ValidationError) Error() string {
	if e.Base.Message != "" {
		return "vsax: validation error - " + e.Base.Message
	}
	return "vsax: validation error"
}
func (e *ValidationError) Unwrap() error { return ErrBadRequest }