/*
	'actual' should be an `*errors.Error`; 'expected' should be an `*errors.ErrorClass`;
	we'll check that the error is under the umbrella of the error class.
*/
func ShouldBeErrorClass(actual interface{}, expected ...interface{}) string {
	err, ok := actual.(error)
	if !ok {
		return fmt.Sprintf("You must provide an `error` as the first argument to this assertion; got `%T`", actual)
	}

	var class *errors.ErrorClass
	switch len(expected) {
	case 0:
		return "You must provide a spacemonkey `ErrorClass` as the expectation parameter to this assertion."
	case 1:
		cls, ok := expected[0].(*errors.ErrorClass)
		if !ok {
			return "You must provide a spacemonkey `ErrorClass` as the expectation parameter to this assertion."
		}
		class = cls
	default:
		return "You must provide one parameter as an expectation to this assertion."
	}

	// checking if this is nil is surprisingly complicated due to https://golang.org/doc/faq#nil_error
	if reflect.ValueOf(err).IsNil() {
		return fmt.Sprintf("Expected error to be of class %q but it was nil!", class.String())
	}

	spaceClass := errors.GetClass(err)
	if spaceClass.Is(class) {
		return ""
	}
	return fmt.Sprintf("Expected error to be of class %q but it had %q instead!  (Full message: %s)", class.String(), spaceClass.String(), err.Error())
}

/*
	'actual' should be a `func()`; 'expected' should be an `*errors.ErrorClass`;
	we'll run the function, and check that it panics, and that the error is under the umbrella of the error class.
*/
func ShouldPanicWith(actual interface{}, expected ...interface{}) string {
	fn, ok := actual.(func())
	if !ok {
		return fmt.Sprintf("You must provide a `func()` as the first argument to this assertion; got `%T`", actual)
	}

	var errClass *errors.ErrorClass
	switch len(expected) {
	case 0:
		return "You must provide a spacemonkey `ErrorClass` as the expectation parameter to this assertion."
	case 1:
		cls, ok := expected[0].(*errors.ErrorClass)
		if !ok {
			return "You must provide a spacemonkey `ErrorClass` as the expectation parameter to this assertion."
		}
		errClass = cls
	default:
		return "You must provide one parameter as an expectation to this assertion."
	}

	var caught error
	try.Do(
		fn,
	).CatchAll(func(err error) {
		caught = err
	}).Done()

	if caught == nil {
		return fmt.Sprintf("Expected error to be of class %q but no error was raised!", errClass.String())
	}
	spaceClass := errors.GetClass(caught)
	if spaceClass.Is(errClass) {
		return ""
	}
	return fmt.Sprintf("Expected error to be of class %q but it had %q instead!  (Full message: %s)", errClass.String(), spaceClass.String(), caught.Error())
}

	EXIT_JOB          = ExitCode(10) // used to indicate a job reported a nonzero exit code (from cli commands that execute a single job).
)

var ExitCodeKey = errors.GenSym()

/*
	CLI errors are the last line: they should be formatted to be user-facing.
	The main method will convert a CLIError into a short and well-formatted
	message, and will *not* include stack traces unless the user is running
	with debug mode enabled.

	CLI errors are an appropriate wrapping for anything where we can map a
	problem onto something the user can understand and fix.  Errors that are
	a repeatr bug or unknown territory should *not* be mapped into a CLIError.
*/
var Error *errors.ErrorClass = errors.NewClass("CLIError")

/*
	Use this to set a specific error code the process should exit with
	when producing a `cli.Error`.

	Example: `cli.Error.NewWith("something terrible!", SetExitCode(EXIT_BADARGS))`
*/
func SetExitCode(code ExitCode) errors.ErrorOption {
	return errors.SetData(ExitCodeKey, code)
}

/*
	Exit errors may be raised to immediately transition to we're done (and
	specify an `ExitCode`), but generate slightly less of a sadface than
	`cli.Error`: use them for graceful exits.

package scheduler

import (
	"github.com/spacemonkeygo/errors"
)

// grouping, do not instantiate
var Error *errors.ErrorClass = errors.NewClass("SchedulerError")

// error when a scheduler's queue was full and could not enqueue a forumla.
var QueueFullError *errors.ErrorClass = Error.NewClass("QueueFullError")

}

/*
	RecordIterator is used for walking Bucket contents in hash-ready order.
	It's specified separately from Record for three reasons: There will be many
	Record objects, and so they should be small (the iterators tend to require
	at least another two words of memory); and the Record objects are
	serializable the same way for all implementations of Bucket (the iterators
	may work differently depending on how data is heaped in the Bucket impl).
*/
type RecordIterator interface {
	treewalk.Node
	Record() Record
}

var InvalidFilesystem *errors.ErrorClass = errors.NewClass("InvalidFilesystem")

/*
	PathCollision is reported when the same file path is submitted to a `Bucket`
	more than once.  (Some formats, for example tarballs, allow the same filename
	to be recorded twice.  We consider this poor behavior since most actual
	filesystems of course will not tolerate this, and also because it begs the
	question of which should be sorted first when creating a deterministic
	hash of the whole tree.)
*/
var PathCollision *errors.ErrorClass = InvalidFilesystem.NewClass("PathCollision")

/*
	MissingTree is reported when iteration over a filled bucket encounters
	a file that has no parent nodes.  I.e., if there's a file path "./a/b",
	and there's no entries for "./a", it's a MissingTree error.

package fs

import (
	"github.com/spacemonkeygo/errors"
)

var Error *errors.ErrorClass = errors.NewClass("FSError") // grouping, do not instantiate

/*
	`BreakoutError` is raised when processing a filesystem description where links
	(symlinks, hardlinks) are constructed in such a way that they would reach
	out of the base directory.  Encountering these in a well-formed filesystem
	description is basically an attempted attack.
*/
var BreakoutError *errors.ErrorClass = Error.NewClass("FSBreakoutError")

func ioError(err error) {
	panic(Error.Wrap(errors.IOError.Wrap(err)))
}