package cmd

import "errors"

// Sentinel errors recognized by Execute → exit code mapping.
//
// exists  → ErrNotFound  →  1
// download without --url/--exec, key missing → ErrMissNoFallback → 3
// --exec script failed → the script's own exit status
// any other error → 2
var (
	ErrNotFound       = errors.New("cacher: key not found")
	ErrMissNoFallback = errors.New("cacher: cache miss and no --url/--exec fallback")
)

func exitCodeFor(err error) int {
	// A failed --exec script reports its own status: the caller wrote
	// that script and its exit code says more than a generic 2.
	var coded interface{ ExitCode() int }
	switch {
	case err == nil:
		return 0
	case errors.Is(err, ErrNotFound):
		return 1
	case errors.Is(err, ErrMissNoFallback):
		return 3
	case errors.As(err, &coded):
		return coded.ExitCode()
	default:
		return 2
	}
}