package verification

// Requirement represents a validation check that needs to pass in order for a Verified form a consensus type to be issued.
type Requirement int

// results collects positive verification results.
// This bitmap can be used to test which verifications have been successfully completed in order to
// decide whether it is safe to issue a "Verified" type variant.
type results struct {
	done map[Requirement]error
	reqs []Requirement
}

func newResults(reqs ...Requirement) *results {
	return &results{done: make(map[Requirement]error, len(reqs)), reqs: reqs}
}

func (r *results) record(req Requirement, err error) {
	r.done[req] = err
}

// allSatisfied returns true if there is a nil error result for every Requirement.
func (r *results) allSatisfied() bool {
	if len(r.done) != len(r.reqs) {
		return false
	}
	for i := range r.reqs {
		err, ok := r.done[r.reqs[i]]
		if !ok || err != nil {
			return false
		}
	}
	return true
}

func (r *results) executed(req Requirement) bool {
	_, ok := r.done[req]
	return ok
}

func (r *results) result(req Requirement) error {
	return r.done[req]
}

func (r *results) errors(err error) error {
	return newVerificationMultiError(r, err)
}

func (r *results) failures() map[Requirement]error {
	fail := make(map[Requirement]error, len(r.done))
	for i := range r.reqs {
		req := r.reqs[i]
		err, ok := r.done[req]
		if !ok {
			fail[req] = ErrMissingVerification
			continue
		}
		if err != nil {
			fail[req] = err
		}
	}
	return fail
}