package indexer

import (
	"encoding/json"
	"errors"
	"time"
)

type PeerRecordValidator struct{}

func (v PeerRecordValidator) Validate(key string, value []byte) error {

	var rec PeerRecord
	if err := json.Unmarshal(value, &rec); err != nil {
		return errors.New("invalid json")
	}

	// PeerID must exist
	if rec.PeerID == "" {
		return errors.New("missing peerID")
	}

	// Expiry check
	if rec.ExpiryDate.Before(time.Now().UTC()) {
		return errors.New("record expired")
	}

	// Signature verification
	rec2 := PeerRecord{
		Name:   rec.Name,
		DID:    rec.DID,
		PubKey: rec.PubKey,
		PeerID: rec.PeerID,
	}

	if _, err := rec2.Verify(); err != nil {
		return errors.New("invalid signature")
	}

	return nil
}

func (v PeerRecordValidator) Select(key string, values [][]byte) (int, error) {

	var newest time.Time
	index := 0

	for i, val := range values {
		var rec PeerRecord
		if err := json.Unmarshal(val, &rec); err != nil {
			continue
		}

		if rec.ExpiryDate.After(newest) {
			newest = rec.ExpiryDate
			index = i
		}
	}

	return index, nil
}