/
epoch.go
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/
epoch.go
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// Copyright © 2022 Weald Technology Trading
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package util
import (
"context"
"strconv"
"github.com/attestantio/go-eth2-client/spec/phase0"
"github.com/pkg/errors"
"github.com/wealdtech/ethdo/services/chaintime"
)
// ParseEpoch parses input to calculate the desired epoch.
func ParseEpoch(_ context.Context, chainTime chaintime.Service, epochStr string) (phase0.Epoch, error) {
currentEpoch := chainTime.CurrentEpoch()
switch epochStr {
case "", "current", "head", "-0":
return currentEpoch, nil
case "last":
if currentEpoch > 0 {
currentEpoch--
}
return currentEpoch, nil
default:
val, err := strconv.ParseInt(epochStr, 10, 64)
if err != nil {
return 0, errors.Wrap(err, "failed to parse epoch")
}
if val >= 0 {
return phase0.Epoch(val), nil
}
if phase0.Epoch(-val) > currentEpoch {
return 0, nil
}
return currentEpoch + phase0.Epoch(val), nil
}
}