// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.

package types

import (
	"fmt"
)

// Position describes the position in the block lattice of an entity.
type Position struct {
	Round  uint64 `json:"round"`
	Height uint64 `json:"height"`
}

func (pos Position) String() string {
	return fmt.Sprintf("Position{Round:%d Height:%d}", pos.Round, pos.Height)
}

// Equal checks if two positions are equal.
func (pos Position) Equal(other Position) bool {
	return pos.Round == other.Round && pos.Height == other.Height
}

// Newer checks if one block is newer than another one on the same chain.
// If two blocks on different chain compared by this function, it would panic.
func (pos Position) Newer(other Position) bool {
	return pos.Round > other.Round ||
		(pos.Round == other.Round && pos.Height > other.Height)
}

// Older checks if one block is older than another one on the same chain.
// If two blocks on different chain compared by this function, it would panic.
func (pos Position) Older(other Position) bool {
	return pos.Round < other.Round ||
		(pos.Round == other.Round && pos.Height < other.Height)
}