package types

import (
	"bytes"
	"fmt"
	"io"

	. "github.com/tendermint/go-common"
	"github.com/tendermint/go-crypto"
	"github.com/tendermint/go-wire"
)

// Volatile state for each Validator
// Also persisted with the state, but fields change
// every height|round so they don't go in merkle.Tree
type Validator struct {
	Address          []byte        `json:"address"`
	PubKey           crypto.PubKey `json:"pub_key"`
	LastCommitHeight int           `json:"last_commit_height"`
	VotingPower      int64         `json:"voting_power"`
	Accum            int64         `json:"accum"`
}

// Creates a new copy of the validator so we can mutate accum.
// Panics if the validator is nil.
func (v *Validator) Copy() *Validator {
	vCopy := *v
	return &vCopy
}

// Returns the one with higher Accum.
func (v *Validator) CompareAccum(other *Validator) *Validator {
	if v == nil {
		return other
	}
	if v.Accum > other.Accum {
		return v
	} else if v.Accum < other.Accum {
		return other
	} else {
		if bytes.Compare(v.Address, other.Address) < 0 {
			return v
		} else if bytes.Compare(v.Address, other.Address) > 0 {
			return other
		} else {
			PanicSanity("Cannot compare identical validators")
			return nil
		}
	}
}

func (v *Validator) String() string {
	if v == nil {
		return "nil-Validator"
	}
	return fmt.Sprintf("Validator{%X %v %v VP:%v A:%v}",
		v.Address,
		v.PubKey,
		v.LastCommitHeight,
		v.VotingPower,
		v.Accum)
}

func (v *Validator) Hash() []byte {
	return wire.BinaryRipemd160(v)
}

//-------------------------------------

var ValidatorCodec = validatorCodec{}

type validatorCodec struct{}

func (vc validatorCodec) Encode(o interface{}, w io.Writer, n *int, err *error) {
	wire.WriteBinary(o.(*Validator), w, n, err)
}

func (vc validatorCodec) Decode(r io.Reader, n *int, err *error) interface{} {
	return wire.ReadBinary(&Validator{}, r, 0, n, err)
}

func (vc validatorCodec) Compare(o1 interface{}, o2 interface{}) int {
	PanicSanity("ValidatorCodec.Compare not implemented")
	return 0
}