package core

import (
	"bytes"
	"time"

	tmbytes "github.com/tendermint/tendermint/libs/bytes"
	"github.com/tendermint/tendermint/p2p"
	ctypes "github.com/tendermint/tendermint/rpc/core/types"
	rpctypes "github.com/tendermint/tendermint/rpc/jsonrpc/types"
	sm "github.com/tendermint/tendermint/state"
	"github.com/tendermint/tendermint/types"
)

// Status returns Tendermint status including node info, pubkey, latest block
// hash, app hash, block height and time.
// More: https://docs.tendermint.com/master/rpc/#/Info/status
func Status(ctx *rpctypes.Context) (*ctypes.ResultStatus, error) {
	var (
		earliestBlockMeta     *types.BlockMeta
		earliestBlockHash     tmbytes.HexBytes
		earliestAppHash       tmbytes.HexBytes
		earliestBlockTimeNano int64
	)
	earliestBlockHeight := env.BlockStore.Base()
	earliestBlockMeta = env.BlockStore.LoadBlockMeta(earliestBlockHeight)
	if earliestBlockMeta != nil {
		earliestAppHash = earliestBlockMeta.Header.AppHash
		earliestBlockHash = earliestBlockMeta.BlockID.Hash
		earliestBlockTimeNano = earliestBlockMeta.Header.Time.UnixNano()
	}

	var latestHeight int64
	if env.ConsensusReactor.WaitSync() {
		latestHeight = env.BlockStore.Height()
	} else {
		latestHeight = env.ConsensusState.GetLastHeight()
	}

	var (
		latestBlockMeta     *types.BlockMeta
		latestBlockHash     tmbytes.HexBytes
		latestAppHash       tmbytes.HexBytes
		latestBlockTimeNano int64
	)
	if latestHeight != 0 {
		latestBlockMeta = env.BlockStore.LoadBlockMeta(latestHeight)
		latestBlockHash = latestBlockMeta.BlockID.Hash
		latestAppHash = latestBlockMeta.Header.AppHash
		latestBlockTimeNano = latestBlockMeta.Header.Time.UnixNano()
	}

	var votingPower int64
	if val := validatorAtHeight(latestHeight); val != nil {
		votingPower = val.VotingPower
	}

	result := &ctypes.ResultStatus{
		NodeInfo: env.P2PTransport.NodeInfo().(p2p.DefaultNodeInfo),
		SyncInfo: ctypes.SyncInfo{
			LatestBlockHash:     latestBlockHash,
			LatestAppHash:       latestAppHash,
			LatestBlockHeight:   latestHeight,
			LatestBlockTime:     time.Unix(0, latestBlockTimeNano),
			EarliestBlockHash:   earliestBlockHash,
			EarliestAppHash:     earliestAppHash,
			EarliestBlockHeight: earliestBlockHeight,
			EarliestBlockTime:   time.Unix(0, earliestBlockTimeNano),
			CatchingUp:          env.ConsensusReactor.WaitSync(),
		},
		ValidatorInfo: ctypes.ValidatorInfo{
			Address:     env.PubKey.Address(),
			PubKey:      env.PubKey,
			VotingPower: votingPower,
		},
	}

	return result, nil
}

func validatorAtHeight(h int64) *types.Validator {
	privValAddress := env.PubKey.Address()

	// If we're still at height h, search in the current validator set.
	lastBlockHeight, vals := env.ConsensusState.GetValidators()
	if lastBlockHeight == h {
		for _, val := range vals {
			if bytes.Equal(val.Address, privValAddress) {
				return val
			}
		}
	}

	// If we've moved to the next height, retrieve the validator set from DB.
	if lastBlockHeight > h {
		vals, err := sm.LoadValidators(env.StateDB, h)
		if err != nil {
			return nil // should not happen
		}
		_, val := vals.GetByAddress(privValAddress)
		return val
	}

	return nil
}