package zec

import (
	"encoding/json"

	"github.com/golang/glog"
	"github.com/juju/errors"
	"github.com/trezor/blockbook/bchain"
	"github.com/trezor/blockbook/bchain/coins/btc"
	"github.com/trezor/blockbook/common"
)

// ZCashRPC is an interface to JSON-RPC bitcoind service
type ZCashRPC struct {
	*btc.BitcoinRPC
}

// ResGetBlockChainInfo is a response to GetChainInfo request
type ResGetBlockChainInfo struct {
	Error  *bchain.RPCError `json:"error"`
	Result struct {
		Chain         string            `json:"chain"`
		Blocks        int               `json:"blocks"`
		Headers       int               `json:"headers"`
		Bestblockhash string            `json:"bestblockhash"`
		Difficulty    common.JSONNumber `json:"difficulty"`
		Pruned        bool              `json:"pruned"`
		SizeOnDisk    int64             `json:"size_on_disk"`
		Consensus     struct {
			Chaintip  string `json:"chaintip"`
			Nextblock string `json:"nextblock"`
		} `json:"consensus"`
	} `json:"result"`
}

// NewZCashRPC returns new ZCashRPC instance
func NewZCashRPC(config json.RawMessage, pushHandler func(bchain.NotificationType)) (bchain.BlockChain, error) {
	b, err := btc.NewBitcoinRPC(config, pushHandler)
	if err != nil {
		return nil, err
	}
	z := &ZCashRPC{
		BitcoinRPC: b.(*btc.BitcoinRPC),
	}
	z.RPCMarshaler = btc.JSONMarshalerV1{}
	z.ChainConfig.SupportsEstimateSmartFee = false
	return z, nil
}

// Initialize initializes ZCashRPC instance
func (z *ZCashRPC) Initialize() error {
	ci, err := z.GetChainInfo()
	if err != nil {
		return err
	}
	chainName := ci.Chain

	params := GetChainParams(chainName)

	z.Parser = NewZCashParser(params, z.ChainConfig)

	// parameters for getInfo request
	if params.Net == MainnetMagic {
		z.Testnet = false
		z.Network = "livenet"
	} else {
		z.Testnet = true
		z.Network = "testnet"
	}

	glog.Info("rpc: block chain ", params.Name)

	return nil
}

// GetChainInfo return info about the blockchain
func (z *ZCashRPC) GetChainInfo() (*bchain.ChainInfo, error) {
	chainInfo := ResGetBlockChainInfo{}
	err := z.Call(&btc.CmdGetBlockChainInfo{Method: "getblockchaininfo"}, &chainInfo)
	if err != nil {
		return nil, err
	}
	if chainInfo.Error != nil {
		return nil, chainInfo.Error
	}

	networkInfo := btc.ResGetNetworkInfo{}
	err = z.Call(&btc.CmdGetNetworkInfo{Method: "getnetworkinfo"}, &networkInfo)
	if err != nil {
		return nil, err
	}
	if networkInfo.Error != nil {
		return nil, networkInfo.Error
	}

	return &bchain.ChainInfo{
		Bestblockhash:   chainInfo.Result.Bestblockhash,
		Blocks:          chainInfo.Result.Blocks,
		Chain:           chainInfo.Result.Chain,
		Difficulty:      string(chainInfo.Result.Difficulty),
		Headers:         chainInfo.Result.Headers,
		SizeOnDisk:      chainInfo.Result.SizeOnDisk,
		Version:         string(networkInfo.Result.Version),
		Subversion:      string(networkInfo.Result.Subversion),
		ProtocolVersion: string(networkInfo.Result.ProtocolVersion),
		Timeoffset:      networkInfo.Result.Timeoffset,
		Consensus:       chainInfo.Result.Consensus,
		Warnings:        networkInfo.Result.Warnings,
	}, nil
}

// GetBlock returns block with given hash.
func (z *ZCashRPC) GetBlock(hash string, height uint32) (*bchain.Block, error) {
	var err error
	if hash == "" && height > 0 {
		hash, err = z.GetBlockHash(height)
		if err != nil {
			return nil, err
		}
	}

	glog.V(1).Info("rpc: getblock (verbosity=1) ", hash)

	res := btc.ResGetBlockThin{}
	req := btc.CmdGetBlock{Method: "getblock"}
	req.Params.BlockHash = hash
	req.Params.Verbosity = 1
	err = z.Call(&req, &res)

	if err != nil {
		return nil, errors.Annotatef(err, "hash %v", hash)
	}
	if res.Error != nil {
		return nil, errors.Annotatef(res.Error, "hash %v", hash)
	}

	txs := make([]bchain.Tx, 0, len(res.Result.Txids))
	for _, txid := range res.Result.Txids {
		tx, err := z.GetTransaction(txid)
		if err != nil {
			if err == bchain.ErrTxNotFound {
				glog.Errorf("rpc: getblock: skipping transanction in block %s due error: %s", hash, err)
				continue
			}
			return nil, err
		}
		txs = append(txs, *tx)
	}
	block := &bchain.Block{
		BlockHeader: res.Result.BlockHeader,
		Txs:         txs,
	}
	return block, nil
}

// GetTransactionForMempool returns a transaction by the transaction ID.
// It could be optimized for mempool, i.e. without block time and confirmations
func (z *ZCashRPC) GetTransactionForMempool(txid string) (*bchain.Tx, error) {
	return z.GetTransaction(txid)
}

// GetMempoolEntry returns mempool data for given transaction
func (z *ZCashRPC) GetMempoolEntry(txid string) (*bchain.MempoolEntry, error) {
	return nil, errors.New("GetMempoolEntry: not implemented")
}

// GetBlockRaw is not supported
func (z *ZCashRPC) GetBlockRaw(hash string) (string, error) {
	return "", errors.New("GetBlockRaw: not supported")
}