// VulcanizeDB
// Copyright © 2019 Vulcanize

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program 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 Affero General Public License for more details.

// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package node

import (
	"context"
	"fmt"
	"regexp"
	"strconv"
	"strings"

	"github.com/ethereum/go-ethereum/core/types"
	"github.com/ethereum/go-ethereum/p2p"
	log "github.com/sirupsen/logrus"

	"github.com/vulcanize/vulcanizedb/pkg/eth/core"
)

type IPropertiesReader interface {
	NodeInfo() (id string, name string)
	NetworkID() float64
	GenesisBlock() string
}

type PropertiesReader struct {
	client core.RPCClient
}

type ParityClient struct {
	PropertiesReader
}

type GethClient struct {
	PropertiesReader
}

type InfuraClient struct {
	PropertiesReader
}

type GanacheClient struct {
	PropertiesReader
}

func MakeNode(rpcClient core.RPCClient) core.Node {
	pr := makePropertiesReader(rpcClient)
	id, name := pr.NodeInfo()
	return core.Node{
		GenesisBlock: pr.GenesisBlock(),
		NetworkID:    fmt.Sprintf("%f", pr.NetworkID()),
		ID:           id,
		ClientName:   name,
	}
}

func makePropertiesReader(client core.RPCClient) IPropertiesReader {
	switch getNodeType(client) {
	case core.GETH:
		return GethClient{PropertiesReader: PropertiesReader{client: client}}
	case core.PARITY:
		return ParityClient{PropertiesReader: PropertiesReader{client: client}}
	case core.INFURA:
		return InfuraClient{PropertiesReader: PropertiesReader{client: client}}
	case core.GANACHE:
		return GanacheClient{PropertiesReader: PropertiesReader{client: client}}
	default:
		return PropertiesReader{client: client}
	}
}

func getNodeType(client core.RPCClient) core.NodeType {
	// TODO: fix this
	// This heuristics for figuring out the node type are not usefull...
	// for example we often port forward remote nodes to localhost
	// and geth does not have to expose the admin api...
	if strings.Contains(client.IpcPath(), "infura") {
		return core.INFURA
	}
	if strings.Contains(client.IpcPath(), "127.0.0.1") || strings.Contains(client.IpcPath(), "localhost") {
		return core.GANACHE
	}
	modules, _ := client.SupportedModules()
	if _, ok := modules["admin"]; ok {
		return core.GETH
	}
	return core.PARITY
}

func (reader PropertiesReader) NetworkID() float64 {
	var version string
	err := reader.client.CallContext(context.Background(), &version, "net_version")
	if err != nil {
		log.Error(err)
	}
	networkID, _ := strconv.ParseFloat(version, 64)
	return networkID
}

func (reader PropertiesReader) GenesisBlock() string {
	var header *types.Header
	blockZero := "0x0"
	includeTransactions := false
	err := reader.client.CallContext(context.Background(), &header, "eth_getBlockByNumber", blockZero, includeTransactions)
	if err != nil {
		log.Error(err)
	}
	return header.Hash().Hex()
}

func (reader PropertiesReader) NodeInfo() (string, string) {
	var info p2p.NodeInfo
	err := reader.client.CallContext(context.Background(), &info, "admin_nodeInfo")
	if err != nil {
		log.Error(err)
	}
	return info.ID, info.Name
}

func (client ParityClient) NodeInfo() (string, string) {
	nodeInfo := client.parityNodeInfo()
	id := client.parityID()
	return id, nodeInfo
}

func (client InfuraClient) NodeInfo() (string, string) {
	return "infura", "infura"
}

func (client GanacheClient) NodeInfo() (string, string) {
	return "ganache", "ganache"
}

func (client ParityClient) parityNodeInfo() string {
	var nodeInfo core.ParityNodeInfo
	err := client.client.CallContext(context.Background(), &nodeInfo, "parity_versionInfo")
	if err != nil {
		log.Error(err)
	}
	return nodeInfo.String()
}

func (client ParityClient) parityID() string {
	var enodeID = regexp.MustCompile(`^enode://(.+)@.+$`)
	var enodeURL string
	err := client.client.CallContext(context.Background(), &enodeURL, "parity_enode")
	if err != nil {
		log.Error(err)
	}
	enode := enodeID.FindStringSubmatch(enodeURL)
	if len(enode) < 2 {
		return ""
	}
	return enode[1]
}