// Copyright 2017 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"math/rand"
	"path/filepath"
	"strconv"
	"strings"
	"text/template"

	"github.com/ethereum/go-ethereum/common"
	"github.com/ethereum/go-ethereum/log"
)

// nodeDockerfile is the Dockerfile required to run an Ethereum node.
var nodeDockerfile = `
FROM ethereum/client-go:latest

ADD genesis.json /genesis.json
{{if .Unlock}}
	ADD signer.json /signer.json
	ADD signer.pass /signer.pass
{{end}}
RUN \
  echo 'geth --cache 512 init /genesis.json' > geth.sh && \{{if .Unlock}}
	echo 'mkdir -p /root/.ethereum/keystore/ && cp /signer.json /root/.ethereum/keystore/' >> geth.sh && \{{end}}
	echo $'geth --networkid {{.NetworkID}} --cache 512 --port {{.Port}} --maxpeers {{.Peers}} {{.LightFlag}} --ethstats \'{{.Ethstats}}\' {{if .BootV4}}--bootnodesv4 {{.BootV4}}{{end}} {{if .BootV5}}--bootnodesv5 {{.BootV5}}{{end}} {{if .Etherbase}}--etherbase {{.Etherbase}} --mine --minerthreads 1{{end}} {{if .Unlock}}--unlock 0 --password /signer.pass --mine{{end}} --targetgaslimit {{.GasTarget}} --gasprice {{.GasPrice}}' >> geth.sh

ENTRYPOINT ["/bin/sh", "geth.sh"]
`

// nodeComposefile is the docker-compose.yml file required to deploy and maintain
// an Ethereum node (bootnode or miner for now).
var nodeComposefile = `
version: '2'
services:
  {{.Type}}:
    build: .
    image: {{.Network}}/{{.Type}}
    ports:
      - "{{.FullPort}}:{{.FullPort}}"
      - "{{.FullPort}}:{{.FullPort}}/udp"{{if .Light}}
      - "{{.LightPort}}:{{.LightPort}}/udp"{{end}}
    volumes:
      - {{.Datadir}}:/root/.ethereum{{if .Ethashdir}}
      - {{.Ethashdir}}:/root/.ethash{{end}}
    environment:
      - FULL_PORT={{.FullPort}}/tcp
      - LIGHT_PORT={{.LightPort}}/udp
      - TOTAL_PEERS={{.TotalPeers}}
      - LIGHT_PEERS={{.LightPeers}}
      - STATS_NAME={{.Ethstats}}
      - MINER_NAME={{.Etherbase}}
      - GAS_TARGET={{.GasTarget}}
      - GAS_PRICE={{.GasPrice}}
    logging:
      driver: "json-file"
      options:
        max-size: "1m"
        max-file: "10"
    restart: always
`

// deployNode deploys a new Ethereum node container to a remote machine via SSH,
// docker and docker-compose. If an instance with the specified network name
// already exists there, it will be overwritten!
func deployNode(client *sshClient, network string, bootv4, bootv5 []string, config *nodeInfos, nocache bool) ([]byte, error) {
	kind := "sealnode"
	if config.keyJSON == "" && config.etherbase == "" {
		kind = "bootnode"
		bootv4 = make([]string, 0)
		bootv5 = make([]string, 0)
	}
	// Generate the content to upload to the server
	workdir := fmt.Sprintf("%d", rand.Int63())
	files := make(map[string][]byte)

	lightFlag := ""
	if config.peersLight > 0 {
		lightFlag = fmt.Sprintf("--lightpeers=%d --lightserv=50", config.peersLight)
	}
	dockerfile := new(bytes.Buffer)
	template.Must(template.New("").Parse(nodeDockerfile)).Execute(dockerfile, map[string]interface{}{
		"NetworkID": config.network,
		"Port":      config.portFull,
		"Peers":     config.peersTotal,
		"LightFlag": lightFlag,
		"BootV4":    strings.Join(bootv4, ","),
		"BootV5":    strings.Join(bootv5, ","),
		"Ethstats":  config.ethstats,
		"Etherbase": config.etherbase,
		"GasTarget": uint64(1000000 * config.gasTarget),
		"GasPrice":  uint64(1000000000 * config.gasPrice),
		"Unlock":    config.keyJSON != "",
	})
	files[filepath.Join(workdir, "Dockerfile")] = dockerfile.Bytes()

	composefile := new(bytes.Buffer)
	template.Must(template.New("").Parse(nodeComposefile)).Execute(composefile, map[string]interface{}{
		"Type":       kind,
		"Datadir":    config.datadir,
		"Ethashdir":  config.ethashdir,
		"Network":    network,
		"FullPort":   config.portFull,
		"TotalPeers": config.peersTotal,
		"Light":      config.peersLight > 0,
		"LightPort":  config.portFull + 1,
		"LightPeers": config.peersLight,
		"Ethstats":   config.ethstats[:strings.Index(config.ethstats, ":")],
		"Etherbase":  config.etherbase,
		"GasTarget":  config.gasTarget,
		"GasPrice":   config.gasPrice,
	})
	files[filepath.Join(workdir, "docker-compose.yaml")] = composefile.Bytes()

	files[filepath.Join(workdir, "genesis.json")] = config.genesis
	if config.keyJSON != "" {
		files[filepath.Join(workdir, "signer.json")] = []byte(config.keyJSON)
		files[filepath.Join(workdir, "signer.pass")] = []byte(config.keyPass)
	}
	// Upload the deployment files to the remote server (and clean up afterwards)
	if out, err := client.Upload(files); err != nil {
		return out, err
	}
	defer client.Run("rm -rf " + workdir)

	// Build and deploy the boot or seal node service
	if nocache {
		return nil, client.Stream(fmt.Sprintf("cd %s && docker-compose -p %s build --pull --no-cache && docker-compose -p %s up -d --force-recreate", workdir, network, network))
	}
	return nil, client.Stream(fmt.Sprintf("cd %s && docker-compose -p %s up -d --build --force-recreate", workdir, network))
}

// nodeInfos is returned from a boot or seal node status check to allow reporting
// various configuration parameters.
type nodeInfos struct {
	genesis    []byte
	network    int64
	datadir    string
	ethashdir  string
	ethstats   string
	portFull   int
	portLight  int
	enodeFull  string
	enodeLight string
	peersTotal int
	peersLight int
	etherbase  string
	keyJSON    string
	keyPass    string
	gasTarget  float64
	gasPrice   float64
}

// Report converts the typed struct into a plain string->string map, cotnaining
// most - but not all - fields for reporting to the user.
func (info *nodeInfos) Report() map[string]string {
	report := map[string]string{
		"Data directory":             info.datadir,
		"Listener port (full nodes)": strconv.Itoa(info.portFull),
		"Peer count (all total)":     strconv.Itoa(info.peersTotal),
		"Peer count (light nodes)":   strconv.Itoa(info.peersLight),
		"Ethstats username":          info.ethstats,
	}
	if info.peersLight > 0 {
		// Light server enabled
		report["Listener port (light nodes)"] = strconv.Itoa(info.portLight)
	}
	if info.gasTarget > 0 {
		// Miner or signer node
		report["Gas limit (baseline target)"] = fmt.Sprintf("%0.3f MGas", info.gasTarget)
		report["Gas price (minimum accepted)"] = fmt.Sprintf("%0.3f GWei", info.gasPrice)

		if info.etherbase != "" {
			// Ethash proof-of-work miner
			report["Ethash directory"] = info.ethashdir
			report["Miner account"] = info.etherbase
		}
		if info.keyJSON != "" {
			// Clique proof-of-authority signer
			var key struct {
				Address string `json:"address"`
			}
			if err := json.Unmarshal([]byte(info.keyJSON), &key); err == nil {
				report["Signer account"] = common.HexToAddress(key.Address).Hex()
			} else {
				log.Error("Failed to retrieve signer address", "err", err)
			}
		}
	}
	return report
}

// checkNode does a health-check against an boot or seal node server to verify
// whether it's running, and if yes, whether it's responsive.
func checkNode(client *sshClient, network string, boot bool) (*nodeInfos, error) {
	kind := "bootnode"
	if !boot {
		kind = "sealnode"
	}
	// Inspect a possible bootnode container on the host
	infos, err := inspectContainer(client, fmt.Sprintf("%s_%s_1", network, kind))
	if err != nil {
		return nil, err
	}
	if !infos.running {
		return nil, ErrServiceOffline
	}
	// Resolve a few types from the environmental variables
	totalPeers, _ := strconv.Atoi(infos.envvars["TOTAL_PEERS"])
	lightPeers, _ := strconv.Atoi(infos.envvars["LIGHT_PEERS"])
	gasTarget, _ := strconv.ParseFloat(infos.envvars["GAS_TARGET"], 64)
	gasPrice, _ := strconv.ParseFloat(infos.envvars["GAS_PRICE"], 64)

	// Container available, retrieve its node ID and its genesis json
	var out []byte
	if out, err = client.Run(fmt.Sprintf("docker exec %s_%s_1 geth --exec admin.nodeInfo.id attach", network, kind)); err != nil {
		return nil, ErrServiceUnreachable
	}
	id := bytes.Trim(bytes.TrimSpace(out), "\"")

	if out, err = client.Run(fmt.Sprintf("docker exec %s_%s_1 cat /genesis.json", network, kind)); err != nil {
		return nil, ErrServiceUnreachable
	}
	genesis := bytes.TrimSpace(out)

	keyJSON, keyPass := "", ""
	if out, err = client.Run(fmt.Sprintf("docker exec %s_%s_1 cat /signer.json", network, kind)); err == nil {
		keyJSON = string(bytes.TrimSpace(out))
	}
	if out, err = client.Run(fmt.Sprintf("docker exec %s_%s_1 cat /signer.pass", network, kind)); err == nil {
		keyPass = string(bytes.TrimSpace(out))
	}
	// Run a sanity check to see if the devp2p is reachable
	port := infos.portmap[infos.envvars["FULL_PORT"]]
	if err = checkPort(client.server, port); err != nil {
		log.Warn(fmt.Sprintf("%s devp2p port seems unreachable", strings.Title(kind)), "server", client.server, "port", port, "err", err)
	}
	// Assemble and return the useful infos
	stats := &nodeInfos{
		genesis:    genesis,
		datadir:    infos.volumes["/root/.ethereum"],
		ethashdir:  infos.volumes["/root/.ethash"],
		portFull:   infos.portmap[infos.envvars["FULL_PORT"]],
		portLight:  infos.portmap[infos.envvars["LIGHT_PORT"]],
		peersTotal: totalPeers,
		peersLight: lightPeers,
		ethstats:   infos.envvars["STATS_NAME"],
		etherbase:  infos.envvars["MINER_NAME"],
		keyJSON:    keyJSON,
		keyPass:    keyPass,
		gasTarget:  gasTarget,
		gasPrice:   gasPrice,
	}
	stats.enodeFull = fmt.Sprintf("enode://%s@%s:%d", id, client.address, stats.portFull)
	if stats.portLight != 0 {
		stats.enodeLight = fmt.Sprintf("enode://%s@%s:%d?discport=%d", id, client.address, stats.portFull, stats.portLight)
	}
	return stats, nil
}