// Copyright © 2020 Vulcanize, Inc
//
// 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 cmd

import (
	"sync"

	"github.com/ethereum/go-ethereum/rpc"
	log "github.com/sirupsen/logrus"
	"github.com/spf13/cobra"

	"github.com/vulcanize/vulcanizedb/pkg/super_node"
	"github.com/vulcanize/vulcanizedb/pkg/super_node/config"
)

// superNodeCmd represents the superNode command
var superNodeCmd = &cobra.Command{
	Use:   "superNode",
	Short: "VulcanizeDB SuperNode",
	Long: `This command works alongside a modified geth node which streams
all block and state (diff) data over a websocket subscription. This process 
then converts the eth data to IPLD objects and publishes them to IPFS. Additionally,
it maintains a local index of the IPLD objects' CIDs in Postgres. It then opens up a server which 
relays relevant data to requesting clients.`,
	Run: func(cmd *cobra.Command, args []string) {
		subCommand = cmd.CalledAs()
		logWithCommand = *log.WithField("SubCommand", subCommand)
		superNode()
	},
}

func init() {
	rootCmd.AddCommand(superNodeCmd)
}

func superNode() {
	superNode, superNodeConfig, err := newSuperNode()
	if err != nil {
		logWithCommand.Fatal(err)
	}
	wg := &sync.WaitGroup{}
	var forwardQuitChan chan bool
	var forwardPayloadChan chan interface{}
	if superNodeConfig.Serve {
		forwardQuitChan = make(chan bool)
		forwardPayloadChan = make(chan interface{}, super_node.PayloadChanBufferSize)
		superNode.ScreenAndServe(wg, forwardPayloadChan, forwardQuitChan)
		if err := startServers(superNode, superNodeConfig); err != nil {
			logWithCommand.Fatal(err)
		}
	}
	if superNodeConfig.Sync {
		if err := superNode.SyncAndPublish(wg, forwardPayloadChan, forwardQuitChan); err != nil {
			logWithCommand.Fatal(err)
		}
	}
	if superNodeConfig.BackFill {
		backFiller, err := super_node.NewBackFillService(superNodeConfig.BackFillSettings)
		if err != nil {
			logWithCommand.Fatal(err)
		}
		backFiller.FillGaps(wg, nil)
	}
}

func newSuperNode() (super_node.SuperNode, *config.SuperNode, error) {
	superNodeConfig, err := config.NewSuperNodeConfig()
	if err != nil {
		return nil, nil, err
	}
	sn, err := super_node.NewSuperNode(superNodeConfig)
	if err != nil {
		return nil, nil, err
	}
	return sn, superNodeConfig, nil
}

func startServers(superNode super_node.SuperNode, settings *config.SuperNode) error {
	_, _, err := rpc.StartIPCEndpoint(settings.IPCEndpoint, superNode.APIs())
	if err != nil {
		return err
	}
	_, _, err = rpc.StartWSEndpoint(settings.WSEndpoint, superNode.APIs(), []string{"vdb"}, nil, true)
	if err != nil {
		return err
	}
	return nil
}