// Copyright (C) 2019 Storj Labs, Inc.
// See LICENSE for copying information.

package satellite

import (
	"context"
	"fmt"
	"net"
	"net/http"
	"net/mail"
	"net/smtp"
	"os"
	"path/filepath"
	"time"

	"github.com/zeebo/errs"
	"go.uber.org/zap"
	"golang.org/x/sync/errgroup"
	"google.golang.org/grpc"

	"storj.io/storj/internal/post"
	"storj.io/storj/internal/post/oauth2"
	"storj.io/storj/pkg/accounting"
	"storj.io/storj/pkg/accounting/rollup"
	"storj.io/storj/pkg/accounting/tally"
	"storj.io/storj/pkg/audit"
	"storj.io/storj/pkg/auth/grpcauth"
	"storj.io/storj/pkg/auth/signing"
	"storj.io/storj/pkg/bwagreement"
	"storj.io/storj/pkg/certdb"
	"storj.io/storj/pkg/datarepair/checker"
	"storj.io/storj/pkg/datarepair/irreparable"
	"storj.io/storj/pkg/datarepair/queue"
	"storj.io/storj/pkg/datarepair/repairer"
	"storj.io/storj/pkg/discovery"
	"storj.io/storj/pkg/identity"
	"storj.io/storj/pkg/kademlia"
	"storj.io/storj/pkg/overlay"
	"storj.io/storj/pkg/pb"
	"storj.io/storj/pkg/peertls/tlsopts"
	"storj.io/storj/pkg/pointerdb"
	"storj.io/storj/pkg/server"
	"storj.io/storj/pkg/statdb"
	"storj.io/storj/pkg/storj"
	"storj.io/storj/pkg/transport"
	"storj.io/storj/satellite/console"
	"storj.io/storj/satellite/console/consoleauth"
	"storj.io/storj/satellite/console/consoleweb"
	"storj.io/storj/satellite/mailservice"
	"storj.io/storj/satellite/mailservice/simulate"
	"storj.io/storj/satellite/metainfo"
	"storj.io/storj/storage"
	"storj.io/storj/storage/boltdb"
	"storj.io/storj/storage/storelogger"
)

// DB is the master database for the satellite
type DB interface {
	// CreateTables initializes the database
	CreateTables() error
	// Close closes the database
	Close() error

	// CreateSchema sets the schema
	CreateSchema(schema string) error
	// DropSchema drops the schema
	DropSchema(schema string) error

	// BandwidthAgreement returns database for storing bandwidth agreements
	BandwidthAgreement() bwagreement.DB
	// CertDB returns database for storing uplink's public key & ID
	CertDB() certdb.DB
	// StatDB returns database for storing node statistics
	StatDB() statdb.DB
	// OverlayCache returns database for caching overlay information
	OverlayCache() overlay.DB
	// Accounting returns database for storing information about data use
	Accounting() accounting.DB
	// RepairQueue returns queue for segments that need repairing
	RepairQueue() queue.RepairQueue
	// Irreparable returns database for failed repairs
	Irreparable() irreparable.DB
	// Console returns database for satellite console
	Console() console.DB
}

// Config is the global config satellite
type Config struct {
	Identity identity.Config

	// TODO: switch to using server.Config when Identity has been removed from it
	Server server.Config

	Kademlia  kademlia.Config
	Overlay   overlay.Config
	Discovery discovery.Config

	PointerDB   pointerdb.Config
	BwAgreement bwagreement.Config // TODO: decide whether to keep empty configs for consistency

	Checker  checker.Config
	Repairer repairer.Config
	Audit    audit.Config

	Tally  tally.Config
	Rollup rollup.Config

	Mail    mailservice.Config
	Console consoleweb.Config
}

// Peer is the satellite
type Peer struct {
	// core dependencies
	Log      *zap.Logger
	Identity *identity.FullIdentity
	DB       DB

	Transport transport.Client

	Server *server.Server

	// services and endpoints
	Kademlia struct {
		kdb, ndb storage.KeyValueStore // TODO: move these into DB

		RoutingTable *kademlia.RoutingTable
		Service      *kademlia.Kademlia
		Endpoint     *kademlia.Endpoint
		Inspector    *kademlia.Inspector
	}

	Overlay struct {
		Service   *overlay.Cache
		Endpoint  *overlay.Server
		Inspector *overlay.Inspector
	}

	Discovery struct {
		Service *discovery.Discovery
	}

	Reputation struct {
		Inspector *statdb.Inspector
	}

	Metainfo struct {
		Database   storage.KeyValueStore // TODO: move into pointerDB
		Allocation *pointerdb.AllocationSigner
		Service    *pointerdb.Service
		Endpoint   *pointerdb.Server
		Endpoint2  *metainfo.Endpoint
	}

	Agreements struct {
		Endpoint *bwagreement.Server
	}

	Repair struct {
		Checker   *checker.Checker
		Repairer  *repairer.Service
		Inspector *irreparable.Inspector
	}
	Audit struct {
		Service *audit.Service
	}

	Accounting struct {
		Tally  *tally.Tally
		Rollup *rollup.Rollup
	}

	Mail struct {
		Service *mailservice.Service
	}

	Console struct {
		Listener net.Listener
		Service  *console.Service
		Endpoint *consoleweb.Server
	}
}

// New creates a new satellite
func New(log *zap.Logger, full *identity.FullIdentity, db DB, config *Config) (*Peer, error) {
	peer := &Peer{
		Log:      log,
		Identity: full,
		DB:       db,
	}

	var err error

	{ // setup listener and server
		log.Debug("Starting listener and server")
		sc := config.Server
		options, err := tlsopts.NewOptions(peer.Identity, sc.Config)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		peer.Transport = transport.NewClient(options)

		peer.Server, err = server.New(options, sc.Address, sc.PrivateAddress, grpcauth.NewAPIKeyInterceptor())
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}
	}

	{ // setup overlay
		log.Debug("Starting overlay")
		config := config.Overlay
		peer.Overlay.Service = overlay.NewCache(peer.DB.OverlayCache(), peer.DB.StatDB())

		peer.Transport = peer.Transport.WithObservers(peer.Overlay.Service)

		nodeSelectionConfig := &overlay.NodeSelectionConfig{
			UptimeCount:           config.Node.UptimeCount,
			UptimeRatio:           config.Node.UptimeRatio,
			AuditSuccessRatio:     config.Node.AuditSuccessRatio,
			AuditCount:            config.Node.AuditCount,
			NewNodeAuditThreshold: config.Node.NewNodeAuditThreshold,
			NewNodePercentage:     config.Node.NewNodePercentage,
		}

		peer.Overlay.Endpoint = overlay.NewServer(peer.Log.Named("overlay:endpoint"), peer.Overlay.Service, nodeSelectionConfig)
		pb.RegisterOverlayServer(peer.Server.GRPC(), peer.Overlay.Endpoint)

		peer.Overlay.Inspector = overlay.NewInspector(peer.Overlay.Service)
		pb.RegisterOverlayInspectorServer(peer.Server.PrivateGRPC(), peer.Overlay.Inspector)
	}

	{ // setup kademlia
		log.Debug("Setting up Kademlia")
		config := config.Kademlia
		// TODO: move this setup logic into kademlia package
		if config.ExternalAddress == "" {
			config.ExternalAddress = peer.Addr()
		}

		self := pb.Node{
			Id:   peer.ID(),
			Type: pb.NodeType_SATELLITE,
			Address: &pb.NodeAddress{
				Address: config.ExternalAddress,
			},
			Metadata: &pb.NodeMetadata{
				Wallet: config.Operator.Wallet,
			},
		}

		{ // setup routing table
			// TODO: clean this up, should be part of database
			log.Debug("Setting up routing table")
			bucketIdentifier := peer.ID().String()[:5] // need a way to differentiate between nodes if running more than one simultaneously
			dbpath := filepath.Join(config.DBPath, fmt.Sprintf("kademlia_%s.db", bucketIdentifier))

			if err := os.MkdirAll(config.DBPath, 0777); err != nil && !os.IsExist(err) {
				return nil, err
			}

			dbs, err := boltdb.NewShared(dbpath, kademlia.KademliaBucket, kademlia.NodeBucket)
			if err != nil {
				return nil, errs.Combine(err, peer.Close())
			}
			peer.Kademlia.kdb, peer.Kademlia.ndb = dbs[0], dbs[1]

			peer.Kademlia.RoutingTable, err = kademlia.NewRoutingTable(peer.Log.Named("routing"), self, peer.Kademlia.kdb, peer.Kademlia.ndb, &config.RoutingTableConfig)
			if err != nil {
				return nil, errs.Combine(err, peer.Close())
			}

			peer.Transport = peer.Transport.WithObservers(peer.Kademlia.RoutingTable)
		}

		peer.Kademlia.Service, err = kademlia.NewService(peer.Log.Named("kademlia"), self, peer.Transport, peer.Kademlia.RoutingTable, config)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		peer.Kademlia.Endpoint = kademlia.NewEndpoint(peer.Log.Named("kademlia:endpoint"), peer.Kademlia.Service, peer.Kademlia.RoutingTable, 60*time.Second)
		pb.RegisterNodesServer(peer.Server.GRPC(), peer.Kademlia.Endpoint)

		peer.Kademlia.Inspector = kademlia.NewInspector(peer.Kademlia.Service, peer.Identity)
		pb.RegisterKadInspectorServer(peer.Server.PrivateGRPC(), peer.Kademlia.Inspector)
	}

	{ // setup reputation
		log.Debug("Setting up reputation")
		// TODO: find better structure with overlay
		peer.Reputation.Inspector = statdb.NewInspector(peer.DB.StatDB())
		pb.RegisterStatDBInspectorServer(peer.Server.PrivateGRPC(), peer.Reputation.Inspector)
	}

	{ // setup discovery
		log.Debug("Setting up discovery")
		config := config.Discovery
		peer.Discovery.Service = discovery.New(peer.Log.Named("discovery"), peer.Overlay.Service, peer.Kademlia.Service, peer.DB.StatDB(), config)
	}

	{ // setup metainfo
		log.Debug("Setting up metainfo")
		db, err := pointerdb.NewStore(config.PointerDB.DatabaseURL)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		peer.Metainfo.Database = storelogger.New(peer.Log.Named("pdb"), db)
		peer.Metainfo.Service = pointerdb.NewService(peer.Log.Named("pointerdb"), peer.Metainfo.Database)
		peer.Metainfo.Allocation = pointerdb.NewAllocationSigner(peer.Identity, config.PointerDB.BwExpiration, peer.DB.CertDB())
		peer.Metainfo.Endpoint = pointerdb.NewServer(peer.Log.Named("pointerdb:endpoint"),
			peer.Metainfo.Service,
			peer.Metainfo.Allocation,
			peer.Overlay.Service,
			config.PointerDB,
			peer.Identity, peer.DB.Console().APIKeys())

		// TODO remove duplicated code
		overlayConfig := config.Overlay
		nodeSelectionConfig := &overlay.NodeSelectionConfig{
			UptimeCount:           overlayConfig.Node.UptimeCount,
			UptimeRatio:           overlayConfig.Node.UptimeRatio,
			AuditSuccessRatio:     overlayConfig.Node.AuditSuccessRatio,
			AuditCount:            overlayConfig.Node.AuditCount,
			NewNodeAuditThreshold: overlayConfig.Node.NewNodeAuditThreshold,
			NewNodePercentage:     overlayConfig.Node.NewNodePercentage,
		}

		peer.Metainfo.Endpoint2 = metainfo.NewEndpoint(
			peer.Log.Named("metainfo:endpoint"),
			peer.Metainfo.Service,
			peer.Metainfo.Allocation,
			peer.Overlay.Service,
			peer.DB.Console().APIKeys(),
			signing.SignerFromFullIdentity(peer.Identity),
			nodeSelectionConfig)

		pb.RegisterPointerDBServer(peer.Server.GRPC(), peer.Metainfo.Endpoint)

		pb.RegisterMetainfoServer(peer.Server.GRPC(), peer.Metainfo.Endpoint2)
	}

	{ // setup agreements
		log.Debug("Setting up agreements")
		bwServer := bwagreement.NewServer(peer.DB.BandwidthAgreement(), peer.DB.CertDB(), peer.Identity.Leaf.PublicKey, peer.Log.Named("agreements"), peer.Identity.ID)
		peer.Agreements.Endpoint = bwServer
		pb.RegisterBandwidthServer(peer.Server.GRPC(), peer.Agreements.Endpoint)
	}

	{ // setup datarepair
		log.Debug("Setting up datarepair")
		// TODO: simplify argument list somehow
		peer.Repair.Checker = checker.NewChecker(
			peer.Metainfo.Service,
			peer.DB.StatDB(), peer.DB.RepairQueue(),
			peer.Overlay.Endpoint, peer.DB.Irreparable(),
			0, peer.Log.Named("checker"),
			config.Checker.Interval)

		// TODO remove duplicated code
		overlayConfig := config.Overlay
		nodeSelectionConfig := &overlay.NodeSelectionConfig{
			UptimeCount:           overlayConfig.Node.UptimeCount,
			UptimeRatio:           overlayConfig.Node.UptimeRatio,
			AuditSuccessRatio:     overlayConfig.Node.AuditSuccessRatio,
			AuditCount:            overlayConfig.Node.AuditCount,
			NewNodeAuditThreshold: overlayConfig.Node.NewNodeAuditThreshold,
			NewNodePercentage:     overlayConfig.Node.NewNodePercentage,
		}

		peer.Repair.Repairer = repairer.NewService(
			peer.DB.RepairQueue(),
			&config.Repairer,
			config.Repairer.Interval,
			config.Repairer.MaxRepair,
			peer.Transport,
			peer.Metainfo.Service,
			peer.Metainfo.Allocation,
			peer.Overlay.Service,
			signing.SignerFromFullIdentity(peer.Identity),
			nodeSelectionConfig,
		)

		peer.Repair.Inspector = irreparable.NewInspector(peer.DB.Irreparable())
		pb.RegisterIrreparableInspectorServer(peer.Server.PrivateGRPC(), peer.Repair.Inspector)
	}

	{ // setup audit
		log.Debug("Setting up audits")
		config := config.Audit

		peer.Audit.Service, err = audit.NewService(peer.Log.Named("audit"),
			config,
			peer.DB.StatDB(),
			peer.Metainfo.Service, peer.Metainfo.Allocation,
			peer.Transport, peer.Overlay.Service,
			peer.Identity,
		)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}
	}

	{ // setup accounting
		log.Debug("Setting up accounting")
		peer.Accounting.Tally = tally.New(peer.Log.Named("tally"), peer.DB.Accounting(), peer.DB.BandwidthAgreement(), peer.Metainfo.Service, peer.Overlay.Endpoint, 0, config.Tally.Interval)
		peer.Accounting.Rollup = rollup.New(peer.Log.Named("rollup"), peer.DB.Accounting(), config.Rollup.Interval)
	}

	{ // setup mailservice
		log.Debug("Setting up mail service")
		// TODO(yar): test multiple satellites using same OAUTH credentials
		mailConfig := config.Mail

		// validate from mail address
		from, err := mail.ParseAddress(mailConfig.From)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		// validate smtp server address
		host, _, err := net.SplitHostPort(mailConfig.SMTPServerAddress)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		var sender mailservice.Sender
		switch mailConfig.AuthType {
		case "oauth2":
			creds := oauth2.Credentials{
				ClientID:     mailConfig.ClientID,
				ClientSecret: mailConfig.ClientSecret,
				TokenURI:     mailConfig.TokenURI,
			}
			token, err := oauth2.RefreshToken(creds, mailConfig.RefreshToken)
			if err != nil {
				return nil, errs.Combine(err, peer.Close())
			}

			sender = &post.SMTPSender{
				From: *from,
				Auth: &oauth2.Auth{
					UserEmail: from.Address,
					Storage:   oauth2.NewTokenStore(creds, *token),
				},
				ServerAddress: mailConfig.SMTPServerAddress,
			}
		case "plain":
			sender = &post.SMTPSender{
				From:          *from,
				Auth:          smtp.PlainAuth("", mailConfig.PlainLogin, mailConfig.PlainPassword, host),
				ServerAddress: mailConfig.SMTPServerAddress,
			}
		default:
			sender = &simulate.LinkClicker{}
		}

		peer.Mail.Service, err = mailservice.New(
			peer.Log.Named("mailservice:service"),
			sender,
			mailConfig.TemplatePath,
		)

		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}
	}

	{ // setup console
		log.Debug("Setting up console")
		consoleConfig := config.Console

		peer.Console.Listener, err = net.Listen("tcp", consoleConfig.Address)
		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		peer.Console.Service, err = console.NewService(
			peer.Log.Named("console:service"),
			// TODO(yar): use satellite key
			&consoleauth.Hmac{Secret: []byte("my-suppa-secret-key")},
			peer.DB.Console(),
			consoleConfig.PasswordCost,
		)

		if err != nil {
			return nil, errs.Combine(err, peer.Close())
		}

		peer.Console.Endpoint = consoleweb.NewServer(
			peer.Log.Named("console:endpoint"),
			consoleConfig,
			peer.Console.Service,
			peer.Mail.Service,
			peer.Console.Listener,
		)
	}

	return peer, nil
}

func ignoreCancel(err error) error {
	if err == context.Canceled || err == grpc.ErrServerStopped || err == http.ErrServerClosed {
		return nil
	}
	return err
}

// Run runs storage node until it's either closed or it errors.
func (peer *Peer) Run(ctx context.Context) error {
	group, ctx := errgroup.WithContext(ctx)

	group.Go(func() error {
		return ignoreCancel(peer.Kademlia.Service.Bootstrap(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Kademlia.Service.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Discovery.Service.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Repair.Checker.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Repair.Repairer.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Accounting.Tally.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Accounting.Rollup.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Audit.Service.Run(ctx))
	})
	group.Go(func() error {
		// TODO: move the message into Server instead
		// Don't change the format of this comment, it is used to figure out the node id.
		peer.Log.Sugar().Infof("Node %s started", peer.Identity.ID)
		peer.Log.Sugar().Infof("Public server started on %s", peer.Addr())
		peer.Log.Sugar().Infof("Private server started on %s", peer.PrivateAddr())
		return ignoreCancel(peer.Server.Run(ctx))
	})
	group.Go(func() error {
		return ignoreCancel(peer.Console.Endpoint.Run(ctx))
	})

	return group.Wait()
}

// Close closes all the resources.
func (peer *Peer) Close() error {
	var errlist errs.Group

	// TODO: ensure that Close can be called on nil-s that way this code won't need the checks.

	// close servers, to avoid new connections to closing subsystems
	if peer.Server != nil {
		errlist.Add(peer.Server.Close())
	}

	if peer.Console.Endpoint != nil {
		errlist.Add(peer.Console.Endpoint.Close())
	} else {
		if peer.Console.Listener != nil {
			errlist.Add(peer.Console.Listener.Close())
		}
	}

	// close services in reverse initialization order
	if peer.Repair.Repairer != nil {
		errlist.Add(peer.Repair.Repairer.Close())
	}
	if peer.Repair.Checker != nil {
		errlist.Add(peer.Repair.Checker.Close())
	}

	if peer.Agreements.Endpoint != nil {
		errlist.Add(peer.Agreements.Endpoint.Close())
	}

	if peer.Metainfo.Endpoint != nil {
		errlist.Add(peer.Metainfo.Endpoint.Close())
	}
	if peer.Metainfo.Database != nil {
		errlist.Add(peer.Metainfo.Database.Close())
	}

	if peer.Discovery.Service != nil {
		errlist.Add(peer.Discovery.Service.Close())
	}

	// TODO: add kademlia.Endpoint for consistency
	if peer.Kademlia.Service != nil {
		errlist.Add(peer.Kademlia.Service.Close())
	}
	if peer.Kademlia.RoutingTable != nil {
		errlist.Add(peer.Kademlia.RoutingTable.Close())
	}

	if peer.Overlay.Endpoint != nil {
		errlist.Add(peer.Overlay.Endpoint.Close())
	}
	if peer.Overlay.Service != nil {
		errlist.Add(peer.Overlay.Service.Close())
	}

	if peer.Kademlia.ndb != nil || peer.Kademlia.kdb != nil {
		errlist.Add(peer.Kademlia.kdb.Close())
		errlist.Add(peer.Kademlia.ndb.Close())
	}

	return errlist.Err()
}

// ID returns the peer ID.
func (peer *Peer) ID() storj.NodeID { return peer.Identity.ID }

// Local returns the peer local node info.
func (peer *Peer) Local() pb.Node { return peer.Kademlia.RoutingTable.Local() }

// Addr returns the public address.
func (peer *Peer) Addr() string { return peer.Server.Addr().String() }

// PrivateAddr returns the private address.
func (peer *Peer) PrivateAddr() string { return peer.Server.PrivateAddr().String() }