// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information

// Package testplanet implements the full network wiring for testing
package testplanet

import (
	"context"
	"errors"
	"io"
	"io/ioutil"
	"net"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/zeebo/errs"
	"go.uber.org/zap"
	"go.uber.org/zap/zaptest"
	"google.golang.org/grpc"

	"storj.io/storj/internal/memory"
	"storj.io/storj/pkg/bwagreement"
	"storj.io/storj/pkg/datarepair/checker"
	"storj.io/storj/pkg/datarepair/repairer"
	"storj.io/storj/pkg/discovery"
	"storj.io/storj/pkg/kademlia"
	"storj.io/storj/pkg/node"
	"storj.io/storj/pkg/overlay"
	"storj.io/storj/pkg/pb"
	"storj.io/storj/pkg/piecestore/psserver"
	"storj.io/storj/pkg/pointerdb"
	"storj.io/storj/pkg/provider"
	"storj.io/storj/pkg/storj"
	"storj.io/storj/pkg/utils"
	"storj.io/storj/satellite"
	"storj.io/storj/satellite/satellitedb"
	"storj.io/storj/storagenode"
	"storj.io/storj/storagenode/storagenodedb"
)

// Peer represents one of StorageNode or Satellite
type Peer interface {
	ID() storj.NodeID
	Addr() string
	Local() pb.Node

	Run(context.Context) error
	Close() error

	NewNodeClient() (node.Client, error)
}

// Planet is a full storj system setup.
type Planet struct {
	log       *zap.Logger
	directory string // TODO: ensure that everything is in-memory to speed things up
	started   bool

	peers     []Peer
	databases []io.Closer

	nodeInfos []pb.Node
	nodes     []*Node

	Satellites   []*satellite.Peer
	StorageNodes []*storagenode.Peer
	Uplinks      []*Node

	identities *Identities
}

// New creates a new full system with the given number of nodes.
func New(t zaptest.TestingT, satelliteCount, storageNodeCount, uplinkCount int) (*Planet, error) {
	var log *zap.Logger
	if t == nil {
		log = zap.NewNop()
	} else {
		log = zaptest.NewLogger(t)
	}

	return NewWithLogger(log, satelliteCount, storageNodeCount, uplinkCount)
}

// NewWithLogger creates a new full system with the given number of nodes.
func NewWithLogger(log *zap.Logger, satelliteCount, storageNodeCount, uplinkCount int) (*Planet, error) {
	planet := &Planet{
		log:        log,
		identities: NewPregeneratedIdentities(),
	}

	var err error
	planet.directory, err = ioutil.TempDir("", "planet")
	if err != nil {
		return nil, err
	}

	planet.Satellites, err = planet.newSatellites(satelliteCount)
	if err != nil {
		return nil, utils.CombineErrors(err, planet.Shutdown())
	}

	planet.StorageNodes, err = planet.newStorageNodes(storageNodeCount)
	if err != nil {
		return nil, utils.CombineErrors(err, planet.Shutdown())
	}

	planet.Uplinks, err = planet.newUplinks("uplink", uplinkCount)
	if err != nil {
		return nil, utils.CombineErrors(err, planet.Shutdown())
	}

	// init Satellites
	for _, satellite := range planet.Satellites {
		satellite.Kademlia.Service.SetBootstrapNodes(planet.nodeInfos)
	}
	// init storage nodes
	for _, storageNode := range planet.StorageNodes {
		storageNode.Kademlia.SetBootstrapNodes(planet.nodeInfos)
	}

	return planet, nil
}

// Start starts all the nodes.
func (planet *Planet) Start(ctx context.Context) {
	for _, peer := range planet.peers {
		go func(peer Peer) {
			err := peer.Run(ctx)
			if err == grpc.ErrServerStopped {
				err = nil
			}
			if err != nil {
				// TODO: better error handling
				panic(err)
			}
		}(peer)
	}

	planet.started = true
}

// Size returns number of nodes in the network
func (planet *Planet) Size() int { return len(planet.nodes) + len(planet.peers) }

// Shutdown shuts down all the nodes and deletes temporary directories.
func (planet *Planet) Shutdown() error {
	var errlist errs.Group
	if !planet.started {
		errlist.Add(errors.New("Start was never called"))
	}

	// shutdown in reverse order
	for i := len(planet.nodes) - 1; i >= 0; i-- {
		node := planet.nodes[i]
		errlist.Add(node.Shutdown())
	}
	for i := len(planet.peers) - 1; i >= 0; i-- {
		peer := planet.peers[i]
		errlist.Add(peer.Close())
	}
	for _, db := range planet.databases {
		errlist.Add(db.Close())
	}

	errlist.Add(os.RemoveAll(planet.directory))
	return errlist.Err()
}

// newUplinks creates initializes uplinks
func (planet *Planet) newUplinks(prefix string, count int) ([]*Node, error) {
	var xs []*Node
	for i := 0; i < count; i++ {
		node, err := planet.newUplink(prefix + strconv.Itoa(i))
		if err != nil {
			return nil, err
		}
		xs = append(xs, node)
	}

	return xs, nil
}

// newSatellites initializes satellites
func (planet *Planet) newSatellites(count int) ([]*satellite.Peer, error) {
	var xs []*satellite.Peer
	defer func() {
		for _, x := range xs {
			planet.peers = append(planet.peers, x)
			planet.nodeInfos = append(planet.nodeInfos, x.Local())
		}
	}()

	for i := 0; i < count; i++ {
		prefix := "satellite" + strconv.Itoa(i)
		log := planet.log.Named(prefix)

		storageDir := filepath.Join(planet.directory, prefix)
		if err := os.MkdirAll(storageDir, 0700); err != nil {
			return nil, err
		}

		identity, err := planet.NewIdentity()
		if err != nil {
			return nil, err
		}

		db, err := satellitedb.NewInMemory()
		if err != nil {
			return nil, err
		}

		err = db.CreateTables()
		if err != nil {
			return nil, err
		}

		planet.databases = append(planet.databases, db)

		config := satellite.Config{
			PublicAddress: "127.0.0.1:0",
			Kademlia: kademlia.Config{
				Alpha:  5,
				DBPath: storageDir, // TODO: replace with master db
				Operator: kademlia.OperatorConfig{
					Email:  prefix + "@example.com",
					Wallet: "0x" + strings.Repeat("00", 20),
				},
			},
			Overlay: overlay.Config{
				RefreshInterval: 30 * time.Second,
				Node: overlay.NodeSelectionConfig{
					UptimeRatio:       0,
					UptimeCount:       0,
					AuditSuccessRatio: 0,
					AuditCount:        0,
				},
			},
			Discovery: discovery.Config{
				RefreshInterval: 1 * time.Second,
			},
			PointerDB: pointerdb.Config{
				DatabaseURL:          "bolt://" + filepath.Join(storageDir, "pointers.db"),
				MinRemoteSegmentSize: 0, // TODO: fix tests to work with 1024
				MaxInlineSegmentSize: 8000,
				Overlay:              true,
				BwExpiration:         45,
			},
			BwAgreement: bwagreement.Config{},
			Checker: checker.Config{
				Interval: 30 * time.Second,
			},
			Repairer: repairer.Config{
				MaxRepair:     10,
				Interval:      time.Hour,
				OverlayAddr:   "", // overridden in satellite.New
				PointerDBAddr: "", // overridden in satellite.New
				MaxBufferMem:  4 * memory.MB,
				APIKey:        "",
			},
			// TODO: Audit    audit.Config
		}

		peer, err := satellite.New(log, identity, db, &config)
		if err != nil {
			return xs, err
		}

		log.Debug("id=" + peer.ID().String() + " addr=" + peer.Addr())
		xs = append(xs, peer)
	}
	return xs, nil
}

// newStorageNodes initializes storage nodes
func (planet *Planet) newStorageNodes(count int) ([]*storagenode.Peer, error) {
	var xs []*storagenode.Peer
	defer func() {
		for _, x := range xs {
			planet.peers = append(planet.peers, x)
			planet.nodeInfos = append(planet.nodeInfos, x.Local())
		}
	}()

	for i := 0; i < count; i++ {
		prefix := "storage" + strconv.Itoa(i)
		log := planet.log.Named(prefix)
		storageDir := filepath.Join(planet.directory, prefix)

		if err := os.MkdirAll(storageDir, 0700); err != nil {
			return nil, err
		}

		identity, err := planet.NewIdentity()
		if err != nil {
			return nil, err
		}

		db, err := storagenodedb.NewInMemory(storageDir)
		if err != nil {
			return nil, err
		}

		// TODO: err = db.CreateTables()
		// if err != nil {
		// 	return nil, err
		// }

		planet.databases = append(planet.databases, db)

		config := storagenode.Config{
			PublicAddress: "127.0.0.1:0",
			Kademlia: kademlia.Config{
				Alpha:  5,
				DBPath: storageDir, // TODO: replace with master db
				Operator: kademlia.OperatorConfig{
					Email:  prefix + "@example.com",
					Wallet: "0x" + strings.Repeat("00", 20),
				},
			},
			Storage: psserver.Config{
				Path:                   "", // TODO: this argument won't be needed with master storagenodedb
				AllocatedDiskSpace:     memory.TB,
				AllocatedBandwidth:     memory.TB,
				KBucketRefreshInterval: time.Minute,
			},
		}

		peer, err := storagenode.New(log, identity, db, config)
		if err != nil {
			return xs, err
		}

		log.Debug("id=" + peer.ID().String() + " addr=" + peer.Addr())
		xs = append(xs, peer)
	}
	return xs, nil
}

// NewIdentity creates a new identity for a node
func (planet *Planet) NewIdentity() (*provider.FullIdentity, error) {
	return planet.identities.NewIdentity()
}

// NewListener creates a new listener
func (planet *Planet) NewListener() (net.Listener, error) {
	return net.Listen("tcp", "127.0.0.1:0")
}