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

package segment

import (
	"context"
	"fmt"
	"io"
	"time"

	"go.uber.org/zap"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	monkit "gopkg.in/spacemonkeygo/monkit.v2"

	"storj.io/storj/pkg/dht"
	"storj.io/storj/pkg/eestream"
	"storj.io/storj/pkg/paths"
	"storj.io/storj/pkg/piecestore/rpc/client"
	"storj.io/storj/pkg/ranger"
	"storj.io/storj/pkg/storage/ec"
	opb "storj.io/storj/protos/overlay"
	ppb "storj.io/storj/protos/pointerdb"
)

var (
	mon = monkit.Package()
)

// Meta describes associated Nodes and if data is Inline or Remote
type Meta struct {
	Inline bool
	Nodes  []dht.NodeID
}

// Store allows Put, Get, Delete, and List methods on paths
type Store interface {
	Put(ctx context.Context, path paths.Path, data io.Reader, metadata []byte,
		expiration time.Time) error
	Get(ctx context.Context, path paths.Path) (ranger.Ranger, Meta, error)
	Delete(ctx context.Context, path paths.Path) error
	List(ctx context.Context, startingPath, endingPath paths.Path) (
		paths []paths.Path, truncated bool, err error)
}

type segmentStore struct {
	oc opb.OverlayClient
	ec ecclient.Client
	pc ppb.PointerDBClient
	rs eestream.RedundancyStrategy
}

// NewSegmentStore creates a new instance of segmentStore
func NewSegmentStore(oc opb.OverlayClient, ec ecclient.Client, pc ppb.PointerDBClient,
	rs eestream.RedundancyStrategy) Store {
	return &segmentStore{oc: oc, ec: ec, pc: pc, rs: rs}
}

// Put uploads a file to an erasure code client
func (s *segmentStore) Put(ctx context.Context, path paths.Path, data io.Reader,
	metadata []byte, expiration time.Time) (err error) {
	defer mon.Task()(&ctx)(&err)

	// uses overlay client to request a list of nodes
	nodeRes, err := s.oc.FindStorageNodes(ctx, &opb.FindStorageNodesRequest{})
	if err != nil {
		return Error.Wrap(err)
	}

	pieceID := client.NewPieceID()

	// puts file to ecclient
	err = s.ec.Put(ctx, nodeRes.GetNodes(), s.rs, pieceID, data, expiration)
	if err != nil {
		zap.S().Error("Failed putting nodes to ecclient")
		return Error.Wrap(err)
	}

	var remotePieces []*ppb.RemotePiece
	for i := range nodeRes.Nodes {
		remotePieces = append(remotePieces, &ppb.RemotePiece{
			PieceNum: int64(i),
			NodeId:   nodeRes.Nodes[i].Id,
		})
	}

	// creates pointer
	pr := ppb.PutRequest{
		Path: []byte(fmt.Sprintf("%s", path)),
		Pointer: &ppb.Pointer{
			Type: ppb.Pointer_REMOTE,
			Remote: &ppb.RemoteSegment{
				Redundancy: &ppb.RedundancyScheme{
					Type:             ppb.RedundancyScheme_RS,
					MinReq:           int64(s.rs.RequiredCount()),
					Total:            int64(s.rs.TotalCount()),
					RepairThreshold:  int64(s.rs.Min),
					SuccessThreshold: int64(s.rs.Opt),
				},
				PieceId:      string(pieceID),
				RemotePieces: remotePieces,
			},
		},
		APIKey: nil,
	}

	// puts pointer to pointerDB
	_, err = s.pc.Put(ctx, &pr)
	if err != nil || status.Code(err) == codes.Internal {
		zap.L().Error("failed to put", zap.Error(err))
		return Error.Wrap(err)
	}
	return nil
}

// Get retrieves a file from the erasure code client with help from overlay and pointerdb
func (s *segmentStore) Get(ctx context.Context, path paths.Path) (ranger.Ranger, Meta, error) {
	m := Meta{
		Inline: true,
		Nodes:  nil,
	}
	return nil, m, nil
}

// Delete issues deletes of a file to all piece stores and deletes from pointerdb
func (s *segmentStore) Delete(ctx context.Context, path paths.Path) error {
	return nil
}

// List lists paths stored in the pointerdb
func (s *segmentStore) List(ctx context.Context, startingPath, endingPath paths.Path) (
	paths []paths.Path, truncated bool, err error) {
	return nil, true, nil
}