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

package kademlia

import (
	"context"
	"encoding/hex"
	"fmt"
	"strconv"
	"time"

	bkad "github.com/coyle/kademlia"

	"storj.io/storj/protos/overlay"
)

// RouteTable implements the RoutingTable interface
type RouteTable struct {
	ht  *bkad.HashTable
	dht *bkad.DHT
}

// NewRouteTable returns a newly configured instance of a RouteTable
func NewRouteTable(dht Kademlia) RouteTable {
	return RouteTable{
		ht:  dht.dht.HT,
		dht: dht.dht,
	}
}

// LocalID returns the local nodes ID
func (rt RouteTable) LocalID() NodeID {
	return NodeID(rt.dht.GetSelfID())
}

// K returns the currently configured maximum of nodes to store in a bucket
func (rt RouteTable) K() int {
	return rt.dht.NumNodes()
}

// CacheSize returns the total current size of the cache
func (rt RouteTable) CacheSize() int {
	// TODO: How is this calculated ? size of the routing table ? is it total bytes, mb, kb etc .?
	return 0
}

// GetBucket retrieves a bucket from the local node
func (rt RouteTable) GetBucket(id string) (bucket Bucket, ok bool) {
	i, err := hex.DecodeString(id)
	if err != nil {
		return KBucket{}, false
	}
	b := rt.ht.GetBucket(i)
	if b == nil {
		return KBucket{}, false
	}

	return KBucket{
		nodes: convertNetworkNodes(b),
	}, true
}

// GetBuckets retrieves all buckets from the local node
func (rt RouteTable) GetBuckets() (k []Bucket, err error) {
	bs := []Bucket{}
	b := rt.ht.GetBuckets()
	for i, v := range b {
		bs[i] = KBucket{nodes: convertNetworkNodes(v)}
	}

	return bs, nil
}

// FindNear finds all Nodes near the provided nodeID up to the provided limit
func (rt RouteTable) FindNear(id NodeID, limit int) ([]*overlay.Node, error) {
	return convertNetworkNodes(rt.ht.GetClosestContacts([]byte(id), limit)), nil
}

// ConnectionSuccess handles the details of what kademlia should do when
// a successful connection is made to node on the network
func (rt RouteTable) ConnectionSuccess(id string, address overlay.NodeAddress) {
	// TODO: What should we do ?
	return
}

// ConnectionFailed handles the details of what kademlia should do when
// a connection fails for a node on the network
func (rt RouteTable) ConnectionFailed(id string, address overlay.NodeAddress) {
	// TODO: What should we do ?
	return
}

// SetBucketTimestamp updates the last updated time for a bucket
func (rt RouteTable) SetBucketTimestamp(id string, now time.Time) error {
	i, err := strconv.Atoi(id)
	if err != nil {
		return NodeErr.New("unable to convert id to int")
	}

	rt.ht.SetBucketTime(i, now)

	return nil
}

// GetBucketTimestamp retrieves the last updated time for a bucket
func (rt RouteTable) GetBucketTimestamp(id string, bucket Bucket) (time.Time, error) {
	return rt.dht.GetExpirationTime([]byte(id)), nil
}

// GetNodeRoutingTable gets a routing table for a given node rather than the local node's routing table
func GetNodeRoutingTable(ctx context.Context, ID NodeID) (RouteTable, error) {
	fmt.Println("GetNodeRoutingTable")
	fmt.Println("id: ", ID)
	return RouteTable{}, nil
}