package main

import log "github.com/sirupsen/logrus"

//import "io/ioutil"
import "fmt"
import "strconv"

const appPrefix = "steem-block-fetcher"

type SteemDataStorer interface {
	SetCurrentBlockHeight() error
	ForceSetCurrentBlockHeight(BlockNumber) error
	CurrentBlockHeight() BlockNumber
	HaveOpsForBlock(BlockNumber) bool
	StoreBlockOps(BlockNumber, *[]byte) error
}

// SteemDataStore is the object with which the rest of this tool interacts
type SteemDataStore struct {
	kv KVStorer
}

func NewSteemDataStore(dir string) *SteemDataStore {
	self := new(SteemDataStore)
	self.kv = NewRedisKVStore()
	return self
}

func (self *SteemDataStore) ForceSetCurrentBlockHeight(blockNum BlockNumber) error {
	keyname := fmt.Sprintf("%s:global:CurrentBlockHeight", appPrefix)
	value := fmt.Sprintf("%d", blockNum)
	return self.kv.Put(&keyname, &value)
}

// this function searches for the highest contiguously stored blocknum
// and updates the memo in the db
func (self *SteemDataStore) SetCurrentBlockHeight() error {
	nextVal := self.FindHighestContiguousBlockInDb(self.CurrentBlockHeight())
	keyname := fmt.Sprintf("%s:global:CurrentBlockHeight", appPrefix)
	value := fmt.Sprintf("%d", nextVal)
	log.Infof("updating our current highest block in db to %d", nextVal)
	return self.kv.Put(&keyname, &value)
}

func (self *SteemDataStore) FindHighestContiguousBlockInDb(from BlockNumber) BlockNumber {
	last := from

	var keyname string
	var try BlockNumber

	for {
		try = BlockNumber(uint64(last) + 1)
		keyname = fmt.Sprintf("%s:BlockOps:%d", appPrefix, try)
		exists, _ := self.kv.Exists(&keyname)
		if exists == false {
			log.Debugf("cannot find block %d in db, highest found is %d", try, last)
			return last
		} else {
			last = try
		}
	}
}

func (self *SteemDataStore) StoreBlockOps(blockNum BlockNumber, blockOps *[]byte) error {
	keyname := fmt.Sprintf("%s:BlockOps:%d", appPrefix, blockNum)
	value := string(*blockOps)
	return self.kv.Put(&keyname, &value)
}

func (self *SteemDataStore) HaveOpsForBlock(blockNum BlockNumber) bool {
	panic("unimplemented")
}

func (self *SteemDataStore) CurrentBlockHeight() BlockNumber {
	keyname := fmt.Sprintf("%s:global:CurrentBlockHeight", appPrefix)
	val, err := self.kv.Get(&keyname)
	if err != nil {
		// assume this is key not found, initialize key to default
		self.ForceSetCurrentBlockHeight(0)
		// retry
		return self.CurrentBlockHeight()
	}
	intval, err := strconv.ParseUint(*val, 10, 64)
	return BlockNumber(intval)
}