package godis

import (
	SortedSet "github.com/hdt3213/godis/datastruct/sortedset"
	"github.com/hdt3213/godis/interface/redis"
	"github.com/hdt3213/godis/redis/reply"
	"strconv"
	"strings"
)

func (db *DB) getAsSortedSet(key string) (*SortedSet.SortedSet, reply.ErrorReply) {
	entity, exists := db.GetEntity(key)
	if !exists {
		return nil, nil
	}
	sortedSet, ok := entity.Data.(*SortedSet.SortedSet)
	if !ok {
		return nil, &reply.WrongTypeErrReply{}
	}
	return sortedSet, nil
}

func (db *DB) getOrInitSortedSet(key string) (sortedSet *SortedSet.SortedSet, inited bool, errReply reply.ErrorReply) {
	sortedSet, errReply = db.getAsSortedSet(key)
	if errReply != nil {
		return nil, false, errReply
	}
	inited = false
	if sortedSet == nil {
		sortedSet = SortedSet.Make()
		db.PutEntity(key, &DataEntity{
			Data: sortedSet,
		})
		inited = true
	}
	return sortedSet, inited, nil
}

// ZAdd adds member into sorted set
func ZAdd(db *DB, args [][]byte) redis.Reply {
	if len(args) < 3 || len(args)%2 != 1 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zadd' command")
	}
	key := string(args[0])
	size := (len(args) - 1) / 2
	elements := make([]*SortedSet.Element, size)
	for i := 0; i < size; i++ {
		scoreValue := args[2*i+1]
		member := string(args[2*i+2])
		score, err := strconv.ParseFloat(string(scoreValue), 64)
		if err != nil {
			return reply.MakeErrReply("ERR value is not a valid float")
		}
		elements[i] = &SortedSet.Element{
			Member: member,
			Score:  score,
		}
	}

	// lock
	db.Lock(key)
	defer db.UnLock(key)

	// get or init entity
	sortedSet, _, errReply := db.getOrInitSortedSet(key)
	if errReply != nil {
		return errReply
	}

	i := 0
	for _, e := range elements {
		if sortedSet.Add(e.Member, e.Score) {
			i++
		}
	}

	db.AddAof(makeAofCmd("zadd", args))

	return reply.MakeIntReply(int64(i))
}

// ZScore gets score of a member in sortedset
func ZScore(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) != 2 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zscore' command")
	}
	key := string(args[0])
	member := string(args[1])

	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return &reply.NullBulkReply{}
	}

	element, exists := sortedSet.Get(member)
	if !exists {
		return &reply.NullBulkReply{}
	}
	value := strconv.FormatFloat(element.Score, 'f', -1, 64)
	return reply.MakeBulkReply([]byte(value))
}

// ZRank gets index of a member in sortedset, ascending order, start from 0
func ZRank(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) != 2 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrank' command")
	}
	key := string(args[0])
	member := string(args[1])

	// get entity
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return &reply.NullBulkReply{}
	}

	rank := sortedSet.GetRank(member, false)
	if rank < 0 {
		return &reply.NullBulkReply{}
	}
	return reply.MakeIntReply(rank)
}

// ZRevRank gets index of a member in sortedset, descending order, start from 0
func ZRevRank(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) != 2 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrevrank' command")
	}
	key := string(args[0])
	member := string(args[1])

	// get entity
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return &reply.NullBulkReply{}
	}

	rank := sortedSet.GetRank(member, true)
	if rank < 0 {
		return &reply.NullBulkReply{}
	}
	return reply.MakeIntReply(rank)
}

// ZCard gets number of members in sortedset
func ZCard(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) != 1 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zcard' command")
	}
	key := string(args[0])

	// get entity
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return reply.MakeIntReply(0)
	}

	return reply.MakeIntReply(int64(sortedSet.Len()))
}

// ZRange gets members in range, sort by score in ascending order
func ZRange(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) != 3 && len(args) != 4 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrange' command")
	}
	withScores := false
	if len(args) == 4 {
		if strings.ToUpper(string(args[3])) != "WITHSCORES" {
			return reply.MakeErrReply("syntax error")
		}
		withScores = true
	}
	key := string(args[0])
	start, err := strconv.ParseInt(string(args[1]), 10, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not an integer or out of range")
	}
	stop, err := strconv.ParseInt(string(args[2]), 10, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not an integer or out of range")
	}
	return range0(db, key, start, stop, withScores, false)
}

// ZRevRange gets members in range, sort by score in descending order
func ZRevRange(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) != 3 && len(args) != 4 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrevrange' command")
	}
	withScores := false
	if len(args) == 4 {
		if string(args[3]) != "WITHSCORES" {
			return reply.MakeErrReply("syntax error")
		}
		withScores = true
	}
	key := string(args[0])
	start, err := strconv.ParseInt(string(args[1]), 10, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not an integer or out of range")
	}
	stop, err := strconv.ParseInt(string(args[2]), 10, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not an integer or out of range")
	}
	return range0(db, key, start, stop, withScores, true)
}

func range0(db *DB, key string, start int64, stop int64, withScores bool, desc bool) redis.Reply {
	// lock key
	db.locker.RLock(key)
	defer db.locker.RUnLock(key)

	// get data
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return &reply.EmptyMultiBulkReply{}
	}

	// compute index
	size := sortedSet.Len() // assert: size > 0
	if start < -1*size {
		start = 0
	} else if start < 0 {
		start = size + start
	} else if start >= size {
		return &reply.EmptyMultiBulkReply{}
	}
	if stop < -1*size {
		stop = 0
	} else if stop < 0 {
		stop = size + stop + 1
	} else if stop < size {
		stop = stop + 1
	} else {
		stop = size
	}
	if stop < start {
		stop = start
	}

	// assert: start in [0, size - 1], stop in [start, size]
	slice := sortedSet.Range(start, stop, desc)
	if withScores {
		result := make([][]byte, len(slice)*2)
		i := 0
		for _, element := range slice {
			result[i] = []byte(element.Member)
			i++
			scoreStr := strconv.FormatFloat(element.Score, 'f', -1, 64)
			result[i] = []byte(scoreStr)
			i++
		}
		return reply.MakeMultiBulkReply(result)
	}
	result := make([][]byte, len(slice))
	i := 0
	for _, element := range slice {
		result[i] = []byte(element.Member)
		i++
	}
	return reply.MakeMultiBulkReply(result)
}

// ZCount gets number of members which score within given range
func ZCount(db *DB, args [][]byte) redis.Reply {
	if len(args) != 3 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zcount' command")
	}
	key := string(args[0])

	min, err := SortedSet.ParseScoreBorder(string(args[1]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	max, err := SortedSet.ParseScoreBorder(string(args[2]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	db.locker.RLock(key)
	defer db.locker.RUnLock(key)

	// get data
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return reply.MakeIntReply(0)
	}

	return reply.MakeIntReply(sortedSet.Count(min, max))
}

/*
 * param limit: limit < 0 means no limit
 */
func rangeByScore0(db *DB, key string, min *SortedSet.ScoreBorder, max *SortedSet.ScoreBorder, offset int64, limit int64, withScores bool, desc bool) redis.Reply {
	// lock key
	db.locker.RLock(key)
	defer db.locker.RUnLock(key)

	// get data
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return &reply.EmptyMultiBulkReply{}
	}

	slice := sortedSet.RangeByScore(min, max, offset, limit, desc)
	if withScores {
		result := make([][]byte, len(slice)*2)
		i := 0
		for _, element := range slice {
			result[i] = []byte(element.Member)
			i++
			scoreStr := strconv.FormatFloat(element.Score, 'f', -1, 64)
			result[i] = []byte(scoreStr)
			i++
		}
		return reply.MakeMultiBulkReply(result)
	}
	result := make([][]byte, len(slice))
	i := 0
	for _, element := range slice {
		result[i] = []byte(element.Member)
		i++
	}
	return reply.MakeMultiBulkReply(result)
}

// ZRangeByScore gets members which score within given range, in ascending order
func ZRangeByScore(db *DB, args [][]byte) redis.Reply {
	if len(args) < 3 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrangebyscore' command")
	}
	key := string(args[0])

	min, err := SortedSet.ParseScoreBorder(string(args[1]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	max, err := SortedSet.ParseScoreBorder(string(args[2]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	withScores := false
	var offset int64 = 0
	var limit int64 = -1
	if len(args) > 3 {
		for i := 3; i < len(args); {
			s := string(args[i])
			if strings.ToUpper(s) == "WITHSCORES" {
				withScores = true
				i++
			} else if strings.ToUpper(s) == "LIMIT" {
				if len(args) < i+3 {
					return reply.MakeErrReply("ERR syntax error")
				}
				offset, err = strconv.ParseInt(string(args[i+1]), 10, 64)
				if err != nil {
					return reply.MakeErrReply("ERR value is not an integer or out of range")
				}
				limit, err = strconv.ParseInt(string(args[i+2]), 10, 64)
				if err != nil {
					return reply.MakeErrReply("ERR value is not an integer or out of range")
				}
				i += 3
			} else {
				return reply.MakeErrReply("ERR syntax error")
			}
		}
	}
	return rangeByScore0(db, key, min, max, offset, limit, withScores, false)
}

// ZRevRangeByScore gets number of members which score within given range, in descending order
func ZRevRangeByScore(db *DB, args [][]byte) redis.Reply {
	if len(args) < 3 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrangebyscore' command")
	}
	key := string(args[0])

	min, err := SortedSet.ParseScoreBorder(string(args[2]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	max, err := SortedSet.ParseScoreBorder(string(args[1]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	withScores := false
	var offset int64 = 0
	var limit int64 = -1
	if len(args) > 3 {
		for i := 3; i < len(args); {
			s := string(args[i])
			if strings.ToUpper(s) == "WITHSCORES" {
				withScores = true
				i++
			} else if strings.ToUpper(s) == "LIMIT" {
				if len(args) < i+3 {
					return reply.MakeErrReply("ERR syntax error")
				}
				offset, err = strconv.ParseInt(string(args[i+1]), 10, 64)
				if err != nil {
					return reply.MakeErrReply("ERR value is not an integer or out of range")
				}
				limit, err = strconv.ParseInt(string(args[i+2]), 10, 64)
				if err != nil {
					return reply.MakeErrReply("ERR value is not an integer or out of range")
				}
				i += 3
			} else {
				return reply.MakeErrReply("ERR syntax error")
			}
		}
	}
	return rangeByScore0(db, key, min, max, offset, limit, withScores, true)
}

// ZRemRangeByScore removes members which score within given range
func ZRemRangeByScore(db *DB, args [][]byte) redis.Reply {
	if len(args) != 3 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zremrangebyscore' command")
	}
	key := string(args[0])

	min, err := SortedSet.ParseScoreBorder(string(args[1]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	max, err := SortedSet.ParseScoreBorder(string(args[2]))
	if err != nil {
		return reply.MakeErrReply(err.Error())
	}

	db.locker.Lock(key)
	defer db.locker.UnLock(key)

	// get data
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return &reply.EmptyMultiBulkReply{}
	}

	removed := sortedSet.RemoveByScore(min, max)
	if removed > 0 {
		db.AddAof(makeAofCmd("zremrangebyscore", args))
	}
	return reply.MakeIntReply(removed)
}

// ZRemRangeByRank removes members within given indexes
func ZRemRangeByRank(db *DB, args [][]byte) redis.Reply {
	if len(args) != 3 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zremrangebyrank' command")
	}
	key := string(args[0])
	start, err := strconv.ParseInt(string(args[1]), 10, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not an integer or out of range")
	}
	stop, err := strconv.ParseInt(string(args[2]), 10, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not an integer or out of range")
	}

	db.locker.Lock(key)
	defer db.locker.UnLock(key)

	// get data
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return reply.MakeIntReply(0)
	}

	// compute index
	size := sortedSet.Len() // assert: size > 0
	if start < -1*size {
		start = 0
	} else if start < 0 {
		start = size + start
	} else if start >= size {
		return reply.MakeIntReply(0)
	}
	if stop < -1*size {
		stop = 0
	} else if stop < 0 {
		stop = size + stop + 1
	} else if stop < size {
		stop = stop + 1
	} else {
		stop = size
	}
	if stop < start {
		stop = start
	}

	// assert: start in [0, size - 1], stop in [start, size]
	removed := sortedSet.RemoveByRank(start, stop)
	if removed > 0 {
		db.AddAof(makeAofCmd("zremrangebyrank", args))
	}
	return reply.MakeIntReply(removed)
}

// ZRem removes given members
func ZRem(db *DB, args [][]byte) redis.Reply {
	// parse args
	if len(args) < 2 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zrem' command")
	}
	key := string(args[0])
	fields := make([]string, len(args)-1)
	fieldArgs := args[1:]
	for i, v := range fieldArgs {
		fields[i] = string(v)
	}

	db.Lock(key)
	defer db.UnLock(key)

	// get entity
	sortedSet, errReply := db.getAsSortedSet(key)
	if errReply != nil {
		return errReply
	}
	if sortedSet == nil {
		return reply.MakeIntReply(0)
	}

	var deleted int64 = 0
	for _, field := range fields {
		if sortedSet.Remove(field) {
			deleted++
		}
	}
	if deleted > 0 {
		db.AddAof(makeAofCmd("zrem", args))
	}
	return reply.MakeIntReply(deleted)
}

// ZIncrBy increments the score of a member
func ZIncrBy(db *DB, args [][]byte) redis.Reply {
	if len(args) != 3 {
		return reply.MakeErrReply("ERR wrong number of arguments for 'zincrby' command")
	}
	key := string(args[0])
	rawDelta := string(args[1])
	field := string(args[2])
	delta, err := strconv.ParseFloat(rawDelta, 64)
	if err != nil {
		return reply.MakeErrReply("ERR value is not a valid float")
	}

	db.locker.Lock(key)
	defer db.locker.UnLock(key)

	// get or init entity
	sortedSet, _, errReply := db.getOrInitSortedSet(key)
	if errReply != nil {
		return errReply
	}

	element, exists := sortedSet.Get(field)
	if !exists {
		sortedSet.Add(field, delta)
		db.AddAof(makeAofCmd("zincrby", args))
		return reply.MakeBulkReply(args[1])
	}
	score := element.Score + delta
	sortedSet.Add(field, score)
	bytes := []byte(strconv.FormatFloat(score, 'f', -1, 64))
	db.AddAof(makeAofCmd("zincrby", args))
	return reply.MakeBulkReply(bytes)
}