package commands

import (
	"errors"
	"redisClone/pkg/core"
	"strconv"
)

func Lrem(args []string, getShard func(k string) *core.Shard) interface{} {
	key := args[1]
	count, err := strconv.Atoi(args[2])
	toBeRemoved := args[3]
	if err != nil {
		return errors.New("value is not an integer")
	}

	s := getShard(key)
	item, exists := s.Data[key]
	if !exists {
		return 0
	}
	list, ok := item.Value.([]string)
	if !ok {
		return errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
	}

	counter := 0
	absCount := count
	if count < 0 {
		absCount = -count
	}

	var newList []string
	if count == 0 {
		newList = []string{}
		for _, value := range list {
			if value == toBeRemoved {
				counter++
			} else {
				newList = append(newList, value)
			}
		}
	} else if count > 0 {
		newList = []string{}
		for _, value := range list {
			if value == toBeRemoved && counter < absCount {
				counter++
			} else {
				newList = append(newList, value)
			}
		}
	} else { // count < 0
		reversedNewList := []string{}
		for i := len(list) - 1; i >= 0; i-- {
			value := list[i]
			if value == toBeRemoved && counter < absCount {
				counter++
			} else {
				reversedNewList = append(reversedNewList, value)
			}
		}
		newList = make([]string, len(reversedNewList))
		for i, v := range reversedNewList {
			newList[len(reversedNewList)-1-i] = v
		}
	}

	if len(newList) == 0 {
		delete(s.Data, key)
	} else {
		item.Value = newList
		s.Data[key] = item
	}
	return counter
}