path: root/handlers.go

package main

import (
	"errors"
	"net"
	"path/filepath"
	"sort"
	"strconv"
	"time"
)

func handleGet(conn net.Conn, args []string) {
	db.mu.Lock()
	defer db.mu.Unlock()

	if len(args) != 2 {
        err := errors.New("wrong number of arguments for 'GET'")
        conn.Write(serializeRESP(err))
		return
    }

    key := args[1]

	item, exists := db.data[key]
	if !exists {
		conn.Write(serializeRESP(nil)) 
        return
	}

	if item.ExpiresAt != nil && time.Now().After(*item.ExpiresAt) {
		delete(db.data, key)
		conn.Write(serializeRESP(nil))
		return
	}

	strValue, ok := item.Value.(string)
	if !ok {
		err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
        conn.Write(serializeRESP(err))
        return
	}

	conn.Write(serializeRESP(strValue))
}

func handleExists(conn net.Conn, args []string) {
	db.mu.Lock()
	defer db.mu.Unlock()

	if len(args) != 2 {
        err := errors.New("wrong number of arguments for 'EXISTS'")
        conn.Write(serializeRESP(err))
		return
    }

	key := args[1]

	_, exists := db.data[key]
	if exists {
		conn.Write(serializeRESP(1))
	} else {
		conn.Write(serializeRESP(0))
	}
}

func handleSet(conn net.Conn, args []string) {
	db.mu.Lock()
	defer db.mu.Unlock()

	if len(args) != 3 {
        err := errors.New("wrong number of arguments for 'SET'")
        conn.Write(serializeRESP(err))
		return
    }

	key := args[1]
	item := Item{Value: args[2]}

	db.data[key] = item
	conn.Write(serializeRESP(SimpleString("OK")))
}

func handleDel(conn net.Conn, args []string) {
	db.mu.Lock()
	defer db.mu.Unlock()

	if len(args) < 2 {
        err := errors.New("wrong number of arguments for 'DEL'")
        conn.Write(serializeRESP(err))
		return
    }

	deletedKeys := 0
	for i := 1; i<len(args);i++{
		_, exists := db.data[args[i]]
		if exists {
			delete(db.data, args[i])
			deletedKeys += 1
		} 
	}
	conn.Write(serializeRESP(deletedKeys))
}

func handleIncr(conn net.Conn, args []string) {
	db.mu.Lock()
	defer db.mu.Unlock()

	if len(args) != 2 {
        err := errors.New("wrong number of arguments for 'INCR'")
        conn.Write(serializeRESP(err))
		return
    }

	key := args[1]

	item, exists := db.data[key]
	if exists {
		strValue, ok := item.Value.(string)
		if !ok {
			err := errors.New("value is not an integer or out of range")
			conn.Write(serializeRESP(err))
			return
		}

		currentInt, err := strconv.Atoi(strValue)
		if err != nil {
			err := errors.New("value is not an integer or out of range")
			conn.Write(serializeRESP(err))
			return
		}

		newValueStr := strconv.Itoa(currentInt + 1)
		db.data[key] = Item{Value: newValueStr}
		conn.Write(serializeRESP(currentInt + 1))
	} else {
		db.data[key] = Item{Value: "1"}
		conn.Write(serializeRESP(1))
	}
}

func handleDecr(conn net.Conn, args []string) {
	db.mu.Lock()
	defer db.mu.Unlock()

	if len(args) != 2 {
        err := errors.New("wrong number of arguments for 'DECR'")
        conn.Write(serializeRESP(err))
		return
    }

	key := args[1]

	item, exists := db.data[key]
	if exists {
		strValue, ok := item.Value.(string)
		if !ok {
			err := errors.New("value is not an integer or out of range")
			conn.Write(serializeRESP(err))
			return
		}

		currentInt, err := strconv.Atoi(strValue)
		if err != nil {
			err := errors.New("value is not an integer or out of range")
			conn.Write(serializeRESP(err))
			return
		}

		newValueStr := strconv.Itoa(currentInt - 1)
		db.data[key] = Item{Value:newValueStr}
		conn.Write(serializeRESP(currentInt - 1))
	} else {
		db.data[key] = Item{Value: "-1"}
		conn.Write(serializeRESP(-1))
	}
}

func handlePing(conn net.Conn, args []string) {
	if len(args) != 1 {
        err :=