Fix: Unsafe world accessor

bot/provider/basic.go

@@ -123,8 +123,6 @@ func RunTransactions(c *Client, cancel context.CancelFunc) error {
 // I don't have to code all the physic by myself
 // thx minecrossoft 🙏
 func Step(cl *Client, cancel context.CancelFunc) error {
-	cancel()
-	return nil
 	feetBlock, err := cl.Player.World.GetBlock(cl.Player.EntityPlayer.Position)
 	if err != nil {
 		return err

bot/provider/events.go

@@ -10,8 +10,6 @@ import (
 	"github.com/Edouard127/go-mc/data/grids"
 	"github.com/Edouard127/go-mc/level"
 	"github.com/Edouard127/go-mc/maths"
-	"github.com/Edouard127/go-mc/save"
-	"github.com/Edouard127/go-mc/save/region"
 	"time"
 	"unsafe"
 
@@ -359,24 +357,6 @@ func SetContainerSlot(c *Client, p pk.Packet, cancel context.CancelFunc) error {
 		return fmt.Errorf("failed to scan SetSlot: %w", err)
 	}
 
-	var chunk save.Chunk
-	for i := range c.Player.World.Columns {
-		r, err := region.Create(fmt.Sprintf("r.%d.%d.mca", i[0], i[1]))
-		if err != nil {
-			return err
-		}
-
-		err = level.ChunkToSave(c.Player.World.Columns[i], &chunk)
-		if err != nil {
-			return err
-		}
-		data, err := chunk.Data(2)
-		if err != nil {
-			return err
-		}
-		r.WriteSector(int(i[0]), int(i[1]), data)
-	}
-
 	c.Player.Manager.StateID = int32(stateId)
 
 	if containerId == -1 && slotId == -1 {
@@ -933,7 +913,7 @@ func SelectAdvancementTab(c *Client, p pk.Packet, cancel context.CancelFunc) err
 	return nil
 }
 
-func WorldBorder(c *Client, p pk.Packet, cancel context.CancelFunc) error {
+func InitializeBorder(c *Client, p pk.Packet, cancel context.CancelFunc) error {
 	var (
 		action         pk.Byte
 		radius         pk.Double
@@ -950,6 +930,9 @@ func WorldBorder(c *Client, p pk.Packet, cancel context.CancelFunc) error {
 		return fmt.Errorf("unable to read WorldBorder packet: %w", err)
 	}
 
+	// When we receive this packet, we know that the client has fully loaded the world.
+	c.World.SafeToAccess = true
+
 	return nil
 }
 

bot/provider/example_test.go

@@ -36,6 +36,7 @@ func TestExampleClient_JoinServer_online(t *testing.T) {
 
 		/* Physic */
 		PacketHandler[Client]{ID: packetid.CPacketChunkData, Priority: 50, F: ChunkData},
+		PacketHandler[Client]{ID: packetid.CPacketInitializeBorder, Priority: 50, F: InitializeBorder},
 		PacketHandler[Client]{ID: packetid.CPacketUnloadChunk, Priority: 50, F: UnloadChunk},
 		PacketHandler[Client]{ID: packetid.CPacketExplosion, Priority: 50, F: Explosion},
 

bot/world/chunks.go

@@ -1,18 +1,21 @@
 package world
 
 import (
+	"context"
 	"fmt"
 	"github.com/Edouard127/go-mc/bot/core"
 	. "github.com/Edouard127/go-mc/level"
 	"github.com/Edouard127/go-mc/level/block"
 	"github.com/Edouard127/go-mc/maths"
 	"math"
 	"sync"
+	"time"
 )
 
 type World struct {
-	Columns  map[ChunkPos]*Chunk
-	Entities map[int32]core.Entity
+	Columns      map[ChunkPos]*Chunk
+	Entities     map[int32]core.Entity
+	SafeToAccess bool
 
 	worldSync   sync.Mutex
 	entityMutex sync.Mutex
@@ -25,9 +28,32 @@ func NewWorld() *World {
 	}
 }
 
+func (w *World) safeLock() {
+	if w.SafeToAccess {
+		return
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*30)
+	defer cancel()
+	for {
+		if w.SafeToAccess {
+			return
+		}
+		select {
+		case <-ctx.Done():
+			panic("world not safe to access")
+		default:
+			time.Sleep(time.Millisecond * 10)
+		}
+	}
+}
+
 func (w *World) GetBlock(pos maths.Vec3d) (*block.Block, error) {
 	w.worldSync.Lock()
 	defer w.worldSync.Unlock()
+	w.safeLock() // As long as the world is empty, we can't get any blocks
+	if len(w.Columns) == 0 {
+		return block.Air, fmt.Errorf("no chunks loaded")
+	}
 	chunk, ok := w.Columns[ChunkPos{int32(pos.X) >> 4, int32(pos.Z) >> 4}]
 	if ok {
 		return chunk.GetBlock(pos)