First completly working solution

client.go

@@ -0,0 +1,148 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"sort"
+)
+
+func GetFile(path string) {
+	request := NewRequest(path)
+
+	udpAddr, err := net.ResolveUDPAddr("udp", "0.0.0.0:13374")
+
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// Dial to the address with UDP
+	conn, err := net.DialUDP("udp", nil, udpAddr)
+
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	_, err = conn.Write(request.ToBytes())
+	if err != nil {
+		panic(err)
+	}
+
+	bytes := make([]byte, PacketSize)
+	file, err := os.Create(path + ".recv")
+	if err != nil {
+		panic(err)
+	}
+
+	_, _, err = conn.ReadFrom(bytes)
+	if err != nil {
+		panic(err)
+	}
+
+	pck := PacketFromBytes(bytes)
+	if pck.flag != PTE {
+		panic("Header flag was supposed to be PTE")
+	}
+
+	size, err := pck.GetUint32Payload()
+	if err != nil {
+		panic(err)
+	}
+
+	file.Truncate(int64(size))
+
+	ackPck := NewAck(&pck)
+	conn.Write(ackPck.ToBytes())
+
+	recvPackets := make([]uint32, 0)
+	var endPacket Packet
+
+	for {
+		_, _, err = conn.ReadFrom(bytes)
+		if err != nil {
+			panic(err)
+		}
+
+		pck := PacketFromBytes(bytes)
+		if pck.flag == End {
+			endPacket = pck
+			break
+		}
+		recvPackets = append(recvPackets, pck.sync)
+
+		offset := (int64(pck.sync) - int64(ackPck.sync+1)) * (PacketSize - int64(HeaderSize))
+		fmt.Printf("Sync: %v, Offset: %v\n", pck.sync, offset)
+
+		_, err = file.WriteAt(pck.data, offset)
+		if err != nil {
+			panic(err)
+		}
+	}
+
+	sort.Slice(recvPackets, func(i, j int) bool {
+		pckI := recvPackets[i]
+		pckJ := recvPackets[j]
+		return pckI < pckJ
+	})
+
+	lostPackets := make([]uint32, 0)
+	lastSync := ackPck.sync
+	needResend := false
+	for _, i := range recvPackets {
+		if lastSync+1 != i {
+			lostPackets = append(lostPackets, i)
+			needResend = true
+		}
+		lastSync = i
+	}
+
+	if !needResend {
+		ack := NewAck(&endPacket)
+		conn.Write(ack.ToBytes())
+	}
+
+	// sort.Slice(recvPackets, func(i, j int) bool {
+	// 	pckI := recvPackets[i]
+	// 	pckJ := recvPackets[j]
+	// 	return pckI.sync < pckJ.sync
+	// })
+
+	// endPacketFound := false
+	// needResend := false
+	// lastSync := request.sync
+	// fmt.Println(lastSync)
+	// endPacketSync, err := endPacket.GetSync()
+	// if err != nil {
+	// 	panic(err)
+	// }
+
+	// for _, packet := range recvPackets {
+	// 	// fmt.Println(packet.sync)
+	// 	// offset := (int64(packet.sync)-1)*PacketSize - int64(HeaderSize)
+	// 	// data := packet.data
+	// 	// fmt.Printf("Data: %v Offset: %v\n", data, offset)
+
+	// 	if lastSync+1 != packet.sync {
+	// 		fmt.Printf("Need Packet %v resend\n", lastSync+1)
+	// 		// Add to slice
+	// 		needResend = true
+	// 		continue
+	// 	}
+
+	// 	fmt.Printf("Writing Packet %v to file\n", packet.sync)
+
+	// 	_, err = file.Write(packet.data)
+	// 	if err != nil {
+	// 		panic(err)
+	// 	}
+
+	// 	if packet.sync == endPacketSync {
+	// 		endPacketFound = true
+	// 	}
+
+	// 	lastSync = packet.sync
+	// }
+
+}