gistfile1.txt

package main

import (
	"bytes"
	"crypto/ed25519"
	"encoding/hex"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"time"

	"github.com/golang/protobuf/proto"
	"github.com/zeebo/blake3"

	"golang-submitmessage/protobufs"
)

const farcasterEpoch int64 = 1609459200 // January 1, 2021 UTC

func main() {

	fid := uint64(18350) // FID of the user submitting the message
	network := protobufs.FarcasterNetwork_FARCASTER_NETWORK_MAINNET

	// Construct the cast add message
	castAdd := &protobufs.CastAddBody{
		Text: "testing testing testing. this is the first cast ever that was written on poiesis and sent directly to the hub that is running on this same machine.",
	}
	// Construct the message data object
	msgData := &protobufs.MessageData{
		Type:      protobufs.MessageType_MESSAGE_TYPE_CAST_ADD,
		Fid:       fid,
		Timestamp: uint32(time.Now().Unix() - farcasterEpoch),
		Network:   network,
		Body:      &protobufs.MessageData_CastAddBody{CastAddBody: castAdd},
	}

	// Serialize the message data to bytes
	msgDataBytes, err := proto.Marshal(msgData)
	if err != nil {
		log.Fatalf("Failed to encode message data: %v", err)
	}

	// Calculate the blake3 hash, truncated to 20 bytes
	hasher := blake3.New()
	hasher.Write(msgDataBytes)
	hash := hasher.Sum(nil)[:20]

	// Construct the actual message
	msg := &protobufs.Message{
		HashScheme:      protobufs.HashScheme_HASH_SCHEME_BLAKE3,
		Hash:            hash,
		SignatureScheme: protobufs.SignatureScheme_SIGNATURE_SCHEME_ED25519,
	}

	// Sign the message
	privateKeyHex := "xxxxxxxxxxxxxxxxxxx"
	privateKeyBytes, err := hex.DecodeString(privateKeyHex)
	if err != nil {
		log.Fatalf("Invalid hex string: %v", err)
	}
	privateKey := ed25519.NewKeyFromSeed(privateKeyBytes)
	signature := ed25519.Sign(privateKey, hash)

	// Continue constructing the message
	msg.Signature = signature
	msg.Signer = privateKey.Public().(ed25519.PublicKey)

	// Serialize the message
	msg.DataBytes = msgDataBytes
	msgBytes, err := proto.Marshal(msg)
	if err != nil {
		log.Fatalf("Failed to encode message: %v", err)
	}

	// Finally, submit the message to the network
	url := "http://127.0.0.1:2281/v1/submitMessage"
	resp, err := http.Post(url, "application/octet-stream", bytes.NewBuffer(msgBytes))
	if err != nil {
		log.Fatalf("Failed to send POST request: %v", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode == http.StatusOK {
		fmt.Println("Successfully sent the message.")
	} else {
		bodyBytes, _ := ioutil.ReadAll(resp.Body)
		bodyString := string(bodyBytes)
		fmt.Printf("Failed to send the message. HTTP status: %d\nResponse: %s\n", resp.StatusCode, bodyString)
	}
}