From 7e95ced104f4d9481b179a8452e5ce03c174eb63 Mon Sep 17 00:00:00 2001
From: Claude <developers@lethean.io>
Date: Mon, 23 Feb 2026 00:03:14 +0000
Subject: [PATCH] feat(tui): add cmd/chain binary wiring Frame + P2P sync

Co-Authored-By: Charon <charon@lethean.io>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 cmd/chain/main.go | 175 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 175 insertions(+)
 create mode 100644 cmd/chain/main.go

diff --git a/cmd/chain/main.go b/cmd/chain/main.go
new file mode 100644
index 0000000..ccd595b
--- /dev/null
+++ b/cmd/chain/main.go
@@ -0,0 +1,175 @@
+// Copyright (c) 2017-2026 Lethean (https://lt.hn)
+//
+// Licensed under the European Union Public Licence (EUPL) version 1.2.
+// SPDX-License-Identifier: EUPL-1.2
+
+package main
+
+import (
+	"context"
+	"crypto/rand"
+	"encoding/binary"
+	"flag"
+	"fmt"
+	"log"
+	"net"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"time"
+
+	cli "forge.lthn.ai/core/cli/pkg/cli"
+	store "forge.lthn.ai/core/go-store"
+
+	"forge.lthn.ai/core/go-blockchain/chain"
+	"forge.lthn.ai/core/go-blockchain/config"
+	"forge.lthn.ai/core/go-blockchain/p2p"
+	"forge.lthn.ai/core/go-blockchain/tui"
+	levin "forge.lthn.ai/core/go-p2p/node/levin"
+)
+
+func main() {
+	dataDir := flag.String("data-dir", defaultDataDir(), "blockchain data directory")
+	seed := flag.String("seed", "seeds.lthn.io:36942", "seed peer address (host:port)")
+	testnet := flag.Bool("testnet", false, "use testnet")
+	flag.Parse()
+
+	if err := os.MkdirAll(*dataDir, 0o755); err != nil {
+		log.Fatalf("create data dir: %v", err)
+	}
+
+	dbPath := filepath.Join(*dataDir, "chain.db")
+	s, err := store.New(dbPath)
+	if err != nil {
+		log.Fatalf("open store: %v", err)
+	}
+	defer s.Close()
+
+	c := chain.New(s)
+	node := tui.NewNode(c)
+
+	cfg := config.Mainnet
+	forks := config.MainnetForks
+	if *testnet {
+		cfg = config.Testnet
+		forks = config.TestnetForks
+		if *seed == "seeds.lthn.io:36942" {
+			*seed = "localhost:46942"
+		}
+	}
+
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer cancel()
+
+	// Start P2P sync in background.
+	go syncLoop(ctx, c, &cfg, forks, *seed)
+
+	status := tui.NewStatusModel(node)
+	explorer := tui.NewExplorerModel(c)
+	hints := tui.NewKeyHintsModel()
+
+	frame := cli.NewFrame("HCF")
+	frame.Header(status)
+	frame.Content(explorer)
+	frame.Footer(hints)
+	frame.Run()
+}
+
+func syncLoop(ctx context.Context, c *chain.Chain, cfg *config.ChainConfig, forks []config.HardFork, seed string) {
+	opts := chain.SyncOptions{
+		VerifySignatures: false,
+		Forks:            forks,
+	}
+
+	for {
+		select {
+		case <-ctx.Done():
+			return
+		default:
+		}
+
+		if err := syncOnce(ctx, c, cfg, opts, seed); err != nil {
+			log.Printf("sync: %v (retrying in 10s)", err)
+			select {
+			case <-ctx.Done():
+				return
+			case <-time.After(10 * time.Second):
+			}
+			continue
+		}
+
+		// Synced -- wait before polling again.
+		select {
+		case <-ctx.Done():
+			return
+		case <-time.After(30 * time.Second):
+		}
+	}
+}
+
+func syncOnce(ctx context.Context, c *chain.Chain, cfg *config.ChainConfig, opts chain.SyncOptions, seed string) error {
+	conn, err := net.DialTimeout("tcp", seed, 10*time.Second)
+	if err != nil {
+		return fmt.Errorf("dial %s: %w", seed, err)
+	}
+	defer conn.Close()
+
+	lc := levin.NewConnection(conn)
+
+	var peerIDBuf [8]byte
+	rand.Read(peerIDBuf[:])
+	peerID := binary.LittleEndian.Uint64(peerIDBuf[:])
+
+	localHeight, _ := c.Height()
+
+	req := p2p.HandshakeRequest{
+		NodeData: p2p.NodeData{
+			NetworkID: cfg.NetworkID,
+			PeerID:    peerID,
+			LocalTime: time.Now().Unix(),
+			MyPort:    0,
+		},
+		PayloadData: p2p.CoreSyncData{
+			CurrentHeight:  localHeight,
+			ClientVersion:  config.ClientVersion,
+			NonPruningMode: true,
+		},
+	}
+	payload, err := p2p.EncodeHandshakeRequest(&req)
+	if err != nil {
+		return fmt.Errorf("encode handshake: %w", err)
+	}
+	if err := lc.WritePacket(p2p.CommandHandshake, payload, true); err != nil {
+		return fmt.Errorf("write handshake: %w", err)
+	}
+
+	hdr, data, err := lc.ReadPacket()
+	if err != nil {
+		return fmt.Errorf("read handshake: %w", err)
+	}
+	if hdr.Command != uint32(p2p.CommandHandshake) {
+		return fmt.Errorf("unexpected command %d", hdr.Command)
+	}
+
+	var resp p2p.HandshakeResponse
+	if err := resp.Decode(data); err != nil {
+		return fmt.Errorf("decode handshake: %w", err)
+	}
+
+	localSync := p2p.CoreSyncData{
+		CurrentHeight:  localHeight,
+		ClientVersion:  config.ClientVersion,
+		NonPruningMode: true,
+	}
+	p2pConn := chain.NewLevinP2PConn(lc, resp.PayloadData.CurrentHeight, localSync)
+
+	return c.P2PSync(ctx, p2pConn, opts)
+}
+
+func defaultDataDir() string {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return ".lethean"
+	}
+	return filepath.Join(home, ".lethean", "chain")
+}