Add the worker setup wizard (setup, --config, --check) to worker-agent

coordinator/cmd/worker-agent/main.go

@@ -1,14 +1,24 @@
 // Command worker-agent is the Go worker agent: a coordinator client that
-// executes SDK workloads in a Python subprocess per claimed task.
+// executes SDK workloads in a Python subprocess per claimed task. It also
+// carries the local setup wizard (`worker-agent setup`) so a machine that
+// installs only the worker can configure and start itself without a
+// coordinator on site.
 package main
 
 import (
+	"context"
 	"flag"
 	"fmt"
 	"log/slog"
+	"net/http"
 	"os"
+	"os/exec"
+	"os/signal"
+	"syscall"
+	"time"
 
 	"github.com/emil28092005/SciMesh/coordinator/internal/agent"
+	"github.com/emil28092005/SciMesh/coordinator/internal/agent/setupui"
 )
 
 // version is injected at build time (-ldflags "-X main.version=...") and
@@ -16,13 +26,44 @@ import (
 var version = "dev"
 
 func main() {
-	showVersion := flag.Bool("version", false, "print the build version and exit")
-	flag.Parse()
+	if len(os.Args) > 1 && os.Args[1] == "setup" {
+		os.Exit(runSetup(os.Args[2:]))
+	}
+
+	fs := flag.NewFlagSet("worker-agent", flag.ExitOnError)
+	showVersion := fs.Bool("version", false, "print the build version and exit")
+	configPath := fs.String("config", "", "path to a JSON config file (SCIMESH_WORKER_CONFIG overrides the default)")
+	checkMode := fs.Bool("check", false, "run the preflight check (coordinator + local runtime) and exit 0/1")
+	checkURL := fs.String("coordinator-url", "", "coordinator URL to probe in --check mode")
+	_ = fs.Parse(os.Args[1:])
+
+	agent.Version = version
+
 	if *showVersion {
 		fmt.Println("worker-agent " + version)
 		return
 	}
-	config, err := agent.LoadConfig()
+
+	if *checkMode {
+		url := *checkURL
+		if url == "" {
+			url = os.Getenv("COORDINATOR_URL")
+		}
+		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+		defer cancel()
+		if url == "" {
+			fmt.Println("check: no coordinator URL (pass --coordinator-url or set COORDINATOR_URL)")
+			os.Exit(1)
+		}
+		report := agent.RunCheck(ctx, url)
+		printCheck(report)
+		if !report.Coordinator.OK || !report.Python.OK || !report.Scimesh.OK {
+			os.Exit(1)
+		}
+		return
+	}
+
+	config, err := loadConfig(*configPath)
 	if err != nil {
 		slog.Error("invalid configuration", "error", err)
 		os.Exit(2)
@@ -42,3 +83,96 @@ func main() {
 		os.Exit(1)
 	}
 }
+
+// loadConfig prefers a --config file; environment variables override the file
+// (see agent.ConfigFile.Config). Without a file, the plain environment path is
+// used exactly as before.
+func loadConfig(configPath string) (*agent.Config, error) {
+	if configPath != "" {
+		return agent.LoadConfigFile(configPath)
+	}
+	envPath := os.Getenv("SCIMESH_WORKER_CONFIG")
+	if envPath != "" {
+		if _, err := os.Stat(envPath); err == nil {
+			return agent.LoadConfigFile(envPath)
+		}
+	}
+	return agent.LoadConfig()
+}
+
+func printCheck(report agent.CheckReport) {
+	fmt.Printf("worker-agent %s\n", report.Agent)
+	line := func(item agent.CheckItem) string {
+		mark := "✗"
+		if item.OK {
+			mark = "✓"
+		}
+		detail := item.Detail
+		if item.Latency > 0 {
+			detail = fmt.Sprintf("%s (%d ms)", detail, item.Latency)
+		}
+		return fmt.Sprintf("  %s %s: %s", mark, item.Name, detail)
+	}
+	fmt.Println(line(report.Coordinator))
+	fmt.Println(line(report.Auth))
+	fmt.Println(line(report.Python))
+	fmt.Println(line(report.Scimesh))
+}
+
+// runSetup serves the local setup wizard until interrupted. It binds the
+// loopback interface only.
+func runSetup(args []string) int {
+	fs := flag.NewFlagSet("worker-agent setup", flag.ContinueOnError)
+	port := fs.Int("port", 0, "listen port (default 12700)")
+	noOpen := fs.Bool("no-open", false, "do not open the browser automatically")
+	if err := fs.Parse(args); err != nil {
+		return 2
+	}
+	logger := slog.New(slog.NewTextHandler(os.Stderr, nil))
+
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
+	defer stop()
+
+	server := setupui.New(logger, setupui.Options{
+		Port: *port,
+		OpenBrowser: func(url string) {
+			if *noOpen {
+				return
+			}
+			openBrowser(url)
+		},
+	})
+	listener, err := server.Listen()
+	if err != nil {
+		logger.Error("setup wizard could not bind the loopback port", "err", err)
+		return 1
+	}
+	url := "http://" + listener.Addr().String()
+	logger.Info("SciMesh worker setup wizard", "url", url, "press-ctrl-c-to-stop", true)
+	server.OpenBrowser(url)
+	// Block until the signal arrives (never returns an error that matters: a
+	// cancelled context is the normal exit path).
+	err = server.Serve(ctx, listener)
+	if err != nil && err != http.ErrServerClosed {
+		logger.Error("setup wizard stopped", "err", err)
+		return 1
+	}
+	return 0
+}
+
+// openBrowser points the user's default browser at the wizard. Best-effort:
+// a missing browser must never fail the setup flow.
+func openBrowser(url string) {
+	for _, candidate := range [][]string{
+		{"xdg-open", url},
+		{"open", url},
+		{"cmd", "/c", "start", url},
+	} {
+		binary, err := exec.LookPath(candidate[0])
+		if err != nil {
+			continue
+		}
+		_ = exec.Command(binary, candidate[1:]...).Start()
+		return
+	}
+}