Add Claude Code stream-json client, report gate, and terminal driver

cmd/byre/main.go

@@ -0,0 +1,209 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"log/slog"
+	"os"
+	"os/exec"
+	"os/signal"
+	"strings"
+
+	"g.fc.run/misc/byre/internal/claude"
+	"g.fc.run/misc/byre/internal/mcp"
+	"g.fc.run/misc/byre/internal/report"
+)
+
+func main() {
+	resume := flag.String("resume", "", "claude session id to resume")
+	flag.Parse()
+
+	dir, err := os.Getwd()
+	if err != nil {
+		fatal("getwd", "err", err)
+	}
+
+	gate := &report.Gate{OnReport: printReport}
+
+	ctx := context.Background()
+	s, err := claude.Start(ctx, claude.Options{
+		Cwd:        dir,
+		Resume:     *resume,
+		GitName:    gitConfig(dir, "user.name"),
+		GitEmail:   gitConfig(dir, "user.email"),
+		MCPServers: []*mcp.Server{{Name: "byre", Version: "0.0.0", Tools: []mcp.Tool{gate.Tool()}}},
+		Hooks: map[string][]claude.HookMatcher{
+			"Stop": {{Func: gate.StopHook}},
+		},
+	})
+	if err != nil {
+		fatal("start claude", "err", err)
+	}
+
+	sigs := make(chan os.Signal, 1)
+	signal.Notify(sigs, os.Interrupt)
+
+	lines := make(chan string)
+	go readLines(lines)
+
+	for {
+		fmt.Print("> ")
+
+		select {
+		case line, ok := <-lines:
+			if !ok {
+				shutdown(s)
+				return
+			}
+			if strings.TrimSpace(line) == "" {
+				continue
+			}
+			gate.Reset()
+			err := s.Send(line)
+			if err != nil {
+				fatal("send", "err", err)
+			}
+			runTurn(ctx, s, sigs)
+
+		case <-sigs:
+			fmt.Println()
+			shutdown(s)
+			return
+		}
+	}
+}
+
+func runTurn(ctx context.Context, s *claude.Session, sigs <-chan os.Signal) {
+	for {
+		select {
+		case ev, ok := <-s.Events():
+			if !ok {
+				fatal("claude exited")
+			}
+			if printEvent(ev) {
+				return
+			}
+
+		case <-sigs:
+			fmt.Println("\n[interrupting]")
+			err := s.Interrupt(ctx)
+			if err != nil {
+				slog.Error("interrupt", "err", err)
+			}
+		}
+	}
+}
+
+func printEvent(ev claude.Event) bool {
+	switch {
+	case ev.Type == "system" && ev.Subtype == "init":
+		info := struct {
+			SessionID string `json:"session_id"`
+			Model     string `json:"model"`
+		}{}
+		err := json.Unmarshal(ev.Raw, &info)
+		if err != nil {
+			fatal("parse init", "err", err)
+		}
+		fmt.Printf("[session %s, %s]\n", info.SessionID, info.Model)
+
+	case ev.Type == "assistant":
+		blocks, err := ev.Blocks()
+		if err != nil {
+			fatal("parse assistant", "err", err)
+		}
+		for _, b := range blocks {
+			switch b.Type {
+			case "text":
+				fmt.Println(b.Text)
+			case "tool_use":
+				fmt.Printf("→ %s %s\n", b.Name, oneLine(string(b.Input), 160))
+			}
+		}
+
+	case ev.Type == "user":
+		blocks, err := ev.Blocks()
+		if err != nil {
+			fatal("parse user", "err", err)
+		}
+		for _, b := range blocks {
+			if b.Type == "tool_result" && b.IsError {
+				fmt.Printf("← error %s\n", oneLine(string(b.Content), 160))
+			}
+		}
+
+	case ev.Type == "result":
+		res, err := ev.Result()
+		if err != nil {
+			fatal("parse result", "err", err)
+		}
+		fmt.Printf("[%s, %d turns, %.1fs, $%.4f]\n", res.Subtype, res.NumTurns, float64(res.DurationMS)/1000, res.TotalCostUSD)
+		return true
+	}
+
+	return false
+}
+
+func printReport(r report.Report) {
+	fmt.Println("── report")
+	sections := []struct {
+		name  string
+		items []string
+	}{
+		{"done", r.Done},
+		{"open questions", r.OpenQuestions},
+		{"next steps", r.NextSteps},
+		{"risks", r.Risks},
+		{"deviations", r.Deviations},
+	}
+	for _, sec := range sections {
+		if len(sec.items) == 0 {
+			continue
+		}
+		fmt.Printf("  %s:\n", sec.name)
+		for _, item := range sec.items {
+			fmt.Printf("    • %s\n", item)
+		}
+	}
+}
+
+func readLines(out chan<- string) {
+	defer close(out)
+	sc := bufio.NewScanner(os.Stdin)
+	for sc.Scan() {
+		out <- sc.Text()
+	}
+}
+
+func shutdown(s *claude.Session) {
+	err := s.Close()
+	if err != nil {
+		slog.Warn("claude exit", "err", err)
+	}
+}
+
+func gitConfig(dir, key string) string {
+	cmd := exec.Command("git", "config", key)
+	cmd.Dir = dir
+	out, err := cmd.Output()
+	if err != nil {
+		fatal("git config", "key", key, "err", err)
+	}
+	return strings.TrimSpace(string(out))
+}
+
+func oneLine(s string, max int) string {
+	s = strings.Join(strings.Fields(s), " ")
+	if len(s) > max {
+		return s[:max] + "…"
+	}
+	return s
+}
+
+func fatal(msg string, args ...any) {
+	slog.Error(msg, args...)
+	os.Exit(1)
+}