checkpoint: scaffold qrunproxy timeline API

cmd/qrunproxy/main.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"context"
+	"embed"
+	"encoding/json"
+	"fmt"
+	"io/fs"
+	"net"
+	"net/http"
+	"os"
+	"os/exec"
+	"strings"
+)
+
+//go:embed static
+var staticFS embed.FS
+
+func main() {
+	addr := ":8080"
+	var runAndExit []string
+
+	for _, arg := range os.Args[1:] {
+		if v, ok := strings.CutPrefix(arg, "--run-and-exit="); ok {
+			runAndExit = strings.Fields(v)
+		} else {
+			addr = arg
+		}
+	}
+
+	show, err := loadMockShow()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error loading show: %v\n", err)
+		os.Exit(1)
+	}
+
+	timeline, err := BuildTimeline(show)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error building timeline: %v\n", err)
+		os.Exit(1)
+	}
+
+	sub, err := fs.Sub(staticFS, "static")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	mux := http.NewServeMux()
+	mux.Handle("/", http.FileServer(http.FS(sub)))
+	mux.HandleFunc("/api/show", func(w http.ResponseWriter, r *http.Request) {
+		writeJSON(w, show)
+	})
+	mux.HandleFunc("/api/timeline", func(w http.ResponseWriter, r *http.Request) {
+		writeJSON(w, timeline)
+	})
+
+	if len(runAndExit) > 0 {
+		ln, err := net.Listen("tcp", addr)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+			os.Exit(1)
+		}
+		srv := &http.Server{Handler: mux}
+		go srv.Serve(ln)
+
+		cmd := exec.Command(runAndExit[0], runAndExit[1:]...)
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+		cmdErr := cmd.Run()
+		srv.Shutdown(context.Background())
+		if cmdErr != nil {
+			fmt.Fprintf(os.Stderr, "Error: %v\n", cmdErr)
+			os.Exit(1)
+		}
+		return
+	}
+
+	fmt.Printf("Listening on %s\n", addr)
+	if err := http.ListenAndServe(addr, mux); err != nil {
+		fmt.Fprintf(os.Stderr, "Error: %v\n", err)
+		os.Exit(1)
+	}
+}
+
+func loadMockShow() (Show, error) {
+	buf, err := staticFS.ReadFile("static/show.json")
+	if err != nil {
+		return Show{}, err
+	}
+	var show Show
+	if err := json.Unmarshal(buf, &show); err != nil {
+		return Show{}, err
+	}
+	return show, nil
+}
+
+func writeJSON(w http.ResponseWriter, v any) {
+	w.Header().Set("Content-Type", "application/json")
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "  ")
+	if err := enc.Encode(v); err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}