feat: initial commit

internal/server/http.go

@@ -0,0 +1,139 @@
+package server
+
+import (
+	"encoding/json"
+	"log/slog"
+	"net/http"
+	"strconv"
+	"time"
+
+	"git.mkz.me/mycroft/root-me-api/internal/scoreboard"
+)
+
+// StatsProvider exposes refresh health (implemented by *scoreboard.Refresher).
+type StatsProvider interface {
+	Stats() (success, failure int64, lastErr error, lastErrAt time.Time)
+}
+
+// HTTPHandler builds the JSON REST mux over the store. stats may be nil.
+func HTTPHandler(store *scoreboard.Store, stats StatsProvider, logger *slog.Logger) http.Handler {
+	if logger == nil {
+		logger = slog.Default()
+	}
+	h := &httpServer{store: store, stats: stats, logger: logger}
+
+	mux := http.NewServeMux()
+	mux.HandleFunc("GET /healthz", h.healthz)
+	mux.HandleFunc("GET /readyz", h.readyz)
+	mux.HandleFunc("GET /v1/scoreboard", h.list)
+	mux.HandleFunc("GET /v1/scoreboard/rank/{rank}", h.byRank)
+	mux.HandleFunc("GET /v1/scoreboard/user/{username}", h.byUser)
+	return mux
+}
+
+type httpServer struct {
+	store  *scoreboard.Store
+	stats  StatsProvider
+	logger *slog.Logger
+}
+
+type listResponse struct {
+	Entries   []scoreboard.Entry `json:"entries"`
+	Total     int                `json:"total"`
+	FetchedAt time.Time          `json:"fetched_at"`
+}
+
+func (h *httpServer) healthz(w http.ResponseWriter, _ *http.Request) {
+	w.WriteHeader(http.StatusOK)
+	_, _ = w.Write([]byte("ok\n"))
+}
+
+func (h *httpServer) readyz(w http.ResponseWriter, _ *http.Request) {
+	body := map[string]any{"ready": h.store.Ready(), "entries": h.store.Len()}
+	if h.stats != nil {
+		ok, fail, lastErr, lastErrAt := h.stats.Stats()
+		body["refresh_success"] = ok
+		body["refresh_failure"] = fail
+		if lastErr != nil {
+			body["last_error"] = lastErr.Error()
+			body["last_error_at"] = lastErrAt
+		}
+	}
+	code := http.StatusOK
+	if !h.store.Ready() {
+		code = http.StatusServiceUnavailable
+	}
+	writeJSON(w, code, body)
+}
+
+func (h *httpServer) list(w http.ResponseWriter, r *http.Request) {
+	if !h.store.Ready() {
+		writeError(w, http.StatusServiceUnavailable, "scoreboard not loaded yet")
+		return
+	}
+	offset, err := intParam(r, "offset", 0)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid offset")
+		return
+	}
+	limit, err := intParam(r, "limit", 0)
+	if err != nil {
+		writeError(w, http.StatusBadRequest, "invalid limit")
+		return
+	}
+	entries, fetchedAt := h.store.List(offset, limit)
+	writeJSON(w, http.StatusOK, listResponse{
+		Entries:   entries,
+		Total:     h.store.Len(),
+		FetchedAt: fetchedAt,
+	})
+}
+
+func (h *httpServer) byRank(w http.ResponseWriter, r *http.Request) {
+	if !h.store.Ready() {
+		writeError(w, http.StatusServiceUnavailable, "scoreboard not loaded yet")
+		return
+	}
+	rank, err := strconv.Atoi(r.PathValue("rank"))
+	if err != nil || rank < 1 {
+		writeError(w, http.StatusBadRequest, "rank must be a positive integer")
+		return
+	}
+	e, ok := h.store.ByRank(rank)
+	if !ok {
+		writeError(w, http.StatusNotFound, "no entry at that rank")
+		return
+	}
+	writeJSON(w, http.StatusOK, e)
+}
+
+func (h *httpServer) byUser(w http.ResponseWriter, r *http.Request) {
+	if !h.store.Ready() {
+		writeError(w, http.StatusServiceUnavailable, "scoreboard not loaded yet")
+		return
+	}
+	e, ok := h.store.ByUsername(r.PathValue("username"))
+	if !ok {
+		writeError(w, http.StatusNotFound, "user not found in scoreboard")
+		return
+	}
+	writeJSON(w, http.StatusOK, e)
+}
+
+func intParam(r *http.Request, name string, def int) (int, error) {
+	v := r.URL.Query().Get(name)
+	if v == "" {
+		return def, nil
+	}
+	return strconv.Atoi(v)
+}
+
+func writeJSON(w http.ResponseWriter, code int, v any) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(code)
+	_ = json.NewEncoder(w).Encode(v)
+}
+
+func writeError(w http.ResponseWriter, code int, msg string) {
+	writeJSON(w, code, map[string]string{"error": msg})
+}