feat: create standalone native fnOS repository

app-src/internal/api/metrics_handler.go

@@ -0,0 +1,47 @@
+package api
+
+import (
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/havline/havline/internal/metrics"
+)
+
+type MetricsHandler struct {
+	store *metrics.Store
+}
+
+func NewMetricsHandler(store *metrics.Store) *MetricsHandler {
+	return &MetricsHandler{store: store}
+}
+
+// History 返回指标历史：窗口内的序列已按桶取平均，前端拿到就能直接画。
+// hours 最多 30 天（＝保留期），buckets 最多 metrics.MaxBuckets。
+func (h *MetricsHandler) History(w http.ResponseWriter, r *http.Request) {
+	hours := 24
+	if raw := r.URL.Query().Get("hours"); raw != "" {
+		if parsed, err := strconv.Atoi(raw); err == nil && parsed > 0 && parsed <= 24*30 {
+			hours = parsed
+		}
+	}
+	buckets := 48
+	if raw := r.URL.Query().Get("buckets"); raw != "" {
+		if parsed, err := strconv.Atoi(raw); err == nil && parsed > 0 {
+			buckets = parsed
+		}
+	}
+	if buckets > metrics.MaxBuckets {
+		buckets = metrics.MaxBuckets
+	}
+	series, err := h.store.Query(r.Context(), time.Duration(hours)*time.Hour, buckets)
+	if err != nil {
+		writeError(r, w, http.StatusInternalServerError, "读取指标历史失败", err)
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{
+		"hours":   hours,
+		"buckets": buckets,
+		"series":  series,
+	})
+}