package service

import (
	"testing"
	"time"
)

// The overview ring is a fresh store per test (the package singleton is fed
// by RefreshStatus in production); these tests pin its contract: only the
// overview keys are written by AppendOverviewSample, samples come back
// through AggregateOverviewMetric, and the window is hard-bounded by the
// single tier's capacity no matter how long the panel runs.

func overviewTestStatus(cpu float64) *Status {
	st := &Status{Cpu: cpu, TcpCount: 3, UdpCount: 2}
	st.Mem.Current = 1
	st.Mem.Total = 4
	st.Swap.Current = 0
	st.Swap.Total = 0
	st.Disk.Current = 1
	st.Disk.Total = 2
	st.NetIO.Up = 100
	st.NetIO.Down = 200
	return st
}

func TestOverviewRingAppendAndAggregate(t *testing.T) {
	s := &ServerService{}
	base := time.Now().Add(-10 * time.Second).Truncate(2 * time.Second)
	for i := range 5 {
		s.AppendOverviewSample(base.Add(time.Duration(i*2)*time.Second), overviewTestStatus(float64(i)))
	}
	// overviewMetrics is the package singleton; the samples just appended
	// must be visible through the aggregate the controller serves.
	out := s.AggregateOverviewMetric("cpu", 2, 60)
	if len(out) == 0 {
		t.Fatal("AggregateOverviewMetric(cpu) returned no points after appends")
	}
	last := out[len(out)-1]
	if got, _ := last["v"].(float64); got != 4 {
		t.Fatalf("last cpu point = %v, want 4", last["v"])
	}
	for _, key := range OverviewMetricKeys {
		if pts := s.AggregateOverviewMetric(key, 2, 60); len(pts) == 0 {
			t.Fatalf("overview key %q has no points after AppendOverviewSample", key)
		}
	}
}

func TestOverviewRingIsBounded(t *testing.T) {
	h := newMetricHistoryWithTiers([]tierSpec{{resolution: 2, capacity: 360}})
	base := time.Unix(1_700_000_000, 0)
	// Feed ten windows' worth of samples; the ring must not grow past its
	// single tier capacity.
	for i := range 3600 {
		h.append("cpu", base.Add(time.Duration(i*2)*time.Second), float64(i))
	}
	// readSamples returns the closed buckets plus the still-open one, so the
	// hard bound is capacity+1.
	raw := h.series["cpu"].tiers[0].readSamples()
	if len(raw) > 361 {
		t.Fatalf("overview tier retained %d samples, want <= 361 (capacity + open bucket)", len(raw))
	}
	if len(raw) == 0 {
		t.Fatal("overview tier retained no samples")
	}
}