package analytics

import (
	"context"
	"encoding/json"
	"strings"
	"testing"

	"github.com/carlosframework/platform/internal/release"
)

func delta(box string, seq int64, pv int64) Delta {
	h := &HLL{}
	h.Add(h64(box + itoa(int(seq))))
	p := NewTopK()
	p.Add("/", pv)
	return Delta{Date: "2026-09-07", Box: box, Seq: seq, Hours: map[string]HourRow{"09": {PV: pv, Bytes: pv * 100}},
		Visitors: h, Pages: p, Referers: NewTopK(), Events: NewTopK()}
}

func TestDayMergeIsSeqIdempotent(t *testing.T) {
	var d Day
	if ok, err := d.Merge(delta("box-a", 5, 10)); !ok || err != nil {
		t.Fatalf("first merge: %v %v", ok, err)
	}
	if ok, _ := d.Merge(delta("box-a", 5, 10)); ok {
		t.Fatal("replaying the same seq must be a no-op")
	}
	if ok, _ := d.Merge(delta("box-a", 4, 10)); ok {
		t.Fatal("an older seq must be a no-op")
	}
	if ok, _ := d.Merge(delta("box-b", 1, 7)); !ok {
		t.Fatal("another box's seq is independent")
	}
	if d.Hours["09"].PV != 17 || d.Pages["/"] != 17 || d.Seq["box-a"] != 5 || d.Seq["box-b"] != 1 || d.V != 1 || d.Date != "2026-09-07" {
		t.Fatalf("merged = %+v", d)
	}
	vis, _ := DecodeHLL(d.Visitors)
	if c := vis.Count(); c < 1.5 || c > 2.5 {
		t.Fatalf("visitors ≈ 2, got %.2f", c)
	}
	b, _ := json.Marshal(d)
	for _, want := range []string{`"v":1`, `"hours"`, `"visitors"`, `"pages"`, `"referers"`, `"events"`, `"seq"`, `"dropped"`, `"countries"`} {
		if !contains(string(b), want) {
			t.Errorf("wire missing %s in %s", want, b)
		}
	}
}

func TestDayMergeReplacesCorruptSketch(t *testing.T) {
	d := Day{Visitors: "garbage!"}
	ok, err := d.Merge(delta("box-a", 1, 5))
	if !ok || err != nil {
		t.Fatalf("merge with corrupt sketch: %v %v", ok, err)
	}
	if d.Hours["09"].PV != 5 || d.Pages["/"] != 5 {
		t.Fatalf("day = %+v", d)
	}
	vis, err := DecodeHLL(d.Visitors)
	if err != nil {
		t.Fatalf("decode replaced sketch: %v", err)
	}
	if c := vis.Count(); c < 0.5 {
		t.Fatalf("expected at least one visitor recorded, got %.2f", c)
	}
}

func TestUpsertDayCASAcrossBoxes(t *testing.T) {
	ctx := context.Background()
	s := release.NewDirStore(t.TempDir())
	if err := UpsertDay(ctx, s, "bab", "web", delta("box-a", 1, 3)); err != nil {
		t.Fatal(err)
	}
	if err := UpsertDay(ctx, s, "bab", "web", delta("box-a", 2, 4)); err != nil {
		t.Fatal(err)
	}
	if err := UpsertDay(ctx, s, "bab", "web", delta("box-a", 2, 4)); err != nil { // retry of an ambiguous put
		t.Fatal(err)
	}
	raw, _, err := s.Get(ctx, must(t)(DayKey("bab", "web", "box-a", "2026-09-07")))
	if err != nil {
		t.Fatal(err)
	}
	var d Day
	json.Unmarshal(raw, &d)
	if d.Hours["09"].PV != 7 || d.Seq["box-a"] != 2 {
		t.Fatalf("day = %+v", d)
	}
	if k := must(t)(DayKey("bab", "web", "box-a", "2026-09-07")); k != "apps/bab/web/analytics/box-a/days/2026-09-07.json" {
		t.Fatal(k)
	}
}

func contains(s, sub string) bool { return strings.Contains(s, sub) }

// must unwraps a key builder's (key, error) for fixtures whose names are
// known good: must(t)(ChunkKey(...)).
func must(t testing.TB) func(string, error) string {
	return func(k string, err error) string {
		t.Helper()
		if err != nil {
			t.Fatal(err)
		}
		return k
	}
}