package main

import (
	"errors"
	"testing"
)

// The search index (to-be 55 §1, AC52): built from the ledger at start, refusing "index not built" meanwhile, kept current
// as the module writes, and answering the questions the knowledge base is asked as the in-memory ranking does: the records
// the questions are about come first.
func TestTheSearchIndexAnswersTheQuestionsAsTheStoreDoes(t *testing.T) {
	f := newFakeLedger(t)
	ls := newLedgerStore(f, newFakeStates())
	w := newWorld(t, ls, fixture())
	w.k.States = newFakeStates()
	ls.indexAsync = true
	if _, err := ls.Search(t.Context(), "merge window", 5); !errors.Is(err, ErrIndexNotBuilt) {
		t.Fatalf("a question before the index was built: %v", err)
	}
	if _, err := w.k.Import("import@test", ImportAsk{}, fixture()); err != nil {
		t.Fatal(err)
	}
	if err := ls.BuildIndex(t.Context()); err != nil {
		t.Fatal(err)
	}
	if st := ls.IndexState(); !st.Built || st.Docs < 20 {
		t.Fatalf("%+v", st)
	}
	mem := imported(t, newMemStore())
	for _, q := range []string{"merge window", "how is the tool runtime chosen", "what holds about resolved names", "a knowledge base the mesh writes"} {
		want, _ := mem.k.Store.Search(t.Context(), q, 3)
		got, err := ls.Search(t.Context(), q, 8)
		if err != nil {
			t.Fatal(err)
		}
		// The ranking differs (the index weighs by how rare a word is), so the record the store puts first is among the
		// first few of the index's.
		found := false
		for _, h := range got {
			found = found || (len(want) > 0 && h.Key == want[0].Key)
		}
		if len(want) > 0 && !found {
			t.Errorf("%q: the store puts %v first, the index %v", q, want[0], got)
		}
	}
	// A new version is in the index at once; a withdrawn record is out of it.
	r, _ := w.k.ReserveNumber("author@g14", KindDecision, "a test record")
	if hits, _ := ls.Search(t.Context(), "zebra quantum", 5); len(hits) != 0 {
		t.Fatalf("%v", hits)
	}
	p := valid(r.Number)
	p.Title = "Zebra quantum processors"
	p.Sections[2].Text = "A zebra quantum processor."
	if _, err := w.k.Propose("author@g14", p); err != nil {
		t.Fatal(err)
	}
	if hits, _ := ls.Search(t.Context(), "zebra quantum", 5); len(hits) == 0 || hits[0].Key.Number != r.Number {
		t.Fatalf("a proposed record is not in the index: %v", hits)
	}
	if _, err := w.k.WithdrawRecord("author@g14", Key{KindDecision, r.Number}, "not needed"); err != nil {
		t.Fatal(err)
	}
	if hits, _ := ls.Search(t.Context(), "zebra quantum", 5); len(hits) != 0 {
		t.Fatalf("a withdrawn record is in the index: %v", hits)
	}
}