package store

import (
	"context"
	"testing"
	"time"
)

// A fresh DB has no marker yet, so the current embedder is recorded and
// nothing is flagged.
func TestCheckEmbedderFreshDBRecords(t *testing.T) {
	s := newTestStore(t)
	ctx := context.Background()

	stored, mismatch, err := s.CheckEmbedder(ctx, "multilingual-e5-small@384")
	if err != nil {
		t.Fatalf("CheckEmbedder: %v", err)
	}
	if mismatch {
		t.Fatal("fresh DB reported a mismatch")
	}
	if stored != "multilingual-e5-small@384" {
		t.Fatalf("stored = %q", stored)
	}
	got, err := s.Meta(ctx, metaKeyEmbedderID)
	if err != nil {
		t.Fatalf("Meta: %v", err)
	}
	if got != "multilingual-e5-small@384" {
		t.Fatalf("marker not persisted, got %q", got)
	}
}

// The deployed box: notes were written by the old embedder, before the marker
// existed. Claiming them for the current one would hide exactly the problem
// the marker is for, so an unmarked DB that already holds vectors is a
// mismatch.
func TestCheckEmbedderUnmarkedDBWithVectorsIsMismatch(t *testing.T) {
	s := newTestStore(t)
	ctx := context.Background()

	if _, err := s.WriteNote(ctx, time.Now(), "молоко в холодильнике", []float32{0.1, 0.2}, "voice"); err != nil {
		t.Fatalf("WriteNote: %v", err)
	}

	stored, mismatch, err := s.CheckEmbedder(ctx, "multilingual-e5-small@384")
	if err != nil {
		t.Fatalf("CheckEmbedder: %v", err)
	}
	if !mismatch {
		t.Fatal("an unmarked DB with stored vectors should report a mismatch")
	}
	if stored != EmbedderUnknown {
		t.Fatalf("stored = %q, want %q", stored, EmbedderUnknown)
	}
	// It must NOT claim the DB — that would silence the warning on restart.
	got, err := s.Meta(ctx, metaKeyEmbedderID)
	if err != nil {
		t.Fatalf("Meta: %v", err)
	}
	if got != "" {
		t.Fatalf("marker written despite unknown provenance: %q", got)
	}
}

// Both models are 384-dim, so this is the only thing that catches the swap.
func TestCheckEmbedderDifferentModelMismatch(t *testing.T) {
	s := newTestStore(t)
	ctx := context.Background()

	if err := s.SetMeta(ctx, metaKeyEmbedderID, "paraphrase-multilingual-MiniLM-L12-v2@384"); err != nil {
		t.Fatalf("SetMeta: %v", err)
	}
	stored, mismatch, err := s.CheckEmbedder(ctx, "multilingual-e5-small@384")
	if err != nil {
		t.Fatalf("CheckEmbedder: %v", err)
	}
	if !mismatch {
		t.Fatal("different embedder not detected")
	}
	if stored != "paraphrase-multilingual-MiniLM-L12-v2@384" {
		t.Fatalf("stored = %q", stored)
	}
}

// The same embedder must never raise a false alarm, including on re-check.
func TestCheckEmbedderSameModelNoAlarm(t *testing.T) {
	s := newTestStore(t)
	ctx := context.Background()

	for i := 0; i < 2; i++ {
		_, mismatch, err := s.CheckEmbedder(ctx, "multilingual-e5-small@384")
		if err != nil {
			t.Fatalf("CheckEmbedder: %v", err)
		}
		if mismatch {
			t.Fatalf("false alarm on pass %d", i)
		}
	}
}