package graph

import (
	"context"
	"math"
	"os"
	"path/filepath"
	"testing"
	"time"

	"github.com/local/glpi-neural-brain/internal/model"
)

func TestSQLiteRoundTripUsesBinaryFloat32Vectors(t *testing.T) {
	dir := t.TempDir()
	s, err := Open(dir)
	if err != nil {
		t.Fatal(err)
	}
	s.UpsertNode(model.Node{ID: "a", Kind: "knowledge", Label: "A", Origin: "test", Categories: []string{"Netzwerk"}, Metadata: map[string]any{"rank": 2}})
	s.UpsertNode(model.Node{ID: "b", Kind: "knowledge", Label: "B", Origin: "test"})
	s.UpsertEdge(model.Edge{Source: "a", Target: "b", Type: "related_to", Origin: "test", Confidence: .8})
	s.SetVector("a", []float64{.125, -.5, .875})
	if _, err := s.PersistVersionContext(context.Background()); err != nil {
		t.Fatal(err)
	}
	status := s.StorageStatus()
	if status.Backend != "sqlite" || status.VectorBytes != 12 || status.PendingNodes != 0 || status.PendingVectors != 0 {
		t.Fatalf("unexpected storage status: %+v", status)
	}
	if _, err := os.Stat(filepath.Join(dir, "graph-state.json")); !os.IsNotExist(err) {
		t.Fatalf("legacy JSON snapshot must not be created: %v", err)
	}
	if err := s.Close(); err != nil {
		t.Fatal(err)
	}

	reopened, err := Open(dir)
	if err != nil {
		t.Fatal(err)
	}
	defer reopened.Close()
	if got := reopened.Snapshot(); len(got.Nodes) != 2 || len(got.Edges) != 1 {
		t.Fatalf("unexpected round-trip graph: nodes=%d edges=%d", len(got.Nodes), len(got.Edges))
	}
	vector, ok := reopened.Vector("a")
	if !ok || len(vector) != 3 {
		t.Fatalf("vector missing after round trip: %v %v", ok, vector)
	}
	want := []float64{.125, -.5, .875}
	for i := range want {
		if math.Abs(vector[i]-want[i]) > 1e-6 {
			t.Fatalf("vector[%d]=%f want %f", i, vector[i], want[i])
		}
	}
}

func TestSQLitePersistsOnlyDirtyRows(t *testing.T) {
	s, err := Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	defer s.Close()
	s.UpsertNode(model.Node{ID: "a", Kind: "knowledge", Label: "A", Origin: "test"})
	s.UpsertNode(model.Node{ID: "b", Kind: "knowledge", Label: "B", Origin: "test"})
	s.SetVector("a", []float64{1, 0})
	if _, err := s.PersistVersion(); err != nil {
		t.Fatal(err)
	}
	if s.Dirty() {
		t.Fatal("store remained dirty after successful flush")
	}

	n, _ := s.GetNode("a")
	n.Label = "A2"
	s.UpsertNode(n)
	status := s.StorageStatus()
	if status.PendingNodes != 1 || status.PendingEdges != 0 || status.PendingVectors != 0 {
		t.Fatalf("expected one dirty node, got %+v", status)
	}
	if _, err := s.PersistVersion(); err != nil {
		t.Fatal(err)
	}
	if status = s.StorageStatus(); status.PendingNodes != 0 || s.Dirty() {
		t.Fatalf("dirty rows were not cleared: %+v", status)
	}
}

func TestSQLiteExportCreatesPortableDatabase(t *testing.T) {
	s, err := Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	defer s.Close()
	s.UpsertNode(model.Node{ID: "portable", Kind: "knowledge", Label: "Portable", Origin: "test"})
	s.SetVector("portable", []float64{1, 2, 3, 4})
	exportDir := t.TempDir()
	destination := filepath.Join(exportDir, "graph.db")
	if err := s.Export(context.Background(), destination); err != nil {
		t.Fatal(err)
	}
	copyStore, err := Open(exportDir)
	if err != nil {
		t.Fatal(err)
	}
	defer copyStore.Close()
	if _, ok := copyStore.GetNode("portable"); !ok {
		t.Fatal("exported database did not contain graph node")
	}
	if vector, ok := copyStore.Vector("portable"); !ok || len(vector) != 4 {
		t.Fatalf("exported database did not contain vector: %v %v", ok, vector)
	}
}

func TestReplaceOriginsLeavesUnchangedKnowledgeClean(t *testing.T) {
	s, err := Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	defer s.Close()
	updated := time.Date(2026, 8, 4, 12, 0, 0, 0, time.UTC)
	nodes := []model.Node{
		{ID: "a", Kind: "knowledge", Label: "A", Summary: "gleich", Origin: "kb", UpdatedAt: updated},
		{ID: "b", Kind: "knowledge", Label: "B", Summary: "gleich", Origin: "kb", UpdatedAt: updated},
	}
	edges := []model.Edge{{Source: "a", Target: "b", Type: "related_to", Origin: "kb", Weight: 1}}
	s.ReplaceOrigins([]string{"kb"}, nodes, edges)
	s.SetVector("a", []float64{1, 0, 0})
	if _, err := s.PersistVersion(); err != nil {
		t.Fatal(err)
	}
	version := s.Version()

	s.ReplaceOrigins([]string{"kb"}, nodes, edges)
	if s.Dirty() {
		t.Fatalf("unchanged KB scan marked SQLite rows dirty: %+v", s.StorageStatus())
	}
	if s.Version() != version {
		t.Fatalf("unchanged KB scan changed graph version: got %d want %d", s.Version(), version)
	}
	if _, ok := s.Vector("a"); !ok {
		t.Fatal("unchanged KB scan discarded embedding")
	}
}

func TestReplaceOriginsInvalidatesOnlyChangedEmbedding(t *testing.T) {
	s, err := Open(t.TempDir())
	if err != nil {
		t.Fatal(err)
	}
	defer s.Close()
	updated := time.Date(2026, 8, 4, 12, 0, 0, 0, time.UTC)
	nodes := []model.Node{{ID: "a", Kind: "knowledge", Label: "A", Summary: "alt", Origin: "kb", UpdatedAt: updated}}
	s.ReplaceOrigins([]string{"kb"}, nodes, nil)
	s.SetVector("a", []float64{1, 0, 0})
	if _, err := s.PersistVersion(); err != nil {
		t.Fatal(err)
	}

	nodes[0].Summary = "neu"
	nodes[0].UpdatedAt = updated.Add(time.Minute)
	s.ReplaceOrigins([]string{"kb"}, nodes, nil)
	if _, ok := s.Vector("a"); ok {
		t.Fatal("changed embedding input retained stale vector")
	}
	status := s.StorageStatus()
	if status.PendingNodes != 1 || status.PendingDeletions != 1 {
		t.Fatalf("expected changed node and vector deletion, got %+v", status)
	}
}

func TestEmbeddingModelIdentityInvalidatesImportedVectors(t *testing.T) {
	dir := t.TempDir()
	s, err := Open(dir)
	if err != nil {
		t.Fatal(err)
	}
	s.ConfigureEmbeddingIdentity("embeddinggemma", "sha256:d1")
	s.UpsertNode(model.Node{ID: "a", Kind: "knowledge", Label: "A", Origin: "test"})
	s.SetVector("a", []float64{1, 2, 3})
	if _, err := s.PersistVersion(); err != nil {
		t.Fatal(err)
	}
	if err := s.Close(); err != nil {
		t.Fatal(err)
	}

	reopened, err := Open(dir)
	if err != nil {
		t.Fatal(err)
	}
	defer reopened.Close()
	if removed := reopened.ConfigureEmbeddingIdentity("embeddinggemma", "sha256:d2"); removed != 1 {
		t.Fatalf("removed vectors=%d want 1", removed)
	}
	if _, ok := reopened.Vector("a"); ok {
		t.Fatal("vector from a different embedding model remained available")
	}
	status := reopened.StorageStatus()
	if status.EmbeddingModel != "embeddinggemma" || status.EmbeddingDigest != "sha256:d2" || !status.PendingMetadata || status.PendingDeletions != 1 {
		t.Fatalf("unexpected model-change status: %+v", status)
	}
}