package queryd

import (
	"context"
	"database/sql"
	"errors"
	"strings"
	"testing"
	"time"

	"git.agentview.dev/profit/golangLAKEHOUSE/internal/catalogd"
)

// fakeExecer records every SQL string Exec'd against it.
type fakeExecer struct {
	calls []string
}

func (f *fakeExecer) ExecContext(_ context.Context, q string, _ ...any) (sql.Result, error) {
	f.calls = append(f.calls, q)
	return nil, nil
}

// fakeCatalog returns a fixed manifest list and an optional error.
type fakeCatalog struct {
	manifests []*catalogd.Manifest
	err       error
}

func (f *fakeCatalog) List(_ context.Context) ([]*catalogd.Manifest, error) {
	return f.manifests, f.err
}

func mkManifest(name, fp string, updatedAt time.Time, key string) *catalogd.Manifest {
	return &catalogd.Manifest{
		Name:              name,
		DatasetID:         "id-" + name,
		SchemaFingerprint: fp,
		Objects:           []catalogd.Object{{Key: key, Size: 1024}},
		CreatedAt:         updatedAt,
		UpdatedAt:         updatedAt,
	}
}

func TestRefresh_CreatesViewsForNewManifests(t *testing.T) {
	exec := &fakeExecer{}
	cat := &fakeCatalog{manifests: []*catalogd.Manifest{
		mkManifest("workers", "fp1", time.Unix(100, 0), "datasets/workers/fp1.parquet"),
	}}
	r := NewRegistrar(exec, cat, "lakehouse-go-primary")

	stats, err := r.Refresh(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if stats.Created != 1 || stats.Updated != 0 || stats.Dropped != 0 {
		t.Errorf("stats: got %+v, want {Created:1}", stats)
	}
	if len(exec.calls) != 1 {
		t.Fatalf("calls: got %d, want 1", len(exec.calls))
	}
	got := exec.calls[0]
	wantHas := []string{
		`CREATE OR REPLACE VIEW "workers"`,
		`read_parquet('s3://lakehouse-go-primary/datasets/workers/fp1.parquet')`,
	}
	for _, w := range wantHas {
		if !strings.Contains(got, w) {
			t.Errorf("missing %q in %q", w, got)
		}
	}
}

func TestRefresh_SkipsUnchangedUpdatedAt(t *testing.T) {
	exec := &fakeExecer{}
	t1 := time.Unix(100, 0)
	cat := &fakeCatalog{manifests: []*catalogd.Manifest{
		mkManifest("workers", "fp1", t1, "k1"),
	}}
	r := NewRegistrar(exec, cat, "b")

	if _, err := r.Refresh(context.Background()); err != nil {
		t.Fatal(err)
	}
	// Second refresh with same updated_at — should skip.
	stats, err := r.Refresh(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if stats.Skipped != 1 || stats.Created != 0 || stats.Updated != 0 {
		t.Errorf("second refresh stats: got %+v, want {Skipped:1}", stats)
	}
	// Only the first refresh should have produced an Exec call.
	if len(exec.calls) != 1 {
		t.Errorf("calls: got %d, want 1 (skip should not Exec)", len(exec.calls))
	}
}

func TestRefresh_RebuildsOnUpdatedAtBump(t *testing.T) {
	exec := &fakeExecer{}
	t1 := time.Unix(100, 0)
	cat := &fakeCatalog{manifests: []*catalogd.Manifest{
		mkManifest("workers", "fp1", t1, "k1"),
	}}
	r := NewRegistrar(exec, cat, "b")
	_, _ = r.Refresh(context.Background())

	// Bump updated_at — same name + fp, but updated_at changed (idempotent re-register on ingestd).
	t2 := time.Unix(200, 0)
	cat.manifests[0].UpdatedAt = t2
	stats, err := r.Refresh(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if stats.Updated != 1 {
		t.Errorf("expected Updated:1 on updated_at bump, got %+v", stats)
	}
	if len(exec.calls) != 2 {
		t.Errorf("calls: got %d, want 2 (initial + rebuild)", len(exec.calls))
	}
}

func TestRefresh_DropsViewForRemovedManifest(t *testing.T) {
	exec := &fakeExecer{}
	t1 := time.Unix(100, 0)
	cat := &fakeCatalog{manifests: []*catalogd.Manifest{
		mkManifest("workers", "fp1", t1, "k1"),
		mkManifest("retired", "fp2", t1, "k2"),
	}}
	r := NewRegistrar(exec, cat, "b")
	_, _ = r.Refresh(context.Background())

	// "retired" disappears from the catalog → registrar should DROP its view.
	cat.manifests = cat.manifests[:1]
	stats, err := r.Refresh(context.Background())
	if err != nil {
		t.Fatal(err)
	}
	if stats.Dropped != 1 {
		t.Errorf("expected Dropped:1, got %+v", stats)
	}
	// Find the DROP VIEW call.
	var found bool
	for _, c := range exec.calls {
		if strings.HasPrefix(c, `DROP VIEW IF EXISTS "retired"`) {
			found = true
		}
	}
	if !found {
		t.Errorf("DROP VIEW not emitted; calls=%v", exec.calls)
	}
}

func TestRefresh_QuotesAndEscapesNames(t *testing.T) {
	exec := &fakeExecer{}
	weird := `my "weird" dataset` // contains internal double quotes
	cat := &fakeCatalog{manifests: []*catalogd.Manifest{
		mkManifest(weird, "fp", time.Unix(1, 0), "k"),
	}}
	r := NewRegistrar(exec, cat, "b")

	if _, err := r.Refresh(context.Background()); err != nil {
		t.Fatal(err)
	}
	got := exec.calls[0]
	wantQuoted := `"my ""weird"" dataset"`
	if !strings.Contains(got, wantQuoted) {
		t.Errorf("identifier not properly quoted: got %q, want substring %q", got, wantQuoted)
	}
}

func TestRefresh_PropagatesCatalogError(t *testing.T) {
	exec := &fakeExecer{}
	cat := &fakeCatalog{err: errors.New("catalog down")}
	r := NewRegistrar(exec, cat, "b")
	_, err := r.Refresh(context.Background())
	if err == nil || !strings.Contains(err.Error(), "catalog down") {
		t.Errorf("expected wrapped catalog error, got %v", err)
	}
}

func TestRefresh_ManifestWithNoObjectsErrors(t *testing.T) {
	exec := &fakeExecer{}
	m := mkManifest("empty", "fp", time.Unix(1, 0), "k")
	m.Objects = nil // pathological — registrar shouldn't synthesize an empty SQL.
	cat := &fakeCatalog{manifests: []*catalogd.Manifest{m}}
	r := NewRegistrar(exec, cat, "b")
	_, err := r.Refresh(context.Background())
	if err == nil || !strings.Contains(err.Error(), "no objects") {
		t.Errorf("expected 'no objects' error, got %v", err)
	}
}