package store_test

import (
	"context"
	"errors"
	"testing"
	"time"

	"github.com/wotra/wotra/internal/domain"
	"github.com/wotra/wotra/internal/store"
)

func mustSyncStore(t *testing.T) *store.SyncStore {
	t.Helper()
	db, err := store.Open(":memory:")
	if err != nil {
		t.Fatal(err)
	}
	t.Cleanup(func() { db.Close() })
	return store.NewSyncStore(db)
}

func TestSyncPullNormal(t *testing.T) {
	s := mustSyncStore(t)
	ctx := context.Background()

	e1 := &domain.Entry{ID: "e1", DayKey: "2026-04-01", UpdatedAt: time.Now().UnixMilli()}
	e2 := &domain.Entry{ID: "e2", DayKey: "2026-04-02", UpdatedAt: time.Now().UnixMilli()}
	if err := s.LogEntry(ctx, e1); err != nil {
		t.Fatal(err)
	}
	if err := s.LogEntry(ctx, e2); err != nil {
		t.Fatal(err)
	}

	changes, ver, err := s.Pull(ctx, 0)
	if err != nil {
		t.Fatalf("Pull: %v", err)
	}
	if len(changes) != 2 {
		t.Fatalf("expected 2 changes, got %d", len(changes))
	}
	if ver != 2 {
		t.Fatalf("expected server_version=2, got %d", ver)
	}

	// Incremental pull: since=1 should return only e2.
	changes2, ver2, err := s.Pull(ctx, 1)
	if err != nil {
		t.Fatal(err)
	}
	if len(changes2) != 1 || changes2[0].EntityID != "e2" {
		t.Fatalf("expected [e2], got %+v", changes2)
	}
	if ver2 != 2 {
		t.Fatalf("expected ver=2, got %d", ver2)
	}
}

func TestSyncPruneStaleClient(t *testing.T) {
	s := mustSyncStore(t)
	ctx := context.Background()

	// Log two entries then prune all of them (zero TTL).
	e1 := &domain.Entry{ID: "e1", DayKey: "2026-01-01", UpdatedAt: time.Now().UnixMilli()}
	e2 := &domain.Entry{ID: "e2", DayKey: "2026-01-02", UpdatedAt: time.Now().UnixMilli()}
	if err := s.LogEntry(ctx, e1); err != nil {
		t.Fatal(err)
	}
	if err := s.LogEntry(ctx, e2); err != nil {
		t.Fatal(err)
	}

	// Prune with -1ms TTL → cutoff is 1ms in the future, so all rows are pruned.
	if err := s.Prune(ctx, -time.Millisecond); err != nil {
		t.Fatalf("Prune: %v", err)
	}

	// A stale client (since=0) should get ErrSyncStale.
	_, _, err := s.Pull(ctx, 0)
	if !errors.Is(err, store.ErrSyncStale) {
		t.Fatalf("expected ErrSyncStale, got %v", err)
	}
}

func TestSyncPruneNoRows(t *testing.T) {
	s := mustSyncStore(t)
	ctx := context.Background()

	// Prune on empty log is a no-op.
	if err := s.Prune(ctx, 30*24*time.Hour); err != nil {
		t.Fatalf("Prune on empty log: %v", err)
	}

	changes, ver, err := s.Pull(ctx, 0)
	if err != nil {
		t.Fatalf("Pull: %v", err)
	}
	if len(changes) != 0 {
		t.Fatalf("expected 0 changes, got %d", len(changes))
	}
	if ver != 0 {
		t.Fatalf("expected ver=0, got %d", ver)
	}
}

func TestSyncClientAheadOfMarker(t *testing.T) {
	s := mustSyncStore(t)
	ctx := context.Background()

	// Log two entries, prune all, then log a third.
	e1 := &domain.Entry{ID: "e1", DayKey: "2026-01-01", UpdatedAt: time.Now().UnixMilli()}
	e2 := &domain.Entry{ID: "e2", DayKey: "2026-01-02", UpdatedAt: time.Now().UnixMilli()}
	if err := s.LogEntry(ctx, e1); err != nil {
		t.Fatal(err)
	}
	if err := s.LogEntry(ctx, e2); err != nil {
		t.Fatal(err)
	}
	if err := s.Prune(ctx, -time.Millisecond); err != nil {
		t.Fatal(err)
	}
	// Marker is at version 2. Log a new entry → version 3.
	e3 := &domain.Entry{ID: "e3", DayKey: "2026-04-01", UpdatedAt: time.Now().UnixMilli()}
	if err := s.LogEntry(ctx, e3); err != nil {
		t.Fatal(err)
	}

	// A client with since=2 is past the marker — should get only e3.
	changes, ver, err := s.Pull(ctx, 2)
	if err != nil {
		t.Fatalf("expected no error for up-to-date client, got %v", err)
	}
	if len(changes) != 1 || changes[0].EntityID != "e3" {
		t.Fatalf("expected [e3], got %+v", changes)
	}
	if ver != 3 {
		t.Fatalf("expected ver=3, got %d", ver)
	}
}