package mongo

import (
	"strings"
	"testing"

	"go.mongodb.org/mongo-driver/v2/bson"
)

func TestEncodeDecodePageCursor(t *testing.T) {
	encoded, err := encodePageCursor("created_at", -1, int64(1700000000), "507f1f77bcf86cd799439011", "abc123", 10)
	if err != nil {
		t.Fatalf("encode: %v", err)
	}
	if strings.Contains(encoded, "+") || strings.Contains(encoded, "/") {
		t.Fatalf("expected URL-safe cursor, got %q", encoded)
	}

	decoded, err := decodePageCursor(encoded)
	if err != nil {
		t.Fatalf("decode: %v", err)
	}

	if decoded.SortField != "created_at" || decoded.SortOrder != -1 {
		t.Fatalf("unexpected sort: %+v", decoded)
	}
	if decoded.FiltersHash != "abc123" || decoded.PageOffset != 10 {
		t.Fatalf("unexpected metadata: %+v", decoded)
	}
}

func TestBuildListPaginationCursorAndOffsetConflict(t *testing.T) {
	_, err := BuildListPagination(10, 5, "cursor-token", "created_at", "desc", bson.M{}, ListPaginationOptions{})
	if err == nil {
		t.Fatal("expected error when cursor and offset are both set")
	}
}

func TestBuildListPaginationOffsetMode(t *testing.T) {
	p, err := BuildListPagination(10, 20, "", "created_at", "desc", bson.M{"status": "active"}, ListPaginationOptions{})
	if err != nil {
		t.Fatalf("build: %v", err)
	}
	if p.Skip != 20 || p.Limit != 10 || p.Cursor != "" {
		t.Fatalf("unexpected pagination: %+v", p)
	}
}

func TestHashFilterStable(t *testing.T) {
	a := HashFilter(bson.M{"status": "active"})
	b := HashFilter(bson.M{"status": "active"})
	if a == "" || a != b {
		t.Fatalf("expected stable non-empty hash, got %q and %q", a, b)
	}
}

func TestDocumentSortValueNestedField(t *testing.T) {
	doc := bson.M{
		"_id": bson.NewObjectID(),
		"address": bson.M{
			"country": "US",
			"state":   "NY",
		},
	}

	country, err := documentSortValue(doc, "address.country")
	if err != nil {
		t.Fatalf("address.country: %v", err)
	}
	if country != "US" {
		t.Fatalf("expected US, got %v", country)
	}

	state, err := documentSortValue(doc, "address.state")
	if err != nil {
		t.Fatalf("address.state: %v", err)
	}
	if state != "NY" {
		t.Fatalf("expected NY, got %v", state)
	}
}