using ZB.MOM.WW.CBDD.Core;
using ZB.MOM.WW.CBDD.Core.Collections;
using ZB.MOM.WW.CBDD.Core.Storage;
using ZB.MOM.WW.CBDD.Core.Transactions;
using ZB.MOM.WW.CBDD.Shared;
using ZB.MOM.WW.CBDD.Shared.TestDbContext_TestDbContext_Mappers;
using Xunit;

namespace ZB.MOM.WW.CBDD.Tests;

public class InsertBulkTests : IDisposable
{
    private readonly string _testFile;
    private readonly Shared.TestDbContext _db;

    /// <summary>
    /// Initializes a new instance of the <see cref="InsertBulkTests"/> class.
    /// </summary>
    public InsertBulkTests()
    {
        _testFile = Path.GetTempFileName();
        _db = new Shared.TestDbContext(_testFile);
    }

    /// <summary>
    /// Disposes test resources.
    /// </summary>
    public void Dispose()
    {
        _db.Dispose();
    }

    /// <summary>
    /// Verifies bulk inserts are immediately persisted and visible.
    /// </summary>
    [Fact]
    public void InsertBulk_PersistsData_ImmediatelyVisible()
    {
        var users = new List<User>();
        for (int i = 0; i < 50; i++)
        {
            users.Add(new User { Id = ZB.MOM.WW.CBDD.Bson.ObjectId.NewObjectId(), Name = $"User {i}", Age = 20 });
        }

        _db.Users.InsertBulk(users);
        _db.SaveChanges();

        var insertedUsers = _db.Users.FindAll().ToList();

        insertedUsers.Count.ShouldBe(50);
    }

    /// <summary>
    /// Verifies bulk inserts spanning multiple pages persist correctly.
    /// </summary>
    [Fact]
    public void InsertBulk_SpanningMultiplePages_PersistsCorrectly()
    {
        // 16KB page. User ~50 bytes. 400 users -> ~20KB -> 2 pages.
        var users = new List<User>();
        for (int i = 0; i < 400; i++)
        {
            users.Add(new User { Id = ZB.MOM.WW.CBDD.Bson.ObjectId.NewObjectId(), Name = $"User {i} with some long padding text to ensure we fill space {new string('x', 50)}", Age = 20 });
        }

        _db.Users.InsertBulk(users);
        _db.SaveChanges();

        _db.Users.Count().ShouldBe(400);
    }
}