ChatBot/ChatBot.Tests/Models/ChatSessionEntityTests.cs

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Text.Json;
using ChatBot.Models.Entities;
using FluentAssertions;

namespace ChatBot.Tests.Models;

public class ChatSessionEntityTests
{
    [Fact]
    public void Constructor_ShouldInitializePropertiesWithDefaultValues()
    {
        // Arrange & Act
        var entity = new ChatSessionEntity();

        // Assert
        entity.Id.Should().Be(0);
        entity.SessionId.Should().Be(string.Empty);
        entity.ChatId.Should().Be(0);
        entity.ChatType.Should().Be("private");
        entity.ChatTitle.Should().Be(string.Empty);
        entity.Model.Should().Be(string.Empty);
        entity.CreatedAt.Should().BeCloseTo(DateTime.UtcNow, TimeSpan.FromSeconds(1));
        entity.LastUpdatedAt.Should().BeCloseTo(DateTime.UtcNow, TimeSpan.FromSeconds(1));
        entity.MaxHistoryLength.Should().Be(30);
        entity.Messages.Should().NotBeNull();
        entity.Messages.Should().BeEmpty();
    }

    [Fact]
    public void Id_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedId = 123;

        // Act
        entity.Id = expectedId;

        // Assert
        entity.Id.Should().Be(expectedId);
    }

    [Fact]
    public void SessionId_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedSessionId = "session-123";

        // Act
        entity.SessionId = expectedSessionId;

        // Assert
        entity.SessionId.Should().Be(expectedSessionId);
    }

    [Fact]
    public void ChatId_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedChatId = 987654321L;

        // Act
        entity.ChatId = expectedChatId;

        // Assert
        entity.ChatId.Should().Be(expectedChatId);
    }

    [Fact]
    public void ChatType_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedChatType = "group";

        // Act
        entity.ChatType = expectedChatType;

        // Assert
        entity.ChatType.Should().Be(expectedChatType);
    }

    [Fact]
    public void ChatTitle_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedChatTitle = "My Test Group";

        // Act
        entity.ChatTitle = expectedChatTitle;

        // Assert
        entity.ChatTitle.Should().Be(expectedChatTitle);
    }

    [Fact]
    public void Model_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedModel = "llama3.1:8b";

        // Act
        entity.Model = expectedModel;

        // Assert
        entity.Model.Should().Be(expectedModel);
    }

    [Fact]
    public void CreatedAt_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedDate = DateTime.UtcNow.AddDays(-1);

        // Act
        entity.CreatedAt = expectedDate;

        // Assert
        entity.CreatedAt.Should().Be(expectedDate);
    }

    [Fact]
    public void LastUpdatedAt_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedDate = DateTime.UtcNow.AddHours(-2);

        // Act
        entity.LastUpdatedAt = expectedDate;

        // Assert
        entity.LastUpdatedAt.Should().Be(expectedDate);
    }

    [Fact]
    public void MaxHistoryLength_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedLength = 50;

        // Act
        entity.MaxHistoryLength = expectedLength;

        // Assert
        entity.MaxHistoryLength.Should().Be(expectedLength);
    }

    [Fact]
    public void Messages_ShouldBeSettable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var expectedMessages = new List<ChatMessageEntity>
        {
            new() { Content = "Test message 1", Role = "user" },
            new() { Content = "Test message 2", Role = "assistant" },
        };

        // Act
        entity.Messages = expectedMessages;

        // Assert
        entity.Messages.Should().BeSameAs(expectedMessages);
        entity.Messages.Should().HaveCount(2);
    }

    [Theory]
    [InlineData("private")]
    [InlineData("group")]
    [InlineData("supergroup")]
    [InlineData("channel")]
    public void ChatType_ShouldAcceptValidTypes(string chatType)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.ChatType = chatType;

        // Assert
        entity.ChatType.Should().Be(chatType);
    }

    [Theory]
    [InlineData("")]
    [InlineData("a")]
    [InlineData("very long chat type name")]
    public void ChatType_ShouldAcceptVariousLengths(string chatType)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.ChatType = chatType;

        // Assert
        entity.ChatType.Should().Be(chatType);
    }

    [Theory]
    [InlineData("")]
    [InlineData("Short title")]
    [InlineData("A very long chat title that contains a lot of text and should still be valid")]
    public void ChatTitle_ShouldAcceptVariousLengths(string chatTitle)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.ChatTitle = chatTitle;

        // Assert
        entity.ChatTitle.Should().Be(chatTitle);
    }

    [Theory]
    [InlineData("")]
    [InlineData("llama3.1:8b")]
    [InlineData("gpt-4")]
    [InlineData("claude-3-sonnet")]
    public void Model_ShouldAcceptVariousModels(string model)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.Model = model;

        // Assert
        entity.Model.Should().Be(model);
    }

    [Theory]
    [InlineData("")]
    [InlineData("session-123")]
    [InlineData("very-long-session-id-that-exceeds-normal-length")]
    public void SessionId_ShouldAcceptVariousLengths(string sessionId)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.SessionId = sessionId;

        // Assert
        entity.SessionId.Should().Be(sessionId);
    }

    [Theory]
    [InlineData(0L)]
    [InlineData(123456789L)]
    [InlineData(-987654321L)]
    [InlineData(long.MaxValue)]
    [InlineData(long.MinValue)]
    public void ChatId_ShouldAcceptVariousValues(long chatId)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.ChatId = chatId;

        // Assert
        entity.ChatId.Should().Be(chatId);
    }

    [Theory]
    [InlineData(0)]
    [InlineData(1)]
    [InlineData(30)]
    [InlineData(100)]
    [InlineData(int.MaxValue)]
    public void MaxHistoryLength_ShouldAcceptVariousValues(int maxHistoryLength)
    {
        // Arrange
        var entity = new ChatSessionEntity();

        // Act
        entity.MaxHistoryLength = maxHistoryLength;

        // Assert
        entity.MaxHistoryLength.Should().Be(maxHistoryLength);
    }

    [Fact]
    public void CreatedAt_ShouldDefaultToCurrentUtcTime()
    {
        // Arrange
        var beforeCreation = DateTime.UtcNow;

        // Act
        var entity = new ChatSessionEntity();

        // Assert
        entity.CreatedAt.Should().BeOnOrAfter(beforeCreation);
        entity.CreatedAt.Should().BeOnOrBefore(DateTime.UtcNow);
    }

    [Fact]
    public void LastUpdatedAt_ShouldDefaultToCurrentUtcTime()
    {
        // Arrange
        var beforeCreation = DateTime.UtcNow;

        // Act
        var entity = new ChatSessionEntity();

        // Assert
        entity.LastUpdatedAt.Should().BeOnOrAfter(beforeCreation);
        entity.LastUpdatedAt.Should().BeOnOrBefore(DateTime.UtcNow);
    }

    [Fact]
    public void AllProperties_ShouldBeMutable()
    {
        // Arrange
        var entity = new ChatSessionEntity();
        var messages = new List<ChatMessageEntity>
        {
            new() { Content = "Test", Role = "user" },
        };

        // Act
        entity.Id = 1;
        entity.SessionId = "test-session";
        entity.ChatId = 123456789L;
        entity.ChatType = "group";
        entity.ChatTitle = "Test Group";
        entity.Model = "llama3.1:8b";
        entity.CreatedAt = DateTime.UtcNow.AddDays(-1);
        entity.LastUpdatedAt = DateTime.UtcNow.AddHours(-1);
        entity.MaxHistoryLength = 50;
        entity.Messages = messages;

        // Assert
        entity.Id.Should().Be(1);
        entity.SessionId.Should().Be("test-session");
        entity.ChatId.Should().Be(123456789L);
        entity.ChatType.Should().Be("group");
        entity.ChatTitle.Should().Be("Test Group");
        entity.Model.Should().Be("llama3.1:8b");
        entity.CreatedAt.Should().BeCloseTo(DateTime.UtcNow.AddDays(-1), TimeSpan.FromSeconds(1));
        entity
            .LastUpdatedAt.Should()
            .BeCloseTo(DateTime.UtcNow.AddHours(-1), TimeSpan.FromSeconds(1));
        entity.MaxHistoryLength.Should().Be(50);
        entity.Messages.Should().BeSameAs(messages);
    }

    [Fact]
    public void Entity_ShouldHaveCorrectTableAttribute()
    {
        // Arrange
        var entityType = typeof(ChatSessionEntity);
        var tableAttribute =
            entityType.GetCustomAttributes(typeof(TableAttribute), false).FirstOrDefault()
            as TableAttribute;

        // Assert
        tableAttribute.Should().NotBeNull();
        tableAttribute!.Name.Should().Be("chat_sessions");
    }

    [Fact]
    public void Id_ShouldHaveKeyAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.Id));
        var keyAttribute =
            property?.GetCustomAttributes(typeof(KeyAttribute), false).FirstOrDefault()
            as KeyAttribute;

        // Assert
        keyAttribute.Should().NotBeNull();
    }

    [Fact]
    public void Id_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.Id));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("id");
    }

    [Fact]
    public void SessionId_ShouldHaveRequiredAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.SessionId));
        var requiredAttribute =
            property?.GetCustomAttributes(typeof(RequiredAttribute), false).FirstOrDefault()
            as RequiredAttribute;

        // Assert
        requiredAttribute.Should().NotBeNull();
    }

    [Fact]
    public void SessionId_ShouldHaveStringLengthAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.SessionId));
        var stringLengthAttribute =
            property?.GetCustomAttributes(typeof(StringLengthAttribute), false).FirstOrDefault()
            as StringLengthAttribute;

        // Assert
        stringLengthAttribute.Should().NotBeNull();
        stringLengthAttribute!.MaximumLength.Should().Be(50);
    }

    [Fact]
    public void SessionId_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.SessionId));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("session_id");
    }

    [Fact]
    public void ChatId_ShouldHaveRequiredAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatId));
        var requiredAttribute =
            property?.GetCustomAttributes(typeof(RequiredAttribute), false).FirstOrDefault()
            as RequiredAttribute;

        // Assert
        requiredAttribute.Should().NotBeNull();
    }

    [Fact]
    public void ChatId_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatId));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("chat_id");
    }

    [Fact]
    public void ChatType_ShouldHaveRequiredAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatType));
        var requiredAttribute =
            property?.GetCustomAttributes(typeof(RequiredAttribute), false).FirstOrDefault()
            as RequiredAttribute;

        // Assert
        requiredAttribute.Should().NotBeNull();
    }

    [Fact]
    public void ChatType_ShouldHaveStringLengthAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatType));
        var stringLengthAttribute =
            property?.GetCustomAttributes(typeof(StringLengthAttribute), false).FirstOrDefault()
            as StringLengthAttribute;

        // Assert
        stringLengthAttribute.Should().NotBeNull();
        stringLengthAttribute!.MaximumLength.Should().Be(20);
    }

    [Fact]
    public void ChatType_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatType));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("chat_type");
    }

    [Fact]
    public void ChatTitle_ShouldHaveStringLengthAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatTitle));
        var stringLengthAttribute =
            property?.GetCustomAttributes(typeof(StringLengthAttribute), false).FirstOrDefault()
            as StringLengthAttribute;

        // Assert
        stringLengthAttribute.Should().NotBeNull();
        stringLengthAttribute!.MaximumLength.Should().Be(200);
    }

    [Fact]
    public void ChatTitle_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.ChatTitle));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("chat_title");
    }

    [Fact]
    public void Model_ShouldHaveStringLengthAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.Model));
        var stringLengthAttribute =
            property?.GetCustomAttributes(typeof(StringLengthAttribute), false).FirstOrDefault()
            as StringLengthAttribute;

        // Assert
        stringLengthAttribute.Should().NotBeNull();
        stringLengthAttribute!.MaximumLength.Should().Be(100);
    }

    [Fact]
    public void Model_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.Model));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("model");
    }

    [Fact]
    public void CreatedAt_ShouldHaveRequiredAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.CreatedAt));
        var requiredAttribute =
            property?.GetCustomAttributes(typeof(RequiredAttribute), false).FirstOrDefault()
            as RequiredAttribute;

        // Assert
        requiredAttribute.Should().NotBeNull();
    }

    [Fact]
    public void CreatedAt_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(nameof(ChatSessionEntity.CreatedAt));
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("created_at");
    }

    [Fact]
    public void LastUpdatedAt_ShouldHaveRequiredAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(
            nameof(ChatSessionEntity.LastUpdatedAt)
        );
        var requiredAttribute =
            property?.GetCustomAttributes(typeof(RequiredAttribute), false).FirstOrDefault()
            as RequiredAttribute;

        // Assert
        requiredAttribute.Should().NotBeNull();
    }

    [Fact]
    public void LastUpdatedAt_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(
            nameof(ChatSessionEntity.LastUpdatedAt)
        );
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("last_updated_at");
    }

    [Fact]
    public void MaxHistoryLength_ShouldHaveColumnAttribute()
    {
        // Arrange
        var property = typeof(ChatSessionEntity).GetProperty(
            nameof(ChatSessionEntity.MaxHistoryLength)
        );
        var columnAttribute =
            property?.GetCustomAttributes(typeof(ColumnAttribute), false).FirstOrDefault()
            as ColumnAttribute;

        // Assert
        columnAttribute.Should().NotBeNull();
        columnAttribute!.Name.Should().Be("max_history_length");
    }

    [Fact]
    public void JsonSerialization_RoundTrip_ShouldPreserveScalarProperties()
    {
        // Arrange
        var original = new ChatSessionEntity
        {
            Id = 101,
            SessionId = "session-json-1",
            ChatId = 123456789L,
            ChatType = "group",
            ChatTitle = "Test Group",
            Model = "llama3.1:8b",
            CreatedAt = DateTime.UtcNow.AddMinutes(-10),
            LastUpdatedAt = DateTime.UtcNow.AddMinutes(-5),
            MaxHistoryLength = 77,
            Messages = new List<ChatMessageEntity>(),
        };

        var options = new JsonSerializerOptions
        {
            PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
            WriteIndented = false,
            DefaultIgnoreCondition = System
                .Text
                .Json
                .Serialization
                .JsonIgnoreCondition
                .WhenWritingNull,
        };

        // Act
        var json = JsonSerializer.Serialize(original, options);
        var deserialized = JsonSerializer.Deserialize<ChatSessionEntity>(json, options)!;

        // Assert
        deserialized.Id.Should().Be(original.Id);
        deserialized.SessionId.Should().Be(original.SessionId);
        deserialized.ChatId.Should().Be(original.ChatId);
        deserialized.ChatType.Should().Be(original.ChatType);
        deserialized.ChatTitle.Should().Be(original.ChatTitle);
        deserialized.Model.Should().Be(original.Model);
        deserialized.MaxHistoryLength.Should().Be(original.MaxHistoryLength);
        // Allow small delta for DateTime serialization
        deserialized.CreatedAt.Should().BeCloseTo(original.CreatedAt, TimeSpan.FromSeconds(1));
        deserialized
            .LastUpdatedAt.Should()
            .BeCloseTo(original.LastUpdatedAt, TimeSpan.FromSeconds(1));
        deserialized.Messages.Should().NotBeNull();
        deserialized.Messages.Should().BeEmpty();
    }
}