using MessageService.Domain.Entities;
using MessageService.Domain.Enums;
using MessageService.Infrastructure;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using Microsoft.EntityFrameworkCore.Migrations;
using Xunit;

namespace MessageService.Tests;

public sealed class ConversationModelTests
{
    [Fact]
    public void Conversation_read_state_and_unread_count_are_consistent()
    {
        var conversation = new Conversation(
            Guid.NewGuid(), Guid.NewGuid(), string.Empty, "target", null, 0, ChatType.PRIVATE, string.Empty);

        conversation.IncrementUnread();
        conversation.IncrementUnread();
        conversation.MarkAsRead(12);

        Assert.Equal(0, conversation.UnreadCount);
        Assert.Equal(12, conversation.LastReadSequenceId);
    }

    [Fact]
    public void Marking_conversation_read_does_not_change_last_message_activity()
    {
        var conversation = new Conversation(
            Guid.NewGuid(), Guid.NewGuid(), string.Empty, "target", null, 1, ChatType.PRIVATE, "old");
        var messageTime = new DateTimeOffset(2026, 9, 13, 8, 30, 0, TimeSpan.Zero);
        conversation.UpdateLastMessage("new", messageTime);

        conversation.MarkAsRead(42);

        Assert.Equal(messageTime, conversation.LastMessageTime);
        Assert.Equal(42, conversation.LastReadSequenceId);
        Assert.Equal(0, conversation.UnreadCount);
    }

    [Fact]
    public void Active_conversation_key_is_generated_and_unique()
    {
        using var db = CreateContext();
        var entity = db.Model.FindEntityType(typeof(Conversation));
        var property = entity!.FindProperty("ActiveConversationKey");
        var index = entity.GetIndexes().Single(item => item.Properties.Contains(property!));

        Assert.NotNull(property!.GetComputedColumnSql());
        Assert.True(index.IsUnique);
    }

    [Fact]
    public void Migration_script_contains_deduplication_and_active_unique_index()
    {
        using var db = CreateContext();
        var migrator = db.Database.GetService<IMigrator>();

        var script = migrator.GenerateScript(
            "20260909000100_ApiAlignmentFixes",
            "20260911000100_ConversationUniqueness");

        Assert.Contains("conversation_dedup", script);
        Assert.Contains("UX_conversations_ActiveConversationKey", script);
        Assert.Contains("ROW_NUMBER() OVER", script);
    }

    [Fact]
    public void Activity_migration_backfills_latest_message_time_and_adds_search_index()
    {
        using var db = CreateContext();
        var migrator = db.Database.GetService<IMigrator>();

        var script = migrator.GenerateScript(
            "20260911000100_ConversationUniqueness",
            "20260913000100_ConversationActivityAndMessageSearch");

        Assert.Contains("LastMessageTime", script);
        Assert.Contains("MAX(`message`.`CreationTime`)", script);
        Assert.Contains("IX_messages_StreamKey_MsgType_State_SequenceId", script);
    }

    private static MessageDbContext CreateContext()
    {
        const string connectionString = "Server=localhost;Database=im_message_tests;User=test;Password=test";
        var options = new DbContextOptionsBuilder<MessageDbContext>()
            .UseMySql(connectionString, new MySqlServerVersion(new Version(8, 0, 36)))
            .Options;
        return new MessageDbContext(options, null!);
    }
}