namespace GmRelay.Bot.Tests.Infrastructure.Database;

public sealed class PlatformIdentityMigrationTests
{
    [Fact]
    public async Task MigrationV016_ShouldAddPlatformIdentityColumns()
    {
        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V016__add_platform_identity.sql");

        Assert.Contains("players", migration, StringComparison.Ordinal);
        Assert.Contains("platform", migration, StringComparison.Ordinal);
        Assert.Contains("external_user_id", migration, StringComparison.Ordinal);
        Assert.Contains("external_username", migration, StringComparison.Ordinal);

        Assert.Contains("game_groups", migration, StringComparison.Ordinal);
        Assert.Contains("external_group_id", migration, StringComparison.Ordinal);
        Assert.Contains("external_channel_id", migration, StringComparison.Ordinal);
    }

    [Fact]
    public async Task MigrationV016_ShouldCreatePlatformMessagesTable()
    {
        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V016__add_platform_identity.sql");

        Assert.Contains("CREATE TABLE platform_messages", migration, StringComparison.Ordinal);
        Assert.Contains("platform", migration, StringComparison.Ordinal);
        Assert.Contains("group_id", migration, StringComparison.Ordinal);
        Assert.Contains("batch_id", migration, StringComparison.Ordinal);
        Assert.Contains("session_id", migration, StringComparison.Ordinal);
        Assert.Contains("external_thread_id", migration, StringComparison.Ordinal);
        Assert.Contains("external_message_id", migration, StringComparison.Ordinal);
        Assert.Contains("purpose", migration, StringComparison.Ordinal);
    }

    [Fact]
    public async Task MigrationV016_ShouldBackfillExistingTelegramData()
    {
        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V016__add_platform_identity.sql");

        Assert.Contains("UPDATE players", migration, StringComparison.Ordinal);
        Assert.Contains("UPDATE game_groups", migration, StringComparison.Ordinal);
        Assert.Contains("'Telegram'", migration, StringComparison.Ordinal);
        Assert.Contains("telegram_id", migration, StringComparison.Ordinal);
        Assert.Contains("telegram_chat_id", migration, StringComparison.Ordinal);
    }

    [Fact]
    public async Task MigrationV016_ShouldNotDropLegacyTelegramColumns()
    {
        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V016__add_platform_identity.sql");

        Assert.DoesNotContain("DROP COLUMN telegram_id", migration, StringComparison.OrdinalIgnoreCase);
        Assert.DoesNotContain("DROP COLUMN telegram_chat_id", migration, StringComparison.OrdinalIgnoreCase);
        Assert.DoesNotContain("DROP COLUMN telegram_username", migration, StringComparison.OrdinalIgnoreCase);
        Assert.DoesNotContain("DROP COLUMN gm_telegram_id", migration, StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public async Task Code_ShouldQueryPlayersUsingExternalUserIdFallback()
    {
        var createHandler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/CreateSessionHandler.cs");

        Assert.Contains("external_user_id", createHandler, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Code_ShouldQueryGroupsUsingExternalGroupIdFallback()
    {
        var createHandler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/CreateSessionHandler.cs");

        Assert.Contains("external_group_id", createHandler, StringComparison.Ordinal);
    }

    [Fact]
    public async Task JoinSessionHandler_ShouldDualWritePlatformIdentity()
    {
        var handler = await ReadRepositoryFileAsync("src/GmRelay.Bot/Features/Sessions/CreateSession/JoinSessionHandler.cs");

        Assert.Contains("external_user_id", handler, StringComparison.Ordinal);
        Assert.Contains("external_username", handler, StringComparison.Ordinal);
        Assert.Contains("platform", handler, StringComparison.Ordinal);
    }

    [Fact]
    public async Task WebSessionService_ShouldDualWritePlatformIdentity()
    {
        var service = await ReadRepositoryFileAsync("src/GmRelay.Web/Services/SessionService.cs");

        Assert.Contains("external_user_id", service, StringComparison.Ordinal);
        Assert.Contains("external_username", service, StringComparison.Ordinal);
        Assert.Contains("platform", service, StringComparison.Ordinal);
    }

    [Fact]
    public async Task AttendanceStatsFunction_ShouldReferenceExternalUsername()
    {
        var statsMigration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V012__add_attendance_stats.sql");

        Assert.Contains("external_username", statsMigration, StringComparison.Ordinal);
    }

    [Fact]
    public async Task MigrationV017_ShouldAllowPlayersWithoutLegacyTelegramId()
    {
        var migration = await ReadRepositoryFileAsync("src/GmRelay.Bot/Migrations/V017__allow_platform_neutral_players.sql");

        Assert.Contains("ALTER TABLE players", migration, StringComparison.Ordinal);
        Assert.Contains("telegram_id DROP NOT NULL", migration, StringComparison.Ordinal);
    }

    private static async Task<string> ReadRepositoryFileAsync(string relativePath)
    {
        var directory = new DirectoryInfo(AppContext.BaseDirectory);
        while (directory is not null)
        {
            var candidate = Path.Combine(directory.FullName, relativePath);
            if (File.Exists(candidate))
            {
                return await File.ReadAllTextAsync(candidate);
            }

            directory = directory.Parent;
        }

        throw new FileNotFoundException($"Could not locate repository file '{relativePath}'.");
    }
}