// Copyright (C) 2021-present sam (starshines.gay)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

using System.Data;
using System.Data.Common;
using System.Diagnostics.CodeAnalysis;
using Npgsql;
using Serilog;

namespace Catalogger.Backend.Database;

public class DatabaseConnection(NpgsqlConnection inner) : DbConnection, IDisposable
{
    public NpgsqlConnection Inner => inner;

    private bool _hasClosed;

    public override async Task OpenAsync(CancellationToken cancellationToken) =>
        await inner.OpenAsync(cancellationToken);

    public override async Task CloseAsync()
    {
        if (_hasClosed)
        {
            await inner.CloseAsync();
            return;
        }

        DatabasePool.DecrementConnections();
        _hasClosed = true;
        await inner.CloseAsync();
    }

    protected override async ValueTask<DbTransaction> BeginDbTransactionAsync(
        IsolationLevel isolationLevel,
        CancellationToken cancellationToken
    ) => await inner.BeginTransactionAsync(isolationLevel, cancellationToken);

    public new void Dispose()
    {
        Dispose(true);
        GC.SuppressFinalize(this);
    }

    protected override void Dispose(bool disposing)
    {
        Log.Error("Called Dispose method on DbConnection, should call DisposeAsync!");
        Log.Warning("CloseAsync will be called synchronously.");
        CloseAsync().Wait();
        inner.Dispose();
    }

    public override async ValueTask DisposeAsync()
    {
        await CloseAsync();
        await inner.DisposeAsync();
        GC.SuppressFinalize(this);
    }

    protected override DbTransaction BeginDbTransaction(IsolationLevel isolationLevel) =>
        throw new SyncException(nameof(BeginDbTransaction));

    public override void ChangeDatabase(string databaseName) => inner.ChangeDatabase(databaseName);

    public override void Close() => throw new SyncException(nameof(Close));

    public override void Open() => throw new SyncException(nameof(Open));

    [AllowNull]
    public override string ConnectionString
    {
        get => inner.ConnectionString;
        set => inner.ConnectionString = value;
    }

    public override string Database => inner.Database;
    public override ConnectionState State => inner.State;
    public override string DataSource => inner.DataSource;
    public override string ServerVersion => inner.ServerVersion;

    protected override DbCommand CreateDbCommand() => inner.CreateCommand();

    public class SyncException(string method) : Exception($"Tried to use sync method {method}");
}