using SQLite;

namespace ModuleCore.Database;

public class DatabaseManager
{
	private readonly FileInfo _databaseLocation;

	/// <summary>
	/// Creates a new manager for the given database file by name
	/// </summary>
	/// <param name="databaseName">
	/// Filename for the database with no extension. Slashes are accepted and will create directories as needed.
	/// </param>
	public DatabaseManager(string databaseName)
	{
		// Even though the xmldoc says "with no extension", we strip off any extension regardless
		_databaseLocation = new FileInfo(Path.Combine(".", "data", $"{SanitiseFilename(databaseName)}.db"));

		Directory.CreateDirectory(_databaseLocation.DirectoryName!);

		if (!File.Exists(_databaseLocation.FullName))
		{
			var file = File.Create(_databaseLocation.FullName);
			file.Close();
		}
	}

	/// <summary>
	/// Runs the given action within a new database connection
	/// </summary>
	/// <param name="dbAction"></param>
	public void InConnection(Action<SQLiteConnection> dbAction)
	{
		using var conn = new SQLiteConnection(_databaseLocation.FullName);
		dbAction(conn);
	}

	/// <summary>
	/// Runs the given func in a new database connection, returning the result
	/// </summary>
	/// <param name="dbAction"></param>
	/// <typeparam name="T"></typeparam>
	/// <returns></returns>
	public T InConnection<T>(Func<SQLiteConnection, T> dbAction)
	{
		using var conn = new SQLiteConnection(_databaseLocation.FullName);
		return dbAction(conn);
	}

	/// <summary>
	/// Returns a bool for the given query. Convenience method for <see cref="SQLiteConnection.ExecuteScalar"/>.
	/// </summary>
	/// <param name="query">A query starting with SELECT 1, optionally paramaterised with ?</param>
	/// <param name="args">Parameter values</param>
	/// <returns></returns>
	public bool Exists(string query, params object[] args)
	{
		using var conn = new SQLiteConnection(_databaseLocation.FullName);
		var exists = conn.ExecuteScalar<bool?>(query, args);
		return exists ?? false;
	}

	/// <summary>
	/// Deletes the current database file. This will cause any future instance methods to fail on database action if
	/// a new instance is not created.
	/// <para>
	/// This method should be avoided unless calling from a test.
	/// </para>
	/// </summary>
	internal void DeleteDatabase()
	{
		_databaseLocation.Delete();
	}

	/// <summary>
	/// Removes double dots from the filename and removes the file extension
	/// </summary>
	/// <param name="filename"></param>
	/// <returns></returns>
	private string SanitiseFilename(string filename)
	{
		// Honestly not really needed seeing as its just me and this isn't coming from user supplied code, but eh.
		return Path.GetFileNameWithoutExtension(filename.Replace("..", string.Empty));
	}
}