// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System;
 
namespace Microsoft.CodeAnalysis.SQLite.v2.Interop
{
    /// <summary>
    /// Simple wrapper struct for a <see cref="SqlStatement"/> that helps ensure that the statement is always has it's
    /// bindings cleared (<see cref="SqlStatement.ClearBindings"/>) and is <see cref="SqlStatement.Reset"/> after it is
    /// used.
    /// <para/>
    /// See https://sqlite.org/c3ref/stmt.html:
    /// The life-cycle of a prepared statement object usually goes like this:
    ///    1) Create the prepared statement object using sqlite3_prepare_v2().
    ///    2) Bind values to parameters using the sqlite3_bind_* () interfaces.
    ///    3) Run the SQL by calling sqlite3_step() one or more times.
    ///    4) Reset the prepared statement using sqlite3_reset() then go back to step 2. Do this zero or more times.
    ///    5) Destroy the object using sqlite3_finalize().
    ///
    /// This type helps ensure that '4' happens properly by clients executing statement.
    /// Note that destroying/finalizing a statement is not the responsibility of a client
    /// as it will happen to all prepared statemnets when the <see cref="SqlStatement"/> is
    /// <see cref="SqlStatement.Close_OnlyForUseBySqlConnection"/>d.
    /// </summary>
    internal readonly struct ResettableSqlStatement : IDisposable
    {
        public readonly SqlStatement Statement;
 
        public ResettableSqlStatement(SqlStatement statement)
            => Statement = statement;
 
        public void Dispose()
        {
            // Clear out any bindings we've made so the statement doesn't hold onto data longer than necessary.
            Statement.ClearBindings();
 
            // Reset the statement so it can be run again.
            Statement.Reset();
        }
    }
}