using System.Data.Common;
using Microsoft.EntityFrameworkCore.Diagnostics;

namespace ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests;

/// <summary>
/// Records the text of every reader command a context executes, so a query-shape test can
/// assert what a repository method actually reads (e.g. that a delete never SELECTs a fat
/// JSON column).
/// </summary>
public sealed class SqlReaderCommandRecorder : DbCommandInterceptor
{
    private readonly List<string> _commands = new();

    /// <summary>The text of every reader command recorded since the last <see cref="Reset"/>.</summary>
    public IReadOnlyList<string> Commands => _commands;

    /// <summary>Clears all recorded commands.</summary>
    public void Reset() => _commands.Clear();

    /// <summary>
    /// True when any recorded reader command is a SELECT that projects <paramref name="column"/>.
    /// </summary>
    /// <param name="column">Column name to look for.</param>
    /// <returns>Whether a recorded SELECT read the column.</returns>
    public bool AnySelectReads(string column) =>
        _commands.Any(c => c.TrimStart().StartsWith("SELECT", StringComparison.OrdinalIgnoreCase)
                           && c.Contains(column, StringComparison.Ordinal));

    /// <inheritdoc />
    public override InterceptionResult<DbDataReader> ReaderExecuting(
        DbCommand command, CommandEventData eventData, InterceptionResult<DbDataReader> result)
    {
        _commands.Add(command.CommandText);
        return base.ReaderExecuting(command, eventData, result);
    }

    /// <inheritdoc />
    public override ValueTask<InterceptionResult<DbDataReader>> ReaderExecutingAsync(
        DbCommand command, CommandEventData eventData, InterceptionResult<DbDataReader> result,
        CancellationToken cancellationToken = default)
    {
        _commands.Add(command.CommandText);
        return base.ReaderExecutingAsync(command, eventData, result, cancellationToken);
    }
}