CockroachDbInterleaveInParent.cs

using System.Text;
using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata.Internal;

namespace Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;

/// <summary>
///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
///     the same compatibility standards as public APIs. It may be changed or removed without notice in
///     any release. You should only use it directly in your code with extreme caution and knowing that
///     doing so can result in application failures when updating to a new Entity Framework Core release.
/// </summary>
public class CockroachDbInterleaveInParent
{
    private const string AnnotationName = CockroachDbAnnotationNames.InterleaveInParent;

    private readonly IReadOnlyAnnotatable _annotatable;

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    public virtual Annotatable Annotatable => (Annotatable)_annotatable;

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    public CockroachDbInterleaveInParent(IReadOnlyAnnotatable annotatable)
        => _annotatable = annotatable;

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    public virtual string? ParentTableSchema
    {
        get => GetData().ParentTableSchema;
        set
        {
            (var _, var parentTableName, var interleavePrefix) = GetData();
            SetData(value, parentTableName, interleavePrefix);
        }
    }

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    public virtual string ParentTableName
    {
        get => GetData().ParentTableName;
        set
        {
            (var parentTableSchema, var _, var interleavePrefix) = GetData();
            SetData(parentTableSchema, value, interleavePrefix);
        }
    }

    /// <summary>
    ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
    ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
    ///     any release. You should only use it directly in your code with extreme caution and knowing that
    ///     doing so can result in application failures when updating to a new Entity Framework Core release.
    /// </summary>
    public virtual List<string> InterleavePrefix
    {
        get => GetData().InterleavePrefix;
        set
        {
            (var parentTableSchema, var parentTableName, var _) = GetData();
            SetData(parentTableSchema, parentTableName, value);
        }
    }

    private (string? ParentTableSchema, string ParentTableName, List<string> InterleavePrefix) GetData()
    {
        var str = Annotatable[AnnotationName] as string;
        return str is null
            ? (null, null!, null!)
            : Deserialize(str);
    }

    private void SetData(string? parentTableSchema, string parentTableName, List<string> interleavePrefix)
        => Annotatable[AnnotationName] = Serialize(parentTableSchema, parentTableName, interleavePrefix);

    private static string Serialize(string? parentTableSchema, string parentTableName, List<string> interleavePrefix)
    {
        var builder = new StringBuilder();

        EscapeAndQuote(builder, parentTableSchema);
        builder.Append(", ");
        EscapeAndQuote(builder, parentTableName);
        if (interleavePrefix is not null && interleavePrefix.Count > 0)
        {
            builder.Append(", ");
            for (var i = 0; i < interleavePrefix.Count; i++)
            {
                EscapeAndQuote(builder, interleavePrefix[i]);
                if (i < interleavePrefix.Count - 1)
                {
                    builder.Append(", ");
                }
            }
        }
        return builder.ToString();
    }

    internal static (string? ParentTableSchema, string ParentTableName, List<string> InterleavePrefix) Deserialize(string value)
    {
        Check.NotEmpty(value, nameof(value));

        try
        {
            var position = 0;
            var parentTableSchema = ExtractValue(value, ref position);
            var parentTableName = ExtractValue(value, ref position)!;
            var interleavePrefix = new List<string>();
            while (position < value.Length - 1)
            {
                interleavePrefix.Add(ExtractValue(value, ref position)!);
            }

            return (parentTableSchema, parentTableName, interleavePrefix);
        }
        catch (Exception ex)
        {
            throw new ArgumentException($"Couldn't deserialize {nameof(CockroachDbInterleaveInParent)} from annotation", ex);
        }
    }

    private static string? ExtractValue(string value, ref int position)
    {
        position = value.IndexOf('\'', position) + 1;

        var end = value.IndexOf('\'', position);

        while ((end + 1 < value.Length)
               && (value[end + 1] == '\''))
        {
            end = value.IndexOf('\'', end + 2);
        }

        var extracted = value.Substring(position, end - position).Replace("''", "'");
        position = end + 1;

        return extracted.Length == 0 ? null : extracted;
    }

    private static void EscapeAndQuote(StringBuilder builder, object? value)
    {
        builder.Append("'");

        if (value is not null)
        {
            builder.Append(value.ToString()!.Replace("'", "''"));
        }

        builder.Append("'");
    }
}