using System.Collections.Concurrent;
using System.Reflection;
using Connected.Entities.Annotations;
using Connected.Entities.Storage;

namespace Connected.ServiceModel.Client.Data;
internal sealed class DeleteCommandBuilder : CommandBuilder
{
	private static readonly ConcurrentDictionary<string, StorageOperation> _cache;

	static DeleteCommandBuilder()
	{
		_cache = new();
	}

	private static ConcurrentDictionary<string, StorageOperation> Cache => _cache;

	protected override StorageOperation OnBuild()
	{
		WriteLine($"DELETE [{Schema.Schema}].[{Schema.Name}] (");
		WriteWhere();

		var result = new StorageOperation { CommandText = CommandText };

		foreach (var parameter in Parameters)
			result.AddParameter(parameter);

		Cache.TryAdd(Entity.GetType().FullName, result);

		return result;
	}

	private void WriteWhere()
	{
		Write("WHERE ");

		foreach (var property in Properties)
		{
			if (property.GetCustomAttribute<PrimaryKeyAttribute>() is not null)
			{
				var columnName = ColumnName(property);

				CreateParameter(property);

				Write($"{ColumnName} = @{ColumnName}");
			}
		}

		Write(";");
	}

	protected override bool TryGetExisting(out StorageOperation? result)
	{
		return Cache.TryGetValue(Entity.GetType().FullName, out result);
	}
}