using Connected.Data.Storage;
using Connected.Entities.Storage;
using Connected.Interop;
using System.Data;

namespace Connected.Data.Schema.Sql;

internal class SpHelp : SynchronizationQuery<ObjectDescriptor>
{
    private readonly ObjectDescriptor _descriptor;

    public SpHelp()
    {
        _descriptor = new();
    }

    private ObjectDescriptor Result => _descriptor;

    protected override async Task<ObjectDescriptor> OnExecute()
    {
        var operation = new StorageOperation { CommandText = "sp_help", CommandType = CommandType.Text };

        operation.AddParameter(new StorageParameter
        {
            Name = "@objname",
            Type = DbType.String,
            Value = Escape(Context.Schema.SchemaName(), Context.Schema.Name)
        }
        );

        var rdr = await Context.OpenReader(operation);

        try
        {
            ReadMetadata(rdr);
            ReadColumns(rdr);
            ReadIdentity(rdr);
            ReadRowGuid(rdr);
            ReadFileGroup(rdr);
            ReadIndexes(rdr);
            ReadConstraints(rdr);
        }
        finally
        {
            rdr.Close();
        }

        return Result;
    }

    private void ReadMetadata(IDataReader rdr)
    {
        if (rdr.Read())
        {
            Result.MetaData.Name = rdr.GetValue("Name", string.Empty);
            Result.MetaData.Created = rdr.GetValue("Created_datetime", DateTime.MinValue);
            Result.MetaData.Owner = rdr.GetValue("Owner", string.Empty);
            Result.MetaData.Type = rdr.GetValue("Type", string.Empty);
        }
    }

    private void ReadColumns(IDataReader rdr)
    {
        rdr.NextResult();

        while (rdr.Read())
        {
            Result.Columns.Add(new ObjectColumn
            {
                Collation = rdr.GetValue("Collation", string.Empty),
                Computed = !string.Equals(rdr.GetValue("Computed", string.Empty), "no", StringComparison.OrdinalIgnoreCase),
                FixedLenInSource = rdr.GetValue("FixedLenNullInSource", string.Empty),
                Length = rdr.GetValue("Length", 0),
                Name = rdr.GetValue("Column_name", string.Empty),
                Nullable = !string.Equals(rdr.GetValue("Nullable", string.Empty), "no", StringComparison.OrdinalIgnoreCase),
                Precision = TypeConversion.Convert<int>(rdr.GetValue("Prec", string.Empty).Trim()),
                Scale = TypeConversion.Convert<int>(rdr.GetValue("Scale", string.Empty).Trim()),
                TrimTrailingBlanks = rdr.GetValue("TrimTrailingBlanks", string.Empty),
                Type = rdr.GetValue("Type", string.Empty)
            });
        }
    }

    private void ReadIdentity(IDataReader rdr)
    {
        rdr.NextResult();

        if (rdr.Read())
        {
            Result.Identity.Identity = rdr.GetValue("Identity", string.Empty);
            Result.Identity.Increment = rdr.GetValue("Increment", 0);
            Result.Identity.NotForReplication = rdr.GetValue("Not For Replication", 0) != 0;
        }
    }

    private void ReadRowGuid(IDataReader rdr)
    {
        rdr.NextResult();

        if (rdr.Read())
            Result.RowGuid.RowGuidCol = rdr.GetValue("RowGuidCol", string.Empty);
    }

    private void ReadFileGroup(IDataReader rdr)
    {
        rdr.NextResult();

        if (rdr.Read())
            Result.FileGroup.FileGroup = rdr.GetValue("Data_located_on_filegroup", string.Empty);
    }

    private void ReadIndexes(IDataReader rdr)
    {
        rdr.NextResult();

        while (rdr.Read())
        {
            Result.Indexes.Add(new ObjectIndex
            {
                Description = rdr.GetValue("index_description", string.Empty),
                Keys = rdr.GetValue("index_keys", string.Empty),
                Name = rdr.GetValue("index_name", string.Empty)
            });
        }
    }

    private void ReadConstraints(IDataReader rdr)
    {
        rdr.NextResult();

        while (rdr.Read())
        {
            Result.Constraints.Add(new ObjectConstraint
            {
                DeleteAction = rdr.GetValue("delete_action", string.Empty),
                Keys = rdr.GetValue("constraint_keys", string.Empty),
                Name = rdr.GetValue("constraint_name", string.Empty),
                StatusEnabled = rdr.GetValue("status_enabled", string.Empty),
                StatusForReplication = rdr.GetValue("status_for_replication", string.Empty),
                Type = rdr.GetValue("constraint_type", string.Empty),
                UpdateAction = rdr.GetValue("update_action", string.Empty)
            });
        }
    }
}