{

private readonly Lazy<XElement> _data;

public XmlMockAdapter(XElement element)

{

_data = new Lazy<XElement>(() => element);

}

public XmlMockAdapter(string xml)

{

_data = new Lazy<XElement>(() => XElement.Parse(xml));

}

public XElement Data

{

get { return _data.Value; }

}

public override IDictionary<string, object> GetKey(string tableName, IDictionary<string, object> record)

{

return GetKeyFieldNames(tableName).ToDictionary(key => key,

key => record.ContainsKey(key) ? record[key] : null);

}

public override IList<string> GetKeyNames(string tableName)

{

return GetKeyFieldNames(tableName).ToList();

}

public override IDictionary<string, object> Get(string tableName, params object[] keyValues)

{

throw new NotImplementedException();

}

public override IEnumerable<IDictionary<string, object>> Find(string tableName, SimpleExpression criteria)

{

if (criteria == null) return FindAll(tableName);

return GetTableElement(tableName).Elements()

.Where(XmlPredicateBuilder.GetPredicate(criteria))

.Select(e => e.AttributesToDictionary());

}

public override IEnumerable<IDictionary<string, object>> RunQuery(SimpleQuery query, out IEnumerable<SimpleQueryClauseBase> unhandledClauses)

{

unhandledClauses = Enumerable.Empty<SimpleQueryClauseBase>();

var criteria = query.Clauses.OfType<WhereClause>().Aggregate(SimpleExpression.Empty,

(seed, where) => seed && where.Criteria);

return Find(query.TableName, criteria);

}

public override IDictionary<string, object> Insert(string tableName, IDictionary<string, object> data, bool resultRequired)

{

var tableElement = GetTableElement(tableName);

if (tableElement == null)

{

tableElement = new XElement(tableName);

Data.Add(tableElement);

}

var rowNameElement = tableElement.Elements().FirstOrDefault();

var rowName = rowNameElement != null ? rowNameElement.Name : tableName + "_row";

var element = new XElement(rowName);

foreach (var kvp in data)

{

element.Add(new XAttribute(kvp.Key, kvp.Value));

}

tableElement.Add(element);

return data;

}

public override int Update(string tableName, IDictionary<string, object> data, SimpleExpression criteria)

{

int updated = 0;

var elementsToUpdate = GetTableElement(tableName).Elements()

.Where(XmlPredicateBuilder.GetPredicate(criteria));

foreach (var element in elementsToUpdate)

{

foreach (var kvp in data)

{

var attribute = element.TryGetAttribute(kvp.Key);

if (attribute != null)

{

attribute.Value = kvp.Value.ToString();

}

else

{

element.SetAttributeValue(kvp.Key, kvp.Value);

}

}

updated++;

}

return updated;

}

/// <summary>

/// Deletes from the specified table.

/// </summary>

/// <param name="tableName">Name of the table.</param>

/// <param name="criteria">The expression to use as criteria for the delete operation.</param>

/// <returns>The number of records which were deleted.</returns>

public override int Delete(string tableName, SimpleExpression criteria)

{

var elementsToDelete = GetTableElement(tableName).Elements()

.Where(XmlPredicateBuilder.GetPredicate(criteria))

.ToList();

int deleted = elementsToDelete.Count;

foreach (var element in elementsToDelete)

{

element.Remove();

}

return deleted;

}

public override IEnumerable<IEnumerable<IDictionary<string, object>>> RunQueries(SimpleQuery[] queries, List<IEnumerable<SimpleQueryClauseBase>> unhandledClauses)

{

foreach (var query in queries)

{

IEnumerable<SimpleQueryClauseBase> unhandledClausesForThisQuery;

var result = RunQuery(query, out unhandledClausesForThisQuery);

unhandledClauses.Add(unhandledClausesForThisQuery);

yield return result;

}

}

public override bool IsExpressionFunction(string functionName, params object[] args)

{

return false;

}

private IEnumerable<IDictionary<string, object>> FindAll(string tableName)

{

return GetTableElement(tableName).Elements().Select(e => e.AttributesToDictionary());

}

private XElement GetTableElement(string tableName)

{

XElement tableElement = Data.Element(tableName);

if (tableElement == null) throw new UnresolvableObjectException(tableName, string.Format("Table '{0}' not found.", tableName));

return tableElement;

}

/// <summary>

/// Determines whether a relation is valid.

/// </summary>

/// <param name="tableName">Name of the known table.</param>

/// <param name="relatedTableName">Name of the table to test.</param>

/// <returns>

/// <c>true</c> if there is a valid relation; otherwise, <c>false</c>.

/// </returns>

public bool IsValidRelation(string tableName, string relatedTableName)

{

return GetTableElement(tableName).Elements().Any(e => e.Element(relatedTableName) != null);

}

/// <summary>

/// Finds data from a "table" related to the specified "table".

/// </summary>

/// <param name="tableName">Name of the table.</param>

/// <param name="row"></param>

/// <param name="relatedTableName"></param>

/// <returns>The list of records matching the criteria. If no records are found, return an empty list.</returns>

/// <remarks>When implementing the <see cref="Adapter"/> interface, if relationships are not possible, throw a <see cref="NotSupportedException"/>.</remarks>

public object FindRelated(string tableName, IDictionary<string, object> row, string relatedTableName)

{

var criteria = ExpressionHelper.CriteriaDictionaryToExpression(tableName, row);

var relatedTableElement = GetTableElement(tableName).Elements()

.Where(XmlPredicateBuilder.GetPredicate(criteria))

.Single()

.Element(relatedTableName);

if (relatedTableElement != null && relatedTableElement.HasElements)

{

return relatedTableElement.Elements().Select(e => e.AttributesToDictionary());

}

return Enumerable.Empty<IDictionary<string, object>>();

}

private IEnumerable<string> GetKeyFieldNames(string tableName)

{

var keyAttribute = GetTableElement(tableName).Attribute("_keys");

if (keyAttribute == null) return Enumerable.Empty<string>();

return keyAttribute.Value.Split(',');

}