/// <summary>
/// Interpretes the syntax tree and generates a contextual document that can be transformed into
/// a query plan.
/// </summary>
/// <param name="syntaxTree">The syntax tree to create a document for.</param>
/// <returns>IGraphQueryDocument.</returns>
public IGraphQueryDocument CreateDocument(ISyntaxTree syntaxTree)
{
Validation.ThrowIfNull(syntaxTree, nameof(syntaxTree));
// --------------------------------------------
// Step 1: Parse the syntax tree
// --------------------------------------------
// Walk all nodes of the tree and on a "per node" basis perform actions
// that are required of that node be it a specification validation rule or
// an incremental addition to the document context being built.
//
// Note: All packages are rendered and then named fragment nodes are processed first
// as they are required by any operations referenced elsewhere in the document
// --------------------------------------------
var nodeProcessor = new DocumentConstructionRuleProcessor();
var docContext = new DocumentContext(_schema);
var nodeContexts = new List <DocumentConstructionContext>();
foreach (var node in syntaxTree.Nodes)
{
var nodeContext = docContext.ForTopLevelNode(node);
nodeContexts.Add(nodeContext);
}
nodeContexts.Sort(new TopLevelNodeProcessingOrder());
var completedAllSteps = nodeProcessor.Execute(nodeContexts);
// --------------------------------------------
// Step 2: Validate the document parts
// --------------------------------------------
// Inspect the document parts that were generated during part one and, as a whole, run additional
// validation rules and perform final changes before constructing the final document.
// e.g. ensure all fragments were called, all variables were referenced at least once etc.
// --------------------------------------------
if (completedAllSteps)
{
var documentProcessor = new DocumentValidationRuleProcessor();
var validationContexts = new List <DocumentValidationContext>();
foreach (var part in docContext.Children)
{
var partContext = new DocumentValidationContext(docContext, part);
validationContexts.Add(partContext);
}
documentProcessor.Execute(validationContexts);
}
// --------------------------------------------
// Step 3: Build out the final document
// --------------------------------------------
return(docContext.ConstructDocument());
}
