public IEnumerable <IQuerySuggestion> Compute(SuggestionState state)
{
var expected = state.Expected.Find(item =>
item.RuleIndices[0] == QueryParser.RULE_source);
// make sure we are in the select part of a query
if (expected == null)
{
return(Enumerable.Empty <IQuerySuggestion>());
}
// make sure we are in a path pattern
if (state.Caret.ParentToken == null ||
state.Caret.ParentToken.Type != QueryLexer.STRING)
{
return(Enumerable.Empty <IQuerySuggestion>());
}
// make sure the caret is in the pattern (not after the last quote)
if (state.Caret.ParentOffset >= state.Caret.ParentToken.Text.Length &&
state.Caret.ParentToken.Text[state.Caret.ParentOffset - 1] == '\"')
{
return(Enumerable.Empty <IQuerySuggestion>());
}
var patternParts = Split(state.Caret.ParentPrefix);
// if the directory name at the caret is a pattern, don't suggest anything
if (PathPattern.ContainsSpecialCharacters(patternParts.LastPart))
{
return(Enumerable.Empty <IQuerySuggestion>());
}
if (patternParts.LastPart.Length == 0)
{
patternParts.LastPart = "*";
}
else
{
patternParts.LastPart = "*" + patternParts.LastPart + "*";
}
try
{
var pattern = Path.Combine(patternParts.Prefix, patternParts.LastPart);
var finder = _fileSystem.CreateFileFinder(pattern);
var result = finder
.GetDirectories()
.Select(PathUtils.GetLastPart)
.Distinct()
.Select(name => new DirectorySuggestion(state.Caret, name));
return(result);
}
catch (ArgumentException) // the pattern contains invalid characters
{
// suggestions should not throw for invalid input
return(Enumerable.Empty <IQuerySuggestion>());
}
}