public async Task Setup()
{
client = new GraphClient(new Uri("http://localhost:7474"));
await client.ConnectAsync();
await client.Cypher.Match("(m:Movie)").DetachDelete("m").ExecuteWithoutResultsAsync();
await client.Cypher.Match("(m:Person)").DetachDelete("m").ExecuteWithoutResultsAsync();
await client.Cypher.Match("(m:Greeting)").DetachDelete("m").ExecuteWithoutResultsAsync();
}
public async Task <BasicResponseDto> Handle(Command request, CancellationToken cancellationToken)
{
await _client.ConnectAsync();
await _client.ConnectAsync();
var stops = await _client.Cypher.Match($"(stop: Stop) WHERE {request.LineNo} in stop.lines")
.Return(stop => stop.As <Stop>())
.ResultsAsync;
if (!stops.Any())
{
return(new ListResponseDto <int>(false, $"Line with number: {request.LineNo} does not exist."));
}
// Delete old line
foreach (var stopToDelete in stops)
{
if (stopToDelete.lines.Count() == 1)
{
await _client.Cypher.Match($"(stop: Stop {{ name: '{stopToDelete.name}' }})").DetachDelete("stop")
.ExecuteWithoutResultsAsync();
}
else
{
var stopLines = stopToDelete.lines.ToList();
stopLines.RemoveAll(x => x == request.LineNo);
var array = $"[{string.Join(",", stopLines.Distinct().ToArray())}]";
var query = $"stop.lines = {array}";
await _client.Cypher.Match($"(stop: Stop {{ name: '{stopToDelete.name}' }})").Set(query)
.ExecuteWithoutResultsAsync();
}
}
return(new BasicResponseDto(true));
}
public async Task <ListResponseDto <Stop> > Handle(Query request, CancellationToken cancellationToken)
{
await _client.ConnectAsync();
var query = $"(start: Stop {{ name: '{request.StartStop}' }}),(dest: Stop {{ name: '{request.DestStop}' }})";
var result = await _client.Cypher.Match(query).Return <List <Stop> >("shortestPath((start) -[*]- (dest))").ResultsAsync;
if (!result.Any())
{
return(new ListResponseDto <Stop>(true, $"Cannot find connection between {request.StartStop} and {request.DestStop}."));
}
var stops = result.First().Where(s => s.name != null).ToList();
return(new ListResponseDto <Stop>(stops));
}
public async Task <ListResponseDto <int> > Handle(Query request, CancellationToken cancellationToken)
{
await _client.ConnectAsync();
var result = await _client.Cypher.Match("(stop: Stop)")
.Return(stop => stop.As <Stop>())
.ResultsAsync;
if (!result.Any())
{
return(new ListResponseDto <int>(true));
}
var lines = result.SelectMany(x => x.lines).Distinct().ToList();
return(new ListResponseDto <int>(lines));
}
public async Task <ListResponseDto <LineDto> > Handle(Query request, CancellationToken cancellationToken)
{
await _client.ConnectAsync();
var query = $"(line: Line) WHERE line.lineNumber = {request.Number}";
var lines = await _client.Cypher.Match(query)
.Return(line => line.As <Line>())
.ResultsAsync;
if (!lines.Any())
{
return(new ListResponseDto <LineDto>(true, "Line not found."));
}
var lineDto = new LineDto()
{
lineNumber = lines.First().lineNumber,
stops = lines.First().stops
};
return(new ListResponseDto <LineDto>(lineDto));
}
public GraphDbContext(IGraphDbSettings settings)
{
_client = new GraphClient(new Uri(settings.ConnectionString), settings.User, settings.Password);
_client.ConnectAsync().Wait();
}
public async Task <BasicResponseDto> Handle(Command request, CancellationToken cancellationToken)
{
await _client.ConnectAsync();
await _client.ConnectAsync();
var line = await _client.Cypher.Match($"(stop: Stop) WHERE {request.lineNumber} in stop.lines")
.Return(stop => stop.As <Stop>())
.ResultsAsync;
if (line.Any())
{
return(new ListResponseDto <int>(false, $"Line with number: {request.lineNumber} arleady exists."));
}
// Create stops
foreach (var stopName in request.stops)
{
var entities = await _client.Cypher.Match($"(stop: Stop) WHERE stop.name = '{stopName}'")
.Return(stop => stop.As <Stop>())
.ResultsAsync;
var entity = entities.FirstOrDefault();
if (entity == null)
{
var stopQuery = $"(stop: Stop {{ name: '{stopName}', lines: [{request.lineNumber}]}})";
await _client.Cypher.Create(stopQuery)
.ExecuteWithoutResultsAsync();
}
else
{
var stopLines = entity.lines.ToList();
stopLines.Add(request.lineNumber);
var array = $"[{string.Join(",", stopLines.Distinct().ToArray())}]";
var query = $"stop.lines = {array}";
await _client.Cypher.Match($"(stop: Stop {{ name: '{stopName}' }})").Set(query)
.ExecuteWithoutResultsAsync();
}
}
// Create relations
var stopsList = request.stops.ToList();
for (int i = 0; i < stopsList.Count - 1; i++)
{
var start = stopsList.ElementAt(i);
var dest = stopsList.ElementAt(i + 1);
var relationQuery = $"(a)-[r:LEADS_TO]->(b)";
await _client.Cypher.Match($"(a:Stop),(b:Stop) WHERE a.name = '{start}' AND b.name = '{dest}'")
.Merge(relationQuery)
.ExecuteWithoutResultsAsync();
await _client.Cypher.Match($"(a:Stop),(b:Stop) WHERE a.name = '{dest}' AND b.name = '{start}'")
.Merge(relationQuery)
.ExecuteWithoutResultsAsync();
}
// Create line
var arrayOfStops = String.Join(",", request.stops.Select(x => string.Format("\"{0}\"", x)));
var lineQuery = $"(line: Line {{ lineNumber: {request.lineNumber}, stops: [{arrayOfStops}]}})";
await _client.Cypher.Create(lineQuery)
.ExecuteWithoutResultsAsync();
return(new BasicResponseDto(true));
}