Add diagram end point

src/main/ApiUtil.kt

@@ -1,9 +1,13 @@
 package com.github.statnett.loadflowservice
 
+import com.powsybl.iidm.network.Network
 import com.powsybl.loadflow.LoadFlowParameters
 import com.powsybl.loadflow.json.JsonLoadFlowParameters
+import com.powsybl.nad.NetworkAreaDiagram
+import com.powsybl.sld.SingleLineDiagram
 import io.ktor.http.content.*
 import java.io.ByteArrayInputStream
+import java.io.StringWriter
 
 fun busesFromRequest(
     type: String,
@@ -61,3 +65,50 @@ suspend fun multiPartDataHandler(
 fun undoPrettyPrintJson(jsonString: String): String {
     return jsonString.replace("\n", "").replace(" ", "")
 }
+
+enum class DiagramType { Generic, Substation, VoltageLevel }
+
+// Case insensitive enum value matching
+fun getDiagramType(value: String): DiagramType {
+    return try {
+        DiagramType.entries.first { item -> item.toString().lowercase() == value.lowercase() }
+    } catch (e: NoSuchElementException) {
+        DiagramType.Generic
+    }
+
+}
+
+fun singleLineDiagram(type: DiagramType, name: String, network: Network): String {
+    val svgWriter = StringWriter()
+
+    // Declare a writer for metadata
+    val metaDataWriter = StringWriter()
+    when (type) {
+        DiagramType.VoltageLevel -> {
+            SingleLineDiagram.drawVoltageLevel(network, name, svgWriter, metaDataWriter)
+        }
+
+        DiagramType.Substation -> {
+            SingleLineDiagram.drawSubstation(network, name, svgWriter, metaDataWriter)
+        }
+
+        DiagramType.Generic -> {
+            SingleLineDiagram.draw(network, name, svgWriter, metaDataWriter)
+        }
+    }
+    return svgWriter.toString()
+}
+
+fun networkDiagram(network: Network): String {
+    val svgWriter = StringWriter()
+    NetworkAreaDiagram(network).draw(svgWriter)
+    return svgWriter.toString()
+}
+
+fun substationNames(network: Network): List<String> {
+    return network.substations.map { substation -> substation.nameOrId }.toList()
+}
+
+fun voltageLevelNames(network: Network): List<String> {
+    return network.voltageLevels.map { voltageLevel -> voltageLevel.nameOrId }.toList()
+}

src/main/App.kt

@@ -1,13 +1,14 @@
 package com.github.statnett.loadflowservice
 
+import com.powsybl.commons.PowsyblException
 import io.ktor.http.*
 import io.ktor.serialization.kotlinx.json.*
 import io.ktor.server.application.*
 import io.ktor.server.plugins.contentnegotiation.*
+import io.ktor.server.plugins.swagger.*
 import io.ktor.server.request.*
 import io.ktor.server.response.*
 import io.ktor.server.routing.*
-import io.ktor.server.plugins.swagger.*
 
 fun main(args: Array<String>): Unit = io.ktor.server.netty.EngineMain.main(args)
 
@@ -21,7 +22,7 @@ fun Application.module() {
             call.respondText("Hello, world!")
         }
 
-        post("/get-buses") {
+        post("/buses") {
             val files = multiPartDataHandler(call.receiveMultipart())
 
             if (files.isEmpty()) {
@@ -36,6 +37,26 @@ fun Application.module() {
             call.respondText(defaultLoadFlowParameters(), ContentType.Application.Json, HttpStatusCode.OK)
         }
 
+        post("/substation-names") {
+            val files = multiPartDataHandler(call.receiveMultipart())
+            if (files.isEmpty()) {
+                call.response.status(HttpStatusCode.UnprocessableEntity)
+            } else {
+                val network = networkFromFileContent(files[0])
+                call.respond(substationNames(network))
+            }
+        }
+
+        post("/voltage-levels") {
+            val files = multiPartDataHandler(call.receiveMultipart())
+            if (files.isEmpty()) {
+                call.response.status(HttpStatusCode.UnprocessableEntity)
+            } else {
+                val network = networkFromFileContent(files[0])
+                call.respond(voltageLevelNames(network))
+            }
+        }
+
         post("/run-load-flow") {
             val paramContainer = LoadParameterContainer()
             val files = multiPartDataHandler(call.receiveMultipart(), paramContainer::formItemHandler)
@@ -48,6 +69,35 @@ fun Application.module() {
                 call.respond(result)
             }
         }
-        swaggerUI(path="openapi", swaggerFile = "openapi/documentation.yaml")
+
+        post("/diagram/{type}/{name}") {
+            val diagramType = getDiagramType(call.parameters["type"] ?: DiagramType.Generic.toString())
+            val name = call.parameters["name"] ?: ""
+            val files = multiPartDataHandler((call.receiveMultipart()))
+            if (files.isEmpty()) {
+                call.response.status(HttpStatusCode.UnprocessableEntity)
+            } else {
+                try {
+                    val network = networkFromFileContent(files[0])
+                    val diagram = singleLineDiagram(diagramType, name, network)
+                    call.respondText(diagram, ContentType.Image.SVG, HttpStatusCode.OK)
+                } catch (e: PowsyblException) {
+                    call.respondText(e.toString(), ContentType.Text.Plain, HttpStatusCode.BadRequest)
+                }
+
+            }
+        }
+
+        post("/diagram") {
+            val files = multiPartDataHandler((call.receiveMultipart()))
+            if (files.isEmpty()) {
+                call.response.status(HttpStatusCode.UnprocessableEntity)
+            } else {
+                val network = networkFromFileContent(files[0])
+                val diagram = networkDiagram(network)
+                call.respondText(diagram, ContentType.Image.SVG, HttpStatusCode.OK)
+            }
+        }
+        swaggerUI(path = "openapi", swaggerFile = "openapi/documentation.yaml")
     }
 }

src/test/AppTest.kt

@@ -29,7 +29,7 @@ class ApplicationTest {
         testApplication {
             val response =
                 client.submitFormWithBinaryData(
-                    url = "/get-buses",
+                    url = "/buses",
                     formData =
                     formData {
                         append("network", "not file content")
@@ -43,7 +43,7 @@ class ApplicationTest {
         testApplication {
             val response =
                 client.submitFormWithBinaryData(
-                    url = "/get-buses",
+                    url = "/buses",
                     formData = formDataFromFile(ieeeCdfNetwork14File()),
                 )
             assertEquals(HttpStatusCode.OK, response.status)
@@ -95,6 +95,77 @@ class ApplicationTest {
             )
         }
 
+    @Test
+    fun `test response ok network`() =
+        testApplication {
+            val response = client.submitFormWithBinaryData(
+                url = "/diagram",
+                formData = formDataFromFile(ieeeCdfNetwork14File())
+            )
+            val body = response.bodyAsText()
+            assertEquals(ContentType.Image.SVG.toString(), response.headers["Content-Type"])
+            assertTrue(isPlausibleSvg(body))
+            assertEquals(response.status, HttpStatusCode.OK)
+        }
+
+    @Test
+    fun `test bad request when substation does not exist`() =
+        testApplication {
+            val response = client.submitFormWithBinaryData(
+                url = "/diagram/substation/non-existent-station",
+                formData = formDataFromFile(ieeeCdfNetwork14File())
+            )
+            assertEquals(response.status, HttpStatusCode.BadRequest)
+        }
+
+    @Test
+    fun `test response OK and svg produced substation`() =
+        testApplication {
+            val response = client.submitFormWithBinaryData(
+                url = "/diagram/substation/S1",
+                formData = formDataFromFile(ieeeCdfNetwork14File())
+            )
+            assertEquals(response.status, HttpStatusCode.OK)
+            val body = response.bodyAsText()
+            assertTrue(isPlausibleSvg(body))
+        }
+
+    @Test
+    fun `test 11 substation names extracted`() =
+        testApplication {
+            val response = client.submitFormWithBinaryData(
+                url = "/substation-names",
+                formData = formDataFromFile(ieeeCdfNetwork14File())
+            )
+            assertEquals(response.status, HttpStatusCode.OK)
+            val substationNames = response.bodyAsText().split(",")
+            assertEquals(substationNames.size, 11)
+        }
+
+    @Test
+    fun `test 2 voltage levels extracted`() =
+        testApplication {
+            val response = client.submitFormWithBinaryData(
+                url = "/voltage-levels",
+                formData = formDataFromFile(ieeeCdfNetwork14File())
+            )
+            assertEquals(response.status, HttpStatusCode.OK)
+            val voltageLevels = response.bodyAsText().split(",")
+            assertEquals(14, voltageLevels.size)
+        }
+
+    @Test
+    fun `test svg produced for voltage level`() =
+        testApplication {
+            val response = client.submitFormWithBinaryData(
+                url = "/diagram/voltageLevel/VL1",
+                formData = formDataFromFile(ieeeCdfNetwork14File())
+            )
+            assertEquals(response.status, HttpStatusCode.OK)
+            val body = response.bodyAsText()
+            assertTrue(isPlausibleSvg(body))
+            assertEquals(response.headers["Content-Type"].toString(), "image/svg+xml")
+        }
 }
 
 fun formDataFromFile(file: File): List<PartData> {
@@ -116,4 +187,10 @@ fun ieeeCdfNetwork14File(): File {
 
     IeeeCdfNetworkFactory.create14().write("XIIDM", Properties(), Paths.get(file.path))
     return file
+}
+
+// Function for checking some properties of a body to verify that the returned body
+// is a valid svg image
+fun isPlausibleSvg(body: String): Boolean {
+    return body.contains("<svg") && body.contains("<?xml version")
 }