✨ BFF を追加

README.md

@@ -9,6 +9,9 @@ NITO のユーザーアプリのリポジトリです。
 │   アプリケーションのディレクトリ
 ├── app
 │
+│   BFF のディレクトリ
+├── bff
+│
 │   ビルドロジックを集約したディレクトリ
 ├── build-logic
 │

bff/README.md

@@ -0,0 +1,12 @@
+# BFF
+
+NITO の BFF のディレクトリです。
+
+```shell
+./gradlew :bff:run
+```
+
+## アーキテクチャ構成
+
+- [Ktor](https://ktor.io/)
+- [GraphQL Kotlin](https://github.com/ExpediaGroup/graphql-kotlin)

bff/build.gradle.kts

@@ -0,0 +1,40 @@
+import com.expediagroup.graphql.plugin.gradle.config.GraphQLSerializer
+
+plugins {
+    kotlin("jvm")
+    id("io.ktor.plugin") version libs.versions.ktor
+    id("org.jetbrains.kotlin.plugin.serialization") version libs.versions.kotlin
+    id("com.expediagroup.graphql") version libs.versions.graphqlKotlin
+}
+
+group = "club.nito"
+version = "0.1.0"
+
+application {
+    mainClass.set("nito.club.bff.ApplicationKt")
+
+    val isDevelopment: Boolean = project.ext.has("development")
+    applicationDefaultJvmArgs = listOf("-Dio.ktor.development=$isDevelopment")
+}
+
+dependencies {
+    implementation(libs.ktorServerCore)
+    implementation(libs.ktorServerNetty)
+    implementation(libs.ktorServerCors)
+    implementation(libs.ktorServerWebsockets)
+    implementation("io.ktor:ktor-serialization-kotlinx-json-jvm")
+    implementation(libs.logback)
+    implementation(libs.graphqlKotlinKtorServer)
+    testImplementation("io.ktor:ktor-server-tests-jvm")
+    testImplementation(kotlin("test"))
+//    testImplementation("org.jetbrains.kotlin:kotlin-test-junit:$kotlin_version")
+}
+
+graphql {
+    schema {
+        packages = listOf("nito.club.bff")
+    }
+    client {
+        serializer = GraphQLSerializer.KOTLINX
+    }
+}

bff/src/main/kotlin/nito/club/bff/Application.kt

@@ -0,0 +1,3 @@
+package nito.club.bff
+
+fun main(args: Array<String>): Unit = io.ktor.server.netty.EngineMain.main(args)

bff/src/main/kotlin/nito/club/bff/CustomGraphQLContextFactory.kt

@@ -0,0 +1,25 @@
+package nito.club.bff
+
+import com.expediagroup.graphql.generator.extensions.plus
+import com.expediagroup.graphql.server.ktor.DefaultKtorGraphQLContextFactory
+import graphql.GraphQLContext
+import io.ktor.server.request.ApplicationRequest
+import nito.club.bff.schema.models.User
+
+class CustomGraphQLContextFactory : DefaultKtorGraphQLContextFactory() {
+    override suspend fun generateContext(request: ApplicationRequest): GraphQLContext =
+        super.generateContext(request).plus(
+            mutableMapOf<Any, Any>(
+                "user" to User(
+                    email = "[email protected]",
+                    firstName = "Someone",
+                    lastName = "You Don't know",
+                    universityId = 4,
+                ),
+            ).also { map ->
+                request.headers["my-custom-header"]?.let { customHeader ->
+                    map["customHeader"] = customHeader
+                }
+            },
+        )
+}

bff/src/main/kotlin/nito/club/bff/GraphQLModule.kt

@@ -0,0 +1,76 @@
+package nito.club.bff
+
+import com.expediagroup.graphql.dataloader.KotlinDataLoaderRegistryFactory
+import com.expediagroup.graphql.server.ktor.GraphQL
+import com.expediagroup.graphql.server.ktor.graphQLGetRoute
+import com.expediagroup.graphql.server.ktor.graphQLPostRoute
+import com.expediagroup.graphql.server.ktor.graphQLSDLRoute
+import com.expediagroup.graphql.server.ktor.graphQLSubscriptionsRoute
+import com.expediagroup.graphql.server.ktor.graphiQLRoute
+import io.ktor.serialization.kotlinx.KotlinxWebsocketSerializationConverter
+import io.ktor.server.application.Application
+import io.ktor.server.application.install
+import io.ktor.server.plugins.cors.routing.CORS
+import io.ktor.server.routing.Routing
+import io.ktor.server.websocket.WebSockets
+import io.ktor.server.websocket.pingPeriod
+import kotlinx.serialization.json.Json
+import nito.club.bff.schema.BookQueryService
+import nito.club.bff.schema.CourseQueryService
+import nito.club.bff.schema.ExampleSubscriptionService
+import nito.club.bff.schema.HelloQueryService
+import nito.club.bff.schema.LoginMutationService
+import nito.club.bff.schema.UniversityQueryService
+import nito.club.bff.schema.dataloaders.BookDataLoader
+import nito.club.bff.schema.dataloaders.CourseDataLoader
+import nito.club.bff.schema.dataloaders.UniversityDataLoader
+import java.time.Duration
+
+@Suppress("unused")
+fun Application.graphQLModule() {
+    val format = Json {
+        ignoreUnknownKeys = true
+    }
+    install(WebSockets) {
+        pingPeriod = Duration.ofSeconds(1)
+
+        contentConverter = KotlinxWebsocketSerializationConverter(format)
+    }
+    install(CORS) {
+        anyHost()
+    }
+    install(GraphQL) {
+        schema {
+            packages = listOf("nito.club.bff")
+            queries = listOf(
+                HelloQueryService(),
+                BookQueryService(),
+                CourseQueryService(),
+                UniversityQueryService(),
+            )
+            mutations = listOf(
+                LoginMutationService(),
+            )
+            subscriptions = listOf(
+                ExampleSubscriptionService(),
+            )
+        }
+        engine {
+            dataLoaderRegistryFactory = KotlinDataLoaderRegistryFactory(
+                UniversityDataLoader,
+                CourseDataLoader,
+                BookDataLoader,
+            )
+        }
+        server {
+            contextFactory = CustomGraphQLContextFactory()
+        }
+    }
+    install(Routing) {
+        graphQLGetRoute()
+        graphQLPostRoute()
+        graphQLSubscriptionsRoute()
+        graphiQLRoute()
+        graphQLSDLRoute()
+    }
+}

bff/src/main/kotlin/nito/club/bff/GraphQLRoutes.kt

@@ -0,0 +1,56 @@
+package nito.club.bff
+
+import com.expediagroup.graphql.server.ktor.GraphQL
+import com.expediagroup.graphql.server.ktor.KtorGraphQLServer
+import io.ktor.http.ContentType
+import io.ktor.http.HttpStatusCode
+import io.ktor.serialization.kotlinx.serialization
+import io.ktor.server.application.ApplicationCall
+import io.ktor.server.application.call
+import io.ktor.server.application.install
+import io.ktor.server.application.plugin
+import io.ktor.server.plugins.contentnegotiation.ContentNegotiation
+import io.ktor.server.response.respond
+import io.ktor.server.routing.Route
+import io.ktor.server.routing.application
+import io.ktor.server.routing.get
+import io.ktor.server.routing.post
+import kotlinx.serialization.StringFormat
+
+fun Route.graphQLGetRoute(
+    endpoint: String = "graphql",
+    format: StringFormat,
+): Route {
+    val graphQLPlugin = this.application.plugin(GraphQL)
+    return get(endpoint) {
+        graphQLPlugin.server.executeRequest(call)
+    }.apply {
+        install(ContentNegotiation) {
+            serialization(ContentType.Application.Json, format)
+        }
+    }
+}
+
+fun Route.graphQLPostRoute(
+    endpoint: String = "graphql",
+    format: StringFormat,
+): Route {
+    val graphQLPlugin = this.application.plugin(GraphQL)
+    return post(endpoint) {
+        graphQLPlugin.server.executeRequest(call)
+    }.apply {
+        install(ContentNegotiation) {
+            serialization(ContentType.Application.Json, format)
+        }
+    }
+}
+
+private suspend inline fun KtorGraphQLServer.executeRequest(call: ApplicationCall) = try {
+    execute(call.request)?.let {
+        call.respond(it)
+    } ?: call.respond(HttpStatusCode.BadRequest)
+} catch (e: UnsupportedOperationException) {
+    call.respond(HttpStatusCode.MethodNotAllowed)
+} catch (e: Exception) {
+    call.respond(HttpStatusCode.BadRequest)
+}

bff/src/main/kotlin/nito/club/bff/graphql/query/HelloQuery.kt

@@ -0,0 +1,7 @@
+package nito.club.bff.graphql.query
+
+import com.expediagroup.graphql.server.operations.Query
+
+object HelloQuery : Query {
+    fun hello() = "Hello World!"
+}

bff/src/main/kotlin/nito/club/bff/graphql/server/KtorGraphQLContextFactory.kt

@@ -0,0 +1,6 @@
+package nito.club.bff.graphql.server
+
+import com.expediagroup.graphql.server.execution.GraphQLContextFactory
+import io.ktor.server.request.ApplicationRequest
+
+class KtorGraphQLContextFactory : GraphQLContextFactory<ApplicationRequest>

bff/src/main/kotlin/nito/club/bff/graphql/server/KtorGraphQLRequestParser.kt

@@ -0,0 +1,21 @@
+package nito.club.bff.graphql.server
+
+import com.expediagroup.graphql.server.execution.GraphQLRequestParser
+import com.expediagroup.graphql.server.types.GraphQLServerRequest
+import com.fasterxml.jackson.databind.ObjectMapper
+import io.ktor.server.request.ApplicationRequest
+import io.ktor.server.request.receiveText
+import io.ktor.utils.io.errors.IOException
+
+class KtorGraphQLRequestParser(
+    private val mapper: ObjectMapper,
+) : GraphQLRequestParser<ApplicationRequest> {
+    override suspend fun parseRequest(request: ApplicationRequest): GraphQLServerRequest? {
+        try {
+            val rawRequest = request.call.receiveText()
+            return mapper.readValue(rawRequest, GraphQLServerRequest::class.java)
+        } catch (e: IOException) {
+            throw IOException("Unable to parse GraphQL payload.")
+        }
+    }
+}

bff/src/main/kotlin/nito/club/bff/graphql/server/KtorGraphQLSchema.kt

@@ -0,0 +1,28 @@
+package nito.club.bff.graphql.server
+
+import com.expediagroup.graphql.generator.SchemaGeneratorConfig
+import com.expediagroup.graphql.generator.TopLevelObject
+import com.expediagroup.graphql.generator.scalars.IDValueUnboxer
+import com.expediagroup.graphql.generator.toSchema
+import graphql.GraphQL
+import nito.club.bff.graphql.query.HelloQuery
+
+object KtorGraphQLSchema {
+    private val config = SchemaGeneratorConfig(
+        supportedPackages = listOf("club.nito.graphql"),
+    )
+    private val queries = listOf(
+        TopLevelObject(HelloQuery),
+    )
+    private val mutations = listOf<TopLevelObject>()
+
+    private val graphQLSchema = toSchema(
+        config = config,
+        queries = queries,
+        mutations = mutations,
+    )
+
+    fun getGraphQLObject(): GraphQL = GraphQL.newGraphQL(graphQLSchema)
+        .valueUnboxer(IDValueUnboxer())
+        .build()
+}

bff/src/main/kotlin/nito/club/bff/graphql/server/KtorGraphQLServer.kt

@@ -0,0 +1,34 @@
+package nito.club.bff.graphql.server
+
+import com.expediagroup.graphql.server.execution.GraphQLRequestHandler
+import com.expediagroup.graphql.server.execution.GraphQLServer
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import io.ktor.http.HttpStatusCode
+import io.ktor.server.application.ApplicationCall
+import io.ktor.server.request.ApplicationRequest
+import io.ktor.server.response.respond
+
+object KtorGraphQLServer {
+    private val mapper = jacksonObjectMapper()
+    private val ktorGraphQLServer = getGraphQLServer()
+
+    suspend fun handle(applicationCall: ApplicationCall) {
+        val result = ktorGraphQLServer.execute(applicationCall.request)
+
+        if (result != null) {
+            val json = mapper.writeValueAsString(result)
+            applicationCall.response.call.respond(json)
+        } else {
+            applicationCall.response.call.respond(HttpStatusCode.BadRequest, "Invalid request")
+        }
+    }
+
+    private fun getGraphQLServer(): GraphQLServer<ApplicationRequest> {
+        val requestParser = KtorGraphQLRequestParser(mapper)
+        val contextFactory = KtorGraphQLContextFactory()
+        val graphQL = KtorGraphQLSchema.getGraphQLObject()
+        val requestHandler = GraphQLRequestHandler(graphQL)
+
+        return GraphQLServer(requestParser, contextFactory, requestHandler)
+    }
+}

bff/src/main/kotlin/nito/club/bff/schema/BookQueryService.kt

@@ -0,0 +1,18 @@
+package nito.club.bff.schema
+
+import com.expediagroup.graphql.generator.annotations.GraphQLDescription
+import com.expediagroup.graphql.server.operations.Query
+import graphql.schema.DataFetchingEnvironment
+import nito.club.bff.schema.dataloaders.BookDataLoader
+import nito.club.bff.schema.models.Book
+import java.util.concurrent.CompletableFuture
+
+class BookQueryService : Query {
+    @GraphQLDescription("Return list of books based on BookSearchParameter options")
+    @Suppress("unused")
+    fun searchBooks(params: BookSearchParameters, dfe: DataFetchingEnvironment): CompletableFuture<List<Book>> =
+        dfe.getDataLoader<Int, Book>(BookDataLoader.dataLoaderName)
+            .loadMany(params.ids)
+}
+
+data class BookSearchParameters(val ids: List<Int>)

bff/src/main/kotlin/nito/club/bff/schema/CourseQueryService.kt

@@ -0,0 +1,15 @@
+package nito.club.bff.schema
+
+import com.expediagroup.graphql.server.operations.Query
+import graphql.schema.DataFetchingEnvironment
+import nito.club.bff.schema.dataloaders.CourseDataLoader
+import nito.club.bff.schema.models.Course
+import java.util.concurrent.CompletableFuture
+
+class CourseQueryService : Query {
+    fun searchCourses(params: CourseSearchParameters, dfe: DataFetchingEnvironment): CompletableFuture<List<Course>> =
+        dfe.getDataLoader<Int, Course>(CourseDataLoader.dataLoaderName)
+            .loadMany(params.ids)
+}
+
+data class CourseSearchParameters(val ids: List<Int>)