add discord login

- add discord login logics
- add discord api classes, functions.
- add current user's discord guilds. (if session has discordGuilds, return it else return null lists)

webserver/src/main/kotlin/space/mori/chzzk_bot/webserver/Main.kt

@@ -4,6 +4,7 @@ import applicationHttpClient
 import io.github.cdimascio.dotenv.dotenv
 import io.ktor.client.call.*
 import io.ktor.client.request.*
+import io.ktor.client.statement.*
 import io.ktor.http.*
 import io.ktor.serialization.kotlinx.*
 import io.ktor.serialization.kotlinx.json.*
@@ -20,6 +21,9 @@ import io.ktor.server.sessions.*
 import io.ktor.server.websocket.*
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.Json
+import space.mori.chzzk_bot.common.models.User
+import space.mori.chzzk_bot.common.services.UserService
+import space.mori.chzzk_bot.common.utils.getUserInfo
 import space.mori.chzzk_bot.webserver.routes.*
 import java.time.Duration
 
@@ -70,6 +74,29 @@ val server = embeddedServer(Netty, port = 8080, ) {
             )}
             client = applicationHttpClient
         }
+        oauth("auth-oauth-discord") {
+            urlProvider = { "${dotenv["HOST"]}/auth/discord/callback" }
+            providerLookup = { OAuthServerSettings.OAuth2ServerSettings(
+                name = "discord",
+                authorizeUrl = "https://discord.com/oauth2/authorize",
+                accessTokenUrl = "https://discord.com/api/oauth2/token",
+                clientId = dotenv["DISCORD_CLIENT_ID"],
+                clientSecret = dotenv["DISCORD_CLIENT_SECRET"],
+                defaultScopes = listOf(),
+                extraAuthParameters = listOf(
+                    Pair("permissions", "826781355072"),
+                    Pair("response_type", "code"),
+                    Pair("integration_type", "0"),
+                    Pair("scope", "guilds+bot")
+                ),
+                onStateCreated = { call, state ->
+                    call.request.queryParameters["redirectUrl"]?.let {
+                        redirects[state] = it
+                    }
+                }
+            )}
+            client = applicationHttpClient
+        }
     }
     routing {
         route("/auth") {
@@ -88,7 +115,7 @@ val server = embeddedServer(Netty, port = 8080, ) {
                             }.body()
 
                             call.sessions.set(userInfo.response?.let { profile ->
-                                UserSession(state, profile.id)
+                                UserSession(state, profile.id, listOf())
                             })
 
                             redirects[state]?.let { redirect ->
@@ -97,7 +124,28 @@ val server = embeddedServer(Netty, port = 8080, ) {
                             }
                         }
                     }
-                    call.respondRedirect("${ if(dotenv["FRONTEND_HTTPS"].toBoolean()) "https://" else "http://" }${dotenv["FRONTEND"]}")
+                    call.respondRedirect(getFrontendURL(""))
+                }
+                get("/discord/callback") {
+                    val principal = call.principal<OAuthAccessTokenResponse.OAuth2>()
+                    val session = call.sessions.get<UserSession>()
+                    val user = session?.id?.let { UserService.getUserWithNaverId(it)}
+
+                    if(principal != null && session != null && user != null) {
+                        val accessToken = principal.accessToken
+                        val userInfo = getDiscordUser(accessToken)
+                        val guilds = getUserGuilds(accessToken)
+
+                        userInfo?.user?.id?.toLong()?.let { id -> UserService.updateUser(user, id) }
+
+                        call.sessions.set(UserSession(
+                            session.state,
+                            session.id,
+                            guilds.map { it.id }
+                        ))
+                    } else {
+                        call.respondRedirect(getFrontendURL(""))
+                    }
                 }
             }
             get("/logout") {
@@ -145,10 +193,14 @@ fun stop() {
     server.stop()
 }
 
+fun getFrontendURL(path: String)
+    = "${if(dotenv["FRONTEND_HTTPS"].toBoolean()) "https://" else "http://" }${dotenv["FRONTEND"]}${path}";
+
 @Serializable
 data class UserSession(
     val state: String,
-    val id: String
+    val id: String,
+    val discordGuildList: List<String>
 )
 
 @Serializable
@@ -158,3 +210,65 @@ data class NaverMeAPI(
 
 @Serializable
 data class NaverAPI<T>(val resultcode: String, val message: String, val response: T?)
+
+@Serializable
+data class DiscordMeAPI(
+    val application: DiscordApplicationAPI,
+    val scopes: List<String>,
+    val user: DiscordUserAPI
+)
+
+@Serializable
+data class DiscordApplicationAPI(
+    val id: String,
+    val name: String,
+    val icon: String,
+    val description: String,
+    val hook: Boolean,
+    val bot_public: Boolean,
+    val bot_require_code_grant: Boolean,
+    val verify_key: String
+)
+
+@Serializable
+data class DiscordUserAPI(
+    val id: String,
+    val username: String,
+    val avatar: String,
+    val discriminator: String,
+    val global_name: String,
+    val public_flags: Int
+)
+
+@Serializable
+data class DiscordGuildListAPI(
+    val id: String,
+    val name: String,
+    val icon: String,
+    val banner: String,
+    val owner: Boolean,
+    val permissions: Int,
+    val features: List<String>,
+    val approximate_member_count: Int,
+    val approximate_presence_count: Int,
+)
+
+suspend fun getDiscordUser(accessToken: String): DiscordMeAPI? {
+    val response: HttpResponse = applicationHttpClient.get("https://discord.com/api/oauth2/@me") {
+        headers {
+            append(HttpHeaders.Authorization, "Bearer $accessToken")
+        }
+    }
+
+    return response.body<DiscordMeAPI?>()
+}
+
+suspend fun getUserGuilds(accessToken: String): List<DiscordGuildListAPI> {
+    val response = applicationHttpClient.get("https://discord.com/api/users/@me/") {
+        headers {
+            append(HttpHeaders.Authorization, "Bearer $accessToken")
+        }
+    }
+
+    return response.body<List<DiscordGuildListAPI>>()
+}

webserver/src/main/kotlin/space/mori/chzzk_bot/webserver/routes/ApiDiscordRoutes.kt

@@ -52,6 +52,20 @@ fun Route.apiDiscordRoutes() {
 
             call.respond(HttpStatusCode.OK)
         }
+        get {
+            val session = call.sessions.get<UserSession>()
+            if(session == null) {
+                call.respond(HttpStatusCode.BadRequest, "Session is required")
+                return@get
+            }
+            val user = UserService.getUserWithNaverId(session.id)
+            if(user == null) {
+                call.respond(HttpStatusCode.BadRequest, "User does not exist")
+                return@get
+            }
+            call.respond(HttpStatusCode.OK, session.discordGuildList)
+            return@get
+        }
     }
 }