feat: initial db persistence

src/main/kotlin/at/dokkae/homepage/Homepage.kt

@@ -1,7 +1,10 @@
 package at.dokkae.homepage
 
 import at.dokkae.homepage.extensions.Precompiled
+import at.dokkae.homepage.repository.MessageRepository
+import at.dokkae.homepage.repository.impls.JooqMessageRepository
 import at.dokkae.homepage.templates.Index
+import io.github.cdimascio.dotenv.dotenv
 import org.http4k.core.HttpHandler
 import org.http4k.core.Method.*
 import org.http4k.core.Response
@@ -22,30 +25,43 @@ import org.http4k.sse.SseResponse
 import org.http4k.template.JTETemplates
 import org.http4k.template.ViewModel
 import org.jetbrains.kotlin.backend.common.push
+import org.jooq.SQLDialect
+import org.jooq.impl.DSL
+import java.sql.DriverManager
 import java.time.Instant
 import java.util.UUID
 import java.util.concurrent.CopyOnWriteArrayList
 import kotlin.concurrent.thread
 
-data class Message (
+data class Message(
     val author: String,
     val content: String,
-    val createdAt: Instant = Instant.now(),
+
     val id: UUID = UUID.randomUUID(),
+    val createdAt: Instant = Instant.now(),
+    val updatedAt: Instant? = null
 ) : ViewModel {
+    init {
+        require(author.length <= 31) { "Author must be 31 characters or less" }
+        require(content.length <= 255) { "Content must be 255 characters or less" }
+    }
+
+
     override fun template(): String = "partials/Message"
 }
 
 fun main() {
-    val messages = CopyOnWriteArrayList<Message>()
-    val subscribers = CopyOnWriteArrayList<Sse>()
-    val renderer = JTETemplates().Precompiled("build/classes/jte")
+    val env = dotenv()
 
-    messages.push(Message("Kurisu", "Hello World!"))
-    messages.push(Message("Violet", "Haii Kurisu!"))
+    val connection = DriverManager.getConnection(env["DB_URL"], env["DB_USERNAME"], env["DB_PASSWORD"])
+    val dslContext = DSL.using(connection, SQLDialect.POSTGRES)
+    val messageRepository: MessageRepository = JooqMessageRepository(dslContext)
+
+    val subscribers = CopyOnWriteArrayList<Sse>()
+    val renderer = JTETemplates().Precompiled("build/generated-resources/jte")
 
     val indexHandler: HttpHandler = {
-        Response(Status.OK).body(renderer(Index(messages)))
+        Response(Status.OK).body(renderer(Index(messageRepository.findAll())))
     }
 
     val sse = sse(
@@ -72,12 +88,12 @@ fun main() {
                 val msg = Message(author, message)
                 val sseMsg = SseMessage.Data(renderer(msg))
 
-                messages.push(msg)
+                messageRepository.save(msg)
                 subscribers.forEach {
                     thread { it.send(sseMsg) }
                 }
 
-                Response(Status.OK)
+                Response(Status.CREATED)
             }
         }
     )

src/main/kotlin/at/dokkae/homepage/repository/MessageRepository.kt

@@ -0,0 +1,8 @@
+package at.dokkae.homepage.repository
+
+import at.dokkae.homepage.Message
+
+interface MessageRepository {
+    fun save(message: Message): Message
+    fun findAll(): List<Message>
+}

src/main/kotlin/at/dokkae/homepage/repository/impls/JooqMessageRepository.kt

@@ -0,0 +1,40 @@
+package at.dokkae.homepage.repository.impls
+
+import at.dokkae.homepage.Message
+import at.dokkae.homepage.generated.jooq.tables.records.MessageRecord
+import at.dokkae.homepage.generated.jooq.tables.references.MESSAGE
+import at.dokkae.homepage.repository.MessageRepository
+import org.jooq.DSLContext
+import org.jooq.impl.DSL
+
+class JooqMessageRepository(
+    private val dslContext: DSLContext
+) : MessageRepository {
+    override fun save(message: Message): Message = dslContext.transactionResult { config ->
+        val ctx = DSL.using(config)
+
+        ctx.insertInto(MESSAGE)
+            .set(MESSAGE.ID, message.id)
+            .set(MESSAGE.AUTHOR, message.author)
+            .set(MESSAGE.CONTENT, message.content)
+            .onDuplicateKeyUpdate()
+            .set(MESSAGE.AUTHOR, message.author)
+            .set(MESSAGE.CONTENT, message.content)
+            .returning()
+            .fetchOne()!!
+            .toMessage()
+    }
+
+    override fun findAll(): List<Message> = dslContext.selectFrom(MESSAGE)
+        .orderBy(MESSAGE.CREATED_AT.desc())
+        .fetch { it.toMessage() }
+
+
+    private fun MessageRecord.toMessage(): Message = Message(
+        id = this.id,
+        author = this.author,
+        content = this.content,
+        createdAt = this.createdAt!!.toInstant(),
+        updatedAt = this.updatedAt?.toInstant(),
+    )
+}

src/main/resources/db/migration/V001__add_update_and_create_timestamp_triggers.sql

@@ -0,0 +1,18 @@
+create or replace function handle_timestamps()
+    returns trigger as
+$$
+begin
+    if lower(tg_op) = 'insert' then
+        new.created_at = coalesce(new.created_at, current_timestamp);
+        new.updated_at = coalesce(new.updated_at, current_timestamp);
+    elsif lower(tg_op) = 'update' then
+        if new.created_at is distinct from old.created_at then
+            raise exception 'Direct modification of created_at is not allowed.';
+        end if;
+
+        new.updated_at = current_timestamp;
+    end if;
+
+    return new;
+end;
+$$ language plpgsql;

src/main/resources/db/migration/V002__add_message_table.sql

@@ -0,0 +1,13 @@
+create table message (
+    id uuid not null primary key,
+    author varchar(31) not null,
+    content varchar(255) not null,
+
+    created_at timestamptz not null default current_timestamp,
+    updated_at timestamptz
+);
+
+create trigger handle_message_timestamps
+    before insert or update on message
+    for each row
+    execute function handle_timestamps();