Add JAGGRAB request codec

Signed-off-by: Graham <gpe@openrs2.org>

protocol/src/main/kotlin/org/openrs2/protocol/jaggrab/JaggrabRequest.kt

@@ -0,0 +1,3 @@
+package org.openrs2.protocol.jaggrab
+
+public data class JaggrabRequest(public val path: String)

protocol/src/main/kotlin/org/openrs2/protocol/jaggrab/JaggrabRequestDecoder.kt

@@ -0,0 +1,19 @@
+package org.openrs2.protocol.jaggrab
+
+import io.netty.channel.ChannelHandler
+import io.netty.channel.ChannelHandlerContext
+import io.netty.handler.codec.DecoderException
+import io.netty.handler.codec.MessageToMessageDecoder
+
+@ChannelHandler.Sharable
+public object JaggrabRequestDecoder : MessageToMessageDecoder<String>() {
+    private const val PREFIX = "JAGGRAB "
+
+    override fun decode(ctx: ChannelHandlerContext, msg: String, out: MutableList<Any>) {
+        if (!msg.startsWith(PREFIX)) {
+            throw DecoderException("JAGGRAB request has invalid prefix")
+        }
+
+        out += JaggrabRequest(msg.substring(PREFIX.length))
+    }
+}

protocol/src/main/kotlin/org/openrs2/protocol/jaggrab/JaggrabRequestEncoder.kt

@@ -0,0 +1,12 @@
+package org.openrs2.protocol.jaggrab
+
+import io.netty.channel.ChannelHandler
+import io.netty.channel.ChannelHandlerContext
+import io.netty.handler.codec.MessageToMessageEncoder
+
+@ChannelHandler.Sharable
+public object JaggrabRequestEncoder : MessageToMessageEncoder<JaggrabRequest>() {
+    override fun encode(ctx: ChannelHandlerContext, msg: JaggrabRequest, out: MutableList<Any>) {
+        out += "JAGGRAB ${msg.path}\n\n"
+    }
+}

protocol/src/test/kotlin/org/openrs2/protocol/jaggrab/JaggrabRequestDecoderTest.kt

@@ -0,0 +1,27 @@
+package org.openrs2.protocol.jaggrab
+
+import io.netty.channel.embedded.EmbeddedChannel
+import io.netty.handler.codec.DecoderException
+import org.junit.jupiter.api.assertThrows
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+object JaggrabRequestDecoderTest {
+    @Test
+    fun testDecode() {
+        val channel = EmbeddedChannel(JaggrabRequestDecoder)
+        channel.writeInbound("JAGGRAB /runescape.pack200")
+
+        val actual = channel.readInbound<JaggrabRequest>()
+        assertEquals(JaggrabRequest("/runescape.pack200"), actual)
+    }
+
+    @Test
+    fun testInvalid() {
+        val channel = EmbeddedChannel(JaggrabRequestDecoder)
+
+        assertThrows<DecoderException> {
+            channel.writeInbound("Hello, world!")
+        }
+    }
+}

protocol/src/test/kotlin/org/openrs2/protocol/jaggrab/JaggrabRequestEncoderTest.kt

@@ -0,0 +1,16 @@
+package org.openrs2.protocol.jaggrab
+
+import io.netty.channel.embedded.EmbeddedChannel
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+object JaggrabRequestEncoderTest {
+    @Test
+    fun testEncode() {
+        val channel = EmbeddedChannel(JaggrabRequestEncoder)
+        channel.writeOutbound(JaggrabRequest("/runescape.pack200"))
+
+        val actual = channel.readOutbound<String>()
+        assertEquals("JAGGRAB /runescape.pack200\n\n", actual)
+    }
+}