From 96bb989ad50b56fdc0a96e2d5e8ef4ced244d3ec Mon Sep 17 00:00:00 2001
From: mae <mae@maestoso.online>
Date: Sun, 16 Nov 2025 15:09:29 -0600
Subject: [PATCH] write to fd

---
 cmd/plt-build/src/main/go/pltbuild.c          | 26 +++++++++++++
 cmd/plt-build/src/main/go/pltbuild.go         | 38 +++++++++++++++++++
 cmd/plt-build/src/main/go/pltbuild.h          | 17 +++++++++
 .../kotlin/moe/rosa/planterette/dsl/DSL.kt    | 20 +++++++++-
 .../kotlin/moe/rosa/planterette/jni/GoFile.kt |  5 +++
 5 files changed, 104 insertions(+), 2 deletions(-)
 create mode 100644 cmd/plt-build/src/main/go/pltbuild.c
 create mode 100644 cmd/plt-build/src/main/go/pltbuild.go
 create mode 100644 cmd/plt-build/src/main/go/pltbuild.h
 create mode 100644 cmd/plt-build/src/main/kotlin/moe/rosa/planterette/jni/GoFile.kt

diff --git a/cmd/plt-build/src/main/go/pltbuild.c b/cmd/plt-build/src/main/go/pltbuild.c
new file mode 100644
index 0000000..7b1759a
--- /dev/null
+++ b/cmd/plt-build/src/main/go/pltbuild.c
@@ -0,0 +1,26 @@
+#include "pltbuild.h"
+
+jint throwIOException( JNIEnv *env, char *message) {
+    jclass  exClass;
+    char *className = "java/io/IOException";
+
+    exClass = (*env)->FindClass(env, className);
+    return (*env)->ThrowNew(env, exClass, message);
+}
+
+JNIEXPORT void JNICALL Java_moe_rosa_planterette_jni_GoFile_write__ILnet_java_String_2(JNIEnv *env, jobject obj, jint fd, jstring str) {
+    char *s = (*env)->GetStringUTFChars(env, str, 0);
+    size_t sz = (*env)->GetStringUTFLength(env, str);
+
+    uintptr_t *errno_p = NULL;
+    char **err_str_p = NULL;
+
+    planterette_write(fd, s, sz, errno_p, err_str_p);
+
+    if(errno_p || *err_str_p ) {
+        throwIOException(env, **err_str_p ? *err_str_p : strerror(*errno_p));
+    }
+    
+    (*env)->ReleaseStringUTFChars(env, str, s);
+    free(err_str_p);
+}
diff --git a/cmd/plt-build/src/main/go/pltbuild.go b/cmd/plt-build/src/main/go/pltbuild.go
new file mode 100644
index 0000000..6d91761
--- /dev/null
+++ b/cmd/plt-build/src/main/go/pltbuild.go
@@ -0,0 +1,38 @@
+package _go
+
+//#cgo CFLAGS: -I "$JAVA_HOME/include" -I "$JAVA_HOME/include/linux"
+//#include "pltbuild.h"
+import "C"
+import (
+	"errors"
+	"os"
+	"strconv"
+	"syscall"
+)
+
+//export planterette_write
+func planterette_write(
+	fd C.int,
+	str_p *C.char, str_sz C.size_t,
+	errno_p *C.uintptr_t,
+	err_str_p **C.char,
+) {
+	f := os.NewFile(uintptr(fd), strconv.Itoa(int(fd)))
+	defer f.Close()
+	_, err := f.WriteString(C.GoStringN(str_p, C.int(str_sz)))
+	if err == nil {
+		return
+	}
+
+	var pathError *os.PathError
+	if errors.As(err, &pathError) {
+		var errno syscall.Errno
+		if errors.As(pathError.Err, &errno) {
+			*errno_p = C.uintptr_t(errno)
+			return
+		}
+	}
+
+	*err_str_p = C.CString(err.Error())
+	return
+}
diff --git a/cmd/plt-build/src/main/go/pltbuild.h b/cmd/plt-build/src/main/go/pltbuild.h
new file mode 100644
index 0000000..93e3cec
--- /dev/null
+++ b/cmd/plt-build/src/main/go/pltbuild.h
@@ -0,0 +1,17 @@
+#include <jni.h>
+
+#include <string.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#ifndef _PLTBUILD_H
+#define _PLTBUILD_H
+
+/*
+ * moe/rosa/planterette/jni/GoFile#write(ILnet/java/String;)V
+ */
+JNIEXPORT void JNICALL Java_moe_rosa_planterette_jni_GoFile_write__ILnet_java_String_2(JNIEnv *, jobject, jint, jstring);
+
+extern void planterette_write(int fd, char *str_p, size_t str_sz,  uintptr_t *errno_p,  char **err_str_p);
+
+#endif
\ No newline at end of file
diff --git a/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/dsl/DSL.kt b/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/dsl/DSL.kt
index 91185f5..1b25526 100644
--- a/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/dsl/DSL.kt
+++ b/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/dsl/DSL.kt
@@ -1,8 +1,11 @@
 @file:Suppress("unused")
 package moe.rosa.planterette.dsl
 
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.json.Json
 import moe.rosa.planterette.api.Capability
 import moe.rosa.planterette.api.Manifest
+import moe.rosa.planterette.jni.GoFile
 
 
 @Target(AnnotationTarget.TYPE, AnnotationTarget.CLASS, AnnotationTarget.FUNCTION)
@@ -38,8 +41,21 @@ data class PlanteretteBlock(
     var metadata: MetadataBlock,
     var executable: ExecutableBlock,
     var capabilities: CapabilitiesBlock,
-    var permissions: PermissionsBlock
-)
+    var permissions: PermissionsBlock,
+    var buildGuard: Boolean = false
+) {
+    // NOTE the two underscores are because this function is only intended to be added at runtime
+    @OptIn(ExperimentalSerializationApi::class)
+    @Suppress("FunctionName")
+    fun __build(args: Array<out String>): PlanteretteBlock {
+        if(!buildGuard) {
+            val manifest = Manifest(metadata.metadata, executable.executable, capabilities.capabilities, permissions.permissions)
+            GoFile.write(args[0].toInt(), Json.encodeToString(manifest))
+            buildGuard = true
+        }
+        return this;
+    }
+}
 
 @MetadataBlockMarker
 data class MetadataBlock(var metadata: Manifest.Metadata)
diff --git a/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/jni/GoFile.kt b/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/jni/GoFile.kt
new file mode 100644
index 0000000..0fc62f5
--- /dev/null
+++ b/cmd/plt-build/src/main/kotlin/moe/rosa/planterette/jni/GoFile.kt
@@ -0,0 +1,5 @@
+package moe.rosa.planterette.jni
+
+object GoFile {
+    external fun write(fd: Int, str: String)
+}
\ No newline at end of file