From 5c84278667eb022c48f9e0940ae2016e6285ef41 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Sat, 14 May 2022 19:26:07 -0700
Subject: [PATCH] Scripting: Start exporting some constants

---
 include/mgba/script/context.h | 10 ++++++++++
 src/script/context.c          | 24 +++++++++++++++++++-----
 src/script/stdlib.c           | 20 ++++++++++++++++++++
 3 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/include/mgba/script/context.h b/include/mgba/script/context.h
index 8104295d7..74385c291 100644
--- a/include/mgba/script/context.h
+++ b/include/mgba/script/context.h
@@ -14,6 +14,9 @@ CXX_GUARD_START
 #include <mgba-util/table.h>
 #include <mgba-util/vfs.h>
 
+#define mSCRIPT_CONSTANT_PAIR(NS, CONST) { #CONST, mScriptValueCreateFromSInt(NS ## _ ## CONST) }
+#define mSCRIPT_CONSTANT_SENTINEL { NULL, NULL }
+
 struct mScriptFrame;
 struct mScriptFunction;
 struct mScriptEngineContext;
@@ -25,6 +28,7 @@ struct mScriptContext {
 	struct Table weakrefs;
 	uint32_t nextWeakref;
 	struct Table callbacks;
+	struct mScriptValue* constants;
 };
 
 struct mScriptEngine2 {
@@ -50,6 +54,11 @@ struct mScriptEngineContext {
 	const char* (*getError)(struct mScriptEngineContext*);
 };
 
+struct mScriptKVPair {
+	const char* key;
+	struct mScriptValue* value;
+};
+
 void mScriptContextInit(struct mScriptContext*);
 void mScriptContextDeinit(struct mScriptContext*);
 
@@ -70,6 +79,7 @@ struct mScriptValue* mScriptContextAccessWeakref(struct mScriptContext*, struct
 void mScriptContextClearWeakref(struct mScriptContext*, uint32_t weakref);
 
 void mScriptContextAttachStdlib(struct mScriptContext* context);
+void mScriptContextExportConstants(struct mScriptContext* context, const char* nspace, struct mScriptKVPair* constants);
 
 void mScriptContextTriggerCallback(struct mScriptContext*, const char* callback);
 void mScriptContextAddCallback(struct mScriptContext*, const char* callback, struct mScriptValue* value);
diff --git a/src/script/context.c b/src/script/context.c
index 2ee2dead0..b3ec04ffd 100644
--- a/src/script/context.c
+++ b/src/script/context.c
@@ -8,11 +8,6 @@
 #include <mgba/internal/script/lua.h>
 #endif
 
-struct mScriptKVPair {
-	const char* key;
-	struct mScriptValue* value;
-};
-
 struct mScriptFileInfo {
 	const char* name;
 	struct VFile* vf;
@@ -61,6 +56,7 @@ void mScriptContextInit(struct mScriptContext* context) {
 	TableInit(&context->weakrefs, 0, (void (*)(void*)) mScriptValueDeref);
 	context->nextWeakref = 1;
 	HashTableInit(&context->callbacks, 0, (void (*)(void*)) mScriptValueDeref);
+	context->constants = NULL;
 }
 
 void mScriptContextDeinit(struct mScriptContext* context) {
@@ -223,6 +219,24 @@ void mScriptContextAddCallback(struct mScriptContext* context, const char* callb
 	mScriptValueWrap(fn, mScriptListAppend(list->value.opaque));
 }
 
+void mScriptContextExportConstants(struct mScriptContext* context, const char* nspace, struct mScriptKVPair* constants) {
+	if (!context->constants) {
+		context->constants = mScriptValueAlloc(mSCRIPT_TYPE_MS_TABLE);
+	}
+	struct mScriptValue* table = mScriptValueAlloc(mSCRIPT_TYPE_MS_TABLE);
+	size_t i;
+	for (i = 0; constants[i].key; ++i) {
+		struct mScriptValue* key = mScriptStringCreateFromUTF8(constants[i].key);
+		mScriptTableInsert(table, key, constants[i].value);
+		mScriptValueDeref(key);
+		mScriptValueDeref(constants[i].value);
+	}
+	struct mScriptValue* key = mScriptStringCreateFromUTF8(nspace);
+	mScriptTableInsert(context->constants, key, table);
+	mScriptValueDeref(key);
+	mScriptValueDeref(table);
+}
+
 bool mScriptContextLoadVF(struct mScriptContext* context, const char* name, struct VFile* vf) {
 	struct mScriptFileInfo info = {
 		.name = name,
diff --git a/src/script/stdlib.c b/src/script/stdlib.c
index 08871fb49..78d57deb8 100644
--- a/src/script/stdlib.c
+++ b/src/script/stdlib.c
@@ -5,6 +5,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include <mgba/script/context.h>
 
+#include <mgba/core/core.h>
+#include <mgba/core/serialize.h>
+
 struct mScriptCallbackAdapter {
 	struct mScriptContext* context;
 };
@@ -34,4 +37,21 @@ void mScriptContextAttachStdlib(struct mScriptContext* context) {
 	};
 	lib->flags = mSCRIPT_VALUE_FLAG_FREE_BUFFER;
 	mScriptContextSetGlobal(context, "callbacks", lib);
+
+	mScriptContextExportConstants(context, "SAVESTATE", (struct mScriptKVPair[]) {
+		mSCRIPT_CONSTANT_PAIR(SAVESTATE, SCREENSHOT),
+		mSCRIPT_CONSTANT_PAIR(SAVESTATE, SAVEDATA),
+		mSCRIPT_CONSTANT_PAIR(SAVESTATE, CHEATS),
+		mSCRIPT_CONSTANT_PAIR(SAVESTATE, RTC),
+		mSCRIPT_CONSTANT_PAIR(SAVESTATE, METADATA),
+		mSCRIPT_CONSTANT_PAIR(SAVESTATE, ALL),
+		mSCRIPT_CONSTANT_SENTINEL
+	});
+	mScriptContextExportConstants(context, "PLATFORM", (struct mScriptKVPair[]) {
+		mSCRIPT_CONSTANT_PAIR(mPLATFORM, NONE),
+		mSCRIPT_CONSTANT_PAIR(mPLATFORM, GBA),
+		mSCRIPT_CONSTANT_PAIR(mPLATFORM, GB),
+		mSCRIPT_CONSTANT_SENTINEL
+	});
+	mScriptContextSetGlobal(context, "C", context->constants);
 }