Add basic lua scripting capabilities (#4341)

The scripting capabilities is locked behind a cmake flag, and is not enabled by default.

Co-authored-by: nerix <nerixdev@outlook.de>
Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/controllers/plugins/LuaUtilities.cpp

@@ -0,0 +1,196 @@
+#ifdef CHATTERINO_HAVE_PLUGINS
+#    include "controllers/plugins/LuaUtilities.hpp"
+
+#    include "common/Channel.hpp"
+#    include "common/QLogging.hpp"
+#    include "controllers/commands/CommandContext.hpp"
+
+#    include <lauxlib.h>
+#    include <lua.h>
+
+#    include <climits>
+#    include <cstdlib>
+
+namespace chatterino::lua {
+
+void stackDump(lua_State *L, const QString &tag)
+{
+    qCDebug(chatterinoLua) << "--------------------";
+    auto count = lua_gettop(L);
+    if (!tag.isEmpty())
+    {
+        qCDebug(chatterinoLua) << "Tag: " << tag;
+    }
+    qCDebug(chatterinoLua) << "Count elems: " << count;
+    for (int i = 1; i <= count; i++)
+    {
+        auto typeint = lua_type(L, i);
+        if (typeint == LUA_TSTRING)
+        {
+            QString str;
+            lua::peek(L, &str, i);
+            qCDebug(chatterinoLua)
+                << "At" << i << "is a" << lua_typename(L, typeint) << "("
+                << typeint << "): " << str;
+        }
+        else if (typeint == LUA_TTABLE)
+        {
+            qCDebug(chatterinoLua)
+                << "At" << i << "is a" << lua_typename(L, typeint) << "("
+                << typeint << ")"
+                << "its length is " << lua_rawlen(L, i);
+        }
+        else
+        {
+            qCDebug(chatterinoLua)
+                << "At" << i << "is a" << lua_typename(L, typeint) << "("
+                << typeint << ")";
+        }
+    }
+    qCDebug(chatterinoLua) << "--------------------";
+}
+
+QString humanErrorText(lua_State *L, int errCode)
+{
+    QString errName;
+    switch (errCode)
+    {
+        case LUA_OK:
+            return "ok";
+        case LUA_ERRRUN:
+            errName = "(runtime error)";
+            break;
+        case LUA_ERRMEM:
+            errName = "(memory error)";
+            break;
+        case LUA_ERRERR:
+            errName = "(error while handling another error)";
+            break;
+        case LUA_ERRSYNTAX:
+            errName = "(syntax error)";
+            break;
+        case LUA_YIELD:
+            errName = "(illegal coroutine yield)";
+            break;
+        case LUA_ERRFILE:
+            errName = "(file error)";
+            break;
+        default:
+            errName = "(unknown error type)";
+    }
+    QString errText;
+    if (peek(L, &errText))
+    {
+        errName += " " + errText;
+    }
+    return errName;
+}
+
+StackIdx pushEmptyArray(lua_State *L, int countArray)
+{
+    lua_createtable(L, countArray, 0);
+    return lua_gettop(L);
+}
+
+StackIdx pushEmptyTable(lua_State *L, int countProperties)
+{
+    lua_createtable(L, 0, countProperties);
+    return lua_gettop(L);
+}
+
+StackIdx push(lua_State *L, const QString &str)
+{
+    return lua::push(L, str.toStdString());
+}
+
+StackIdx push(lua_State *L, const std::string &str)
+{
+    lua_pushstring(L, str.c_str());
+    return lua_gettop(L);
+}
+
+StackIdx push(lua_State *L, const CommandContext &ctx)
+{
+    auto outIdx = pushEmptyTable(L, 2);
+
+    push(L, ctx.words);
+    lua_setfield(L, outIdx, "words");
+    push(L, ctx.channel->getName());
+    lua_setfield(L, outIdx, "channel_name");
+
+    return outIdx;
+}
+
+StackIdx push(lua_State *L, const bool &b)
+{
+    lua_pushboolean(L, int(b));
+    return lua_gettop(L);
+}
+
+bool peek(lua_State *L, double *out, StackIdx idx)
+{
+    int ok{0};
+    auto v = lua_tonumberx(L, idx, &ok);
+    if (ok != 0)
+    {
+        *out = v;
+    }
+    return ok != 0;
+}
+
+bool peek(lua_State *L, QString *out, StackIdx idx)
+{
+    size_t len{0};
+    const char *str = lua_tolstring(L, idx, &len);
+    if (str == nullptr)
+    {
+        return false;
+    }
+    if (len >= INT_MAX)
+    {
+        assert(false && "string longer than INT_MAX, shit's fucked, yo");
+    }
+    *out = QString::fromUtf8(str, int(len));
+    return true;
+}
+
+bool peek(lua_State *L, QByteArray *out, StackIdx idx)
+{
+    size_t len{0};
+    const char *str = lua_tolstring(L, idx, &len);
+    if (str == nullptr)
+    {
+        return false;
+    }
+    if (len >= INT_MAX)
+    {
+        assert(false && "string longer than INT_MAX, shit's fucked, yo");
+    }
+    *out = QByteArray(str, int(len));
+    return true;
+}
+
+bool peek(lua_State *L, std::string *out, StackIdx idx)
+{
+    size_t len{0};
+    const char *str = lua_tolstring(L, idx, &len);
+    if (str == nullptr)
+    {
+        return false;
+    }
+    if (len >= INT_MAX)
+    {
+        assert(false && "string longer than INT_MAX, shit's fucked, yo");
+    }
+    *out = std::string(str, len);
+    return true;
+}
+
+QString toString(lua_State *L, StackIdx idx)
+{
+    size_t len{};
+    const auto *ptr = luaL_tolstring(L, idx, &len);
+    return QString::fromUtf8(ptr, int(len));
+}
+}  // namespace chatterino::lua
+#endif