initial support for lua, WIP

1 files changed, 179 insertions, 0 deletions

diff --git a/plugins.go b/plugins.go
new file mode 100644
index 0000000..d64f65b
--- /dev/null
+++ b/plugins.go
@@ -0,0 +1,179 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"reflect"
+
+	lua "github.com/yuin/gopher-lua"
+)
+
+func registerStrucAsLuaMetaTable[T any](
+	luaState *lua.LState,
+	checkStruct func(luaState *lua.LState) *T,
+	structType T,
+	metaTableName string,
+) {
+	metaTable := luaState.NewTypeMetatable(metaTableName)
+
+	luaState.SetGlobal(metaTableName, metaTable)
+
+	luaState.SetField(
+		metaTable,
+		"new",
+		luaState.NewFunction(
+			newStructFunctionFactory(structType, metaTableName),
+		),
+	)
+
+	var zero [0]T
+
+	luaState.SetField(
+		metaTable,
+		"__index",
+		luaState.SetFuncs(
+			luaState.NewTable(),
+			luaTableGenFactory(reflect.TypeOf(zero),
+				checkStruct,
+			),
+		),
+	)
+}
+
+func newStructFunctionFactory[T any](structType T, metaTableName string) func(*lua.LState) int {
+	return func(luaState *lua.LState) int {
+		structInstance := &structType
+		ud := luaState.NewUserData()
+		ud.Value = structInstance
+		luaState.SetMetatable(ud, luaState.GetTypeMetatable(metaTableName))
+		luaState.Push(ud)
+
+		return 1
+	}
+}
+
+func checkStruct[T any](luaState *lua.LState) *T {
+	userData := luaState.CheckUserData(1)
+	if v, ok := userData.Value.(*T); ok {
+		return v
+	}
+
+	luaState.ArgError(1, "got wrong struct")
+
+	return nil
+}
+
+func getterSetterFactory[T any](
+	fieldName string,
+	fieldType reflect.Type,
+	checkStruct func(luaState *lua.LState) *T,
+) func(*lua.LState) int {
+	return func(luaState *lua.LState) int {
+		genericStruct := checkStruct(luaState)
+
+		structValue := reflect.ValueOf(genericStruct).Elem()
+
+		fieldValue := structValue.FieldByName(fieldName)
+
+		if luaState.GetTop() == 2 { //nolint: mnd,gomnd
+			switch fieldType.Kind() {
+			case reflect.String:
+				fieldValue.SetString(luaState.CheckString(2)) //nolint: mnd,gomnd
+			case reflect.Float64:
+				fieldValue.SetFloat(float64(luaState.CheckNumber(2))) //nolint: mnd,gomnd
+			case reflect.Float32:
+				fieldValue.SetFloat(float64(luaState.CheckNumber(2))) //nolint: mnd,gomnd
+			case reflect.Int8:
+				fieldValue.SetInt(int64(luaState.CheckInt(2))) //nolint: mnd,gomnd
+			case reflect.Int16:
+				fieldValue.SetInt(int64(luaState.CheckInt(2))) //nolint: mnd,gomnd
+			case reflect.Int:
+				fieldValue.SetInt(int64(luaState.CheckInt(2))) //nolint: mnd,gomnd
+			case reflect.Int32:
+				fieldValue.SetInt(int64(luaState.CheckInt(2))) //nolint: mnd,gomnd
+			case reflect.Int64:
+				fieldValue.SetInt(int64(luaState.CheckInt(2))) //nolint: mnd,gomnd
+			case reflect.Bool:
+				fieldValue.SetBool(luaState.CheckBool(2)) //nolint: mnd,gomnd
+			default:
+				log.Print("unsupported type")
+			}
+
+			return 0
+		}
+
+		switch fieldType.Kind() {
+		case reflect.String:
+			luaState.Push(lua.LString(fieldValue.Interface().(string)))
+		case reflect.Float64:
+			luaState.Push(lua.LNumber(fieldValue.Interface().(float64)))
+		case reflect.Float32:
+			luaState.Push(lua.LNumber(fieldValue.Float()))
+		case reflect.Int8:
+			luaState.Push(lua.LNumber(fieldValue.Int()))
+		case reflect.Int16:
+			luaState.Push(lua.LNumber(fieldValue.Int()))
+		case reflect.Int:
+			luaState.Push(lua.LNumber(fieldValue.Int()))
+		case reflect.Int32:
+			luaState.Push(lua.LNumber(fieldValue.Int()))
+		case reflect.Int64:
+			luaState.Push(lua.LNumber(fieldValue.Int()))
+		case reflect.Bool:
+			luaState.Push(lua.LBool(fieldValue.Bool()))
+		default:
+			log.Print("unsupported type")
+		}
+
+		return 1
+	}
+}
+
+func luaTableGenFactory[T any](
+	structType reflect.Type,
+	checkStructType func(luaState *lua.LState) *T) map[string]lua.LGFunction {
+	tableMethods := make(map[string]lua.LGFunction)
+
+	for _, field := range reflect.VisibleFields(structType) {
+		tableMethods[field.Name] = getterSetterFactory(field.Name, field.Type, checkStructType)
+	}
+
+	return tableMethods
+}
+
+func RegisterCustomLuaTypes(luaState *lua.LState) {
+	registerStrucAsLuaMetaTable(luaState, checkStruct, TomlConfig{}, "toml_config")
+	registerStrucAsLuaMetaTable(luaState, checkStruct, CustomCommand{}, "custom_command")
+}
+
+func returnAllPlugins(pluginPath string) ([]string, error) {
+	pluginList := make([]string, 0)
+
+	files, err := os.ReadDir(pluginPath)
+	if err != nil {
+		return pluginList, fmt.Errorf("Error reading plugins directory: %v", err)
+	}
+
+	for _, file := range files {
+		pluginList = append(pluginList, file.Name())
+	}
+
+	return pluginList, nil
+}
+
+func LoadAllPlugins(appConfig *TomlConfig) {
+	luaState := lua.NewState()
+	defer luaState.Close()
+
+	RegisterCustomLuaTypes(luaState)
+
+	allPlugins, err := returnAllPlugins(appConfig.PluginPath)
+	if err != nil {
+		luaState.Close()
+
+		log.Fatal(err) //nolint: gocritic
+	}
+
+	log.Println(allPlugins)
+}