package runner

import (
	_ "embed"
	"sync"
	"sync/atomic"

	"Moonshark/core/utils/logger"

	luajit "git.sharkk.net/Sky/LuaJIT-to-Go"
)

//go:embed sandbox.lua
var sandboxLuaCode string

// Global bytecode cache to improve performance
var (
	sandboxBytecode atomic.Pointer[[]byte]
	bytecodeOnce    sync.Once
)

// precompileSandboxCode compiles the sandbox.lua code to bytecode once
func precompileSandboxCode() {
	// Create temporary state for compilation
	tempState := luajit.New()
	if tempState == nil {
		logger.ErrorCont("Failed to create temp Lua state for bytecode compilation")
		return
	}
	defer tempState.Close()
	defer tempState.Cleanup()

	code, err := tempState.CompileBytecode(sandboxLuaCode, "sandbox.lua")
	if err != nil {
		logger.ErrorCont("Failed to compile sandbox code: %v", err)
		return
	}

	bytecode := make([]byte, len(code))
	copy(bytecode, code)
	sandboxBytecode.Store(&bytecode)

	logger.ServerCont("Successfully precompiled sandbox.lua to bytecode (%d bytes)", len(code))
}

// loadSandboxIntoState loads the sandbox code into a Lua state
func loadSandboxIntoState(state *luajit.State, verbose bool) error {
	bytecodeOnce.Do(precompileSandboxCode)

	bytecode := sandboxBytecode.Load()
	if bytecode != nil && len(*bytecode) > 0 {
		if verbose {
			logger.ServerCont("Loading sandbox.lua from precompiled bytecode") // piggyback off Sandbox.go's Setup()
		}
		return state.LoadAndRunBytecode(*bytecode, "sandbox.lua")
	}

	// Fallback to direct execution
	if verbose {
		logger.WarningCont("Using non-precompiled sandbox.lua (bytecode compilation failed)")
	}
	return state.DoString(sandboxLuaCode)
}