package runner

import (
	"fmt"
	"sync"

	"github.com/goccy/go-json"
	"github.com/valyala/fasthttp"

	"Moonshark/utils/logger"

	"maps"

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

// Error represents a simple error string
type Error string

func (e Error) Error() string {
	return string(e)
}

// Error types
var (
	ErrSandboxNotInitialized = Error("sandbox not initialized")
)

// Sandbox provides a secure execution environment for Lua scripts
type Sandbox struct {
	modules map[string]any
	debug   bool
	mu      sync.RWMutex
}

// NewSandbox creates a new sandbox environment
func NewSandbox() *Sandbox {
	return &Sandbox{
		modules: make(map[string]any, 8),
		debug:   false,
	}
}

// AddModule adds a module to the sandbox environment
func (s *Sandbox) AddModule(name string, module any) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.modules[name] = module
	logger.Debugf("Added module: %s", name)
}

// Setup initializes the sandbox in a Lua state
func (s *Sandbox) Setup(state *luajit.State, verbose bool) error {
	if verbose {
		logger.Debugf("Setting up sandbox...")
	}

	if err := loadSandboxIntoState(state, verbose); err != nil {
		logger.Errorf("Failed to load sandbox: %v", err)
		return err
	}

	if err := s.registerCoreFunctions(state); err != nil {
		logger.Errorf("Failed to register core functions: %v", err)
		return err
	}

	s.mu.RLock()
	for name, module := range s.modules {
		logger.Debugf("Registering module: %s", name)
		if err := state.PushValue(module); err != nil {
			s.mu.RUnlock()
			logger.Errorf("Failed to register module %s: %v", name, err)
			return err
		}
		state.SetGlobal(name)
	}
	s.mu.RUnlock()

	if verbose {
		logger.Debugf("Sandbox setup complete")
	}
	return nil
}

// registerCoreFunctions registers all built-in functions in the Lua state
func (s *Sandbox) registerCoreFunctions(state *luajit.State) error {
	if err := state.RegisterGoFunction("__http_request", httpRequest); err != nil {
		return err
	}

	if err := state.RegisterGoFunction("__generate_token", generateToken); err != nil {
		return err
	}

	if err := state.RegisterGoFunction("__json_marshal", jsonMarshal); err != nil {
		return err
	}

	if err := state.RegisterGoFunction("__json_unmarshal", jsonUnmarshal); err != nil {
		return err
	}

	if err := RegisterSQLiteFunctions(state); err != nil {
		return err
	}

	if err := RegisterFSFunctions(state); err != nil {
		return err
	}

	if err := RegisterPasswordFunctions(state); err != nil {
		return err
	}

	if err := RegisterUtilFunctions(state); err != nil {
		return err
	}

	if err := RegisterCryptoFunctions(state); err != nil {
		return err
	}

	if err := RegisterEnvFunctions(state); err != nil {
		return err
	}

	return nil
}

// Execute runs a Lua script in the sandbox with the given context
func (s *Sandbox) Execute(state *luajit.State, bytecode []byte, ctx *Context) (*Response, error) {
	// Load bytecode - pushes function onto stack
	if err := state.LoadBytecode(bytecode, "script"); err != nil {
		return nil, fmt.Errorf("failed to load bytecode: %w", err)
	}

	// Stack: [function]
	state.GetGlobal("__execute_script") // Stack: [function, __execute_script]
	state.PushCopy(-2)                  // Stack: [function, __execute_script, function]

	// Push context using PushValue
	if err := state.PushValue(ctx.Values); err != nil {
		state.Pop(3)
		return nil, fmt.Errorf("failed to push context: %w", err)
	}
	// Stack: [function, __execute_script, function, context]

	// Call __execute_script(function, context)
	if err := state.Call(2, 1); err != nil {
		state.Pop(1) // Clean up original function
		return nil, fmt.Errorf("script execution failed: %w", err)
	}
	// Stack: [function, result]

	response := NewResponse()
	if result, err := state.ToValue(-1); err == nil {
		response.Body = result
	}

	state.SetTop(0) // Clear stack

	extractHTTPResponseData(state, response)
	return response, nil
}

// extractResponseData pulls response info from the Lua state using new API
func extractHTTPResponseData(state *luajit.State, response *Response) {
	state.GetGlobal("__http_response")
	if !state.IsTable(-1) {
		state.Pop(1)
		return
	}

	// Use new field getters with defaults
	response.Status = int(state.GetFieldNumber(-1, "status", 200))

	// Extract headers using ForEachTableKV
	if headerTable, ok := state.GetFieldTable(-1, "headers"); ok {
		switch headers := headerTable.(type) {
		case map[string]any:
			for k, v := range headers {
				if str, ok := v.(string); ok {
					response.Headers[k] = str
				}
			}
		case map[string]string:
			maps.Copy(response.Headers, headers)
		}
	}

	// Extract cookies using ForEachArray
	state.GetField(-1, "cookies")
	if state.IsTable(-1) {
		state.ForEachArray(-1, func(i int, s *luajit.State) bool {
			if s.IsTable(-1) {
				extractCookie(s, response)
			}
			return true
		})
	}
	state.Pop(1)

	// Extract metadata
	if metadata, ok := state.GetFieldTable(-1, "metadata"); ok {
		if metaMap, ok := metadata.(map[string]any); ok {
			maps.Copy(response.Metadata, metaMap)
		}
	}

	// Extract session data
	if session, ok := state.GetFieldTable(-1, "session"); ok {
		switch sessMap := session.(type) {
		case map[string]any:
			maps.Copy(response.SessionData, sessMap)
		case map[string]string:
			for k, v := range sessMap {
				response.SessionData[k] = v
			}
		case map[string]int:
			for k, v := range sessMap {
				response.SessionData[k] = v
			}
		default:
			logger.Debugf("Unexpected session type: %T", session)
		}
	}

	state.Pop(1) // Pop __http_response
}

// extractCookie pulls cookie data from the current table on the stack using new API
func extractCookie(state *luajit.State, response *Response) {
	cookie := fasthttp.AcquireCookie()

	// Use new field getters with defaults
	name := state.GetFieldString(-1, "name", "")
	if name == "" {
		fasthttp.ReleaseCookie(cookie)
		return
	}

	cookie.SetKey(name)
	cookie.SetValue(state.GetFieldString(-1, "value", ""))
	cookie.SetPath(state.GetFieldString(-1, "path", "/"))
	cookie.SetDomain(state.GetFieldString(-1, "domain", ""))
	cookie.SetHTTPOnly(state.GetFieldBool(-1, "http_only", false))
	cookie.SetSecure(state.GetFieldBool(-1, "secure", false))
	cookie.SetMaxAge(int(state.GetFieldNumber(-1, "max_age", 0)))

	response.Cookies = append(response.Cookies, cookie)
}

// jsonMarshal converts a Lua value to a JSON string with validation
func jsonMarshal(state *luajit.State) int {
	if err := state.CheckExactArgs(1); err != nil {
		return state.PushError("json marshal: %v", err)
	}

	value, err := state.SafeToTable(1)
	if err != nil {
		// Try as generic value if not a table
		value, err = state.ToValue(1)
		if err != nil {
			return state.PushError("json marshal error: %v", err)
		}
	}

	bytes, err := json.Marshal(value)
	if err != nil {
		return state.PushError("json marshal error: %v", err)
	}

	state.PushString(string(bytes))
	return 1
}

// jsonUnmarshal converts a JSON string to a Lua value with validation
func jsonUnmarshal(state *luajit.State) int {
	if err := state.CheckExactArgs(1); err != nil {
		return state.PushError("json unmarshal: %v", err)
	}

	jsonStr, err := state.SafeToString(1)
	if err != nil {
		return state.PushError("json unmarshal: expected string, got %s", state.GetType(1))
	}

	var value any
	if err := json.Unmarshal([]byte(jsonStr), &value); err != nil {
		return state.PushError("json unmarshal error: %v", err)
	}

	if err := state.PushValue(value); err != nil {
		return state.PushError("json unmarshal error: %v", err)
	}
	return 1
}