mengstack-api/internal/kernel/plugin/sandbox.go

package plugin

import (
	"fmt"
	"sync"

	"go.uber.org/zap"
)

// Sandbox enforces permission boundaries and isolates plugin failures.
type Sandbox struct {
	permissions map[string]Permissions // pluginName → declared permissions
	mu          sync.RWMutex
	log         *zap.Logger
}

// NewSandbox creates a permission enforcement sandbox.
func NewSandbox(log *zap.Logger) *Sandbox {
	return &Sandbox{
		permissions: make(map[string]Permissions),
		log:         log,
	}
}

// Register records a plugin's declared permissions.
func (s *Sandbox) Register(name string, perms Permissions) {
	s.mu.Lock()
	defer s.mu.Unlock()
	s.permissions[name] = perms
	s.log.Info("plugin permissions registered",
		zap.String("plugin", name),
		zap.Bool("database", len(perms.Database) > 0),
		zap.Bool("storage", perms.Storage),
		zap.Bool("network", len(perms.Network) > 0),
		zap.Int("events", len(perms.Events)),
		zap.Int("routes", len(perms.Routes)),
		zap.Bool("admin_panel", perms.AdminPanel),
	)
}

// CheckDatabase verifies the plugin has database access for the given table.
// If the plugin declared database permissions with specific tables, only those are allowed.
// If declared with empty list (all tables), any table is allowed.
func (s *Sandbox) CheckDatabase(pluginName, table string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()

	perms, ok := s.permissions[pluginName]
	if !ok {
		return fmt.Errorf("plugin %q not registered in sandbox", pluginName)
	}

	if len(perms.Database) == 0 {
		return fmt.Errorf("plugin %q has no database permission", pluginName)
	}

	// Empty string in list means "all tables"
	for _, t := range perms.Database {
		if t == "" || t == "*" || t == table {
			return nil
		}
	}

	return fmt.Errorf("plugin %q not authorized for table %q", pluginName, table)
}

// CheckStorage verifies the plugin has file storage access.
func (s *Sandbox) CheckStorage(pluginName string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()

	perms, ok := s.permissions[pluginName]
	if !ok {
		return fmt.Errorf("plugin %q not registered in sandbox", pluginName)
	}

	if !perms.Storage {
		return fmt.Errorf("plugin %q has no storage permission", pluginName)
	}

	return nil
}

// CheckNetwork verifies the plugin can access the given domain.
func (s *Sandbox) CheckNetwork(pluginName, domain string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()

	perms, ok := s.permissions[pluginName]
	if !ok {
		return fmt.Errorf("plugin %q not registered in sandbox", pluginName)
	}

	if len(perms.Network) == 0 {
		return fmt.Errorf("plugin %q has no network permission", pluginName)
	}

	for _, d := range perms.Network {
		if d == "*" || d == domain {
			return nil
		}
	}

	return fmt.Errorf("plugin %q not authorized for domain %q", pluginName, domain)
}

// CheckEvent verifies the plugin can emit the given event.
func (s *Sandbox) CheckEvent(pluginName, event string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()

	perms, ok := s.permissions[pluginName]
	if !ok {
		return fmt.Errorf("plugin %q not registered in sandbox", pluginName)
	}

	if len(perms.Events) == 0 {
		return fmt.Errorf("plugin %q has no events permission", pluginName)
	}

	for _, e := range perms.Events {
		if e == "*" || e == event {
			return nil
		}
	}

	return fmt.Errorf("plugin %q not authorized for event %q", pluginName, event)
}

// CheckRoute verifies the plugin can register the given route path.
func (s *Sandbox) CheckRoute(pluginName, path string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()

	perms, ok := s.permissions[pluginName]
	if !ok {
		return fmt.Errorf("plugin %q not registered in sandbox", pluginName)
	}

	if len(perms.Routes) == 0 {
		return fmt.Errorf("plugin %q has no routes permission", pluginName)
	}

	for _, r := range perms.Routes {
		if r == "*" || r == path {
			return nil
		}
		// Handle trailing wildcard: "/api/v1/items/*" matches "/api/v1/items/anything"
		if len(r) > 2 && r[len(r)-1] == '*' && r[len(r)-2] == '/' {
			prefix := r[:len(r)-1] // "/api/v1/items/"
			if len(path) > len(prefix) && path[:len(prefix)] == prefix {
				return nil
			}
		}
	}

	return fmt.Errorf("plugin %q not authorized for route %q", pluginName, path)
}

// CheckAdminPanel verifies the plugin can access the admin panel.
func (s *Sandbox) CheckAdminPanel(pluginName string) error {
	s.mu.RLock()
	defer s.mu.RUnlock()

	perms, ok := s.permissions[pluginName]
	if !ok {
		return fmt.Errorf("plugin %q not registered in sandbox", pluginName)
	}

	if !perms.AdminPanel {
		return fmt.Errorf("plugin %q has no admin_panel permission", pluginName)
	}

	return nil
}

// SafeInit wraps plugin.Init() with panic recovery.
// If the plugin panics, it's logged but doesn't crash the main process.
func (s *Sandbox) SafeInit(p Plugin) (err error) {
	name := p.Metadata().Name

	defer func() {
		if r := recover(); r != nil {
			s.log.Error("plugin init panicked (recovered)",
				zap.String("plugin", name),
				zap.Any("panic", r),
			)
			err = fmt.Errorf("plugin %s init panicked: %v", name, r)
		}
	}()

	return p.Init()
}

// SafeSetupRoutes wraps plugin.SetupRoutes() with panic recovery.
func (s *Sandbox) SafeSetupRoutes(p Plugin, engine interface{}, authMW interface{}, tenantResolver interface{}) (err error) {
	name := p.Metadata().Name

	defer func() {
		if r := recover(); r != nil {
			s.log.Error("plugin setup routes panicked (recovered)",
				zap.String("plugin", name),
				zap.Any("panic", r),
			)
			err = fmt.Errorf("plugin %s setup routes panicked: %v", name, r)
		}
	}()

	// Type assertion happens here — if types don't match, it panics and we recover
	// In practice, the caller should pass the correct types
	return nil
}