Attractor/App/Web Process Bundle Bridge/SBRProcessBundleBridge.m

//
//  SBRProcessBundleBridge.m
//  SBrowser
//
//  Created by James Magahern on 7/22/20.
//

#import "SBRProcessBundleBridge.h"

#import "SBRWebProcessDelegate.h"
#import "SBRWebProcessProxy.h"

#import <WebKit/_WKRemoteObjectInterface.h>
#import <WebKit/_WKRemoteObjectRegistry.h>
#import <WebKit/_WKProcessPoolConfiguration.h>
#import <WebKit/_WKUserStyleSheet.h>

#import <WebKit/WKProcessPoolPrivate.h>
#import <WebKit/WKWebViewPrivate.h>
#import <WebKit/WKWebViewConfigurationPrivate.h>
#import <WebKit/WKUserContentControllerPrivate.h>

@interface SBRProcessBundleBridge () <SBRWebProcessDelegate>

@end

@implementation SBRProcessBundleBridge {
    WKWebView              *_webView;
    WKWebViewConfiguration *_webViewConfiguration;
    WKProcessPool          *_processPool;
    id<SBRWebProcessProxy> _webProcessProxy;
    
    _WKUserStyleSheet     *_darkModeStyleSheet;
}

- (void)tearDown
{
    [[_webView _remoteObjectRegistry] unregisterExportedObject:self interface:[self _webProcessDelegateInterface]];
}

- (_WKRemoteObjectInterface *)_webProcessDelegateInterface
{
    static dispatch_once_t onceToken;
    static _WKRemoteObjectInterface *interface = nil;
    dispatch_once(&onceToken, ^{
        interface = [_WKRemoteObjectInterface remoteObjectInterfaceWithProtocol:@protocol(SBRWebProcessDelegate)];
    });
    
    return interface;
}

- (_WKRemoteObjectInterface *)_webProcessProxyInterface
{
    static dispatch_once_t onceToken;
    static _WKRemoteObjectInterface *interface = nil;
    dispatch_once(&onceToken, ^{
        interface = [_WKRemoteObjectInterface remoteObjectInterfaceWithProtocol:@protocol(SBRWebProcessProxy)];
    });
    
    return interface;
}

- (WKWebView *)webView
{
    if (!_webView) {
        // Inject bundle
        _WKProcessPoolConfiguration *poolConfiguration = [[_WKProcessPoolConfiguration alloc] init];
        NSURL *bundleURL = [[[NSBundle mainBundle] builtInPlugInsURL] URLByAppendingPathComponent:@"SBrowserProcessBundle.bundle"];
        
        // Make sure it exists. Bail if otherwise.
        NSBundle *pluginBundle = [NSBundle bundleWithURL:bundleURL];
        NSAssert(pluginBundle != nil, @"Attix process bundle not found at %@", bundleURL.path);
        
        [poolConfiguration setInjectedBundleURL:bundleURL];

        // Set up process pool
        _processPool = [[WKProcessPool alloc] _initWithConfiguration:poolConfiguration];
        
        // Initialize allowed origins now
        NSArray<NSString *> *allowedOrigins = [[_policyDataSource allowedOriginsForScriptResources] allObjects];
        [_processPool _setObject:allowedOrigins forBundleParameter:SBRGetAllowedOriginsKey()];
        [_processPool _setObject:@(_allowAllScripts) forBundleParameter:SBRGetAllScriptsAllowedKey()];
        
        WKWebViewConfiguration *configuration = [[WKWebViewConfiguration alloc] init];
        configuration.processPool = _processPool;
        
        // Instantiate web view
        WKWebView *webView = [[WKWebView alloc] initWithFrame:CGRectZero configuration:configuration];
        
        // Configure proxy interface (interface to remote web process)
        _webProcessProxy = [[webView _remoteObjectRegistry] remoteObjectProxyWithInterface:[self _webProcessProxyInterface]];
        
        // Configure delegate interface (registering us as the web process delegate for the remote process)
        [[webView _remoteObjectRegistry] registerExportedObject:self interface:[self _webProcessDelegateInterface]];
        
        _webView = webView;
        _webViewConfiguration = configuration;
    }
    
    return _webView;
}

#pragma mark <SBRWebProcessDelegate>

- (void)webProcessDidConnect
{
    NSLog(@"SBRProcessBundleBridge: did connect. Saying hello, syncing allowlist");
    _webContentProcessConnected = YES;
    
    [_webProcessProxy hello];
    [self policyDataSourceDidChange];
}

- (void)webProcessDidAllowScriptWithOrigin:(NSString *)origin
{
    [[self delegate] webProcess:self didAllowScriptResourceFromOrigin:origin];
}

- (void)webProcessDidBlockScriptWithOrigin:(NSString *)origin
{
    [[self delegate] webProcess:self didBlockScriptResourceFromOrigin:origin];
}

#pragma mark Actions

- (void)policyDataSourceDidChange
{
    NSArray<NSString *> *allowedOrigins = [[_policyDataSource allowedOriginsForScriptResources] allObjects];
    [_processPool _setObject:allowedOrigins forBundleParameter:SBRGetAllowedOriginsKey()];
    [_webProcessProxy syncAllowedResourceOrigins:allowedOrigins];
}

- (void)setAllowAllScripts:(BOOL)allowAllScripts
{
    _allowAllScripts = allowAllScripts;
    [_processPool _setObject:@(_allowAllScripts) forBundleParameter:SBRGetAllScriptsAllowedKey()];
    [_webProcessProxy setAllScriptsAllowed:allowAllScripts];
}

- (void)setDarkModeEnabled:(BOOL)darkModeEnabled
{
    _darkModeEnabled = darkModeEnabled;
    
    WKUserContentController *userContentController = [_webViewConfiguration userContentController];
    
    if (darkModeEnabled) {
        if (!_darkModeStyleSheet) {
            NSURL *styleSheetURL = [[NSBundle mainBundle] URLForResource:@"darkmode" withExtension:@"css"];
            NSString *styleSheetSource = [NSString stringWithContentsOfURL:styleSheetURL encoding:NSUTF8StringEncoding error:nil];
            _darkModeStyleSheet = [[_WKUserStyleSheet alloc] initWithSource:styleSheetSource forMainFrameOnly:NO];
        }
        
        [userContentController _addUserStyleSheet:_darkModeStyleSheet];
    } else if (_darkModeStyleSheet) {
        [userContentController _removeUserStyleSheet:_darkModeStyleSheet];
    }
}

@end