Tweak.x

// Headers
#import <CoreFoundation/CoreFoundation.h>
#import <Foundation/Foundation.h>
#import <Foundation/NSUserDefaults+Private.h>
#import <libSandy.h>

// Required for the actual hook
@interface _WKProcessPoolConfiguration : NSObject
- (void)setJITEnabled:(BOOL)enabled;
@end

// Log macro, an absolute staple.
#define LOG(fmt, ...) NSLog(@"[Lightshield] " fmt, ##__VA_ARGS__)

// Not sure if you can tell, but I didn't initially plan for this tweak to support preferences.
// The original game plan was to include a Control Center module that would reload WebContent with JIT enabled/disabled, but I just absolutely could not get that to cooperate. For those smarter than me, keep _allProcessPoolsForTesting and _terminateAllWebContentProcesses in mind.
static NSUserDefaults *defaults;
static BOOL enabled;

%hook _WKProcessPoolConfiguration

- (id)init {
    id result = %orig;
    if (result && enabled) {
        [result setJITEnabled:NO];
        LOG(@"hit init hook");
    }
    return result;
}

// This is the most important hook, the init hook can be skipped but this cannot be
- (void)setJITEnabled:(BOOL)jitEnabled {
	if (enabled) {
		LOG(@"setJITEnabled called, responding no");
	    %orig(NO);
    } else {
    	%orig(jitEnabled);
    }
}

%end

%ctor {
	// Apply sandbox profile via libSandy so we can actually read our preferences (and check that libSandy actually worked).
	int result = libSandy_applyProfile("Lightshield_Preferences");
	if (result != 0) {
		LOG(@"unable to apply sandbox profile.");
		// Results from here on out are basically unexpected.
	}
	defaults = [[NSUserDefaults alloc] initWithSuiteName:@"/var/mobile/Library/Preferences/cc.forcequit.lightshield.plist"];
	// Set enabled variable
	NSNumber *enabledValue = [defaults objectForKey:@"enabled"];
	enabled = (enabledValue)? [enabledValue boolValue] : YES;
}