//
//  SQRLShipItLauncher.m
//  Squirrel
//
//  Created by Justin Spahr-Summers on 2013-08-12.
//  Copyright (c) 2013 GitHub. All rights reserved.
//

#import "SQRLShipItLauncher.h"
#import "EXTScope.h"
#import "SQRLDirectoryManager.h"
#import <ReactiveCocoa/ReactiveCocoa.h>
#import <Security/Security.h>
#import <ServiceManagement/ServiceManagement.h>
#import <launch.h>
#import "SQRLAuthorization.h"

NSString * const SQRLShipItLauncherErrorDomain = @"SQRLShipItLauncherErrorDomain";

const NSInteger SQRLShipItLauncherErrorCouldNotStartService = 1;

@implementation SQRLShipItLauncher

+ (NSString *)shipItJobLabel {
	return [SQRLDirectoryManager.currentApplicationManager.applicationIdentifier stringByAppendingString:@".ShipIt"];
}

+ (RACSignal *)shipItJobDictionary {
	NSString *jobLabel = self.shipItJobLabel;

	return [[[RACSignal
		defer:^{
			SQRLDirectoryManager *directoryManager = [[SQRLDirectoryManager alloc] initWithApplicationIdentifier:jobLabel];
			return [RACSignal zip:@[
				[directoryManager shipItStdoutURL],
				[directoryManager shipItStderrURL],
				[directoryManager shipItStateURL]
			]];
		}]
		reduceEach:^(NSURL *stdoutURL, NSURL *stderrURL, NSURL *shipItStateURL) {
			NSBundle *squirrelBundle = [NSBundle bundleForClass:self.class];
			NSAssert(squirrelBundle != nil, @"Could not open Squirrel.framework bundle");

			NSMutableDictionary *jobDict = [NSMutableDictionary dictionary];
			jobDict[@(LAUNCH_JOBKEY_LABEL)] = jobLabel;
			jobDict[@(LAUNCH_JOBKEY_NICE)] = @(-1);
			jobDict[@(LAUNCH_JOBKEY_ENABLETRANSACTIONS)] = @NO;
			jobDict[@(LAUNCH_JOBKEY_THROTTLEINTERVAL)] = @2;
			jobDict[@(LAUNCH_JOBKEY_KEEPALIVE)] = @{
				@(LAUNCH_JOBKEY_KEEPALIVE_SUCCESSFULEXIT): @NO
			};

			jobDict[@(LAUNCH_JOBKEY_MACHSERVICES)] = @{
				jobLabel: @YES
			};

			NSMutableArray *arguments = [[NSMutableArray alloc] init];
			[arguments addObject:[squirrelBundle URLForResource:@"ShipIt" withExtension:nil].path];

			// Pass in the service name so ShipIt knows how to broadcast itself.
			[arguments addObject:jobLabel];

			// We need to pass the path to ShipIt rather than having ShipIt
			// calculate the path itself. This is because ShipIt may run as a
			// different user if it had to escalate to be able to replace the
			// bundle.
			[arguments addObject:shipItStateURL.path];

			jobDict[@(LAUNCH_JOBKEY_PROGRAMARGUMENTS)] = arguments;
			jobDict[@(LAUNCH_JOBKEY_STANDARDOUTPATH)] = stdoutURL.path;
			jobDict[@(LAUNCH_JOBKEY_STANDARDERRORPATH)] = stderrURL.path;

			return jobDict;
		}]
		setNameWithFormat:@"+shipItJobDictionary"];
}

+ (RACSignal *)shipItAuthorization {
	return [[RACSignal
		createSignal:^ RACDisposable * (id<RACSubscriber> subscriber) {
			AuthorizationItem rightItems[] = {
				{
					.name = kSMRightModifySystemDaemons,
				},
			};

			AuthorizationRights rights = {
				.count = sizeof(rightItems) / sizeof(*rightItems),
				.items = rightItems,
			};

			NSString *prompt = NSLocalizedString(@"An update is ready to install.", @"SQRLShipItLauncher, launch shipit, authorization prompt");

			NSString *iconName = [NSBundle.mainBundle objectForInfoDictionaryKey:@"CFBundleIconFile"];
			NSString *iconPath = (iconName == nil ? nil : [NSBundle.mainBundle.resourceURL URLByAppendingPathComponent:iconName].path);

			AuthorizationItem environmentItems[] = {
				{
					.name = kAuthorizationEnvironmentPrompt,
					.valueLength = strlen(prompt.UTF8String),
					.value = (void *)prompt.UTF8String,
				},
				{
					.name = kAuthorizationEnvironmentIcon,
					.valueLength = iconPath == nil ? 0 : strlen(iconPath.UTF8String),
					.value = (void *)iconPath.UTF8String,
				},
			};

			AuthorizationEnvironment environment = {
				.count = sizeof(environmentItems) / sizeof(*environmentItems),
				.items = environmentItems,
			};

			AuthorizationRef authorization = NULL;
			OSStatus authorizationError = AuthorizationCreate(&rights, &environment, kAuthorizationFlagInteractionAllowed | kAuthorizationFlagExtendRights, &authorization);

			if (authorizationError == noErr) {
				[subscriber sendNext:[[SQRLAuthorization alloc] initWithAuthorization:authorization]];
				[subscriber sendCompleted];
			} else {
				[subscriber sendError:[NSError errorWithDomain:NSOSStatusErrorDomain code:authorizationError userInfo:nil]];
			}

			return nil;
		}]
		setNameWithFormat:@"+shipItAuthorization"];
}

+ (RACSignal *)launchPrivileged:(BOOL)privileged {
	return [[[RACSignal
		zip:@[
			self.shipItJobDictionary,
			(privileged ? self.shipItAuthorization : [RACSignal return:nil])
		] reduce:^(NSDictionary *jobDictionary, SQRLAuthorization *authorizationValue) {
			CFStringRef domain = (privileged ? kSMDomainSystemLaunchd : kSMDomainUserLaunchd);

			AuthorizationRef authorization = authorizationValue.authorization;

			CFErrorRef cfError;
			if (!SMJobRemove(domain, (__bridge CFStringRef)self.shipItJobLabel, authorization, true, &cfError)) {
				NSError *error = CFBridgingRelease(cfError);
				cfError = NULL;

				if (![error.domain isEqual:(__bridge id)kSMErrorDomainLaunchd] || error.code != kSMErrorJobNotFound) {
					NSLog(@"Could not remove previous ShipIt job: %@", error);
				}
			}

			if (!SMJobSubmit(domain, (__bridge CFDictionaryRef)jobDictionary, authorization, &cfError)) {
				return [RACSignal error:CFBridgingRelease(cfError)];
			}

			return [RACSignal empty];
		}]
		flatten]
		setNameWithFormat:@"+launchPrivileged: %i", (int)privileged];
}

@end
