bundesmessenger-ios/Riot/ViewController/Widgets/IntegrationManagerViewController.m

/*
 Copyright 2017 Vector Creations Ltd

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

#import "IntegrationManagerViewController.h"

#import "WidgetManager.h"

#import <JavaScriptCore/JavaScriptCore.h>

NSString *kJavascriptSendResponseToModular = @"riotIOS.sendResponse('%@', %@);";


@interface IntegrationManagerViewController ()
{
    MXSession *mxSession;
    NSString *roomId;
    NSString *screen;
    NSString *widgetId;
    NSString *scalarToken;

    MXHTTPOperation *operation;
}

@end

@implementation IntegrationManagerViewController

- (instancetype)initForMXSession:(MXSession *)theMXSession inRoom:(NSString *)theRoomId screen:(NSString *)theScreen widgetId:(NSString *)theWidgetId
{
    self = [super init];
    if (self)
    {
        mxSession = theMXSession;
        roomId = theRoomId;
        screen = theScreen;
        widgetId = theWidgetId;
    }
    return self;
}

- (void)destroy
{
    [super destroy];

    [operation cancel];
    operation = nil;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    webView.scalesPageToFit = NO;

    webView.delegate = self;
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    if (!self.URL && !operation)
    {
        __weak __typeof__(self) weakSelf = self;

        [self startActivityIndicator];

        // Make sure we a scalar token
        operation = [[WidgetManager sharedManager] getScalarTokenForMXSession:mxSession success:^(NSString *theScalarToken) {

            typeof(self) self = weakSelf;

            if (self)
            {
                self->operation = nil;
                [self stopActivityIndicator];

                scalarToken = theScalarToken;

                // Launch the webview on the right modular webapp page
                self.URL = [self interfaceUrl];
            }

        } failure:^(NSError *error) {

            typeof(self) self = weakSelf;
            
            if (self)
            {
                self->operation = nil;
                [self stopActivityIndicator];
            }
        }];
    }
}

#pragma mark - Private methods

/**
 Build the URL to use in the Modular interface webapp.
 */
- (NSString *)interfaceUrl
{
    NSMutableString *url;

    if (scalarToken)
    {
        url = [NSMutableString stringWithFormat:@"%@?scalar_token=%@&room_id=%@",
               [[NSUserDefaults standardUserDefaults] objectForKey:@"integrationsUiUrl"],
               [scalarToken stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding],
               [roomId stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]
               ];

        if (screen)
        {
            [url appendString:@"&screen="];
            [url appendString:[screen stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
        }

        if (widgetId)
        {
            [url appendString:@"&integ_id="];
            [url appendString:[widgetId stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
        }
    }
    
    return url;
}

- (void)enableDebug
{
    // Setup console.log() -> NSLog() route
    JSContext *ctx = [webView valueForKeyPath:@"documentView.webView.mainFrame.javaScriptContext"];
    ctx[@"console"][@"log"] = ^(JSValue * msg) {
        NSLog(@"-- JavaScript: %@", msg);
    };

    // Redirect all console.* logging methods to console.log
    [webView stringByEvaluatingJavaScriptFromString:@"console.debug = console.log; console.info = console.log; console.warn = console.log; console.error = console.log;"];
}

#pragma mark - UIWebViewDelegate

-(void)webViewDidFinishLoad:(UIWebView *)theWebView
{
    [self enableDebug];

    // Setup js code
    NSString *path = [[NSBundle mainBundle] pathForResource:@"IntegrationManager" ofType:@"js"];
    NSString *js = [NSString stringWithContentsOfFile:path encoding:NSUTF8StringEncoding error:nil];
    [webView stringByEvaluatingJavaScriptFromString:js];
}

- (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType
{
    NSString *urlString = [[request URL] absoluteString];

    if ([urlString hasPrefix:@"js:"])
    {
        // Listen only to scheme of the JS-UIWebView bridge
        NSString *jsonString = [[[urlString componentsSeparatedByString:@"js:"] lastObject]  stringByReplacingPercentEscapesUsingEncoding:NSASCIIStringEncoding];
        NSData *jsonData = [jsonString dataUsingEncoding:NSUTF8StringEncoding];

        NSError *error;
        NSDictionary *parameters = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers
                                                                     error:&error];
        if (!error)
        {
            [self onMessage:parameters];
        }

        return NO;
    }
    return YES;
}

#pragma mark - Modular postMessage API

- (void)onMessage:(NSDictionary*)JSData
{
    NSDictionary *eventData;
    MXJSONModelSetDictionary(eventData, JSData[@"event.data"]);

    NSString *roomIdInEvent, *userId, *action;

    MXJSONModelSetString(roomIdInEvent, eventData[@"room_id"]);
    MXJSONModelSetString(userId, eventData[@"user_id"]);
    MXJSONModelSetString(action, eventData[@"action"]);

    if (!roomIdInEvent)
    {
        [self sendLocalisedError:@"widget_integration_missing_room_id" toEvent:eventData];
        return;
    }

    if (![roomIdInEvent isEqualToString:roomId])
    {
        [self sendError:[NSString stringWithFormat:NSLocalizedStringFromTable(@"widget_integration_room_not_visible", @"Vector", nil), roomIdInEvent] toEvent:eventData];
        return;
    }


    // These APIs don't require userId
    if ([@"join_rules_state" isEqualToString:action])
    {
        //getJoinRules(event, roomId);
        return;
    }
    else if ([@"set_plumbing_state" isEqualToString:action])
    {
        //setPlumbingState(event, roomId, event.data.status);
        return;
    }
    else if ([@"get_membership_count" isEqualToString:action])
    {
        //getMembershipCount(event, roomId);
        return;
    }
    else if ([@"set_widget" isEqualToString:action])
    {
        //setWidget(event, roomId);
        return;
    }
    else if ([@"get_widgets" isEqualToString:action])
    {
        [self getWidgets:eventData];
        return;
    }
    else if ([@"can_send_event" isEqualToString:action])
    {
        [self canSendEvent:eventData];
        return;
    }


    if (!userId)
    {
        [self sendLocalisedError:@"widget_integration_missing_user_id" toEvent:eventData];
        return;
    }

    if ([@"membership_state" isEqualToString:action])
    {
        [self getMembershipState:userId eventData:eventData];
    }
    else if ([@"invite" isEqualToString:action])
    {
        //inviteUser(event, roomId, userId);
    }
    else if ([@"bot_options" isEqualToString:action])
    {
        //botOptions(event, roomId, userId);
    }
    else if ([@"set_bot_options" isEqualToString:action])
    {
        //setBotOptions(event, roomId, userId);
    }
    else if ([@"set_bot_power" isEqualToString:action])
    {
        //setBotPower(event, roomId, userId, event.data.level);
    }
    else
    {
        NSLog(@"[IntegrationManagerViewControllerVC] Unhandled postMessage event with action %@: %@", action, JSData);
    }
}

- (void)sendBoolResponse:(BOOL)response toEvent:(NSDictionary*)eventData
{
    // Convert BOOL to "true" or "false"
    NSString *js = [NSString stringWithFormat:kJavascriptSendResponseToModular,
                    eventData[@"_id"],
                    response ? @"true" : @"false"];

    [webView stringByEvaluatingJavaScriptFromString:js];
}

- (void)sendNSObjectResponse:(NSObject*)response toEvent:(NSDictionary*)eventData
{
    NSString *jsString;

    if (response)
    {
        // Convert response into a JS object through a JSON string
        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:response
                                                           options:0
                                                             error:0];
        NSString *jsonString = [[NSString alloc] initWithData:jsonData encoding:NSUTF8StringEncoding];

        jsString = [NSString stringWithFormat:@"JSON.parse('%@')", jsonString];
    }
    else
    {
        jsString = @"null";
    }

    NSString *js = [NSString stringWithFormat:kJavascriptSendResponseToModular,
                    eventData[@"_id"],
                    jsString];

    [webView stringByEvaluatingJavaScriptFromString:js];
}

- (void)sendError:(NSString*)message toEvent:(NSDictionary*)eventData
{
    // TODO: JS has an additional optional parameter: nestedError
    [self sendNSObjectResponse:@{
                                 @"error": @{
                                         @"message": message
                                         }
                                 }
                       toEvent:eventData];
}

- (void)sendLocalisedError:(NSString*)errorKey toEvent:(NSDictionary*)eventData
{
    [self sendError:NSLocalizedStringFromTable(errorKey, @"Vector", nil) toEvent:eventData];
}

#pragma mark - Modular postMessage Implementation

- (MXRoom *)roomCheckWithEvent:(NSDictionary*)eventData
{
    MXRoom *room = [mxSession roomWithRoomId:roomId];
    if (!room)
    {
        [self sendLocalisedError:@"widget_integration_room_not_recognised" toEvent:eventData];
    }

    return room;
}

- (void)getWidgets:(NSDictionary*)eventData
{
    MXRoom *room = [self roomCheckWithEvent:eventData];

    if (room)
    {
        NSArray<Widget*> *widgets = [[WidgetManager sharedManager] widgetsInRoom:room];

        NSMutableArray<NSDictionary*> *widgetStateEvents = [NSMutableArray arrayWithCapacity:widgets.count];

        for (Widget *widget in widgets)
        {
            [widgetStateEvents addObject:widget.widgetEvent.JSONDictionary];
        }

        [self sendNSObjectResponse:widgetStateEvents toEvent:eventData];
    }
}

- (void)canSendEvent:(NSDictionary*)eventData
{
    NSString *eventType;
    BOOL isState = NO;

    MXRoom *room = [self roomCheckWithEvent:eventData];

    if (room)
    {
        if (room.state.membership != MXMembershipJoin)
        {
            [self sendLocalisedError:@"widget_integration_must_be_in_room" toEvent:eventData];
            return;
        }

        MXJSONModelSetString(eventType, eventData[@"event_type"]);
        MXJSONModelSetBoolean(isState, eventData[@"is_state"]);

        MXRoomPowerLevels *powerLevels = room.state.powerLevels;
        NSInteger userPowerLevel = [powerLevels powerLevelOfUserWithUserID:mxSession.myUser.userId];

        BOOL canSend = NO;

        if (isState)
        {
            canSend = (userPowerLevel >= [powerLevels minimumPowerLevelForSendingEventAsStateEvent:eventType]);
        }
        else
        {
            canSend = (userPowerLevel >= [powerLevels minimumPowerLevelForSendingEventAsMessage:eventType]);
        }

        if (canSend)
        {
            [self sendBoolResponse:YES toEvent:eventData];
        }
        else
        {
            [self sendLocalisedError:@"widget_integration_no_permission_in_room" toEvent:eventData];
        }
    }
}

- (void)getMembershipState:(NSString*)userId eventData:(NSDictionary*)eventData
{
    MXRoom *room = [self roomCheckWithEvent:eventData];

    if (room)
    {
        MXRoomMember *member = [room.state memberWithUserId:userId];
        [self sendNSObjectResponse:member.originalEvent.JSONDictionary toEvent:eventData];
    }
}

@end