threema-ios/Threema/BallotMessageDecoder.m

//  _____ _
// |_   _| |_  _ _ ___ ___ _ __  __ _
//   | | | ' \| '_/ -_) -_) '  \/ _` |_
//   |_| |_||_|_| \___\___|_|_|_\__,_(_)
//
// Threema iOS Client
// Copyright (c) 2014-2020 Threema GmbH
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License, version 3,
// as published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

#import "BallotMessageDecoder.h"
#import "BallotManager.h"
#import "BallotKeys.h"

#ifdef DEBUG
static const DDLogLevel ddLogLevel = DDLogLevelVerbose;
#else
static const DDLogLevel ddLogLevel = DDLogLevelWarning;
#endif

@interface BallotMessageDecoder ()

@property EntityManager *entityManager;
@property BallotManager *ballotManager;

@end

@implementation BallotMessageDecoder

+ (instancetype)messageDecoder {
    BallotMessageDecoder *decoder = [[BallotMessageDecoder alloc] init];
    
    EntityManager *entityManager =[[EntityManager alloc] init];
    decoder.entityManager = entityManager;
    
    BallotManager *manager = [BallotManager ballotManagerWithEntityManager:entityManager];
    decoder.ballotManager = manager;
    
    return decoder;
}

- (BallotMessage *)decodeCreateBallotFromBox:(BoxBallotCreateMessage *)boxMessage forConversation:(Conversation *)conversation {
    return [self decodeBallotCreateMessage:boxMessage forConversation:conversation];
}


- (BallotMessage *)decodeCreateBallotFromGroupBox:(GroupBallotCreateMessage *)boxMessage forConversation:(Conversation *)conversation {
    return [self decodeBallotCreateMessage:boxMessage forConversation:conversation];
}

- (NSString *)decodeCreateBallotTitleFromBox:(BoxBallotCreateMessage *)boxMessage {
    NSError *error;
    NSDictionary *json = (NSDictionary *)[NSJSONSerialization JSONObjectWithData:boxMessage.jsonData options:0 error:&error];
    if (json == nil) {
        DDLogError(@"Error parsing ballot json data %@, %@", error, [error userInfo]);
        return nil;
    }
    
    return [json objectForKey: JSON_KEY_TITLE];
}

- (NSNumber *)decodeNotificationCreateBallotStateFromBox:(BoxBallotCreateMessage *)boxMessage {
    NSData *jsonData;
    if ([boxMessage isKindOfClass:[BoxBallotCreateMessage class]]) {
        jsonData = ((BoxBallotCreateMessage *)boxMessage).jsonData;
    } else if ([boxMessage isKindOfClass:[GroupBallotCreateMessage class]]) {
        jsonData = ((GroupBallotCreateMessage *)boxMessage).jsonData;
    } else {
        DDLogError(@"Ballot decode: invalid message type");
        return nil;
    }
    
    NSError *error;
    NSDictionary *json = (NSDictionary *)[NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
    return [json objectForKey: JSON_KEY_STATE];
}

- (BallotMessage *)decodeBallotCreateMessage:(AbstractMessage *)boxMessage forConversation:(Conversation *)conversation {
    
    NSData *ballotId;
    NSData *jsonData;
    if ([boxMessage isKindOfClass:[BoxBallotCreateMessage class]]) {
        ballotId = ((BoxBallotCreateMessage *)boxMessage).ballotId;
        jsonData = ((BoxBallotCreateMessage *)boxMessage).jsonData;
    } else if ([boxMessage isKindOfClass:[GroupBallotCreateMessage class]]) {
        ballotId = ((GroupBallotCreateMessage *)boxMessage).ballotId;
        jsonData = ((GroupBallotCreateMessage *)boxMessage).jsonData;
    } else {
        DDLogError(@"Ballot decode: invalid message type");
        return nil;
    }

    /* Create Message in DB */
    BallotMessage *message = [_entityManager.entityCreator ballotMessageFromBox:boxMessage];
    
    Ballot *ballot = [_entityManager.entityFetcher ballotForBallotId:ballotId];
    if (ballot != nil) {
        [self updateExistingBallot:ballot jsonData:jsonData];
    } else {
        ballot = [self createNewBallotWithId:ballotId creatorId:boxMessage.fromIdentity jsonData:jsonData];
    }
    
    // error parsing data
    if (ballot == nil) {
        if (message) {
            [[_entityManager entityDestroyer] deleteObjectWithObject:message];
        }
        
        return nil;
    }
    
    ballot.modifyDate = [NSDate date];
    ballot.conversation = conversation;
    message.ballot = ballot;
    
    return message;
}


- (BOOL)decodeVoteFromGroupBox:(GroupBallotVoteMessage *)boxMessage {
    return [self decodeVoteForIdentity:boxMessage.fromIdentity ballotId:boxMessage.ballotId jsonData:boxMessage.jsonChoiceData];
}

- (BOOL)decodeVoteFromBox:(BoxBallotVoteMessage *)boxMessage {
    return [self decodeVoteForIdentity:boxMessage.fromIdentity ballotId:boxMessage.ballotId jsonData:boxMessage.jsonChoiceData];
}

- (BOOL)decodeVoteForIdentity:(NSString *)contactId ballotId:(NSData *)ballotId jsonData:(NSData *)jsonData {
    
    Ballot *ballot = [_entityManager.entityFetcher ballotForBallotId:ballotId];
    
    if (ballot == nil) {
        DDLogError(@"no ballot found for vote");
        return NO;
    }

    if (ballot.isClosed) {
        DDLogError(@"ballot already closed");
        return NO;
    }

    ballot.modifyDate = [NSDate date];
    [ballot incrementUnreadUpdateCount];
    
    return [self parseJsonVoteData:jsonData forContact:contactId inBallot:ballot];
}

- (void)updateExistingBallot:(Ballot *)ballot jsonData:(NSData *)jsonData {
    ballot.modifyDate = [NSDate date];
    [ballot incrementUnreadUpdateCount];

    [self parseJsonCreateData:jsonData forBallot:ballot];
}

- (Ballot *)createNewBallotWithId:(NSData *)ballotId creatorId:(NSString *)creatorId jsonData:(NSData *)jsonData {
    Ballot *ballot = [_entityManager.entityCreator ballot];
    ballot.id = ballotId;
    ballot.creatorId = creatorId;
    ballot.createDate = [NSDate date];
    
    if ([self parseJsonCreateData:jsonData forBallot:ballot]) {
        return ballot;
    }
    
    // parse failed: remove the ballot we just created
    [[_entityManager entityDestroyer] deleteObjectWithObject:ballot];
    return nil;
}

- (BOOL)parseJsonVoteData:(NSData *)jsonData forContact:(NSString *)contactId inBallot:(Ballot *)ballot {
    NSError *error;
    NSArray *choiceArray = (NSArray *)[NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
    if (choiceArray == nil) {
        DDLogError(@"Error parsing ballot vote data %@, %@", error, [error userInfo]);
        return NO;
    }
    
    for (NSArray *choice in choiceArray) {
        if ([choice count] != 2) {
            //ignore invalid entries
            continue;
        }
        
        NSNumber *choiceId = [choice objectAtIndex:0];
        NSNumber *value = [choice objectAtIndex:1];
        
        [_ballotManager updateBallot:ballot choiceId:choiceId withResult:value forContact:contactId];
    }
    
    return YES;
}

- (BOOL)parseJsonCreateData:(NSData *)jsonData forBallot:(Ballot *)ballot {
    NSError *error;
    NSDictionary *json = (NSDictionary *)[NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error];
    if (json == nil) {
        DDLogError(@"Error parsing ballot json data %@, %@", error, [error userInfo]);
        return NO;
    }
    
    ballot.title = [json objectForKey: JSON_KEY_TITLE];
    ballot.type = [json objectForKey: JSON_KEY_TYPE];
    ballot.state = [json objectForKey: JSON_KEY_STATE];
    ballot.assessmentType = [json objectForKey: JSON_KEY_ASSESSMENT_TYPE];
    ballot.choicesType = [json objectForKey: JSON_KEY_CHOICES_TYPE];

    NSArray *choicesArray = [json objectForKey: JSON_KEY_CHOICES];
    NSArray *participantIds = [json objectForKey: JSON_KEY_PARTICIPANTS];
    
    NSMutableSet *choices = [NSMutableSet set];
    for (NSDictionary *choiceData in choicesArray) {
        BallotChoice *choice = [self handleChoiceData: choiceData participantIds: participantIds forBallot: ballot];
        
        [choices addObject: choice];
    }
    
    ballot.choices = choices;
    
    return YES;
}

- (BallotChoice *)handleChoiceData:(NSDictionary *)choiceData participantIds: (NSArray *) participantIds forBallot:(Ballot *)ballot {
    NSNumber *choiceId = [choiceData objectForKeyedSubscript: JSON_CHOICE_KEY_ID];
    
    BallotChoice *choice = [_entityManager.entityFetcher ballotChoiceForBallotId:ballot.id choiceId:choiceId];
    if (choice == nil) {
        choice = [_entityManager.entityCreator ballotChoice];
        choice.id = [choiceData objectForKeyedSubscript: JSON_CHOICE_KEY_ID];
    }
    
    choice.ballot = ballot;
    choice.name = [choiceData objectForKeyedSubscript: JSON_CHOICE_KEY_NAME];
    choice.orderPosition = [choiceData objectForKeyedSubscript: JSON_CHOICE_KEY_ORDER_POSITION];
    
    NSArray *choiceResult = [choiceData objectForKeyedSubscript: JSON_CHOICE_KEY_RESULT];
    
    if ([choiceResult count] != [participantIds count]) {
        DDLogError(@"Invalid ballot create message: choice result array count does not match participant array count");
        return choice;
    }
    
    NSInteger i=0;
    for (NSNumber *value in choiceResult) {
        NSString *contactId = [participantIds objectAtIndex: i];
        
        [_ballotManager updateBallot:ballot choiceId:choice.id withResult:value forContact:contactId];
        
        i++;
    }
    
    return choice;
}

@end