//  Created by Frederic Jacobs on 21/11/15.
//  Copyright © 2015 Open Whisper Systems. All rights reserved.

#import "ContactsUpdater.h"

#import "Contact.h"
#import "Cryptography.h"
#import "PhoneNumber.h"
#import "OWSError.h"
#import "TSContactsIntersectionRequest.h"
#import "TSNetworkManager.h"
#import "TSStorageManager.h"

NS_ASSUME_NONNULL_BEGIN

@implementation ContactsUpdater

+ (instancetype)sharedUpdater {
    static dispatch_once_t onceToken;
    static id sharedInstance = nil;
    dispatch_once(&onceToken, ^{
        sharedInstance = [self new];
    });
    return sharedInstance;
}

- (nullable SignalRecipient *)synchronousLookup:(NSString *)identifier error:(NSError **)error
{
    dispatch_semaphore_t sema = dispatch_semaphore_create(0);

    __block SignalRecipient *recipient;

    // Assigning to a pointer parameter within the block is not preventing the referenced error from being dealloc
    // Instead, we avoid ambiguity in ownership by assigning to a local __block variable ensuring the error will be
    // retained until our error parameter can take ownership.
    __block NSError *retainedError;
    [self lookupIdentifier:identifier
        success:^(NSSet<NSString *> *matchedIds) {
            if (matchedIds.count == 1) {
                recipient = [SignalRecipient recipientWithTextSecureIdentifier:identifier];
            } else {
                retainedError = [NSError errorWithDomain:@"contactsmanager.notfound" code:NOTFOUND_ERROR userInfo:nil];
            }
            dispatch_semaphore_signal(sema);
        }
        failure:^(NSError *lookupError) {
            retainedError = lookupError;
            dispatch_semaphore_signal(sema);
        }];

    dispatch_semaphore_wait(sema, DISPATCH_TIME_FOREVER);
    *error = retainedError;
    return recipient;
}


- (void)lookupIdentifier:(NSString *)identifier
                 success:(void (^)(NSSet<NSString *> *matchedIds))success
                 failure:(void (^)(NSError *error))failure
{
    if (!identifier) {
        failure(OWSErrorWithCodeDescription(OWSErrorCodeInvalidMethodParameters, @"Cannot lookup nil identifier"));
        return;
    }

    [self contactIntersectionWithSet:[NSSet setWithObject:identifier] success:success failure:failure];
}

- (void)updateSignalContactIntersectionWithABContacts:(NSArray<Contact *> *)abContacts
                                              success:(void (^)())success
                                              failure:(void (^)(NSError *error))failure {
    NSMutableSet<NSString *> *abPhoneNumbers = [NSMutableSet set];

    for (Contact *contact in abContacts) {
        for (PhoneNumber *phoneNumber in contact.parsedPhoneNumbers) {
            [abPhoneNumbers addObject:phoneNumber.toE164];
        }
    }

    NSMutableSet *recipientIds = [NSMutableSet set];
    [[TSStorageManager sharedManager]
            .dbConnection readWithBlock:^(YapDatabaseReadTransaction *_Nonnull transaction) {
      NSArray *allRecipientKeys = [transaction allKeysInCollection:[SignalRecipient collection]];
      [recipientIds addObjectsFromArray:allRecipientKeys];
    }];

    NSMutableSet<NSString *> *allContacts = [[abPhoneNumbers setByAddingObjectsFromSet:recipientIds] mutableCopy];

    [self contactIntersectionWithSet:allContacts
                             success:^(NSSet<NSString *> *matchedIds) {
                                 [recipientIds minusSet:matchedIds];

                                 // Cleaning up unregistered identifiers
                                 [[TSStorageManager sharedManager].dbConnection
                                     readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
                                         for (NSString *identifier in recipientIds) {
                                             SignalRecipient *recipient =
                                                 [SignalRecipient fetchObjectWithUniqueID:identifier
                                                                              transaction:transaction];

                                             [recipient removeWithTransaction:transaction];
                                         }
                                     }];

                                 DDLogInfo(@"%@ successfully intersected contacts.", self.tag);
                                 success();
                             }
                             failure:failure];
}

- (void)contactIntersectionWithSet:(NSSet<NSString *> *)idSet
                           success:(void (^)(NSSet<NSString *> *matchedIds))success
                           failure:(void (^)(NSError *error))failure {
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
      NSMutableDictionary *phoneNumbersByHashes = [NSMutableDictionary dictionary];
      for (NSString *identifier in idSet) {
          [phoneNumbersByHashes setObject:identifier
                                   forKey:[Cryptography truncatedSHA1Base64EncodedWithoutPadding:identifier]];
      }
      NSArray *hashes = [phoneNumbersByHashes allKeys];

      TSRequest *request = [[TSContactsIntersectionRequest alloc] initWithHashesArray:hashes];
      [[TSNetworkManager sharedManager] makeRequest:request
          success:^(NSURLSessionDataTask *tsTask, id responseDict) {
            NSMutableDictionary *attributesForIdentifier = [NSMutableDictionary dictionary];
            NSArray *contactsArray                       = [(NSDictionary *)responseDict objectForKey:@"contacts"];

            // Map attributes to phone numbers
            if (contactsArray) {
                for (NSDictionary *dict in contactsArray) {
                    NSString *hash       = [dict objectForKey:@"token"];
                    NSString *identifier = [phoneNumbersByHashes objectForKey:hash];

                    if (!identifier) {
                        DDLogWarn(@"%@ An interesecting hash wasn't found in the mapping.", self.tag);
                        break;
                    }

                    [attributesForIdentifier setObject:dict forKey:identifier];
                }
            }

            // Insert or update contact attributes
            [[TSStorageManager sharedManager]
                    .dbConnection readWriteWithBlock:^(YapDatabaseReadWriteTransaction *transaction) {
              for (NSString *identifier in attributesForIdentifier) {
                  SignalRecipient *recipient =
                      [SignalRecipient recipientWithTextSecureIdentifier:identifier withTransaction:transaction];
                  if (!recipient) {
                      recipient = [[SignalRecipient alloc] initWithTextSecureIdentifier:identifier
                                                                                  relay:nil
                                                                          supportsVoice:NO
                                                                         supportsWebRTC:NO];
                  }

                  NSDictionary *attributes = [attributesForIdentifier objectForKey:identifier];

                  recipient.relay = attributes[@"relay"];
                  recipient.supportsVoice = [attributes[@"voice"] boolValue];
                  // The key for the "supports WebRTC audio/video" property is "video".
                  recipient.supportsWebRTC = [attributes[@"video"] boolValue];

                  [recipient saveWithTransaction:transaction];
              }
            }];

            success([NSSet setWithArray:attributesForIdentifier.allKeys]);
          }
          failure:^(NSURLSessionDataTask *task, NSError *error) {
            failure(error);
          }];
    });
}

#pragma mark - Logging

+ (NSString *)tag
{
    return [NSString stringWithFormat:@"[%@]", self.class];
}

- (NSString *)tag
{
    return self.class.tag;
}

@end

NS_ASSUME_NONNULL_END