//
//  Copyright (c) 2017 Open Whisper Systems. All rights reserved.
//

#import "ContactsViewHelper.h"
#import "ContactTableViewCell.h"
#import "Environment.h"
#import "SignalAccount.h"
#import <SignalServiceKit/Contact.h>
#import <SignalServiceKit/OWSBlockingManager.h>
#import <SignalServiceKit/PhoneNumber.h>
#import <SignalServiceKit/TSAccountManager.h>

NS_ASSUME_NONNULL_BEGIN

@interface ContactsViewHelper ()

@property (nonatomic) NSDictionary<NSString *, SignalAccount *> *signalAccountMap;
@property (nonatomic) NSArray<SignalAccount *> *signalAccounts;

@property (nonatomic) NSArray<NSString *> *blockedPhoneNumbers;

@end

#pragma mark -

@implementation ContactsViewHelper

- (instancetype)init
{
    self = [super init];
    if (!self) {
        return self;
    }

    _blockingManager = [OWSBlockingManager sharedManager];
    _blockedPhoneNumbers = [_blockingManager blockedPhoneNumbers];

    _contactsManager = [Environment getCurrent].contactsManager;
    self.signalAccountMap = self.contactsManager.signalAccountMap;
    self.signalAccounts = self.contactsManager.signalAccounts;

    [self observeNotifications];

    return self;
}

- (void)observeNotifications
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(signalAccountsDidChange:)
                                                 name:OWSContactsManagerSignalAccountsDidChangeNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(blockedPhoneNumbersDidChange:)
                                                 name:kNSNotificationName_BlockedPhoneNumbersDidChange
                                               object:nil];
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)signalAccountsDidChange:(NSNotification *)notification
{
    dispatch_async(dispatch_get_main_queue(), ^{
        [self updateContacts];
    });
}

- (void)blockedPhoneNumbersDidChange:(id)notification
{
    dispatch_async(dispatch_get_main_queue(), ^{
        self.blockedPhoneNumbers = [_blockingManager blockedPhoneNumbers];

        [self updateContacts];
    });
}

#pragma mark - Contacts

- (nullable SignalAccount *)signalAccountForRecipientId:(NSString *)recipientId
{
    OWSAssert([NSThread isMainThread]);
    OWSAssert(recipientId.length > 0);

    return self.signalAccountMap[recipientId];
}

- (BOOL)isSignalAccountHidden:(SignalAccount *)signalAccount
{
    OWSAssert([NSThread isMainThread]);

    if ([self.delegate shouldHideLocalNumber] && [self isCurrentUser:signalAccount]) {
        return YES;
    }

    return NO;
}

- (BOOL)isCurrentUser:(SignalAccount *)signalAccount
{
    OWSAssert([NSThread isMainThread]);

    NSString *localNumber = [TSAccountManager localNumber];
    if ([signalAccount.recipientId isEqualToString:localNumber]) {
        return YES;
    }

    for (PhoneNumber *phoneNumber in signalAccount.contact.parsedPhoneNumbers) {
        if ([[phoneNumber toE164] isEqualToString:localNumber]) {
            return YES;
        }
    }

    return NO;
}

- (NSString *)localNumber
{
    return [TSAccountManager localNumber];
}

- (BOOL)isContactBlocked:(Contact *)contact
{
    OWSAssert([NSThread isMainThread]);

    if (contact.parsedPhoneNumbers.count < 1) {
        // Do not consider contacts without any valid phone numbers to be blocked.
        return NO;
    }

    for (PhoneNumber *phoneNumber in contact.parsedPhoneNumbers) {
        if ([_blockedPhoneNumbers containsObject:phoneNumber.toE164]) {
            return YES;
        }
    }

    return NO;
}

- (BOOL)isRecipientIdBlocked:(NSString *)recipientId
{
    AssertIsOnMainThread();

    return [_blockedPhoneNumbers containsObject:recipientId];
}

- (void)updateContacts
{
    AssertIsOnMainThread();

    NSMutableDictionary<NSString *, SignalAccount *> *signalAccountMap = [NSMutableDictionary new];
    NSMutableArray<SignalAccount *> *signalAccounts = [NSMutableArray new];
    for (SignalAccount *signalAccount in self.contactsManager.signalAccounts) {
        if (![self isSignalAccountHidden:signalAccount]) {
            signalAccountMap[signalAccount.recipientId] = signalAccount;
            [signalAccounts addObject:signalAccount];
        }
    }
    self.signalAccountMap = [signalAccountMap copy];
    self.signalAccounts = [signalAccounts copy];

    [self.delegate contactsViewHelperDidUpdateContacts];
}

- (BOOL)doesSignalAccount:(SignalAccount *)signalAccount matchSearchTerm:(NSString *)searchTerm
{
    OWSAssert(signalAccount);
    OWSAssert(searchTerm.length > 0);

    if ([signalAccount.contact.fullName.lowercaseString containsString:searchTerm.lowercaseString]) {
        return YES;
    }

    NSString *asPhoneNumber = [PhoneNumber removeFormattingCharacters:searchTerm];
    if (asPhoneNumber.length > 0 && [signalAccount.recipientId containsString:asPhoneNumber]) {
        return YES;
    }

    return NO;
}

- (BOOL)doesSignalAccount:(SignalAccount *)signalAccount matchSearchTerms:(NSArray<NSString *> *)searchTerms
{
    OWSAssert(signalAccount);
    OWSAssert(searchTerms.count > 0);

    for (NSString *searchTerm in searchTerms) {
        if (![self doesSignalAccount:signalAccount matchSearchTerm:searchTerm]) {
            return NO;
        }
    }

    return YES;
}

- (NSArray<SignalAccount *> *)signalAccountsMatchingSearchString:(NSString *)searchText
{
    NSArray<NSString *> *searchTerms =
        [[searchText stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]
            componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];

    if (searchTerms.count < 1) {
        return self.signalAccounts;
    }

    return [self.signalAccounts
        filteredArrayUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(SignalAccount *signalAccount,
                                        NSDictionary<NSString *, id> *_Nullable bindings) {
            return [self doesSignalAccount:signalAccount matchSearchTerms:searchTerms];
        }]];
}

@end

NS_ASSUME_NONNULL_END