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

#import "AddToBlockListViewController.h"
#import "BlockListUIUtils.h"
#import "ContactTableViewCell.h"
#import "CountryCodeViewController.h"
#import "Environment.h"
#import "OWSContactsManager.h"
#import "PhoneNumber.h"
#import "StringUtil.h"
#import "UIFont+OWS.h"
#import "UIUtil.h"
#import "UIView+OWS.h"
#import "ViewControllerUtils.h"
#import <SignalServiceKit/OWSBlockingManager.h>
#import <SignalServiceKit/PhoneNumberUtil.h>
#import <SignalServiceKit/TSAccountManager.h>

NS_ASSUME_NONNULL_BEGIN

NSString * const kAddToBlockListViewControllerCellIdentifier = @"kAddToBlockListViewControllerCellIdentifier";

NSString *const kContactsTable_CellReuseIdentifier = @"kContactsTable_CellReuseIdentifier";

#pragma mark -

@interface AddToBlockListViewController () <CountryCodeViewControllerDelegate,
    UITextFieldDelegate,
    UITableViewDataSource,
    UITableViewDelegate>

@property (nonatomic, readonly) OWSBlockingManager *blockingManager;
@property (nonatomic, readonly) NSArray<NSString *> *blockedPhoneNumbers;

@property (nonatomic) UIButton *countryNameButton;
@property (nonatomic) UIButton *countryCodeButton;

@property (nonatomic) UITextField *phoneNumberTextField;

@property (nonatomic) UIButton *blockButton;

@property (nonatomic) UITableView *contactsTableView;

@property (nonatomic) NSString *callingCode;

@property (nonatomic, readonly) OWSContactsManager *contactsManager;
@property (nonatomic) NSArray<Contact *> *contacts;

@end

#pragma mark -

@implementation AddToBlockListViewController

- (void)loadView
{
    [super loadView];
   
    self.view.backgroundColor = [UIColor whiteColor];
    
    _blockingManager = [OWSBlockingManager sharedManager];
    _blockedPhoneNumbers = [_blockingManager blockedPhoneNumbers];
    _contactsManager = [Environment getCurrent].contactsManager;
    self.contacts = [self filteredContacts];

    self.title = NSLocalizedString(@"SETTINGS_ADD_TO_BLOCK_LIST_TITLE", @"Title for the 'add to block list' view.");

    [self createViews];
    
    [self populateDefaultCountryNameAndCode];

    [self addNotificationListeners];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    [self.navigationController.navigationBar setTranslucent:NO];
}

- (void)addNotificationListeners
{
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(blockedPhoneNumbersDidChange:)
                                                 name:kNSNotificationName_BlockedPhoneNumbersDidChange
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(signalRecipientsDidChange:)
                                                 name:OWSContactsManagerSignalRecipientsDidChangeNotification
                                               object:nil];
}

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

- (void)createViews {

    // Block Phone Number Title Row
    UIView *blockPhoneNumberTitleRow =
        [self createTitleRowWithText:NSLocalizedString(@"SETTINGS_ADD_TO_BLOCK_LIST_BLOCK_PHONE_NUMBER_TITLE",
                                         @"Title for the 'block phone number' section of the 'add to block list' view.")
                         previousRow:nil];

    // Country Row
    UIView *countryRow = [self createRowWithHeight:60 previousRow:blockPhoneNumberTitleRow];

    _countryNameButton = [UIButton buttonWithType:UIButtonTypeCustom];
    _countryNameButton.titleLabel.font = [UIFont ows_mediumFontWithSize:16.f];
    [_countryNameButton setTitleColor:[UIColor blackColor]
                             forState:UIControlStateNormal];
    [_countryNameButton
        setTitle:NSLocalizedString(@"REGISTRATION_DEFAULT_COUNTRY_NAME", @"Label for the country code field")
        forState:UIControlStateNormal];
    [_countryNameButton addTarget:self
                           action:@selector(showCountryCodeView:)
                 forControlEvents:UIControlEventTouchUpInside];
    [countryRow addSubview:_countryNameButton];
    [_countryNameButton autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:20.f];
    [_countryNameButton autoVCenterInSuperview];

    _countryCodeButton = [UIButton buttonWithType:UIButtonTypeCustom];
    _countryCodeButton.titleLabel.font = [UIFont ows_mediumFontWithSize:16.f];
    _countryCodeButton.contentHorizontalAlignment = UIControlContentHorizontalAlignmentRight;
    [_countryCodeButton setTitleColor:[UIColor ows_signalBrandBlueColor]
                             forState:UIControlStateNormal];
    [_countryCodeButton addTarget:self
                           action:@selector(showCountryCodeView:)
                 forControlEvents:UIControlEventTouchUpInside];
    [countryRow addSubview:_countryCodeButton];
    [_countryCodeButton autoPinEdgeToSuperviewEdge:ALEdgeRight withInset:16.f];
    [_countryCodeButton autoPinEdge:ALEdgeLeft toEdge:ALEdgeRight ofView:_countryNameButton withOffset:0];
    [_countryCodeButton autoVCenterInSuperview];

    // Border Row
    UIView *borderRow1 = [self createRowWithHeight:1 previousRow:countryRow];
    UIColor *borderColor = [UIColor colorWithRed:0.75f green:0.75f blue:0.75f alpha:1.f];
    borderRow1.backgroundColor = borderColor;

    // Phone Number Row
    UIView *phoneNumberRow = [self createRowWithHeight:60 previousRow:borderRow1];

    UILabel *phoneNumberLabel = [UILabel new];
    phoneNumberLabel.font = [UIFont ows_mediumFontWithSize:16.f];
    phoneNumberLabel.textColor = [UIColor blackColor];
    phoneNumberLabel.text
        = NSLocalizedString(@"REGISTRATION_PHONENUMBER_BUTTON", @"Label for the phone number textfield");
    [phoneNumberRow addSubview:phoneNumberLabel];
    [phoneNumberLabel autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:20.f];
    [phoneNumberLabel autoVCenterInSuperview];

    _phoneNumberTextField = [UITextField new];
    _phoneNumberTextField.font = [UIFont ows_mediumFontWithSize:16.f];
    _phoneNumberTextField.textAlignment = NSTextAlignmentRight;
    _phoneNumberTextField.textColor = [UIColor ows_signalBrandBlueColor];
    _phoneNumberTextField.placeholder = NSLocalizedString(
        @"REGISTRATION_ENTERNUMBER_DEFAULT_TEXT", @"Placeholder text for the phone number textfield");
    _phoneNumberTextField.keyboardType = UIKeyboardTypeNumberPad;
    _phoneNumberTextField.delegate = self;
    [_phoneNumberTextField addTarget:self
                              action:@selector(textFieldDidChange:)
                    forControlEvents:UIControlEventEditingChanged];
    [phoneNumberRow addSubview:_phoneNumberTextField];
    [_phoneNumberTextField autoPinEdgeToSuperviewEdge:ALEdgeRight withInset:16.f];
    [_phoneNumberTextField autoPinEdge:ALEdgeLeft toEdge:ALEdgeRight ofView:phoneNumberLabel withOffset:0];
    [_phoneNumberTextField autoVCenterInSuperview];

    // Border Row
    UIView *borderRow2 = [self createRowWithHeight:1 previousRow:phoneNumberRow];
    borderRow2.backgroundColor = borderColor;

    // Block Button Row
    UIView *blockButtonRow = [self createRowWithHeight:60 previousRow:borderRow2];

    // TODO: Eventually we should make a view factory that will allow us to
    //       create views with consistent appearance across the app and move
    //       towards a "design language."
    _blockButton = [UIButton buttonWithType:UIButtonTypeCustom];
    _blockButton.titleLabel.font = [UIFont ows_mediumFontWithSize:16.f];
    [_blockButton setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [_blockButton setBackgroundColor:[UIColor ows_signalBrandBlueColor]];
    _blockButton.clipsToBounds = YES;
    _blockButton.layer.cornerRadius = 3.f;
    [_blockButton setTitle:NSLocalizedString(
                               @"BLOCK_LIST_VIEW_BLOCK_BUTTON", @"A label for the block button in the block list view")
                  forState:UIControlStateNormal];
    [_blockButton addTarget:self action:@selector(blockButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [blockButtonRow addSubview:_blockButton];
    [_blockButton autoCenterInSuperview];
    [_blockButton autoSetDimension:ALDimensionWidth toSize:160];
    [_blockButton autoSetDimension:ALDimensionHeight toSize:40];

    // Separator Row
    UIView *separatorRow = [self createRowWithHeight:10 previousRow:blockButtonRow];

    // Block Contact Title Row
    UIView *blockContactTitleRow =
        [self createTitleRowWithText:NSLocalizedString(@"SETTINGS_ADD_TO_BLOCK_LIST_BLOCK_CONTACT_TITLE",
                                         @"Title for the 'block contact' section of the 'add to block list' view.")
                         previousRow:separatorRow];

    _contactsTableView = [UITableView new];
    _contactsTableView.dataSource = self;
    _contactsTableView.delegate = self;
    [_contactsTableView registerClass:[ContactTableViewCell class]
               forCellReuseIdentifier:kContactsTable_CellReuseIdentifier];
    _contactsTableView.tableFooterView = [[UIView alloc] initWithFrame:CGRectZero];
    [self.view addSubview:_contactsTableView];
    [_contactsTableView autoPinWidthToSuperview];
    [_contactsTableView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:blockContactTitleRow withOffset:10];
    [_contactsTableView autoPinToBottomLayoutGuideOfViewController:self withInset:0];

    [self updateBlockButtonEnabling];
}

- (UIView *)createTitleRowWithText:(NSString *)text previousRow:(nullable UIView *)previousRow
{
    UIView *row = [self createRowWithHeight:40 previousRow:previousRow];

    UILabel *label = [UILabel new];
    label.text = text;
    label.font = [UIFont ows_mediumFontWithSize:20.f];
    label.textColor = [UIColor colorWithWhite:0.3f alpha:1.f];
    label.textAlignment = NSTextAlignmentCenter;
    [row addSubview:label];
    [label autoPinEdgeToSuperviewEdge:ALEdgeLeft withInset:20.f];
    [label autoPinEdgeToSuperviewEdge:ALEdgeRight withInset:20.f];
    [label autoPinEdgeToSuperviewEdge:ALEdgeBottom];

    return row;
}

- (UIView *)createRowWithHeight:(CGFloat)height previousRow:(nullable UIView *)previousRow
{
    UIView *row = [UIView new];
    [self.view addSubview:row];
    [row autoPinWidthToSuperview];
    if (previousRow) {
        [row autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:previousRow withOffset:0];
    } else {
        [row autoPinToTopLayoutGuideOfViewController:self withInset:0];
    }
    [row autoSetDimension:ALDimensionHeight toSize:height];
    return row;
}

#pragma mark - Country

- (void)populateDefaultCountryNameAndCode {
    NSLocale *locale      = NSLocale.currentLocale;
    NSString *countryCode = [locale objectForKey:NSLocaleCountryCode];
    NSNumber *callingCode = [[PhoneNumberUtil sharedUtil].nbPhoneNumberUtil getCountryCodeForRegion:countryCode];
    NSString *countryName = [PhoneNumberUtil countryNameFromCountryCode:countryCode];
    [self updateCountryWithName:countryName
                    callingCode:[NSString stringWithFormat:@"%@%@",
                                 COUNTRY_CODE_PREFIX,
                                 callingCode]
                    countryCode:countryCode];
}

- (void)updateCountryWithName:(NSString *)countryName
                  callingCode:(NSString *)callingCode
                  countryCode:(NSString *)countryCode {

    _callingCode = callingCode;

    NSString *title = [NSString stringWithFormat:@"%@ (%@)",
                       callingCode,
                       countryCode.uppercaseString];
    [_countryCodeButton setTitle:title
                        forState:UIControlStateNormal];
    [_countryCodeButton layoutSubviews];
}

- (void)setCallingCode:(NSString *)callingCode
{
    _callingCode = callingCode;

    [self updateBlockButtonEnabling];
}

#pragma mark - Actions

- (void)showCountryCodeView:(id)sender {
    CountryCodeViewController *countryCodeController = [[UIStoryboard storyboardWithName:@"Registration" bundle:NULL]
        instantiateViewControllerWithIdentifier:@"CountryCodeViewController"];
    countryCodeController.delegate = self;
    countryCodeController.shouldDismissWithoutSegue = YES;
    UINavigationController *navigationController =
        [[UINavigationController alloc] initWithRootViewController:countryCodeController];
    [self presentViewController:navigationController animated:YES completion:[UIUtil modalCompletionBlock]];
}

- (void)blockButtonPressed:(id)sender
{
    [self tryToBlockPhoneNumber];
}

- (void)tryToBlockPhoneNumber
{
    if (![self hasValidPhoneNumber]) {
        OWSAssert(0);
        return;
    }

    NSString *possiblePhoneNumber = [self.callingCode stringByAppendingString:_phoneNumberTextField.text.digitsOnly];
    PhoneNumber *parsedPhoneNumber = [PhoneNumber tryParsePhoneNumberFromUserSpecifiedText:possiblePhoneNumber];
    OWSAssert(parsedPhoneNumber);

    __weak AddToBlockListViewController *weakSelf = self;
    [BlockListUIUtils showBlockPhoneNumberActionSheet:[parsedPhoneNumber toE164]
                                   fromViewController:self
                                      blockingManager:_blockingManager
                                      contactsManager:_contactsManager
                                      completionBlock:^(BOOL isBlocked) {
                                          if (isBlocked) {
                                              // Clear phone number text field if block succeeds.
                                              weakSelf.phoneNumberTextField.text = nil;
                                              [weakSelf.navigationController popViewControllerAnimated:YES];
                                          }
                                      }];
}

- (void)textFieldDidChange:(id)sender
{
    [self updateBlockButtonEnabling];
}

// TODO: We could also do this in registration view.
- (BOOL)hasValidPhoneNumber
{
    if (!self.callingCode) {
        return NO;
    }
    NSString *possiblePhoneNumber = [self.callingCode stringByAppendingString:_phoneNumberTextField.text.digitsOnly];
    PhoneNumber *parsedPhoneNumber = [PhoneNumber tryParsePhoneNumberFromUserSpecifiedText:possiblePhoneNumber];
    // It'd be nice to use [PhoneNumber isValid] but it always returns false for some countries
    // (like afghanistan) and there doesn't seem to be a good way to determine beforehand
    // which countries it can validate for without forking libPhoneNumber.
    return parsedPhoneNumber && parsedPhoneNumber.toE164.length > 1;
}

- (void)updateBlockButtonEnabling
{
    BOOL isEnabled = [self hasValidPhoneNumber];
    _blockButton.enabled = isEnabled;
    [_blockButton setBackgroundColor:(isEnabled ? [UIColor ows_signalBrandBlueColor] : [UIColor lightGrayColor])];
}

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

        [self updateContacts];
    });
}

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

- (void)updateContacts
{
    OWSAssert([NSThread isMainThread]);

    self.contacts = [self filteredContacts];
    [self.contactsTableView reloadData];
}

- (BOOL)isContactBlocked:(Contact *)contact
{
    if (contact.parsedPhoneNumbers.count < 1) {
        // Hide contacts without any valid phone numbers.
        return NO;
    }

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

    return NO;
}

- (BOOL)isContactHidden:(Contact *)contact
{
    if (contact.parsedPhoneNumbers.count < 1) {
        // Hide contacts without any valid phone numbers.
        return YES;
    }

    if ([self isCurrentUserContact:contact]) {
        return YES;
    }

    return NO;
}

- (BOOL)isCurrentUserContact:(Contact *)contact
{
    for (PhoneNumber *phoneNumber in contact.parsedPhoneNumbers) {
        if ([[phoneNumber toE164] isEqualToString:[TSAccountManager localNumber]]) {
            return YES;
        }
    }

    return NO;
}

- (NSArray<Contact *> *_Nonnull)filteredContacts
{
    NSMutableArray<Contact *> *result = [NSMutableArray new];
    for (Contact *contact in self.contactsManager.signalContacts) {
        if (![self isContactHidden:contact]) {
            [result addObject:contact];
        }
    }
    return [result copy];
}

#pragma mark - CountryCodeViewControllerDelegate

- (void)countryCodeViewController:(CountryCodeViewController *)vc
             didSelectCountryCode:(NSString *)countryCode
                      countryName:(NSString *)countryName
                      callingCode:(NSString *)callingCode {

    [self updateCountryWithName:countryName
                    callingCode:callingCode
                    countryCode:countryCode];
}

#pragma mark - UITextFieldDelegate

// TODO: This logic resides in both RegistrationViewController and here.
//       We should refactor it out into a utility function.
- (BOOL)textField:(UITextField *)textField
    shouldChangeCharactersInRange:(NSRange)range
                replacementString:(NSString *)insertionText
{
    [ViewControllerUtils phoneNumberTextField:textField
                shouldChangeCharactersInRange:range
                            replacementString:insertionText
                                  countryCode:_callingCode];

    [self updateBlockButtonEnabling];

    return NO; // inform our caller that we took care of performing the change
}

- (BOOL)textFieldShouldReturn:(UITextField *)textField
{
    [textField resignFirstResponder];
    [self tryToBlockPhoneNumber];
    return NO;
}

#pragma mark - UITableViewDataSource

- (BOOL)hasNoContacts
{
    return self.contacts.count == 0;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (self.hasNoContacts) {
        return 1;
    }
    return (NSInteger)self.contacts.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (self.hasNoContacts) {
        UITableViewCell *cell = [UITableViewCell new];
        cell.textLabel.text = NSLocalizedString(
            @"SETTINGS_BLOCK_LIST_NO_CONTACTS", @"A label that indicates the user has no Signal contacts.");
        cell.textLabel.font = [UIFont ows_regularFontWithSize:15.f];
        cell.textLabel.textColor = [UIColor colorWithWhite:0.5f alpha:1.f];
        cell.textLabel.textAlignment = NSTextAlignmentCenter;
        return cell;
    }

    Contact *contact = self.contacts[(NSUInteger)indexPath.item];

    ContactTableViewCell *cell = [_contactsTableView cellForRowAtIndexPath:indexPath];
    if (!cell) {
        cell = [ContactTableViewCell new];
    }
    cell.isBlocked = [self isContactBlocked:contact];
    [cell configureWithContact:contact contactsManager:self.contactsManager];
    return cell;
}

- (nullable NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section
{
    return NSLocalizedString(
        @"BLOCK_LIST_VIEW_CONTACTS_SECTION_TITLE", @"A title for the contacts section of the block list view.");
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return [ContactTableViewCell rowHeight];
}

#pragma mark - UITableViewDelegate

- (nullable NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (self.hasNoContacts) {
        // Don't let user select the "you have no contacts" cell.
        return nil;
    }

    return indexPath;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    if (self.hasNoContacts) {
        return;
    }

    __weak AddToBlockListViewController *weakSelf = self;
    Contact *contact = self.contacts[(NSUInteger)indexPath.item];
    if ([self isContactBlocked:contact]) {
        NSString *displayName = [_contactsManager displayNameForContact:contact];
        UIAlertController *controller = [UIAlertController
            alertControllerWithTitle:NSLocalizedString(@"BLOCK_LIST_VIEW_ALREADY_BLOCKED_ALERT_TITLE",
                                         @"A title of the alert if user tries to block a user who is already blocked.")
                             message:[NSString
                                         stringWithFormat:NSLocalizedString(
                                                              @"BLOCK_LIST_VIEW_ALREADY_BLOCKED_ALERT_MESSAGE_FORMAT",
                                                              @"A format for the message of the alert if user tries to "
                                                              @"block a user who is already blocked.  Embeds {{the "
                                                              @"blocked user's name or phone number}}."),
                                         displayName]
                      preferredStyle:UIAlertControllerStyleAlert];
        [controller addAction:[UIAlertAction actionWithTitle:NSLocalizedString(@"OK", nil)
                                                       style:UIAlertActionStyleDefault
                                                     handler:nil]];
        [self presentViewController:controller animated:YES completion:nil];
        return;
    }
    [BlockListUIUtils showBlockContactActionSheet:contact
                               fromViewController:self
                                  blockingManager:_blockingManager
                                  contactsManager:_contactsManager
                                  completionBlock:^(BOOL isBlocked) {
                                      if (isBlocked) {
                                          [weakSelf.navigationController popViewControllerAnimated:YES];
                                      }
                                  }];
}

#pragma mark - UIScrollViewDelegate

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    [self.phoneNumberTextField resignFirstResponder];
}

#pragma mark - Logging

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

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

@end

NS_ASSUME_NONNULL_END