/*

 Copyright (C) 2015 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 View controller for displaying the earthquake list.

 */

#import "APLViewController.h"

#import "APLEarthQuakeSource.h"

#import "APLEarthquake.h"

#import "APLEarthquakeTableViewCell.h"

@import MapKit;   // for CLLocationCoordinate2D and MKPlacemark

@interface APLViewController ()

@property (nonatomic, strong) APLEarthQuakeSource *earthQuakeSource;

@property (assign) id localChangedObserver;

@property (nonatomic, strong) UIAlertController *alert;

@end

#pragma mark -

@implementation APLViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    _earthQuakeSource = [[APLEarthQuakeSource alloc] init];

    // listen for incoming earthquakes from our data source using KVO

    [self.earthQuakeSource addObserver:self forKeyPath:@"earthquakes" options:0 context:nil];

    // listen for errors reported by our data source using KVO, so we can report it in our own way

    [self.earthQuakeSource addObserver:self forKeyPath:@"error" options:NSKeyValueObservingOptionNew context:nil];

    // Our NSNotification callback when the user changes the locale (region format) in Settings, so we are notified here to

    // update the date format in the table view cells

    //

    _localChangedObserver =

        [[NSNotificationCenter defaultCenter] addObserverForName:NSCurrentLocaleDidChangeNotification

                                                          object:nil

                                                           queue:nil

                                                      usingBlock:^(NSNotification *notification) {

            [self.tableView reloadData];

        }];

}

- (void)viewDidAppear:(BOOL)animated {

    [super viewDidAppear:animated];

    [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

    [self.earthQuakeSource startEarthQuakeLookup];

}

- (void)dealloc {

    [[NSNotificationCenter defaultCenter] removeObserver:self.localChangedObserver];

}

#pragma mark - UITableViewDelegate

/**

 * The number of rows is equal to the number of earthquakes in the array.

 */

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return self.earthQuakeSource.earthquakes.count;

}

/**

 * Return the proper table view cell for each earthquake

 */

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *kEarthquakeCellID = @"EarthquakeCellID";

    APLEarthquakeTableViewCell *cell = (APLEarthquakeTableViewCell *)[tableView dequeueReusableCellWithIdentifier:kEarthquakeCellID];

    // Get the specific earthquake for this row.

    APLEarthquake *earthquake = self.earthQuakeSource.earthquakes[indexPath.row];

    [cell configureWithEarthquake:earthquake];

    return cell;

}

/**

 * When the user taps a row in the table, display the USGS web page that displays details of the earthquake they selected.

 */

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    // open the earthquake info in Maps, note this will not work in the simulator

    NSIndexPath *selectedIndexPath = (self.tableView).indexPathForSelectedRow;

    APLEarthquake *earthquake = (APLEarthquake *)self.earthQuakeSource.earthquakes[selectedIndexPath.row];

    // create a map region pointing to the earthquake location

    CLLocationCoordinate2D location = (CLLocationCoordinate2D) { earthquake.latitude, earthquake.longitude };

    NSValue *locationValue = [NSValue valueWithMKCoordinate:location];

    MKCoordinateSpan span = (MKCoordinateSpan) { 50, 50 };

    NSValue *spanValue = [NSValue valueWithMKCoordinateSpan:span];

    NSDictionary *launchOptions = @{ MKLaunchOptionsMapTypeKey : @(MKMapTypeStandard),

                                     MKLaunchOptionsMapCenterKey : locationValue,

                                     MKLaunchOptionsMapSpanKey : spanValue,

                                     MKLaunchOptionsShowsTrafficKey : @(NO),

                                     MKLaunchOptionsDirectionsModeDriving : @(NO) };

    // make sure the map item has a pin placed on it with the title as the earthquake location

    MKPlacemark *placemark = [[MKPlacemark alloc] initWithCoordinate:location

                                                   addressDictionary:nil];

    MKMapItem *mapItem = [[MKMapItem alloc] initWithPlacemark:placemark];

    mapItem.name = earthquake.location;

    [mapItem openInMapsWithLaunchOptions:launchOptions];

    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];

}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context

{

    APLEarthQuakeSource *earthQuakeSource = object;

    if ([keyPath isEqualToString:@"earthquakes"])

    {

        dispatch_async(dispatch_get_main_queue(), ^{

            [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

            [self.tableView reloadData];

        });

    }

    else if ([keyPath isEqualToString:@"error"])

    {

        /* Handle errors in the download by showing an alert to the user. This is a very simple way of handling the error, partly because this application does not have any offline functionality for the user. Most real applications should handle the error in a less obtrusive way and provide offline functionality to the user.

            */

        dispatch_async(dispatch_get_main_queue(), ^{

            [UIApplication sharedApplication].networkActivityIndicatorVisible = NO;

            NSError *error = earthQuakeSource.error;

            NSString *errorMessage = error.localizedDescription;

            NSString *alertTitle = NSLocalizedString(@"Error", @"Title for alert displayed when download or parse error occurs.");

            NSString *okTitle = NSLocalizedString(@"OK", @"OK Title for alert displayed when download or parse error occurs.");

            _alert = [UIAlertController alertControllerWithTitle:alertTitle message:errorMessage preferredStyle:UIAlertControllerStyleAlert];

            UIAlertAction *action = [UIAlertAction actionWithTitle:okTitle style:UIAlertActionStyleDefault handler:^(UIAlertAction *act) {

                //..

            }];

            [self.alert addAction:action];

            if (self.presentedViewController == nil) {

                [self presentViewController:self.alert animated:YES completion:^ {

                    //..

                }];

            }

        });

    }

    else {

        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];

    }

}

@end