/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 View controller that sets up the table view and serves as the table view's data source and delegate.

 */

#import "APLViewController.h"

#import "APLAppDelegate.h"

#import "APLRegion.h"

#import "APLTimeZoneWrapper.h"

@interface APLViewController ()

@property (nonatomic) NSArray *displayList;

@property (nonatomic) NSCalendar *calendar;

@end

@implementation APLViewController

#pragma mark - View Life Cycle

- (void)viewDidLoad {

    [super viewDidLoad];

    //  Build Model

    NSCalendar *calendar= [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];

    self.calendar = calendar;

    self.displayList = [self regionsWithCalendar:calendar];

}

#pragma mark - Workers

- (NSArray *)regionsWithCalendar:(NSCalendar *)calendar {

    /*

     Create an array of Region objects.

     Each object represents a geographical region.  Each region contains time zones.

     Much of the information required to display a time zone is expensive to compute, so rather than using NSTimeZone objects directly use wrapper objects that calculate the required derived values on demand and cache the results.

     */

    NSArray *knownTimeZoneNames = [NSTimeZone knownTimeZoneNames];

    NSMutableArray *regions = [[NSMutableArray alloc] init];

    for (NSString *timeZoneName in knownTimeZoneNames) {

        NSArray *components = [timeZoneName componentsSeparatedByString:@"/"];

        NSString *regionName = components[0];

        APLRegion *region = [APLRegion regionNamed:regionName];

        if (region == nil) {

            region = [APLRegion newRegionWithName:regionName];

            region.calendar = calendar;

            [regions addObject:region];

        }

        NSTimeZone *timeZone = [[NSTimeZone alloc] initWithName:timeZoneName];

        [region addTimeZone:timeZone nameComponents:components];

    }

    // Now sort the time zones by name.

    NSDate *date = [[NSDate alloc] init];

    for (APLRegion *region in regions) {

        [region sortZones];

        [region setDate:date];

    }

    // Sort the regions by name.

    NSArray *sortedRegions = [regions sortedArrayUsingComparator:^(APLRegion * region1, APLRegion * region2) {

        NSString *name1 = region1.name;

        NSString *name2 = region2.name;

        // Do comparison

        return [name1 localizedStandardCompare:name2];

    }];

    return sortedRegions;

}

#pragma mark - UITableViewDataSource

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {

    // Number of sections is the number of regions.

    return self.displayList.count;

}

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

    // Number of rows is the number of time zones in the region for the specified section.

    APLRegion *region = self.displayList[section];

    return region.timeZoneWrappers.count;

}

- (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section {

    // The header for the section is the region name -- get this from the region at the section index.

    APLRegion *region = self.displayList[section];

    return region.name;

}

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

    static NSString *MyIdentifier = @"MyIdentifier";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];

    // Get the section index, and so the region for that section.

    APLRegion *region = self.displayList[indexPath.section];

    APLTimeZoneWrapper *timeZoneWrapper = region.timeZoneWrappers[indexPath.row];

    // Set the cell's text to the name of the time zone at the row

    cell.textLabel.text = timeZoneWrapper.timeZoneLocaleName;

    return cell;

}

@end