/*

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

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 Creates and runs an instance of the parser type chosen by the user, and displays the parsed songs in a table. Selecting a row in the table navigates to a detail view for that song.

 */

#import "SongsViewController.h"

#import "DetailController.h"

#import "LibXMLParser.h"

#import "CocoaXMLParser.h"

@interface SongsViewController ()

@property (nonatomic, strong) NSMutableArray *songs;

@property (nonatomic, strong) DetailController *detailController;

@property (nonatomic, strong) iTunesRSSParser *parser;

// When the parsing is finished, the user can return to the ParserChoiceViewController by

// touching the button associated with this action.

//

- (IBAction)returnToParserChoices;

@end

#pragma mark -

@implementation SongsViewController

- (void)viewDidLoad {

    [super viewDidLoad];

    _detailController = [[DetailController alloc] initWithStyle:UITableViewStyleGrouped];

    UIBarButtonItem *doneItem =

        [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone

                                                      target:self

                                                      action:@selector(returnToParserChoices)];

    self.navigationItem.rightBarButtonItem = doneItem;

}

- (void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];

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

    if (selectedRowIndexPath != nil) {

        [self.tableView deselectRowAtIndexPath:selectedRowIndexPath animated:NO];

    }

}

// This method will be called repeatedly - once each time the user choses to parse.

- (void)parseWithParserType:(XMLParserType)parserType {

    self.navigationItem.rightBarButtonItem.enabled = NO;

    // Reset the title

    self.title = NSLocalizedString(@"Getting Top Songs...", @"Waiting for first results label");

    // Allocate the array for song storage, or empty the results of previous parses

    if (self.songs == nil) {

        self.songs = [NSMutableArray array];

    } else {

        [self.songs removeAllObjects];

        [self.tableView reloadData];

    }

    // Determine the Class for the parser

    Class parserClass = nil;

    switch (parserType) {

        case XMLParserTypeLibXMLParser: {

            parserClass = [LibXMLParser class];

        } break;

        case XMLParserTypeNSXMLParser: {

            parserClass = [CocoaXMLParser class];

        } break;

        default: {

            NSAssert1(NO, @"Unknown parser type %d", parserType);

        } break;

    }

    // Create the parser, set its delegate, and start it.

    self.parser = [[parserClass alloc] init];      

    self.parser.delegate = self;

    [self.parser start];

}

#pragma mark - UITableViewDataSource

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

    return (self.songs).count;

}

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

    static NSString *kCellIdentifier = @"MyCell";

    UITableViewCell *cell = [self.tableView dequeueReusableCellWithIdentifier:kCellIdentifier];

    if (cell == nil) {

        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:kCellIdentifier];

        cell.textLabel.font = [UIFont boldSystemFontOfSize:14.0];

        cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;

    }

    cell.textLabel.text = [(self.songs)[indexPath.row] title];

    return cell;

}

#pragma mark - UITableViewDelegate

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

    self.detailController.song = (self.songs)[indexPath.row];

    [self.navigationController pushViewController:self.detailController animated:YES];

}

- (IBAction)returnToParserChoices {

    [self dismissViewControllerAnimated:YES completion:nil];

}

#pragma mark - iTunesRSSParserDelegate

- (void)parserDidEndParsingData:(iTunesRSSParser *)parser {

    self.title = [NSString stringWithFormat:NSLocalizedString(@"Top %d Songs", @"Top Songs format"), (self.songs).count];

    [self.tableView reloadData];

    self.navigationItem.rightBarButtonItem.enabled = YES;

    self.parser = nil;

}

- (void)parser:(iTunesRSSParser *)parser didParseSongs:(NSArray *)parsedSongs {

    [self.songs addObjectsFromArray:parsedSongs];

    // Three scroll view properties are checked to keep the user interface smooth during parse. When new objects are delivered by the parser, the table view is reloaded to display them. If the table is reloaded while the user is scrolling, this can result in eratic behavior. dragging, tracking, and decelerating can be checked for this purpose. When the parser finishes, reloadData will be called in parserDidEndParsingData:, guaranteeing that all data will ultimately be displayed even if reloadData is not called in this method because of user interaction.

    if (!self.tableView.dragging && !self.tableView.tracking && !self.tableView.decelerating) {

        self.title = [NSString stringWithFormat:NSLocalizedString(@"Top %d Songs", @"Top Songs format"), (self.songs).count];

        [self.tableView reloadData];

    }

}

- (void)parser:(iTunesRSSParser *)parser didFailWithError:(NSError *)error {

    // handle errors as appropriate to your application...

}

@end