APICallsViewController.m

/*
 * Copyright 2010 Facebook
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#import "APICallsViewController.h"
#import "HackbookAppDelegate.h"
#import "FBConnect.h"
#import "DataSet.h"
#import "APIResultsViewController.h"
#import "RootViewController.h"

// For re-using table cells
#define TITLE_TAG 1001
#define DESCRIPTION_TAG 1002

@implementation APICallsViewController

@synthesize apiTableView;
@synthesize apiMenuItems;
@synthesize apiHeader;
@synthesize savedAPIResult;
@synthesize locationManager;
@synthesize mostRecentLocation;
@synthesize activityIndicator;
@synthesize messageLabel;
@synthesize messageView;

- (id)initWithIndex:(NSUInteger)index
{
    self = [super init];
    if (self) {
        childIndex = index;
        savedAPIResult = [[NSMutableArray alloc] initWithCapacity:1];
    }
    return self;
}

- (void)dealloc
{
    [apiTableView release];
    [apiMenuItems release];
    [apiHeader release];
    [savedAPIResult release];
    
    [locationManager stopUpdatingLocation];
    locationManager.delegate = nil;
    [locationManager release];
    
    [mostRecentLocation release];
    [activityIndicator release];
    [messageLabel release];
    [messageView release];
    
    [super dealloc];
}

- (void)didReceiveMemoryWarning
{
    // Releases the view if it doesn't have a superview.
    [super didReceiveMemoryWarning];
    
    // Release any cached data, images, etc that aren't in use.
}

#pragma mark - View lifecycle

- (void)loadView
{
    UIView *view = [[UIView alloc] initWithFrame:[UIScreen 
                                                  mainScreen].applicationFrame]; 
    [view setBackgroundColor:[UIColor whiteColor]]; 
    self.view = view; 
    [view release]; 
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate]; 
    NSDictionary *apiData = [[[delegate apiData] apiConfigData] objectAtIndex:childIndex];
    self.navigationItem.title = [apiData objectForKey:@"title"];
    apiMenuItems = [[NSArray arrayWithArray:[apiData objectForKey:@"menu"]] retain];
    apiHeader = [[apiData objectForKey:@"description"] retain];
    
    self.navigationItem.backBarButtonItem =
    [[[UIBarButtonItem alloc] initWithTitle:@"Back"
                                      style:UIBarButtonItemStyleBordered
                                     target:nil
                                     action:nil] autorelease];
    
    // Main Menu Table
    apiTableView = [[UITableView alloc] initWithFrame:self.view.bounds 
                                                            style:UITableViewStylePlain];
    [apiTableView setBackgroundColor:[UIColor whiteColor]];
    apiTableView.dataSource = self;
    apiTableView.delegate = self;
    apiTableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    [self.view addSubview:apiTableView];
    
    // Activity Indicator
    int xPosition = (self.view.bounds.size.width / 2.0) - 15.0;
    int yPosition = (self.view.bounds.size.height / 2.0) - 15.0;
    activityIndicator = [[UIActivityIndicatorView alloc] initWithFrame:CGRectMake(xPosition, yPosition, 30, 30)];
    activityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyleGray;
    [self.view addSubview:activityIndicator];
    
    // Message Label for showing confirmation and status messages
    CGFloat yLabelViewOffset = self.view.bounds.size.height-self.navigationController.navigationBar.frame.size.height-30;
    messageView = [[UIView alloc] 
                    initWithFrame:CGRectMake(0, yLabelViewOffset, self.view.bounds.size.width, 30)];
    messageView.backgroundColor = [UIColor lightGrayColor];
    
    UIView *messageInsetView = [[UIView alloc] initWithFrame:CGRectMake(1, 1, self.view.bounds.size.width-1, 28)]; 
    messageInsetView.backgroundColor = [UIColor colorWithRed:255.0/255.0
                                                   green:248.0/255.0
                                                    blue:228.0/255.0 
                                                   alpha:1];
    messageLabel = [[UILabel alloc] 
                             initWithFrame:CGRectMake(4, 1, self.view.bounds.size.width-10, 26)];
    messageLabel.text = @"";
    messageLabel.font = [UIFont fontWithName:@"Helvetica" size:14.0];
    messageLabel.backgroundColor = [UIColor colorWithRed:255.0/255.0
                                                  green:248.0/255.0
                                                   blue:228.0/255.0 
                                                  alpha:0.6];
    [messageInsetView addSubview:messageLabel];
    [messageView addSubview:messageInsetView];    
    [messageInsetView release];
    messageView.hidden = YES;
    [self.view addSubview:messageView];

}

- (void)viewDidUnload
{
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return YES;
}

#pragma mark - Private Helper Methods
/*
 * This method is called after the user logs out or unauthorized the application
 * and returns the flow back to the main menu.
 */
- (void) backToMain
{
    // Remove saved authorization information
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults removeObjectForKey:@"FBAccessTokenKey"];
    [defaults removeObjectForKey:@"FBExpirationDateKey"];
    [defaults synchronize];
    
    // Pop to main view
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    RootViewController *rootViewController = (RootViewController *) [[self.navigationController viewControllers] objectAtIndex:0];
    // Set the delegate to the main root view controller
    // to ensure if an SSO request comes in this controller
    // will handle it.
    [delegate facebook].sessionDelegate = rootViewController;
    [[delegate navigationController] popToRootViewControllerAnimated:YES];
}

/*
 * This method is called to store the check-in permissions
 * in the app session after the permissions have been updated.
 */
- (void) updateCheckinPermissions
{
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    [[delegate userPermissions] setObject:@"1" forKey:@"user_checkins"];
    [[delegate userPermissions] setObject:@"1" forKey:@"publish_checkins"];
}

/*
 * This method shows the activity indicator and
 * deactivates the table to avoid user input.
 */
- (void) showActivityIndicator
{
    if (![activityIndicator isAnimating]) {
        apiTableView.userInteractionEnabled = NO;
        [activityIndicator startAnimating];   
    }
}

/*
 * This method hides the activity indicator
 * and enables user interaction once more.
 */
- (void) hideActivityIndicator
{
    if ([activityIndicator isAnimating]) {
        [activityIndicator stopAnimating];   
        apiTableView.userInteractionEnabled = YES;
    }
}

/*
 * This method is used to display API confirmation and
 * error messages to the user.
 */
-(void)showMessage:(NSString *)message
{
    
    CGRect labelFrame = messageView.frame;
    labelFrame.origin.y = [UIScreen mainScreen].bounds.size.height - self.navigationController.navigationBar.frame.size.height - 20;
    messageView.frame = labelFrame;
    messageLabel.text = message;
    messageView.hidden = NO;
    
    // Use animation to show the message from the bottom then
    // hide it.
    [UIView animateWithDuration:0.5
                          delay:1.0
                        options: UIViewAnimationCurveEaseOut
                     animations:^{
                         CGRect labelFrame = messageView.frame;
                         labelFrame.origin.y -= labelFrame.size.height;
                         messageView.frame = labelFrame;
                     } 
                     completion:^(BOOL finished){
                         if (finished) {
                             [UIView animateWithDuration:0.5
                                                   delay:3.0
                                                 options: UIViewAnimationCurveEaseOut
                                              animations:^{
                                                  CGRect labelFrame = messageView.frame;
                                                  labelFrame.origin.y += messageView.frame.size.height;
                                                  messageView.frame = labelFrame;
                                              } 
                                              completion:^(BOOL finished){
                                                  if (finished) {
                                                      messageView.hidden = YES;
                                                      messageLabel.text = @"";  
                                                  }
                                              }];
                         }
                     }];
}

/*
 * This method hides the message, only needed if view closed
 * and animation still going on.
 */
-(void)hideMessage
{
    messageView.hidden = YES;
    messageLabel.text = @"";
}

/*
 * This method handles any clean up needed if the view
 * is about to disappear.
 */
- (void)viewWillDisappear:(BOOL)animated {
    [super viewWillDisappear:animated];
    // Hide the activitiy indicator
    [self hideActivityIndicator];
    // Hide the message.
    [self hideMessage];
}

/**
 * Helper method called when a button is clicked
 */
- (void)apiButtonClicked:(id) sender
{    
    // Each menu button in the UITableViewController is initialized
    // with a tag representing the table cell row. When the button
    // is clicked the button is passed along in the sender object.
    // From this object we can then read the tag property to determine
    // which menu button was clicked.
    SEL selector = NSSelectorFromString([[apiMenuItems objectAtIndex:[sender tag]] objectForKey:@"method"]);
    if ([self respondsToSelector:selector]) {
        [self performSelector:selector];
    }
}

/**
 * Helper method to parse URL query parameters
 */
- (NSDictionary *) parseURLParams:(NSString *)query {
	NSArray *pairs = [query componentsSeparatedByString:@"&"];
	NSMutableDictionary *params = [[[NSMutableDictionary alloc] init] autorelease];
	for (NSString *pair in pairs) {
		NSArray *kv = [pair componentsSeparatedByString:@"="];
		NSString *val =
        [[kv objectAtIndex:1]
         stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
        
		[params setObject:val forKey:[kv objectAtIndex:0]];
	}
    return params;
}

#pragma mark - Facebook API Calls
/*
 * Graph API: Method to get the user's friends.
 */
- (void) apiGraphFriends {
    [self showActivityIndicator];
    // Do not set current API as this is commonly called by other methods
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate]; 
    [[delegate facebook] requestWithGraphPath:@"me/friends" andDelegate:self];
}

/*
 * Graph API: Method to get the user's permissions for this app.
 */
- (void) apiGraphUserPermissions {
    [self showActivityIndicator];
    currentAPICall = kAPIGraphUserPermissions;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate]; 
    [[delegate facebook] requestWithGraphPath:@"me/permissions" andDelegate:self];
}

/*
 * Dialog: Authorization to grant the app check-in permissions.
 */
- (void) apiPromptCheckinPermissions {
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    NSArray *checkinPermissions = [[NSArray alloc] initWithObjects:@"user_checkins", @"publish_checkins", nil];
    [delegate facebook].sessionDelegate = self;
    [[delegate facebook] authorize:checkinPermissions];
    [checkinPermissions release];
}

/*
 * --------------------------------------------------------------------------
 * Login and Permissions
 * --------------------------------------------------------------------------
 */

/*
 * iOS SDK method that handles the logout API call and flow. 
 */
- (void)apiLogout {
    currentAPICall = kAPILogout;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    [[delegate facebook] logout:self];
}

/*
 * Graph API: App unauthorize
 */
- (void) apiGraphUserPermissionsDelete {
    [self showActivityIndicator];
    currentAPICall = kAPIGraphUserPermissionsDelete;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    // Passing empty (no) parameters unauthorizes the entire app. To revoke individual permissions
    // add a permission parameter with the name of the permission to revoke.
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:nil];
    [[delegate facebook] requestWithGraphPath:@"me/permissions" 
                                    andParams:params 
                                andHttpMethod:@"DELETE" 
                                  andDelegate:self];
}

/*
 * Dialog: Authorization to grant the app user_likes permission.
 */
- (void)apiPromptExtendedPermissions {
    currentAPICall = kDialogPermissionsExtended;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    NSArray *extendedPermissions = [[NSArray alloc] initWithObjects:@"user_likes", nil];
    [delegate facebook].sessionDelegate = self;
    [[delegate facebook] authorize:extendedPermissions];
    [extendedPermissions release];
}

/**
 * --------------------------------------------------------------------------
 * News Feed
 * --------------------------------------------------------------------------
 */

/*
 * Dialog: Feed for the user
 */
- (void) apiDialogFeedUser {
    currentAPICall = kDialogFeedUser;
    SBJSON *jsonWriter = [[SBJSON new] autorelease];
    
    // The action links to be shown with the post in the feed
    NSArray* actionLinks = [NSArray arrayWithObjects:[NSDictionary dictionaryWithObjectsAndKeys:
                                                           @"Get Started",@"name",@"http://m.facebook.com/apps/hackbookios/",@"link", nil], nil];
    NSString *actionLinksStr = [jsonWriter stringWithObject:actionLinks];
    // Dialog parameters
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"I'm using the Hackbook for iOS app", @"name",
                                   @"Hackbook for iOS.", @"caption",
                                   @"Check out Hackbook for iOS to learn how you can make your iOS apps social using Facebook Platform.", @"description",
                                   @"http://m.facebook.com/apps/hackbookios/", @"link",
                                   @"http://www.facebookmobileweb.com/hackbook/img/facebook_icon_large.png", @"picture",
                                   actionLinksStr, @"actions",
                                   nil];
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];  
    [[delegate facebook] dialog:@"feed"
            andParams:params
          andDelegate:self];
    
}

/*
 * Helper method to first get the user's friends then
 * pick one friend and post on their wall.
 */
- (void) getFriendsCallAPIDialogFeed {
    // Call the friends API first, then set up for targeted Feed Dialog
    currentAPICall = kAPIFriendsForDialogFeed;
    [self apiGraphFriends];
}

/*
 * Dialog: Feed for friend
 */
- (void) apiDialogFeedFriend:(NSString *) friendID {
    currentAPICall = kDialogFeedFriend;
    SBJSON *jsonWriter = [[SBJSON new] autorelease];
    
    NSArray* actionLinks = [NSArray arrayWithObjects:[NSDictionary dictionaryWithObjectsAndKeys:
                                                           @"Get Started",@"name",@"http://m.facebook.com/apps/hackbookios/",@"link", nil], nil];
    NSString *actionLinksStr = [jsonWriter stringWithObject:actionLinks];
    // The "to" parameter targets the post to a friend
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   friendID, @"to",
                                   @"I'm using the Hackbook for iOS app", @"name",
                                   @"Hackbook for iOS.", @"caption",
                                   @"Check out Hackbook for iOS to learn how you can make your iOS apps social using Facebook Platform.", @"description",
                                   @"http://m.facebook.com/apps/hackbookios/", @"link",
                                   @"http://www.facebookmobileweb.com/hackbook/img/facebook_icon_large.png", @"picture",
                                   actionLinksStr, @"actions",
                                   nil];
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];  
    [[delegate facebook] dialog:@"feed"
                      andParams:params
                    andDelegate:self];
    
}

/*
 * --------------------------------------------------------------------------
 * Requests
 * --------------------------------------------------------------------------
 */

/*
 * Dialog: Requests - send to all.
 */
- (void)apiDialogRequestsSendToMany {
    currentAPICall = kDialogRequestsSendToMany;
    SBJSON *jsonWriter = [[SBJSON new] autorelease];
    NSDictionary *gift = [NSDictionary dictionaryWithObjectsAndKeys:
                                 @"5", @"social_karma",
                                 @"1", @"badge_of_awesomeness",
                                 nil];
    
    NSString *giftStr = [jsonWriter stringWithObject:gift];
    NSMutableDictionary* params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"Learn how to make your iOS apps social.",  @"message",
                                   @"Check this out", @"notification_text",
                                   giftStr, @"data",
                                   nil];
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];  
    [[delegate facebook] dialog:@"apprequests"
                      andParams:params
                    andDelegate:self];
}

/*
 * API: Legacy REST for getting the friends using the app. This is a helper method
 * being used to target app requests in follow-on examples.
 */
- (void) apiRESTGetAppUsers {
    [self showActivityIndicator];
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"friends.getAppUsers", @"method",
                                   nil];
    [[delegate facebook] requestWithParams:params
                               andDelegate:self];
}

/*
 * Dialog: Requests - send to friends not currently using the app.
 */
- (void)apiDialogRequestsSendToNonUsers:(NSArray *)selectIDs {
    currentAPICall = kDialogRequestsSendToSelect;
    NSString *selectIDsStr = [selectIDs componentsJoinedByString:@","];
    NSMutableDictionary* params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"Learn how to make your iOS apps social.",  @"message",
                                   @"Check this out", @"notification_text",
                                   selectIDsStr, @"suggestions",
                                   nil];
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];  
    [[delegate facebook] dialog:@"apprequests"
                      andParams:params
                    andDelegate:self];
}

/*
 * Dialog: Requests - send to select users, in this case friends 
 * that are currently using the app.
 */
- (void)apiDialogRequestsSendToUsers:(NSArray *)selectIDs {
    currentAPICall = kDialogRequestsSendToSelect;
    NSString *selectIDsStr = [selectIDs componentsJoinedByString:@","];
    NSMutableDictionary* params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"It's your turn to visit the Hackbook for iOS app.",  @"message",
                                   selectIDsStr, @"suggestions",
                                   nil];
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];  
    [[delegate facebook] dialog:@"apprequests"
                      andParams:params
                    andDelegate:self];
}

/*
 * Dialog: Request - send to a targeted friend.
 */
- (void)apiDialogRequestsSendTarget:(NSString *)friend {
    currentAPICall = kDialogRequestsSendToTarget;
    NSMutableDictionary* params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"Learn how to make your iOS apps social.",  @"message",
                                   friend, @"to",
                                   nil];
    
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];  
    [[delegate facebook] dialog:@"apprequests"
                      andParams:params
                    andDelegate:self];
}

/*
 * Helper method to get friends using the app which will in turn
 * send a request to NON users.
 */
- (void) getAppUsersFriendsNotUsing {
    currentAPICall = kAPIGetAppUsersFriendsNotUsing;
    [self apiRESTGetAppUsers];
}

/*
 * Helper method to get friends using the app which will in turn
 * send a request to current app users.
 */
- (void) getAppUsersFriendsUsing {
    currentAPICall = kAPIGetAppUsersFriendsUsing;
    [self apiRESTGetAppUsers];
}

/*
 * Helper method to get the users friends which will in turn
 * pick one to send a request.
 */
- (void) getUserFriendTargetDialogRequest {
    currentAPICall = kAPIFriendsForTargetDialogRequests;
    [self apiGraphFriends];
}

/*
 * --------------------------------------------------------------------------
 * Graph API
 * --------------------------------------------------------------------------
 */

/*
 * Graph API: Get the user's basic information, picking the name and picture fields.
 */
- (void) apiGraphMe {
    [self showActivityIndicator];
    currentAPICall = kAPIGraphMe;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    NSMutableDictionary* params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"name,picture",  @"fields",
                                   nil];
    [[delegate facebook] requestWithGraphPath:@"me" andParams:params andDelegate:self];
}

/*
 * Graph API: Get the user's friends
 */
- (void) getUserFriends {
    currentAPICall = kAPIGraphUserFriends;
    [self apiGraphFriends];
}

/*
 * Graph API: Get the user's check-ins
 */
- (void) apiGraphUserCheckins {
    [self showActivityIndicator];
    currentAPICall = kAPIGraphUserCheckins;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate]; 
    [[delegate facebook] requestWithGraphPath:@"me/checkins" andDelegate:self];
}

/*
 * Helper method to check the user permissions which were stored in the app session
 * when the app was started. After the check decide on whether to prompt for user
 * check-in permissions first or get the check-in information.
 */
- (void) getPermissionsCallUserCheckins {
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    if ([[delegate userPermissions] objectForKey:@"user_checkins"]) {
        [self apiGraphUserCheckins];
    } else {
        currentAPICall = kDialogPermissionsCheckinForRecent;
        [self apiPromptCheckinPermissions];
    }
}

/*
 * Graph API: Search query to get nearby location.
 */
- (void) apiGraphSearchPlace:(CLLocation *)location
{
    [self showActivityIndicator];
    currentAPICall = kAPIGraphSearchPlace;
    NSString *centerLocation = [[NSString alloc] initWithFormat:@"%f,%f", 
                                location.coordinate.latitude, 
                                location.coordinate.longitude]; 
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    NSMutableDictionary* params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   @"place",  @"type",
                                   centerLocation, @"center",
                                   @"1000",  @"distance",
                                   nil];
    [centerLocation release];
    [[delegate facebook] requestWithGraphPath:@"search" andParams:params andDelegate:self];
}

/*
 * Method called when user location found. Calls the search API with the most
 * recent location reading.
 */
- (void) processLocationData
{
    // Stop updating location information
    [locationManager stopUpdatingLocation];
    locationManager.delegate = nil;
    
    // Call the API to get nearby search results
    [self apiGraphSearchPlace:mostRecentLocation];
}

/*
 * Helper method to kick off GPS to get the user's location. 
 */
- (void) getNearby {
    [self showActivityIndicator];
    // A warning if the user turned off location services.
    if (![CLLocationManager locationServicesEnabled]) {
        UIAlertView *servicesDisabledAlert = [[UIAlertView alloc] initWithTitle:@"Location Services Disabled" message:@"You currently have all location services for this device disabled. If you proceed, you will be asked to confirm whether location services should be reenabled." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [servicesDisabledAlert show];
        [servicesDisabledAlert release];
    }
    // Start the location manager
    self.locationManager = [[[CLLocationManager alloc] init] autorelease];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [locationManager startUpdatingLocation];
    // Time out if it takes too long to get a reading.
    [self performSelector:@selector(processLocationData) withObject:nil afterDelay:15.0];
}

/*
 * Helper method to check the user permissions which were stored in the app session
 * when the app was started. After the check decide on whether to prompt for user
 * check-in permissions first or get the user's location which will in turn search
 * for nearby places the user can then check-in to.
 */
- (void) getPermissionsCallNearby {
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    if ([[delegate userPermissions] objectForKey:@"publish_checkins"]) {
        [self getNearby];
    } else {
        currentAPICall = kDialogPermissionsCheckinForPlaces;
        [self apiPromptCheckinPermissions];
    }
}

/*
 * Graph API: Upload a photo. By default, when using me/photos the photo is uploaded
 * to the application album which is automatically created if it does not exist.
 */
- (void) apiGraphUserPhotosPost {
    [self showActivityIndicator];
    currentAPICall = kAPIGraphUserPhotosPost;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate]; 

    // Download a sample photo
    NSURL *url = [NSURL URLWithString:@"http://www.facebook.com/images/devsite/iphone_connect_btn.jpg"];
    NSData *data = [NSData dataWithContentsOfURL:url];
    UIImage *img  = [[UIImage alloc] initWithData:data];
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   img, @"picture",
                                   nil];
    [[delegate facebook] requestWithGraphPath:@"me/photos"
                          andParams:params
                      andHttpMethod:@"POST"
                        andDelegate:self];
}

/*
 * Graph API: Post a video to the user's wall.
 */
- (void) apiGraphUserVideosPost {
    [self showActivityIndicator];
    currentAPICall = kAPIGraphUserVideosPost;
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate]; 
    
    // Download a sample video
    NSURL *url = [NSURL URLWithString:@"https://developers.facebook.com/attachment/sample.mov"];
    NSData *data = [NSData dataWithContentsOfURL:url];
    NSMutableDictionary *params = [NSMutableDictionary dictionaryWithObjectsAndKeys:
                                   data, @"video.mov",
                                   @"video/quicktime", @"contentType",
                                   @"Video Test Title", @"title",
                                   @"Video Test Description", @"description",
								   nil];
	[[delegate facebook] requestWithGraphPath:@"me/videos"
                         andParams:params
                     andHttpMethod:@"POST"
                       andDelegate:self];
}

#pragma mark - UITableViewDatasource and UITableViewDelegate Methods
- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section
{
    if (section == 0) {
        UITextView *headerTextView = [[[UITextView alloc] 
                     initWithFrame:CGRectMake(10, 10, tableView.bounds.size.width, 60.0)] autorelease];
        headerTextView.textAlignment = UITextAlignmentLeft;
        headerTextView.backgroundColor = [UIColor colorWithRed:0.9
                                                         green:0.9
                                                          blue:0.9 alpha:1]; 
        headerTextView.font = [UIFont fontWithName:@"Helvetica" size:14.0];
        headerTextView.text = self.apiHeader;
        return headerTextView;
    } else {
        return nil;
    }
}

- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section
{
    if (section == 0) {
        // Automatically size the header for this API section
        CGSize constraintSize = CGSizeMake(280.0f, MAXFLOAT);
        
        UIFont *titleFont = [UIFont fontWithName:@"Helvetica" size:14.0];
        CGSize labelSize = [self.apiHeader sizeWithFont:titleFont 
                                constrainedToSize:constraintSize 
                                    lineBreakMode:UILineBreakModeWordWrap];
        return labelSize.height + 20;
    } else {
        return 0.0;
    }
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    if (indexPath.section == 0) {
        return  0.0;
    } else {
        // Automatically size the table row based on the content
        CGSize constraintSize = CGSizeMake(280.0f, MAXFLOAT);
        
        NSString *cellText = [[apiMenuItems objectAtIndex:indexPath.row] objectForKey:@"title"];
        UIFont *cellFont = [UIFont boldSystemFontOfSize:14.0];
        CGSize labelSize = [cellText sizeWithFont:cellFont 
                                constrainedToSize:constraintSize 
                                    lineBreakMode:UILineBreakModeWordWrap];
        
        NSString *detailCellText = [[apiMenuItems objectAtIndex:indexPath.row] objectForKey:@"description"];
        UIFont *detailCellFont = [UIFont fontWithName:@"Helvetica" size:12.0];;
        CGSize detailLabelSize = [detailCellText sizeWithFont:detailCellFont 
                                constrainedToSize:constraintSize 
                                    lineBreakMode:UILineBreakModeWordWrap];
        
        return labelSize.height + detailLabelSize.height + 74;
    }
}

// Customize the number of sections in the table view.
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 2;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if (section == 0) {
        return 0;
    } else {
        return [apiMenuItems count];
    }
}

// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UILabel *textLabel;
    UILabel *detailTextLabel;
    UIButton *button;
    
    UIFont *cellFont = [UIFont boldSystemFontOfSize:14.0];
    UIFont *detailCellFont = [UIFont fontWithName:@"Helvetica" size:12.0];
    
    static NSString *CellIdentifier = @"Cell";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        cell.selectionStyle = UITableViewCellSelectionStyleNone;
        
        // Initialize API title UILabel
        textLabel = [[[UILabel alloc] initWithFrame:CGRectZero] autorelease];
        textLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleRightMargin;
        textLabel.tag = TITLE_TAG;
        textLabel.font = cellFont;
        [cell.contentView addSubview:textLabel];
        
        // Initialize API description UILabel
        detailTextLabel = [[[UILabel alloc] initWithFrame:CGRectZero] autorelease];
        detailTextLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleRightMargin;
        detailTextLabel.tag = DESCRIPTION_TAG;
        detailTextLabel.font = detailCellFont;
        detailTextLabel.textColor = [UIColor darkGrayColor];
        detailTextLabel.lineBreakMode = UILineBreakModeWordWrap;
        detailTextLabel.numberOfLines = 0;
        [cell.contentView addSubview:detailTextLabel];
        
        // Initialize API button UIButton
        button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        button.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleRightMargin;
        [button setBackgroundImage:[[UIImage imageNamed:@"MenuButton.png"] 
                                    stretchableImageWithLeftCapWidth:9 topCapHeight:9] 
                          forState:UIControlStateNormal];
        [button setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
        [button addTarget:self action:@selector(apiButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
        [cell.contentView addSubview:button];
    } else {
        textLabel = (UILabel *) [cell.contentView viewWithTag:TITLE_TAG];
        detailTextLabel = (UILabel *) [cell.contentView viewWithTag:DESCRIPTION_TAG];
        // For the button cannot search by tag since it is not constant
        // and is dynamically used figure out which button is clicked.
        // So instead we loop through subviews of the cell to find the button.
        for (UIView *subview in cell.contentView.subviews) {
            if([subview isKindOfClass:[UIButton class]]) {
                button = (UIButton *) subview;
            }
        }
    }
    
    CGSize constraintSize = CGSizeMake(280.0f, MAXFLOAT);
    
    // The API title
    NSString *cellText = [[apiMenuItems objectAtIndex:indexPath.row] objectForKey:@"title"];
    CGSize labelSize = [cellText sizeWithFont:cellFont 
                            constrainedToSize:constraintSize 
                                lineBreakMode:UILineBreakModeWordWrap];
    textLabel.frame = CGRectMake(20, 2, 
                                  (cell.contentView.frame.size.width-40), 
                                  labelSize.height);
    textLabel.text = cellText;
    
    // The API description
    NSString *detailCellText = [[apiMenuItems objectAtIndex:indexPath.row] objectForKey:@"description"];
    CGSize detailLabelSize = [detailCellText sizeWithFont:detailCellFont 
                                        constrainedToSize:constraintSize 
                                            lineBreakMode:UILineBreakModeWordWrap];
    detailTextLabel.frame = CGRectMake(20, (labelSize.height + 4), 
                                       (cell.contentView.frame.size.width-40), 
                                       detailLabelSize.height);
    detailTextLabel.text = detailCellText;

    
    // The API button
    CGFloat yButtonOffset = labelSize.height + detailLabelSize.height + 15;
    button.frame = CGRectMake(20, yButtonOffset, (cell.contentView.frame.size.width-40), 44);
    [button setTitle:[[apiMenuItems objectAtIndex:indexPath.row] objectForKey:@"button"]
            forState:UIControlStateNormal];
    // Set the tag that will later identify the button that is clicked.
    button.tag = indexPath.row;
    
    
    return cell;
}

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

}

#pragma mark - CLLocationManager Delegate Methods
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
    // We will care about horizontal accuracy for this example
    
    // Try and avoid cached measurements
    NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];
    if (locationAge > 5.0) return;
    // test that the horizontal accuracy does not indicate an invalid measurement
    if (newLocation.horizontalAccuracy < 0) return;
    // test the measurement to see if it is more accurate than the previous measurement
    if (mostRecentLocation == nil || mostRecentLocation.horizontalAccuracy > newLocation.horizontalAccuracy) {
        // Store current location
        self.mostRecentLocation = newLocation;
        if (newLocation.horizontalAccuracy <= locationManager.desiredAccuracy) {
            // Measurement is good
            [self processLocationData];
            // we can also cancel our previous performSelector:withObject:afterDelay: - it's no longer necessary
            [NSObject cancelPreviousPerformRequestsWithTarget:self 
                                                     selector:@selector(processLocationData) 
                                                       object:nil];
        }
    }
}

- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    if ([error code] != kCLErrorLocationUnknown) {
        [locationManager stopUpdatingLocation];
        locationManager.delegate = nil;
    }
    [self hideActivityIndicator];
}

#pragma mark - FBRequestDelegate Methods
/**
 * Called when the Facebook API request has returned a response. This callback
 * gives you access to the raw response. It's called before
 * (void)request:(FBRequest *)request didLoad:(id)result,
 * which is passed the parsed response object.
 */
- (void)request:(FBRequest *)request didReceiveResponse:(NSURLResponse *)response {
    //NSLog(@"received response");
}

/**
 * Called when a request returns and its response has been parsed into
 * an object. The resulting object may be a dictionary, an array, a string,
 * or a number, depending on the format of the API response. If you need access
 * to the raw response, use:
 *
 * (void)request:(FBRequest *)request
 *      didReceiveResponse:(NSURLResponse *)response
 */
- (void)request:(FBRequest *)request didLoad:(id)result {
    [self hideActivityIndicator];
    if ([result isKindOfClass:[NSArray class]] && ([result count] > 0)) {
        result = [result objectAtIndex:0];
    }
    switch (currentAPICall) {
        case kAPIGraphUserPermissionsDelete:
        {
            [self showMessage:@"User uninstalled app"];
            HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
            // Nil out the session variables to prevent
            // the app from thinking there is a valid session
            [delegate facebook].accessToken = nil;
            [delegate facebook].expirationDate = nil;
            [self backToMain];
            break;
        }
        case kAPIFriendsForDialogFeed:
        {
            NSArray *resultData = [result objectForKey:@"data"];
            // Check that the user has friends
            if ([resultData count] > 0) {
                // Pick a random friend to post the feed to
                int randomNumber = arc4random() % [resultData count];
                [self apiDialogFeedFriend:[[resultData objectAtIndex:randomNumber] objectForKey:@"id"]];
            } else {
                [self showMessage:@"You do not have any friends to post to."];
            }
            break;
        }
        case kAPIGetAppUsersFriendsNotUsing:
        {
            // Save friend results
            [savedAPIResult release];
            savedAPIResult = nil;
            // Many results
            if ([result isKindOfClass:[NSArray class]]) {
                savedAPIResult = [[NSMutableArray alloc] initWithArray:result copyItems:YES];
            } else if ([result isKindOfClass:[NSDecimalNumber class]]) {
                savedAPIResult = [[NSMutableArray alloc] initWithObjects:[result stringValue], nil];
            }
            
            // Set up to get friends
            currentAPICall = kAPIFriendsForDialogRequests;
            [self apiGraphFriends];
            break;
        }
        case kAPIGetAppUsersFriendsUsing:
        {
            NSMutableArray *friendsWithApp = [[NSMutableArray alloc] initWithCapacity:1];
            // Many results
            if ([result isKindOfClass:[NSArray class]]) {
                friendsWithApp = [[NSMutableArray alloc] initWithArray:result copyItems:YES];
            } else if ([result isKindOfClass:[NSDecimalNumber class]]) {
                friendsWithApp = [[NSMutableArray alloc] initWithObjects:[result stringValue], nil];
            }
            if ([friendsWithApp count] > 0) {
                [self apiDialogRequestsSendToUsers:friendsWithApp];
            } else {
                [self showMessage:@"None of your friends are using the app."];
            }
            [friendsWithApp release];
            break;
        }
        case kAPIFriendsForDialogRequests:
        {
            NSArray *resultData = [result objectForKey:@"data"];
            if ([resultData count] == 0) {
                [self showMessage:@"You have no friends to select."];
            } else {
                NSMutableArray *friendsWithoutApp = [[NSMutableArray alloc] initWithCapacity:1];
                // Loop through friends and find those who do not have the app
                for (NSDictionary *friendObject in resultData) {
                    BOOL foundFriend = NO;
                    for (NSString *friendWithApp in savedAPIResult) {
                        if ([[friendObject objectForKey:@"id"] isEqualToString:friendWithApp]) {
                            foundFriend = YES;
                            break;
                        }
                    }
                    if (!foundFriend) {
                        [friendsWithoutApp addObject:[friendObject objectForKey:@"id"]];
                    }
                }
                if ([friendsWithoutApp count] > 0) {
                    [self apiDialogRequestsSendToNonUsers:friendsWithoutApp];
                } else {
                    [self showMessage:@"All your friends are using the app."];
                }
                [friendsWithoutApp release];
            }
            break;
        }
        case kAPIFriendsForTargetDialogRequests:
        {
            NSArray *resultData = [result objectForKey:@"data"];
            if ([resultData count] > 0) {
                [self apiDialogRequestsSendTarget:[[resultData objectAtIndex:0] objectForKey:@"id"]];
            } else {
                [self showMessage:@"You have no friends to select."];
            }
            break;
        }
        case kAPIGraphMe:
        {
            NSString *nameID = [[NSString alloc] initWithFormat:@"%@ (%@)", [result objectForKey:@"name"], [result objectForKey:@"id"]];
            NSMutableArray *userData = [[NSMutableArray alloc] initWithObjects:
                                        [NSDictionary dictionaryWithObjectsAndKeys:
                                         [result objectForKey:@"id"], @"id", 
                                         nameID, @"name", 
                                         [result objectForKey:@"picture"], @"details", 
                                         nil], nil];
            // Show the basic user information in a new view controller
            APIResultsViewController *controller = [[APIResultsViewController alloc] 
                                                initWithTitle:@"Your Information" 
                                                data:userData 
                                                action:@""];
            [self.navigationController pushViewController:controller animated:YES];
            [controller release];
            [userData release];
            [nameID release];
            break;
        }
        case kAPIGraphUserFriends:
        {
            NSMutableArray *friends = [[NSMutableArray alloc] initWithCapacity:1];
            NSArray *resultData = [result objectForKey:@"data"];
            if ([resultData count] > 0) {
                for (NSUInteger i=0; i<[resultData count] && i < 25; i++) {
                    [friends addObject:[resultData objectAtIndex:i]];
                }
                // Show the friend information in a new view controller
                APIResultsViewController *controller = [[APIResultsViewController alloc] 
                                                        initWithTitle:@"Friends" 
                                                        data:friends action:@""];
                [self.navigationController pushViewController:controller animated:YES];
                [controller release];
            } else {
                [self showMessage:@"You have no friends."];
            }
            [friends release];
            break;
        }
        case kAPIGraphUserCheckins:
        {
            NSMutableArray *places = [[NSMutableArray alloc] initWithCapacity:1];
            NSArray *resultData = [result objectForKey:@"data"];
            for (NSUInteger i=0; i<[resultData count] && i < 5; i++) {
                NSString *placeID = [[[resultData objectAtIndex:i] objectForKey:@"place"] objectForKey:@"id"];
                NSString *placeName = [[[resultData objectAtIndex:i] objectForKey:@"place"] objectForKey:@"name"];
                NSString *checkinMessage = [[resultData objectAtIndex:i] objectForKey:@"message"] ? 
                    [[resultData objectAtIndex:i] objectForKey:@"message"] : @"";
                [places addObject:[NSDictionary dictionaryWithObjectsAndKeys:
                                   placeID,@"id", 
                                   placeName,@"name",
                                   checkinMessage,@"details",
                                   nil]];
            }
            // Show the user's recent check-ins a new view controller
            APIResultsViewController *controller = [[APIResultsViewController alloc] 
                                                initWithTitle:@"Recent Check-ins" 
                                                data:places 
                                                action:@"recentcheckins"];
            [self.navigationController pushViewController:controller animated:YES];
            [controller release];
            [places release];
            break;
        }
        case kAPIGraphSearchPlace:
        {
            NSMutableArray *places = [[NSMutableArray alloc] initWithCapacity:1];
            NSArray *resultData = [result objectForKey:@"data"];
            for (NSUInteger i=0; i<[resultData count] && i < 5; i++) {
                [places addObject:[resultData objectAtIndex:i]];
            }
            // Show the places nearby in a new view controller
            APIResultsViewController *controller = [[APIResultsViewController alloc] 
                                                initWithTitle:@"Nearby" 
                                                data:places 
                                                action:@"places"];
            [self.navigationController pushViewController:controller animated:YES];
            [controller release];
            [places release];
            break;
        }
        case kAPIGraphUserPhotosPost:
        {
            [self showMessage:@"Photo uploaded successfully."];
            break;
        }
        case kAPIGraphUserVideosPost:
        {
            [self showMessage:@"Video uploaded successfully."];
            break;
        }
        default:
            break;
    }
}

/**
 * Called when an error prevents the Facebook API request from completing
 * successfully.
 */
- (void)request:(FBRequest *)request didFailWithError:(NSError *)error {
    [self hideActivityIndicator];
    NSLog(@"Error message: %@", [[error userInfo] objectForKey:@"error_msg"]);
    [self showMessage:@"Oops, something went haywire."];
}

#pragma mark - FBDialogDelegate Methods

/**
 * Called when a UIServer Dialog successfully return. Using this callback
 * instead of dialogDidComplete: to properly handle successful shares/sends
 * that return ID data back.
 */
- (void)dialogCompleteWithUrl:(NSURL *)url {
    if (![url query]) {
        NSLog(@"User canceled dialog or there was an error");
        return;
    }
    
    NSDictionary *params = [self parseURLParams:[url query]];
    switch (currentAPICall) {
        case kDialogFeedUser:
        case kDialogFeedFriend:
        {
            // Successful posts return a post_id
            if ([params valueForKey:@"post_id"]) {
                [self showMessage:@"Published feed successfully."];
                NSLog(@"Feed post ID: %@", [params valueForKey:@"post_id"]);
            }
            break;
        }
        case kDialogRequestsSendToMany:
        case kDialogRequestsSendToSelect:
        case kDialogRequestsSendToTarget:
        {
            // Successful requests return one or more request_ids.
            // Get any request IDs, will be in the URL in the form
            // request_ids[0]=1001316103543&request_ids[1]=10100303657380180
            NSMutableArray *requestIDs = [[NSMutableArray alloc] init];
            for (NSString *paramKey in params) {
                if ([paramKey hasPrefix:@"request_ids"]) {
                    [requestIDs addObject:[params objectForKey:paramKey]];
                }
            }
            if ([requestIDs count] > 0) {
                [self showMessage:@"Sent request successfully."];
                NSLog(@"Request ID(s): %@", requestIDs);
            }
            break;
        }
        default:
            break;
    }
}

- (void) dialogDidNotComplete:(FBDialog *)dialog {
    NSLog(@"Dialog dismissed.");
}

- (void)dialog:(FBDialog*)dialog didFailWithError:(NSError *)error {
    NSLog(@"Error message: %@", [[error userInfo] objectForKey:@"error_msg"]);
    [self showMessage:@"Oops, something went haywire."];
}

#pragma mark - FBSessionDelegate Methods
/**
 * Called when the user has logged in successfully.
 */
- (void)fbDidLogin {
    HackbookAppDelegate *delegate = (HackbookAppDelegate *) [[UIApplication sharedApplication] delegate];
    
    // Save updated authorization information
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults setObject:[[delegate facebook] accessToken] forKey:@"FBAccessTokenKey"];
    [defaults setObject:[[delegate facebook] expirationDate] forKey:@"FBExpirationDateKey"];
    [defaults synchronize];
    
    // After permissions granted follow up with next API call
    switch (currentAPICall) {
        case kDialogPermissionsCheckinForRecent:
        {
            // After the check-in permissions have been
            // granted, save them in app session then
            // retrieve recent check-ins
            [self updateCheckinPermissions];
            [self apiGraphUserCheckins];
            break;
        }
        case kDialogPermissionsCheckinForPlaces:
        {
            // After the check-in permissions have been
            // granted, save them in app session then
            // get nearby locations
            [self updateCheckinPermissions];
            [self getNearby];
            break;
        } 
        case kDialogPermissionsExtended:
        {
            // In the sample test for getting user_likes
            // permssions, echo that success.
            [self showMessage:@"Permissions granted."];
            break;
        }
        default:
            break;
    }
}

/**
 * Called when the user canceled the authorization dialog.
 */
-(void)fbDidNotLogin:(BOOL)cancelled {
    NSLog(@"did not login");
    [self showMessage:@"Extended permissions not granted."];
}

/**
 * Called when the request logout has succeeded.
 */
- (void)fbDidLogout {
    // Go back to main menu
    [self backToMain];
}


@end