#import "Mapbox.h"

#import "MBXOfflinePacksTableViewController.h"


static NSString * const MBXOfflinePackContextNameKey = @"Name";

static NSString * const MBXOfflinePacksTableViewInactiveCellReuseIdentifier = @"Inactive";
static NSString * const MBXOfflinePacksTableViewActiveCellReuseIdentifier = @"Active";

@implementation MLNOfflinePack (MBXAdditions)

- (NSString *)name {
    NSDictionary *userInfo = [NSKeyedUnarchiver unarchiveObjectWithData:self.context];
    NSAssert([userInfo isKindOfClass:[NSDictionary class]], @"Context of offline pack isn’t a dictionary.");
    NSString *name = userInfo[MBXOfflinePackContextNameKey];
    NSAssert([name isKindOfClass:[NSString class]], @"Name of offline pack isn’t a string.");
    return name;
}

@end

@implementation MLNTilePyramidOfflineRegion (MBXAdditions)

- (void)applyToMapView:(MLNMapView *)mapView {
    mapView.styleURL = self.styleURL;
    [mapView setVisibleCoordinateBounds:self.bounds];
    mapView.zoomLevel = MIN(self.maximumZoomLevel, MAX(self.minimumZoomLevel, mapView.zoomLevel));
}

@end

@implementation MBXOfflinePacksTableViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    [[MLNOfflineStorage sharedOfflineStorage] addObserver:self forKeyPath:@"packs" options:NSKeyValueObservingOptionInitial context:NULL];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(offlinePackProgressDidChange:) name:MLNOfflinePackProgressChangedNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(offlinePackDidReceiveError:) name:MLNOfflinePackErrorNotification object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(offlinePackDidReceiveMaximumAllowedMapboxTiles:) name:MLNOfflinePackMaximumMapboxTilesReachedNotification object:nil];
}

- (void)dealloc {
    [[MLNOfflineStorage sharedOfflineStorage] removeObserver:self forKeyPath:@"packs"];
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary<NSString *, id> *)change context:(void *)context {
    if ([keyPath isEqualToString:@"packs"]) {
        NSKeyValueChange changeKind = [change[NSKeyValueChangeKindKey] unsignedIntegerValue];
        NSIndexSet *indices = change[NSKeyValueChangeIndexesKey];
        NSMutableArray *indexPaths;
        if (indices) {
            indexPaths = [NSMutableArray arrayWithCapacity:indices.count];
            [indices enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL * _Nonnull stop) {
                [indexPaths addObject:[NSIndexPath indexPathForRow:idx inSection:0]];
            }];
        }
        switch (changeKind) {
            case NSKeyValueChangeInsertion:
                [self.tableView insertRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationAutomatic];
                break;

            case NSKeyValueChangeRemoval:
                [self.tableView deleteRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationAutomatic];
                break;

            case NSKeyValueChangeReplacement:
                [self.tableView reloadRowsAtIndexPaths:indexPaths withRowAnimation:UITableViewRowAnimationAutomatic];
                break;

            default:
                [self.tableView reloadData];

                for (MLNOfflinePack *pack in [MLNOfflineStorage sharedOfflineStorage].packs) {
                    if (pack.state == MLNOfflinePackStateUnknown) {
                        [pack requestProgress];
                    }
                }

                break;
        }
    } else {
        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
    }
}

- (IBAction)addCurrentRegion:(id)sender {
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Add Offline Pack" message:@"Choose a name for the pack:" preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField * _Nonnull textField) {
        textField.placeholder = [NSString stringWithFormat:@"%@", MLNStringFromCoordinateBounds(self.mapView.visibleCoordinateBounds)];
    }];
    [alertController addAction:[UIAlertAction actionWithTitle:@"Cancel" style:UIAlertActionStyleCancel handler:nil]];

    UIAlertAction *downloadAction = [UIAlertAction actionWithTitle:@"Download" style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
        MLNMapView *mapView = self.mapView;
        NSAssert(mapView, @"No map view to get the current region from.");

        UITextField *nameField = alertController.textFields.firstObject;
        NSString *name = nameField.text;
        if (!name.length) {
            name = nameField.placeholder;
        }

        MLNTilePyramidOfflineRegion *region = [[MLNTilePyramidOfflineRegion alloc] initWithStyleURL:mapView.styleURL bounds:mapView.visibleCoordinateBounds fromZoomLevel:mapView.zoomLevel toZoomLevel:mapView.maximumZoomLevel];
        id ideographicFontFamilyName = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"MLNIdeographicFontFamilyName"];
        if([ideographicFontFamilyName isKindOfClass:[NSNumber class]] && ![ideographicFontFamilyName boolValue]){
            region.includesIdeographicGlyphs = YES;
        }
        NSData *context = [NSKeyedArchiver archivedDataWithRootObject:@{
            MBXOfflinePackContextNameKey: name,
        }];

        [[MLNOfflineStorage sharedOfflineStorage] addPackForRegion:region withContext:context completionHandler:^(MLNOfflinePack *pack, NSError *error) {
            if (error) {
                NSString *message = [NSString stringWithFormat:@"Mapbox GL was unable to add the offline pack “%@”.", name];
                UIAlertController *errorAlertController = [UIAlertController alertControllerWithTitle:@"Can’t Add Offline Pack" message:message preferredStyle:UIAlertControllerStyleAlert];
                [errorAlertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
                [self presentViewController:errorAlertController animated:YES completion:nil];
            } else {
                [pack resume];
            }
        }];
    }];
    [alertController addAction:downloadAction];
    alertController.preferredAction = downloadAction;

    [self presentViewController:alertController animated:YES completion:nil];
}

- (IBAction)invalidatePacks:(id)sender {
    for (MLNOfflinePack *pack in [MLNOfflineStorage sharedOfflineStorage].packs) {

        CFTimeInterval start = CACurrentMediaTime();
        [[MLNOfflineStorage sharedOfflineStorage] invalidatePack:pack withCompletionHandler:^(NSError * _Nullable error) {
            CFTimeInterval end = CACurrentMediaTime();
            CFTimeInterval difference = end - start;
            NSLog(@"invalidatePack Started: %f Ended: %f Total Time: %f", start, end, difference);
        }];
    }
}


// MARK: - Table view data source

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    return [MLNOfflineStorage sharedOfflineStorage].packs.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    MLNOfflinePack *pack = [MLNOfflineStorage sharedOfflineStorage].packs[indexPath.row];

    NSString *reuseIdentifier = pack.state == MLNOfflinePackStateActive ? MBXOfflinePacksTableViewActiveCellReuseIdentifier : MBXOfflinePacksTableViewInactiveCellReuseIdentifier;
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifier forIndexPath:indexPath];
    [self updateTableViewCell:cell atIndexPath:indexPath forPack:pack];

    return cell;
}

- (void)updateTableViewCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath forPack:(MLNOfflinePack *)pack {
    cell.textLabel.text = pack.name;
    MLNOfflinePackProgress progress = pack.progress;
    NSString *completedString = [NSNumberFormatter localizedStringFromNumber:@(progress.countOfResourcesCompleted)
                                                                 numberStyle:NSNumberFormatterDecimalStyle];
    NSString *expectedString = [NSNumberFormatter localizedStringFromNumber:@(progress.countOfResourcesExpected)
                                                                numberStyle:NSNumberFormatterDecimalStyle];
    NSString *byteCountString = [NSByteCountFormatter stringFromByteCount:progress.countOfBytesCompleted
                                                               countStyle:NSByteCountFormatterCountStyleFile];
    NSString *statusString;
    switch (pack.state) {
        case MLNOfflinePackStateUnknown:
            statusString = @"Calculating progress…";
            break;

        case MLNOfflinePackStateInactive:
            statusString = [NSString stringWithFormat:@"%@ of %@ resources (%@)",
                            completedString, expectedString, byteCountString];
            break;

        case MLNOfflinePackStateComplete:
            statusString = [NSString stringWithFormat:@"%@ resources (%@)",
                            completedString, byteCountString];
            break;

        case MLNOfflinePackStateActive:
            if (progress.countOfResourcesExpected) {
                completedString = [NSNumberFormatter localizedStringFromNumber:@(progress.countOfResourcesCompleted + 1)
                                                                   numberStyle:NSNumberFormatterDecimalStyle];
            }
            if (progress.maximumResourcesExpected > progress.countOfResourcesExpected) {
                expectedString = [NSString stringWithFormat:@"at least %@", expectedString];
            }
            statusString = [NSString stringWithFormat:@"Downloading %@ of %@ resources (%@ so far)…",
                            completedString, expectedString, byteCountString];
            break;

        case MLNOfflinePackStateInvalid:
            NSAssert(NO, @"Invalid offline pack at index path %@", indexPath);
            break;
    }
    cell.detailTextLabel.text = statusString;
}

- (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath {
    if (editingStyle == UITableViewCellEditingStyleDelete) {
        MLNOfflinePack *pack = [MLNOfflineStorage sharedOfflineStorage].packs[indexPath.row];
        [[MLNOfflineStorage sharedOfflineStorage] removePack:pack withCompletionHandler:nil];
    }
}

// MARK: - Table view delegate

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

    MLNOfflinePack *pack = [MLNOfflineStorage sharedOfflineStorage].packs[indexPath.row];
    switch (pack.state) {
        case MLNOfflinePackStateUnknown:
            break;

        case MLNOfflinePackStateComplete:
            if ([pack.region respondsToSelector:@selector(applyToMapView:)]) {
                [pack.region performSelector:@selector(applyToMapView:) withObject:self.mapView];
            }
            [self performSegueWithIdentifier:@"ReturnToMap" sender:self];
            break;

        case MLNOfflinePackStateInactive:
            [pack resume];
            break;

        case MLNOfflinePackStateActive:
            [pack suspend];
            break;

        case MLNOfflinePackStateInvalid:
            NSAssert(NO, @"Invalid offline pack at index path %@", indexPath);
            break;
    }
}

// MARK: - Offline pack delegate

- (void)offlinePackProgressDidChange:(NSNotification *)notification {
    MLNOfflinePack *pack = notification.object;
    NSAssert([pack isKindOfClass:[MLNOfflinePack class]], @"MLNOfflineStorage notification has a non-pack object.");

    NSUInteger index = [[MLNOfflineStorage sharedOfflineStorage].packs indexOfObject:pack];
    if (index == NSNotFound) {
        return;
    }

    NSIndexPath *indexPath = [NSIndexPath indexPathForRow:index inSection:0];
    UITableViewCell *cell = [self.tableView cellForRowAtIndexPath:indexPath];
    [self updateTableViewCell:cell atIndexPath:indexPath forPack:pack];
}

- (void)offlinePackDidReceiveError:(NSNotification *)notification {
    MLNOfflinePack *pack = notification.object;
    NSAssert([pack isKindOfClass:[MLNOfflinePack class]], @"MLNOfflineStorage notification has a non-pack object.");

    NSError *error = notification.userInfo[MLNOfflinePackUserInfoKeyError];
    NSAssert([error isKindOfClass:[NSError class]], @"MLNOfflineStorage notification has a non-error error.");

    NSString *message = [NSString stringWithFormat:@"Mapbox GL encountered an error while downloading the offline pack “%@”: %@", pack.name, error.localizedFailureReason];
    if (error.code == MLNErrorCodeConnectionFailed) {
        NSLog(@"%@", message);
    } else {
        UIAlertController *alertController = [UIAlertController alertControllerWithTitle:@"Error Downloading Offline Pack" message:message preferredStyle:UIAlertControllerStyleAlert];
        [alertController addAction:[UIAlertAction actionWithTitle:@"OK" style:UIAlertActionStyleDefault handler:nil]];
        [self presentViewController:alertController animated:YES completion:nil];
    }
}

- (void)offlinePackDidReceiveMaximumAllowedMapboxTiles:(NSNotification *)notification {
    MLNOfflinePack *pack = notification.object;
    NSAssert([pack isKindOfClass:[MLNOfflinePack class]], @"MLNOfflineStorage notification has a non-pack object.");

    uint64_t maximumCount = [notification.userInfo[MLNOfflinePackUserInfoKeyMaximumCount] unsignedLongLongValue];
    NSLog(@"Offline pack “%@” reached limit of %llu tiles.", pack.name, maximumCount);
}

@end