/*

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

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 An abstract wrapper node around the file system.

 */

#import "FileSystemNode.h"

@interface FileSystemNode ()

@property (strong) NSURL *URL;

@property (assign) BOOL childrenDirty;

@property (strong) NSArray *internalChildren;

@end

#pragma mark -

@implementation FileSystemNode

@dynamic displayName, children, isDirectory, icon, labelColor, documentKind, size, formattedFileSize, creationDate, modificationDate, lastOpened;

- (instancetype)init {

    NSAssert(NO, @"Invalid use of init; use initWithURL to create FileSystemNode");

    return [self init];

}

- (instancetype)initWithURL:(NSURL *)url {

    self = [super init];

    if (self != nil) {

        _URL = url;

    }

    return self;

}

- (NSString *)description {

    return [NSString stringWithFormat:@"%@ - %@", super.description, self.URL];

}

- (NSString *)displayName {

    NSString *displayName = @"";

    NSError *error = nil;

    BOOL success = [self.URL getResourceValue:&displayName forKey:NSURLLocalizedNameKey error:&error];

    // if we got a no value for the localized name, we will try the non-localized name

    if (success && displayName.length > 0) {

        [self.URL getResourceValue:&displayName forKey:NSURLNameKey error:&error];

    }

    else {

        // can't find resource value for the display name, use the localizedDescription as last resort

        return error.localizedDescription;

    }

    return displayName;

}

- (NSImage *)icon {

    return [[NSWorkspace sharedWorkspace] iconForFile:(self.URL).path];

}

- (NSString *)documentKind {

    NSString *kindStr;

    [self.URL getResourceValue:&kindStr forKey:NSURLLocalizedTypeDescriptionKey error:nil];

    return kindStr;

}

- (NSDate *)creationDate {

    NSDate *dateValue;

    [self.URL getResourceValue:&dateValue forKey:NSURLCreationDateKey error:nil];

    return dateValue;

}

- (NSDate *)modificationDate {

    NSDate *dateValue;

    [self.URL getResourceValue:&dateValue forKey:NSURLContentModificationDateKey error:nil];

    return dateValue;

}

- (NSDate *)lastOpened {

    MDItemRef itemRef = MDItemCreateWithURL(nil, (CFURLRef)self.URL);

    NSDate *lastOpenedDate = CFBridgingRelease(MDItemCopyAttribute(itemRef, kMDItemLastUsedDate));

    CFRelease(itemRef);

    return lastOpenedDate;

}

- (NSUInteger)size {

    NSNumber *sizeValue;

    [self.URL getResourceValue:&sizeValue forKey:NSURLFileSizeKey error:nil];

    return [sizeValue unsignedIntegerValue];

}

- (NSString *)formattedFileSize {

    NSString *sizeStr;

    sizeStr = [NSByteCountFormatter stringFromByteCount:[self size] countStyle:NSByteCountFormatterCountStyleFile];

    return sizeStr;

}

- (BOOL)isDirectory {

    id value = nil;

    [self.URL getResourceValue:&value forKey:NSURLIsDirectoryKey error:nil];

    return [value boolValue];

}

- (BOOL)isPackage {

    id value = nil;

    [self.URL getResourceValue:&value forKey:NSURLIsPackageKey error:nil];

    return [value boolValue];

}

- (NSColor *)labelColor {

    id value = nil;

    [self.URL getResourceValue:&value forKey:NSURLLabelColorKey error:nil];

    return value;

}

// We are equal if we represent the same URL. This allows children to reuse the same instances.

//

- (BOOL)isEqual:(id)object {

    if ([object isKindOfClass:[FileSystemNode class]]) {

        FileSystemNode *other = (FileSystemNode *)object;

        return [other.URL isEqual:self.URL];

    } else {

        return NO;

    }

}

- (NSUInteger)hash {

    return self.URL.hash;

}

- (NSArray *)children {

    if (self.internalChildren == nil || self.childrenDirty) {

        // This logic keeps the same pointers around, if possible.

        NSMutableArray *newChildren = [NSMutableArray array];

        CFURLEnumeratorRef enumerator = CFURLEnumeratorCreateForDirectoryURL(NULL, (CFURLRef)self.URL, kCFURLEnumeratorSkipInvisibles, (CFArrayRef)[NSArray array]);

        CFURLRef childURL = nil;

        CFURLEnumeratorResult enumeratorResult;

        do {

                enumeratorResult = CFURLEnumeratorGetNextURL(enumerator, &childURL, NULL);

                if (enumeratorResult == kCFURLEnumeratorSuccess) {

                    FileSystemNode *node = [[FileSystemNode alloc] initWithURL:(__bridge NSURL *)childURL];

                    if (self.internalChildren != nil) {

                        NSInteger oldIndex = [self.internalChildren indexOfObject:(__bridge NSURL *)childURL];

                        if (oldIndex != NSNotFound) {

                            // Use the same pointer value, if possible

                            node = (self.internalChildren)[oldIndex];

                        }

                    }

                    [newChildren addObject:node];

                } else if (enumeratorResult == kCFURLEnumeratorError) {

                    // A possible enhancement would be to present error-based items to the user.

                }

        } while (enumeratorResult != kCFURLEnumeratorEnd);

        CFRelease(enumerator);

        _childrenDirty = NO;

        // Now sort them

        _internalChildren = [newChildren sortedArrayUsingComparator:^(id obj1, id obj2) {

            NSString *objName = [obj1 displayName];

            NSString *obj2Name = [obj2 displayName];

            NSComparisonResult result = [objName compare:obj2Name options:NSNumericSearch | NSCaseInsensitiveSearch | NSWidthInsensitiveSearch | NSForcedOrderingSearch range:NSMakeRange(0, objName.length) locale:[NSLocale currentLocale]];

            return result;

        }];

    }

    return self.internalChildren;

}

- (void)invalidateChildren {

    _childrenDirty = YES;

    for (FileSystemNode *child in self.internalChildren) {

        [child invalidateChildren];

    }

}

@end