/*

 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) NSMutableDictionary *internalChildren;

@end

#pragma mark -

@implementation FileSystemNode

@dynamic displayName, children, isDirectory, icon, labelColor;

- (instancetype)init {

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

    return [self init];

}

- (id)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]];

}

- (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;

}

- (NSArray *)children {

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

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

        NSMutableDictionary *newChildren = [NSMutableDictionary new];

        NSString *parentPath = [self.URL path];

        NSArray *contentsAtPath = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:parentPath error:nil];

        if (contentsAtPath) {   // We don't deal with the error

            for (NSString *filename in contentsAtPath) {

                // Use the filename as a key and see if it was around and reuse it, if possible

                if (self.internalChildren != nil) {

                    FileSystemNode *oldChild = [self.internalChildren objectForKey:filename];

                    if (oldChild != nil) {

                    [newChildren setObject:oldChild forKey:filename];

                    continue;

                    }

                }

                // We didn't find it, add a new one

                NSString *fullPath = [parentPath stringByAppendingPathComponent:filename];

                NSURL *childURL = [NSURL fileURLWithPath:fullPath];

                if (childURL != nil) {

                    // Wrap the child url with our node

                    FileSystemNode *node = [[FileSystemNode alloc] initWithURL:childURL];

                    [newChildren setObject:node forKey:filename];

                }

            }

        }

        self.internalChildren = newChildren;

        self.childrenDirty = NO;

    }

    NSArray *result = [self.internalChildren allValues];

    // Sort the children by the display name and return it

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

        NSString *objName = [obj1 displayName];

        NSString *obj2Name = [obj2 displayName];

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

        return sortedResult;

    }];

    return result;

}

- (void)invalidateChildren {

    _childrenDirty = YES;

    for (FileSystemNode *child in [self.internalChildren allValues]) {

        [child invalidateChildren];

    }

}

@end