/*

     File: FileSystemItem.m

 Abstract:  The data source backend for displaying the file system.

 This object can be improved a great deal; it never frees nodes that are expanded; it also is not too lazy when it comes to computing the children (when the number of children at a level are asked for, it computes the children array).

  Version: 1.2

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 */

#import "FileSystemItem.h"

@implementation FileSystemItem

static FileSystemItem *rootItem = nil;

#define IsALeafNode ((id)-1)

- (id)initWithPath:(NSString *)path parent:(FileSystemItem *)obj {

    if (self = [super init]) {

        relativePath = [[path lastPathComponent] copy];

        parent = obj;

    }

    return self;

}

+ (FileSystemItem *)rootItem {

   if (rootItem == nil) rootItem = [[FileSystemItem alloc] initWithPath:@"/" parent:nil];

   return rootItem;       

}

- (void)dealloc {

    if (children != IsALeafNode) [children release];

    [relativePath release];

    [super dealloc];

}

// Creates and returns the array of children

// Loads children incrementally

//

- (NSArray *)children {

    if (children == NULL) {

        NSFileManager *fileManager = [NSFileManager defaultManager];

        NSString *fullPath = [self fullPath];

        BOOL isDir, valid = [fileManager fileExistsAtPath:fullPath isDirectory:&isDir];

        if (valid && isDir) {

        NSArray *array = [fileManager contentsOfDirectoryAtPath:fullPath error:NULL];

        if (!array) {   // This is unexpected

        children = [[NSMutableArray alloc] init];

        } else {

        NSInteger cnt, numChildren = [array count];

        children = [[NSMutableArray alloc] initWithCapacity:numChildren];

        for (cnt = 0; cnt < numChildren; cnt++) {

            FileSystemItem *item = [[FileSystemItem alloc] initWithPath:[array objectAtIndex:cnt] parent:self];

            [children addObject:item];

            [item release];

        }

        }

        } else {

            children = IsALeafNode;

        }

    }

    return children;

}

- (NSString *)relativePath {

    return relativePath;

}

- (NSString *)fullPath {

    return parent ? [[parent fullPath] stringByAppendingPathComponent:relativePath] : relativePath;

}

- (FileSystemItem *)childAtIndex:(NSInteger)n {

    return [[self children] objectAtIndex:n];

}

- (NSInteger)numberOfChildren {

    id tmp = [self children];

    return (tmp == IsALeafNode) ? (-1) : [tmp count];

}

@end