//
//  MPFunctionLayout.m
//  MathPad
//
//  Created by Kim Wittenburg on 22.04.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

#import "MPFunctionLayout.h"
#import "MPExpressionLayout.h"
#import "MPExpressionStorage.h"
#import "MPFunction.h"

#import "MPSumFunction.h"
#import "MPSumFunctionLayout.h"

@implementation MPFunctionLayout

#pragma mark Creation Methods

+ (instancetype)functionLayoutForFunctionAtIndexPath:(NSIndexPath *)functionPath
                                              parent:(MPExpressionLayout *)parent
{
    MPFunction *function = [parent.expressionStorage symbolAtIndexPath:functionPath];
    Class class = [function class];
    if (class == [MPSumFunction class]) {
        return [[MPSumFunctionLayout alloc] initWithFunctionPath:functionPath parent:parent];
    }
    return nil;
}

- (id)initWithFunctionPath:(NSIndexPath *)functionPath
                    parent:(MPExpressionLayout *)parent
{
    self = [super init];
    if (self) {
        _functionPath = functionPath;
        _parent = parent;
        _childCache = [[NSMutableArray alloc] init];
    }
    return self;
}

#pragma mark Properties

- (MPExpressionStorage *)expressionStorage
{
    return self.parent.expressionStorage;
}

- (MPFunction *)function
{
    return [self.expressionStorage symbolAtIndexPath:self.functionPath];
}

- (NSLayoutManager *)layoutManager
{
    return self.expressionStorage.layoutManager;
}

- (NSTextContainer *)textContainer
{
    return self.expressionStorage.textContainer;
}

- (NSTextStorage *)textStorage
{
    return self.expressionStorage.textStorage;
}

#pragma mark Cache Methods

- (void)invalidate
{
    _valid = NO;
}

- (BOOL)hasCacheForChildAtIndex:(NSUInteger)index
{
    if (index >= _childCache.count) {
        return NO;
    }
    return _childCache[index] != [NSNull null];
}

- (MPExpressionLayout *)expressionLayoutForChildAtIndex:(NSUInteger)index
{
    if ([self hasCacheForChildAtIndex:index]) {
        return _childCache[index];
    }
    while (index >= _childCache.count) {
        [_childCache addObject:[NSNull null]];
    }
    MPExpressionLayout *expressionLayout = [[MPExpressionLayout alloc] initWithExpressionPath:[self.functionPath indexPathByAddingIndex:index] parent:self];
    _childCache[index] = expressionLayout;
    return expressionLayout;
}

#pragma mark Size Calculation Methods

- (NSSize)sizeOfFunction
{
    if (!_valid) {
        _cachedSize = [self calculateSize];
        _valid = YES;
    }
    return _cachedSize;
}

- (NSSize)calculateSize
{
    return NSMakeSize(0, 0);
}

#pragma mark Drawing Methods

- (void)drawFunctionAtPoint:(NSPoint)point
{
}

@end