//
//  MPFunctionLayout.m
//  MathPad
//
//  Created by Kim Wittenburg on 07.08.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

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

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

@implementation MPFunctionLayout

#pragma mark Creation Methods
+ (MPFunctionLayout *)functionLayoutForFunction:(MPFunction *)function
                                         parent:(MPExpressionLayout *)parent
{
    Class class = [function class];
    if (class == [MPSumFunction class]) {
        return [[MPSumFunctionLayout alloc] initWithFunction:function parent:parent];
    }
    return [[self alloc] initWithFunction:function
                                   parent:parent];
}

- (instancetype)initWithFunction:(MPFunction *)function
                          parent:(MPExpressionLayout *)parent
{
    self = [super initWithParent:parent];
    if (self) {
        _function = function;
    }
    return self;
}

#pragma mark Cache Methods
- (CTLineRef)lineForPrivateCacheIndex:(NSUInteger)index
                            generator:(CTLineRef (^)())generator
{
    NSUInteger actualIndex = self.function.numberOfChildren + index;
    id (^actualGenerator)() = ^{
        CTLineRef line = generator();
        return CFBridgingRelease(line);
    };
    id lineObject = [self cachableObjectForIndex:actualIndex
                                       generator:actualGenerator];
    return (__bridge CTLineRef)(lineObject);
}

- (MPLayout *)childLayoutAtIndex:(NSUInteger)index
{
    return [self cachableObjectForIndex:index generator:^id{
        MPExpression *child = [self.function childAtIndex:index];
        MPExpressionLayout *layout = [[MPExpressionLayout alloc] initWithExpression:child
                                                                             parent:self];
        layout.flipped = self.flipped;
        layout.usesSmallSize = (index == 0 || index == 1) ? YES : self.usesSmallSize;
        return layout;
    }];
}

- (NSUInteger)indexOfChildBeforeChildAtIndex:(NSUInteger)index
{
    return NSNotFound;
}

- (NSUInteger)indexOfChildAfterChildAtIndex:(NSUInteger)index
{
    return NSNotFound;
}

@end