//
//  MPPowerFunctionLayout.m
//  MathPad
//
//  Created by Kim Wittenburg on 30.09.14.
//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
//

#import "MPPowerFunctionLayout.h"

#define kMPEmptyBoxHeight (CTFontGetDescent((CTFontRef)self.font) + CTFontGetAscent((CTFontRef)self.font) + CTFontGetLeading((CTFontRef)self.font))
#define kMPEmptyBoxYOrigin (-(CTFontGetDescent((CTFontRef)self.font) + CTFontGetLeading((CTFontRef)self.font)))

#define kPowerFunctionExponentXOffset 1
#define kPowerFunctionTrailingOffset 2

@implementation MPPowerFunctionLayout

- (NSRect)baseBounds
{
    if (NSEqualRects(_baseBounds, NSZeroRect)) {
        return NSMakeRect(0, kMPEmptyBoxYOrigin, 0, kMPEmptyBoxHeight);
    }
    return _baseBounds;
}

- (MPPowerFunction *)powerFunction
{
    return (MPPowerFunction *)self.function;
}

- (NSIndexSet *)indexesOfRemainingChildren
{
    return [NSIndexSet indexSetWithIndex:0];
}

- (NSPoint)offsetOfChildLayoutAtIndex:(NSUInteger)index
{
    CGFloat y = self.baseBounds.size.height / 2;
    return NSMakePoint(kPowerFunctionExponentXOffset, y);
}

- (BOOL)childAtIndexUsesSmallSize:(NSUInteger)index
{
    return YES;
}

- (NSIndexPath *)indexPathForLocalMousePoint:(NSPoint)point
{
    return [[NSIndexPath indexPathWithIndex:0] indexPathByAddingIndex:0];
}

- (NSRect)generateBounds
{
    NSRect exponentBounds = [self childLayoutAtIndex:0].bounds;
    CGFloat y = self.baseBounds.origin.y;
    CGFloat height = -y + [self offsetOfChildLayoutAtIndex:0].y + exponentBounds.size.height + exponentBounds.origin.y;
    CGFloat width = kPowerFunctionExponentXOffset + exponentBounds.size.width + kPowerFunctionTrailingOffset;
    return NSMakeRect(0, y, width, height);
}

- (void)draw
{
    MPLayout *exponentLayout = [self childLayoutAtIndex:0];
    [exponentLayout drawAtPoint:[self offsetOfChildLayoutAtIndex:0]];
}

@end