//
//  DLScrollTabbarView.m
//  DLSlideViewDemo
//
//  Created by Dongle Su on 15-2-12.
//  Copyright (c) 2015年 dongle. All rights reserved.
//

#import "DLScrollTabbarView.h"
#import "DLUtility.h"

#define kTrackViewHeight 2
#define kImageSpacingX 3.0f

#define kLabelTagBase 1000
#define kImageTagBase 2000
#define kSelectedImageTagBase 3000
#define kViewTagBase 4000

@implementation DLScrollTabbarItem
+ (DLScrollTabbarItem *)itemWithTitle:(NSString *)title width:(CGFloat)width{
    DLScrollTabbarItem *item = [[DLScrollTabbarItem alloc] init];
    item.title = title;
    item.width = width;
    return item;
}
@end


@implementation DLScrollTabbarView{
    UIScrollView *scrollView_;
    UIImageView *trackView_;
}

- (void)commonInit{
    _selectedIndex = -1;
    
    scrollView_ = [[UIScrollView alloc] initWithFrame:self.bounds];
    scrollView_.showsHorizontalScrollIndicator = NO;
    [self addSubview:scrollView_];
    
    trackView_ = [[UIImageView alloc] initWithFrame:CGRectMake(0, self.bounds.size.height-kTrackViewHeight-1, self.bounds.size.width, kTrackViewHeight)];
    [scrollView_ addSubview:trackView_];
    trackView_.layer.cornerRadius = 2.0f;
    
}

- (id)initWithCoder:(NSCoder *)aDecoder{
    if (self = [super initWithCoder:aDecoder]) {
        [self commonInit];
    }
    return self;
}

- (id)initWithFrame:(CGRect)frame{
    if (self = [super initWithFrame:frame]) {
        [self commonInit];
    }
    return self;
}

- (void)setBackgroundView:(UIView *)backgroundView{
    if (_backgroundView != backgroundView) {
        [_backgroundView removeFromSuperview];
        [self insertSubview:backgroundView atIndex:0];
        _backgroundView = backgroundView;
    }
}

- (void)setTabItemNormalColor:(UIColor *)tabItemNormalColor{
    _tabItemNormalColor = tabItemNormalColor;
    
    for (int i=0; i<[self tabbarCount]; i++) {
        if (i == self.selectedIndex) {
            continue;
        }
        UILabel *label = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+i];
        label.textColor = tabItemNormalColor;
    }
}

- (void)setTabItemSelectedColor:(UIColor *)tabItemSelectedColor{
    _tabItemSelectedColor = tabItemSelectedColor;
    
    UILabel *label = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+self.selectedIndex];
    label.textColor = tabItemSelectedColor;
}

- (void)setTrackColor:(UIColor *)trackColor{
    _trackColor = trackColor;
    trackView_.backgroundColor = trackColor;
}

- (void)setTabbarItems:(NSArray *)tabbarItems{
    if (_tabbarItems != tabbarItems) {
        _tabbarItems = tabbarItems;

        float height = self.bounds.size.height;
        float x = 0.0f;
        NSInteger i=0;
        for (DLScrollTabbarItem *item in tabbarItems) {
            UIView *backView = [[UIView alloc] initWithFrame:CGRectMake(x, 0, item.width, height)];
            backView.backgroundColor = [UIColor clearColor];
            backView.tag = kViewTagBase + i;
            UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, item.width, height)];
            label.text = item.title;
            label.font = [UIFont systemFontOfSize:self.tabItemNormalFontSize];
            label.backgroundColor = [UIColor clearColor];
            label.textColor = self.tabItemNormalColor;
            [label sizeToFit];
            label.tag = kLabelTagBase+i;

            label.frame = CGRectMake((item.width-label.bounds.size.width)/2.0f, (height-label.bounds.size.height)/2.0f, CGRectGetWidth(label.bounds), CGRectGetHeight(label.bounds));
            [backView addSubview:label];
            UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapAction:)];
            [backView addGestureRecognizer:tap];

            [scrollView_ addSubview:backView];
            x += item.width;
            i++;
        }
        scrollView_.contentSize = CGSizeMake(x, height);

        [self layoutTabbar];
    }
}

- (void)layoutSubviews{
    [super layoutSubviews];
    
    self.backgroundView.frame = self.bounds;
    scrollView_.frame = self.bounds;
    [self layoutTabbar];
}

- (void)layoutTabbar{
//    float width = self.bounds.size.width/self.tabbarItems.count;
//    float height = self.bounds.size.height;
//    float x = 0.0f;
//    for (NSInteger i=0; i<self.tabbarItems.count; i++) {
//        x = i*width;
//        UILabel *label = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+i];
//        UIImageView *imageView = (UIImageView *)[scrollView_ viewWithTag:kImageTagBase+i];
//        UIImageView *selectedIamgeView = (UIImageView *)[scrollView_ viewWithTag:kSelectedImageTagBase+i];
//        label.frame = CGRectMake(x + (width-label.bounds.size.width-CGRectGetWidth(imageView.bounds))/2.0f, (height-label.bounds.size.height)/2.0f, CGRectGetWidth(label.bounds), CGRectGetHeight(label.bounds));
//        imageView.frame = CGRectMake(label.frame.origin.x + label.bounds.size.width+kImageSpacingX, (height-imageView.bounds.size.height)/2.0, CGRectGetWidth(imageView.bounds), CGRectGetHeight(imageView.bounds));
//        selectedIamgeView.frame = imageView.frame;
//    }
    
//    float trackX = width*self.selectedIndex;
//    trackView_.frame = CGRectMake(trackX, trackView_.frame.origin.y, width, kTrackViewHeight);
}

- (NSInteger)tabbarCount{
    return self.tabbarItems.count;
}

- (void)switchingFrom:(NSInteger)fromIndex to:(NSInteger)toIndex percent:(float)percent{
    //DLScrollTabbarItem *fromItem = [self.tabbarItems objectAtIndex:fromIndex];
    UILabel *fromLabel = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+fromIndex];
    fromLabel.textColor = [DLUtility getColorOfPercent:percent between:self.tabItemNormalColor and:self.tabItemSelectedColor];
    
    UILabel *toLabel = nil;
    if (toIndex >= 0 && toIndex < [self tabbarCount]) {
        //DLScrollTabbarItem *toItem = [self.tabbarItems objectAtIndex:toIndex];
        toLabel = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+toIndex];
        toLabel.textColor = [DLUtility getColorOfPercent:percent between:self.tabItemSelectedColor and:self.tabItemNormalColor];
    }
    
    // 计算track view位置和宽度
    CGRect fromRc = [scrollView_ convertRect:fromLabel.bounds fromView:fromLabel];
    CGFloat fromWidth = fromLabel.frame.size.width;
    CGFloat fromX = fromRc.origin.x;
    CGFloat toX;
    CGFloat toWidth;
    if (toLabel) {
        CGRect toRc = [scrollView_ convertRect:toLabel.bounds fromView:toLabel];
        toWidth = toRc.size.width;
        toX = toRc.origin.x;
    }
    else{
        toWidth = fromWidth;
        if (toIndex > fromIndex) {
            toX = fromX + fromWidth;
        }
        else{
            toX = fromX - fromWidth;
        }
    }

    CGFloat width = toWidth * percent + fromWidth*(1-percent);
    CGFloat x = fromX + (toX - fromX)*percent;
    trackView_.frame = CGRectMake(x, trackView_.frame.origin.y, width, CGRectGetHeight(trackView_.bounds));
}

- (void)setSelectedIndex:(NSInteger)selectedIndex{
    if (_selectedIndex != selectedIndex) {
        if (_selectedIndex >= 0) {
            //DLScrollTabbarItem *fromItem = [self.tabbarItems objectAtIndex:_selectedIndex];
            UILabel *fromLabel = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+_selectedIndex];
            fromLabel.textColor = self.tabItemNormalColor;
        }
        
        if (selectedIndex >= 0 && selectedIndex < [self tabbarCount]) {
            //DLScrollTabbarItem *toItem = [self.tabbarItems objectAtIndex:selectedIndex];
            UILabel *toLabel = (UILabel *)[scrollView_ viewWithTag:kLabelTagBase+selectedIndex];
            toLabel.textColor = self.tabItemSelectedColor;
            
            UIView *selectedView = [scrollView_ viewWithTag:kViewTagBase+selectedIndex];
            //CGRect selectedRect = selectedView.frame;
            CGRect rc = selectedView.frame;
            //选中的居中显示
            rc = CGRectMake(CGRectGetMidX(rc) - scrollView_.bounds.size.width/2.0f, rc.origin.y, scrollView_.bounds.size.width, rc.size.height);
// 滚动左右两格到可见位置
//            if (selectedIndex > 0) {
//                UIView *leftView = [scrollView_ viewWithTag:kViewTagBase+selectedIndex-1];
//                rc = CGRectUnion(rc, leftView.frame);
//            }
//            if (selectedIndex < [self tabbarCount]-1) {
//                UIView *rightView = [scrollView_ viewWithTag:kViewTagBase+selectedIndex+1];
//                rc = CGRectUnion(rc, rightView.frame);
//            }
            [scrollView_ scrollRectToVisible:rc animated:YES];
            
            // track view
            CGRect trackRc = [scrollView_ convertRect:toLabel.bounds fromView:toLabel];
            trackView_.frame = CGRectMake(trackRc.origin.x, trackView_.frame.origin.y, trackRc.size.width, CGRectGetHeight(trackView_.bounds));
        }
        
//        float width = self.bounds.size.width/self.tabbarItems.count;
//        float trackX = width*selectedIndex;
//        trackView_.frame = CGRectMake(trackX, trackView_.frame.origin.y, CGRectGetWidth(trackView_.bounds), CGRectGetHeight(trackView_.bounds));
        
        _selectedIndex = selectedIndex;
    }
}

- (void)tapAction:(UITapGestureRecognizer *)tap{
    NSInteger i = tap.view.tag - kViewTagBase;
    self.selectedIndex = i;
    if (self.delegate) {
        [self.delegate DLSlideTabbar:self selectAt:i];
    }
}


@end