//

//  GFBProductViewController.m

//  elmsc

//

//  Created by MAC on 2016/11/26.

//  Copyright © 2016年 GFB Network Technology Co.,Ltd. All rights reserved.

//

#import "GFBProductViewController.h"

#define kScreentW [UIScreen mainScreen].bounds.size.width

#define kScreentH [UIScreen mainScreen].bounds.size.height

#define _maxContentOffSet_Y 30

#define offsetY_maxContentOffSet_Y -30

@interface GFBProductViewController ()<UITableViewDelegate,UITableViewDataSource,UIWebViewDelegate>

@property (nonatomic, strong) UITableView *tableView;

@property (nonatomic, strong) UIWebView *webView;

@property (nonatomic, strong) UIView *contentView;

@property (nonatomic, strong) UILabel *mesLabel;

@property (nonatomic, assign) CGFloat startOffsetY;

@end

@implementation GFBProductViewController

- (void)loadContentView

{

    // first view

    [self.contentView addSubview:self.tableView];

    // second view

    [self.contentView addSubview:self.webView];

    UILabel *hv = self.headLab;

    // headLab

    [self.webView addSubview:hv];

    [self.headLab bringSubviewToFront:self.contentView];

    // 开始监听_webView.scrollView的偏移量

    [_webView.scrollView addObserver:self forKeyPath:@"contentOffset" options:NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld context:nil];

}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context

{

    if(object == _webView.scrollView && [keyPath isEqualToString:@"contentOffset"])

    {

        NSLog(@"----old:%@----new:%@",change[@"old"],change[@"new"]);

        [self headLabAnimation:[change[@"new"] CGPointValue].y];

    }else

    {

        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];

    }

}

// 头部提示文本动画

- (void)headLabAnimation:(CGFloat)offsetY

{

    _mesLabel.alpha = -offsetY/;

    _mesLabel.center = CGPointMake(kScreentW/, -offsetY/.f);

    // 图标翻转，表示已超过临界值，松手就会返回上页

    if(-offsetY>_maxContentOffSet_Y){

        _mesLabel.textColor = [UIColor redColor];

        _mesLabel.text = @"释放，返回详情";

    }else{

        _mesLabel.textColor = [UIColor redColor];

        _mesLabel.text = @"上拉，返回详情";

    }

}

- (UIView *)contentView

{

    if (! _contentView) {

        _contentView = [[UIView alloc]initWithFrame:CGRectMake(, , kScreentW, kScreentH)];

        [self.view addSubview:_contentView];

    }

    return _contentView;

}

- (UILabel *)headLab

{

    if(!_mesLabel){

        _mesLabel = [[UILabel alloc] init];

        _mesLabel.text = @"上拉，返回详情";

        _mesLabel.textAlignment = NSTextAlignmentCenter;

        _mesLabel.font = [UIFont systemFontOfSize:];

    }

    _mesLabel.frame = CGRectMake(, , kScreentW, .f);

    _mesLabel.alpha = .f;

    _mesLabel.textColor = [UIColor redColor];

    return _mesLabel;

}

- (UITableView *)tableView

{

    if(!_tableView){

        _tableView = [[UITableView alloc] initWithFrame:CGRectMake(, , kScreentW, self.contentView.bounds.size.height) style:UITableViewStylePlain];

        //    _tableView.contentSize = CGSizeMake(PDWidth_mainScreen, 800);

        _tableView.dataSource = self;

        _tableView.delegate = self;

        _tableView.rowHeight = .f;

        UILabel *tabFootLab = [[UILabel alloc] initWithFrame:CGRectMake(, , kScreentW, )];

        tabFootLab.text = @"继续拖动，查看图文详情";

        tabFootLab.font = [UIFont systemFontOfSize:];

        tabFootLab.textAlignment = NSTextAlignmentCenter;

        //        tabFootLab.backgroundColor = PDColor_Orange;

        _tableView.tableFooterView = tabFootLab;

    }

    return _tableView;

}

- (UIWebView *)webView

{

    if(!_webView){

        _webView = [[UIWebView alloc] initWithFrame:CGRectMake(, _tableView.contentSize.height, kScreentW, kScreentH)];

        _webView.delegate = self;

        _webView.scrollView.delegate = self;

        [_webView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"https://www.baidu.com"]]];

    }

    return _webView;

}

- (void)viewDidLoad {

    [super viewDidLoad];

    [self setUpUI];

}

#pragma mark---Private Methods 私有方法

- (void) setUpUI

{

     [self loadContentView];

}

#pragma mark-UITableViewDatasource Methods

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

    return ;

}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *ID = @"ID";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];

    if (! cell) {

        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];

    }

    cell.textLabel.text = @"商品测试";

    return cell;

}

#pragma mark--UITableViewDelegate Methods

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath

{

    // 测试跳转

    UIViewController *vc = [UIViewController new];

    vc.view.backgroundColor = [UIColor whiteColor];

    [self.navigationController pushViewController:vc animated:YES];

}

// 进入详情的动画

- (void)goToDetailAnimation

{

    [UIView animateWithDuration:0.3 delay:0.0 options:UIViewAnimationOptionLayoutSubviews animations:^{

        _webView.frame = CGRectMake(, , kScreentW, kScreentH);

        _tableView.frame = CGRectMake(, -self.contentView.bounds.size.height, kScreentW, self.contentView.bounds.size.height);

    } completion:^(BOOL finished) {

    }];

}

// 返回第一个界面的动画

- (void)backToFirstPageAnimation

{

    [UIView animateWithDuration:0.3 delay:0.0 options:UIViewAnimationOptionLayoutSubviews animations:^{

        _tableView.frame = CGRectMake(, , kScreentW, self.contentView.bounds.size.height);

        _webView.frame = CGRectMake(, _tableView.contentSize.height, kScreentW, kScreentH);

    } completion:^(BOOL finished) {

        // 滑动回顶部

        [_webView.scrollView setContentOffset:CGPointZero];

    }];

}

#pragma mark ---- scrollView delegate

-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView

{

    self.startOffsetY = scrollView.contentOffset.y;

}

-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate

{

    CGFloat offsetY = scrollView.contentOffset.y;

    if([scrollView isKindOfClass:[UITableView class]]) // tableView界面上的滚动

    {

        // 能触发翻页的理想值:tableView整体的高度减去屏幕本省的高度

        CGFloat valueNum = _tableView.contentSize.height -kScreentH;

        if ((offsetY - valueNum) > _maxContentOffSet_Y)

        {

            [self goToDetailAnimation]; // 进入图文详情的动画

        }

    }

    else // webView页面上的滚动

    {

        NSLog(@"-----webView-------");

        if (_startOffsetY < offsetY) { // 如果webView向上滑动则返回

            return;

        }

        if(offsetY_maxContentOffSet_Y)

        {

            [self backToFirstPageAnimation]; // 返回基本详情界面的动画

        }

    }

}

- (void)dealloc

{

    [self.webView.scrollView removeObserver:self forKeyPath:@"contentOffset" context:nil ];

}

@end