/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */

#import <QuartzCore/QuartzCore.h>

#import "RCTBridge.h"
#import "RCTDevLoadingView.h"
#import "RCTDefines.h"

#if RCT_DEV

@implementation RCTDevLoadingView
{
  UIWindow *_window;
  UILabel *_label;
  NSDate *_showDate;
}

__attribute__((constructor))
static void RCTDevLoadingViewSetup()
{
  [RCTDevLoadingView sharedInstance];
}

+ (instancetype)sharedInstance
{
  static dispatch_once_t onceToken;
  static RCTDevLoadingView *instance;
  dispatch_once(&onceToken, ^{
    instance = [[RCTDevLoadingView alloc] init];
  });
  return instance;
}

- (instancetype)init
{
  if (self = [super init]) {
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(willStartLoading:)
                                                 name:RCTJavaScriptWillStartLoadingNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(didFinishLoading:)
                                                 name:RCTJavaScriptDidLoadNotification
                                               object:nil];
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(didFinishLoading:)
                                                 name:RCTJavaScriptDidFailToLoadNotification
                                               object:nil];
  }
  return self;
}

- (void)dealloc
{
  [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)willStartLoading:(NSNotification *)notification
{
  NSURL *url = [[notification object] bundleURL];
  dispatch_async(dispatch_get_main_queue(), ^{
    [self showWithURL:url];
  });
}

- (void)didFinishLoading:(__unused NSNotification *)notification
{
  dispatch_async(dispatch_get_main_queue(), ^{
    [self hide];
  });
}

- (void)showWithURL:(NSURL *)URL
{
  _showDate = [NSDate date];
  if (!_window) {
    CGFloat screenWidth = [[UIScreen mainScreen] bounds].size.width;
    _window = [[UIWindow alloc] initWithFrame:CGRectMake(0, 0, screenWidth, 22)];
    _window.backgroundColor = [UIColor blackColor];
    _window.windowLevel = UIWindowLevelStatusBar + 1;

    _label = [[UILabel alloc] initWithFrame:_window.bounds];
    _label.font = [UIFont systemFontOfSize:12.0];
    _label.textColor = [UIColor grayColor];
    _label.textAlignment = NSTextAlignmentCenter;

    [_window addSubview:_label];
    [_window makeKeyAndVisible];
  }

  NSString *source;
  if ([URL isFileURL]) {
    source = @"pre-bundled file";
  } else {
    source = [NSString stringWithFormat:@"%@:%@", [URL host], [URL port]];
  }

  _label.text = [NSString stringWithFormat:@"Loading from %@...", source];
  _window.hidden = NO;
}

- (void)hide
{
  const NSTimeInterval MIN_PRESENTED_TIME = 0.6;
  NSTimeInterval presentedTime = [[NSDate date] timeIntervalSinceDate:_showDate];
  NSTimeInterval delay = MAX(0, MIN_PRESENTED_TIME - presentedTime);

  CGRect windowFrame = _window.frame;
  [UIView animateWithDuration:0.25
                        delay:delay
                      options:0
                   animations:^{
                     _window.frame = CGRectOffset(windowFrame, 0, -windowFrame.size.height);
                   } completion:^(__unused BOOL finished) {
                     _window.frame = windowFrame;
                     _window.hidden = YES;
                   }];
}

@end

#else

@implementation RCTDevLoadingView

+ (instancetype)sharedInstance { return nil; }
- (void)showWithURL:(NSURL *)URL {}
- (void)hide {}

@end

#endif