//
//  CameraUpdateItem.m
//  RCTMGL
//
//  Created by Nick Italiano on 9/6/17.
//  Copyright © 2017 Mapbox Inc. All rights reserved.
//

#import "CameraUpdateItem.h"
#import "CameraMode.h"


@interface MGLMapView(FlyToWithPadding)
- (void)_flyToCamera:(MGLMapCamera *)camera edgePadding:(UIEdgeInsets)insets withDuration:(NSTimeInterval)duration peakAltitude:(CLLocationDistance)peakAltitude completionHandler:(nullable void (^)(void))completion;
@end

@interface RCTMGLCameraWithPadding : MGLMapCamera

@property (nonatomic) MGLMapCamera* _Nonnull camera;
@property (nonatomic) UIEdgeInsets boundsPadding;

@end

@implementation RCTMGLCameraWithPadding

@end

@implementation CameraUpdateItem

- (void)execute:(RCTMGLMapView *)mapView withCompletionHandler:(void (^)(void))completionHandler
{
    if (_cameraStop.mode == [NSNumber numberWithInt:RCT_MAPBOX_CAMERA_MODE_FLIGHT]) {
        [self _flyToCamera:mapView withCompletionHandler:completionHandler];
    } else if (_cameraStop.mode == [NSNumber numberWithInt:RCT_MAPBOX_CAMERA_MODE_EASE]) {
        [self _moveCamera:mapView animated:YES ease:YES withCompletionHandler:completionHandler];
    } else if (_cameraStop.mode == [NSNumber numberWithInt:RCT_MAPBOX_CAMERA_MODE_LINEAR]) {
        [self _moveCamera:mapView animated:YES ease:NO withCompletionHandler:completionHandler];
    } else {
        [self _moveCamera:mapView animated:NO ease:NO withCompletionHandler:completionHandler];
    }
}

- (void)_flyToCamera:(RCTMGLMapView*)mapView withCompletionHandler:(void (^)(void))completionHandler
{
    RCTMGLCameraWithPadding *nextCamera = [self _makeCamera:mapView];

    if ([mapView respondsToSelector:@selector(_flyToCamera:edgePadding:withDuration:peakAltitude:completionHandler:)]) {
        [mapView
           _flyToCamera:nextCamera.camera
           edgePadding:nextCamera.boundsPadding
           withDuration:_cameraStop.duration
           peakAltitude:-1
           completionHandler:completionHandler];
    } else {
        [mapView
           flyToCamera:nextCamera.camera
           withDuration:_cameraStop.duration
           completionHandler:completionHandler];
    }
}

- (void)_moveCamera:(RCTMGLMapView*)mapView animated:(BOOL)animated ease:(BOOL)ease withCompletionHandler:(void (^)(void))completionHandler
{
        RCTMGLCameraWithPadding *nextCamera = [self _makeCamera:mapView];
        NSString *easeFunctionName = ease ? kCAMediaTimingFunctionEaseInEaseOut : kCAMediaTimingFunctionLinear;

        [mapView setCamera:nextCamera.camera
                 withDuration:animated ? _cameraStop.duration : 0
                 animationTimingFunction:[CAMediaTimingFunction functionWithName:easeFunctionName]
                 edgePadding:nextCamera.boundsPadding
                 completionHandler:completionHandler];
}

- (RCTMGLCameraWithPadding*)_makeCamera:(RCTMGLMapView*)mapView
{
    MGLMapCamera *nextCamera = [mapView.camera copy];

    UIEdgeInsets padding = [self _clippedPadding:_cameraStop.padding forView:mapView];
    if (padding.top <= 0 && padding.bottom <= 0) {
      // If all padding properties are 0 in the update, and the bounds and centerCoordinate do not
      // change, the padding doesn't change either. This seems to be a bug in the iOS SDK.
      padding.top = 1.0;
      padding.bottom = 1.0;
    }
  
    bool hasSetAltitude = false;
    
    if ([self _isCoordValid:_cameraStop.coordinate]) {
        MGLCoordinateBounds boundsFromCoord = { .sw =  _cameraStop.coordinate, .ne =  _cameraStop.coordinate };
        MGLMapCamera *boundsCamera = [mapView
            camera:nextCamera
            fittingCoordinateBounds:boundsFromCoord
            edgePadding: padding];
        nextCamera.centerCoordinate = boundsCamera.centerCoordinate;
    } else if ([self _areBoundsValid:_cameraStop.bounds]) {
        MGLMapCamera *boundsCamera = [mapView
            camera:nextCamera
            fittingCoordinateBounds:_cameraStop.bounds
            edgePadding: padding];
        nextCamera.centerCoordinate = boundsCamera.centerCoordinate;
        nextCamera.altitude = boundsCamera.altitude;
        hasSetAltitude = true;
    }
  
    if (_cameraStop.pitch != nil) {
      nextCamera.pitch = [_cameraStop.pitch floatValue];
    }
    
    if (_cameraStop.heading != nil) {
      nextCamera.heading = [_cameraStop.heading floatValue];
    }
    
    if (_cameraStop.zoom != nil && hasSetAltitude == false) {
      nextCamera.altitude = [mapView
           altitudeFromZoom:[_cameraStop.zoom doubleValue]
           atLatitude:nextCamera.centerCoordinate.latitude
           atPitch:nextCamera.pitch];
    }
  
    RCTMGLCameraWithPadding* cameraWithPadding = [[RCTMGLCameraWithPadding alloc] init];
    cameraWithPadding.camera = nextCamera;
    cameraWithPadding.boundsPadding = padding;
    return cameraWithPadding;
}

- (UIEdgeInsets)_clippedPadding:(UIEdgeInsets)padding forView:(RCTMGLMapView*)mapView
{
    UIEdgeInsets result = padding;
    if ((padding.top + padding.bottom) >= mapView.frame.size.height) {
        double totalPadding = padding.top + padding.bottom;
        double extra = totalPadding - mapView.frame.size.height + 1.0;
        result.top -= (padding.top * extra) / totalPadding;
        result.bottom -= (padding.bottom * extra) / totalPadding;
    }
    if ((padding.left + padding.right) >= mapView.frame.size.width) {
        double totalPadding = padding.left + padding.right;
        double extra = totalPadding - mapView.frame.size.width + 1.0;
        result.left -= (padding.left * extra) / totalPadding;
        result.right -= (padding.right * extra) / totalPadding;
    }
    return result;
}

- (BOOL)_areBoundsValid:(MGLCoordinateBounds)bounds {
    BOOL isValid = CLLocationCoordinate2DIsValid(bounds.ne) && CLLocationCoordinate2DIsValid(bounds.sw);
    
    if (!isValid) {
        return NO;
    }
    
    CLLocationCoordinate2D ne = bounds.ne;
    CLLocationCoordinate2D sw = bounds.sw;
    return [self _isCoordValid:ne] && [self _isCoordValid:sw];
}

- (BOOL)_isCoordValid:(CLLocationCoordinate2D)coord
{
    BOOL isValid = CLLocationCoordinate2DIsValid(coord);
    
    if (!isValid) {
        return NO;
    }
    
    return YES;
}

- (BOOL)_hasCenterCoordAndZoom
{
    BOOL isValid = CLLocationCoordinate2DIsValid(_cameraStop.coordinate) && _cameraStop.zoom != nil;
    
    if (!isValid) {
        return NO;
    }
    
    return [self _isCoordValid:_cameraStop.coordinate];
}

@end