KalpeshTalkar/Coffee-With-Intercom

A simple iOS application that reads all the customers from a .txt file and invites all the customers withing 100km range of Intercom office in Dublin.

Coffee-With-Intercom

A simple iOS application that reads all the customers from a .txt file and invites all the customers withing 100km range of Intercom office in Dublin.

Steps to run the app

1. Clone the project.
2. Open terminal and run the command pod install or pod update (If you need to update your version of cocoapods) Install cocoapods $ sudo gem install cocoapod. Refer here: https://guides.cocoapods.org/using/getting-started.html
3. Open Coffee With Intercom.xcworkspace and run the app on any iOS device or iOS simulator.

Distance formula - Approach

1. Initially, the method CLLocation.distance(from: CLLocation) was used to get the distance between each and Intercom's Dublin office.
2. After sudying and understanding the distance formula given by the spherical law of cosines (https://en.wikipedia.org/wiki/Great-circle_distance), the same implementation was done in Swift. Below is the code snippet for reference:

func distanceBetween(latitude1: Double, longitude1: Double, latitude2: Double, longitude2: Double) -> Double {
    let radius: Double = 6378.137.toRadians() // earth's radius in km
        
    let lat1Rad = latitude1.toRadians()
    let lng1Rad = longitude1.toRadians()
    let lat2Rad = latitude2.toRadians()
    let lng2Rad = longitude2.toRadians()
        
    let absLngDiff = abs(lng1Rad - lng2Rad)
        
    let centralAngle = acos(sin(lat1Rad) * sin(lat2Rad) + cos(lat1Rad) * cos(lat2Rad) * cos(absLngDiff))
    let distance = radius * centralAngle
        
    return distance.toDegrees() // Distance in km
}

The distance calculated from the above formula was test by comparing with the distance result using CLLocation.distance(from: CLLocation) and the results matched 🥳.

Output (Screenshots)