#!/usr/bin/swift

import Foundation
import AppKit

let baseURL = "https://www.foto-webcam.eu/webcam/wien/"

do {
    var iter=0
    while true {
        // MacOS apparently ignores setDesktopImageURL with unchanged URL m-(
        let localName = "wienbild-foto-webcam.eu."+String(iter)+".jpg"
        let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
        let filename = paths[0].appendingPathComponent(localName)
        if let url = URL(string: baseURL) {
            let data = try String(contentsOf: url)
            // guessing what the HTML looks like is as bad as guessing
            // what the image URL is?
            let regex = try! NSRegularExpression(pattern: "\"hugeimg\":\"([a-z0-9_./\\\\]+)\"")
            let range = NSRange(location: 0, length: data.utf16.count)
            let matched = regex.firstMatch(in: data, range: range)
            let m = data[Range(matched!.range(at: 1), in:data)!]
            let url = baseURL + m.replacingOccurrences(of: "\\", with: "")
            print(url)
            let imgurl = URL(string: url)!
            let img = try? Data(contentsOf: imgurl)
            if (img != nil)  {
                try? img!.write(to: filename)

                let workspace = NSWorkspace.shared
                if let screen = NSScreen.main  {
                    try workspace.setDesktopImageURL(filename, for: screen, options: [NSWorkspace.DesktopImageOptionKey.imageScaling:1])
                }
            }
        }
        sleep(3600)
        try? FileManager.default.removeItem(at: filename)
        iter+=1
    }
} catch {
   print(error)
}