change proxy on mac osx programmatically

How does one programmatically change proxy settings on a mac osx. I am fluent in ios, and since mac os programming is similar there shouldn't be much problems with it. However I lack the logic needed to create proxy changes programmatically.. Manual tweaking is extremely easy. This is the network tab in System Preferences I am after:

What I have tried:

let dynamicStore: SCDynamicStoreRef = SCDynamicStoreCreate(nil, "setProxy" as CFString, nil, nil)!
let updated = SCDynamicStoreSetValue(dynamicStore, "HTTPProxy" as CFStringRef, "111.222.333.1") // updated is false, indicating unsuccessful operation

Also tried this, but the dictionary returned is read only

let dynamicStore: SCDynamicStoreRef = SCDynamicStoreCreate(nil, "myFunc" as 

    CFString, nil, nil)!

    let proxyDict = SCDynamicStoreCopyProxies(dynamicStore)

    if let proxyDict = SCDynamicStoreCopyProxies(dynamicStore) as NSDictionary? {
        if let port = proxyDict["HTTPPort"] as? Int {
            print("HTTPPort:", port)
            proxyDict["HTTPPort"] = 8088; // can't do that
        }
    }

I am running out of ideas.

Dmitry Isaev

From this answer, here is a sample script:

e=$(networksetup -getsocksfirewallproxy wi-fi | grep "No")

if [ -n "$e" ]; then
  echo "Turning on proxy"
  networksetup -setsocksfirewallproxystate wi-fi on
else
  echo "Turning off proxy"
  networksetup -setsocksfirewallproxystate wi-fi off
fi

It swiches (on/off) the SOCKS proxy for the user's Wi-Fi connection.

You can use this idea to make the script for your needs. You can implement your desired logic in a bash script like that or in Cocoa.

Use networksetup -listallnetworkservices to list all connections.
Use networksetup -setwebproxy to setup proxy for a particular connection.

For example, here's my Terminal output:

$ networksetup -listallnetworkservices
An asterisk (*) denotes that a network service is disabled.
MBBEthernet
Wi-Fi
Wi-Fi Modem Yota 4G LTE
Bluetooth PAN
Thunderbolt Bridge
iPhone

$ networksetup -setwebproxy some bad args
** Error: The parameters were not valid.

$ networksetup -setwebproxy Wi-Fi 1.2.3.4 8080

The last command gave the empty stdout, it means success.