added swift code into repo

Package.swift

@@ -0,0 +1,10 @@
+// swift-tools-version:3.1
+
+import PackageDescription
+
+let package = Package(
+    name: "SteamThing",
+    dependencies : [
+    .Package(url: "https://github.com/SwiftyJSON/SwiftyJSON.git", majorVersion:3)
+    ]
+)

README.md

@@ -1,2 +1,18 @@
 # SteamThing
-A quick tool I made to see what games people have in common across their steam accounts
+
+A tool I made to see what games people have in common across their steam accounts.
+This came about because at LANs there is no easy way to know what games most people have until you get there, and I did this as something to do while home bored, so it might be a bit odd.
+
+## Using it
+
+You will need a Steam API Key before you can use SteamThing, you can get one from [Valve](http://steamcommunity.com/dev).
+Once you have that you can plug it into the code at `Sources/SteamHelper.swift` and then you can build SteamThing.
+
+SteamThing uses the Swift package manager so running `swift build` will handle everything.
+
+Once it is built you can run it from the command line, by default the built SteamThing will be inside the `.build/debug` folder, so you can run this like:
+```
+	.build/debug/SteamThing steamid1 steamid2 steamid3
+```
+This will spit out a list of games that the users with the steam ids steamid1, steamid2, steamid3 all own as well as games that the majority of players own.
+To work out what your/others steam id are, the easiest way is to use the [Steam ID Finder](http://steamidfinder.com).

Sources/SteamHelper.swift

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+//
+//  SteamHelper.swift
+//  SteamThing
+//
+//  Created by Tim Nugent on 26/6/17.
+//
+//
+
+import Foundation
+import SwiftyJSON
+
+let apikey = "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+
+class SteamAPI
+{
+    var games = [Int : Game]()
+    var playersInfo = [Player]()
+
+    func load(playerIDs: [String])
+    {
+        guard let players = self.getPlayerInfo(steamID: playerIDs) else
+        {
+            print("failed to load player info")
+            return
+        }
+        for player in players
+        {
+            //ok go through and run the get games script
+            // but modify it so that it returns how many people own that game
+            self.getGames(steamID: player.steamID)
+        }
+        self.playersInfo = players
+    }
+    private func getGames(steamID : String)
+    {
+        let urlString = "http://api.steampowered.com/IPlayerService/GetOwnedGames/v0001/?key=\(apikey)&steamid=\(steamID)&include_appinfo=1&include_played_free_games=1&format=json"
+        if let url = URL(string: urlString)
+        {
+            do
+            {
+                let contents = try String(contentsOf: url)
+
+                if let jsonData = contents.data(using: .utf8)
+                {
+                    let json = JSON(data: jsonData)
+                    if let gamesList = json["response"]["games"].array
+                    {
+                        for game in gamesList
+                        {
+                            let name = game["name"].stringValue
+                            let appid = game["appid"].intValue
+                            let count = self.games[appid] != nil ? self.games[appid]!.count + 1 : 1
+
+                            self.games[appid] = Game(name: name, appid: appid, count: count)
+                        }
+                    }
+                }
+            }
+            catch
+            {
+                print("Error grabbing games list for steam id \(steamID)")
+            }
+        }
+    }
+    private func getPlayerInfo(steamID : [String]) -> [Player]?
+    {
+        var players : [Player]?
+        let urlString = "http://api.steampowered.com/ISteamUser/GetPlayerSummaries/v0002/?key=\(apikey)&steamids=\(steamID.joined(separator: ",")))"
+        if let url = URL(string: urlString)
+        {
+            do
+            {
+                let contents = try String(contentsOf: url)
+
+                if let jsonData = contents.data(using: .utf8)
+                {
+                    let json = JSON(data: jsonData)
+                    if let playerArray = json["response"]["players"].array
+                    {
+                        for player in playerArray
+                        {
+                            if let playerInfo = player.dictionary
+                            {
+                                let id = playerInfo["steamid"]?.stringValue
+                                let name = playerInfo["personaname"]?.stringValue
+                                let avatar = playerInfo["avatar"]?.stringValue
+
+                                if players == nil
+                                {
+                                    players = [Player]()
+                                }
+                                players?.append(Player(steamID: id!, name: name!, avatar: avatar!))
+                            }
+                        }
+                    }
+                }
+            }
+            catch
+            {
+                print("Error grabbing user information for id \(steamID)")
+            }
+        }
+        return players
+    }
+}
+
+struct Game
+{
+    let name : String
+    let appid : Int
+    var count : Int = 0
+}
+extension Game : Equatable
+{
+    static func ==(lhs: Game, rhs: Game) -> Bool
+    {
+        return lhs.appid == rhs.appid
+    }
+}
+internal struct Player
+{
+    let steamID : String
+    let name : String
+    let avatar : String
+}

Sources/main.swift

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+import Foundation
+
+let steamIDs = Array(CommandLine.arguments[1..<CommandLine.arguments.count])
+
+let steamHelper = SteamAPI()
+steamHelper.load(playerIDs: steamIDs)
+
+let playerNames = steamHelper.playersInfo.map { return $0.name }
+print("\(playerNames.joined(separator: ", ")) all have the following games:")
+
+var games = steamHelper.games.values.filter { $0.count == steamIDs.count }
+games.sorted{$0.name < $1.name}.forEach{print($0.name)}
+
+// going through all games that 2 or more peeps own
+for i in (2...steamIDs.count - 1).reversed()
+{
+    var newGames = steamHelper.games.values.filter { $0.count == i }.filter { !games.contains($0) }
+
+    print("\nThe following \(newGames.count) games are owned by \(i) players:")
+    newGames.sorted { $0.name < $1.name }.forEach { print($0.name) }
+
+    // the new list of already shown games
+    games = steamHelper.games.values.filter { $0.count >= i }
+}