From 5d8cf17e22beb8b220e950ae93ab641644112266 Mon Sep 17 00:00:00 2001
From: Arsen Musayelyan <moussaelianarsen@gmail.com>
Date: Sun, 15 Nov 2020 11:51:49 -0800
Subject: [PATCH] Add comments

---
 Sources/App/routes.swift | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/Sources/App/routes.swift b/Sources/App/routes.swift
index 480cccb..e8aa3f7 100644
--- a/Sources/App/routes.swift
+++ b/Sources/App/routes.swift
@@ -7,57 +7,96 @@ import Leaf
 func routes(_ app: Application) throws {
     // Render home page when root domain is loaded
     app.get { req  -> EventLoopFuture<View> in
+        // Get data from config file at /Resources/config.json
         let fileData = try String(contentsOfFile: "\(app.directory.resourcesDirectory)/config.json").data(using: .utf8)
+        // Decode JSON file to Config struct
         let config: Config = try! JSONDecoder().decode(Config.self, from: fileData!)
+        // Check if user is logged in
         let loginStatus = req.session.data["loggedIn"] ?? "false"
+        // Change loginStatus to a boolean
         let loginBool = loginStatus == "true" ? true : false
+        // Render home.leaf with config and login status as context
         return req.view.render("home", LContext(config: config, loggedIn: loginBool))
     }
 
+    // Return website status when /status/:url is loaded
     app.get("status", ":url") { req -> [String: String] in
+        // Get URL from request parameters
         let url = URL(string: "http://\(req.parameters.get("url")!)")
+        // Configure URLSession
         let config = URLSessionConfiguration.default
+        // Set request timeouts to 5s, then assume offline
         config.timeoutIntervalForRequest = 5
         config.timeoutIntervalForResource = 5
+        // Declare statusDict for storing website status
         var statusDict: [String:String] = [:]
+        // Declare URLSession request using URL from request parameters
         var headReq = URLRequest(url: url!)
+        // Set HEAD request
         headReq.httpMethod = "HEAD"
+        // Set request timeout to 5s, then assume offline
         headReq.timeoutInterval = 5
+        // Create DispatchSemaphore to block thread until request is resolved and status stored
         let semaphore = DispatchSemaphore(value: 0)
+        // Run Async URLSession dataTask
         URLSession.shared.dataTask(with: headReq, completionHandler:  { (_, response, error) in
+            // If the response is valid
             if let httpURLResponse = response as? HTTPURLResponse {
+                // Store status code in statusDict
                 statusDict["code"] = String(httpURLResponse.statusCode)
+                // Store website status in statusDict
                 statusDict["down"] = "false"
             }
+            // Signal DispatchSemaphore to stop blocking
             semaphore.signal()
         }).resume()
+        // Wait for semaphore signal
         semaphore.wait()
+        // If statusDict is empty, return code 0, down true. Otherwise, return statusdict
         return statusDict.count > 0 ? statusDict : ["code": "0", "down": "true"]
     }
 
+    // Render login page on GET request to /login
     app.get("login") { req -> EventLoopFuture<View> in
+        // Get data from config file at /Resources/config.json
         let fileData = try String(contentsOfFile: "\(app.directory.resourcesDirectory)/config.json").data(using: .utf8)
+        // Decode JSON file to Config struct
         let config: Config = try! JSONDecoder().decode(Config.self, from: fileData!)
+        // Render home.leaf with config as context
         return req.view.render("login", LContext(config: config, loggedIn: false))
     }
 
+    // Verify credentials and log in on POST request to /login
     app.post("login") { req -> Response in
+        // Decode POST request data into Login struct
         let data = try req.content.decode(Login.self)
+        // Get data from config file at /Resources/config.json
         let fileData = try String(contentsOfFile: "\(app.directory.resourcesDirectory)/config.json").data(using: .utf8)
+        // Decode JSON file to Config struct
         let config: Config = try! JSONDecoder().decode(Config.self, from: fileData!)
+        // Get password from POST request data
         let loginPassData = data.password?.data(using: .utf8)
+        // Hash password in POST data using SHA256.hash() from SwiftCrypto
         let loginPassHash = SHA256.hash(data: loginPassData ?? "".data(using: .utf8)!)
+        // Convert hash to string
         let stringHash = loginPassHash.map { String(format: "%02hhx", $0) }.joined()
+        // If hash in config matches provided hash
         if stringHash == config.passwordHash {
+            // Set logged in to true in session
             req.session.data["loggedIn"] = "true"
+            // Redirect back to /
             return try req.redirect(to: "/")
         } else {
+            // If hashes do not match, return unauthorized error
             throw Abort(.unauthorized)
         }
     }
 
+    // Destroy session on GET request to logout
     app.get("logout") { req -> Response in
+        // Destroy session
         req.session.destroy()
+        // Redirect back to /
         return try req.redirect(to: "/")
     }