Difference between revisions of "W3911 Sudoku Server"

Revision as of 09:23, 7 October 2021

Within these castle walls be forged Mavens of Computer Science ...

— Merlin, The Coder

Background A Sudoku board is made up of nine boxes. Boxes (container for nine cells) are listed from top-to-bottom, left-to-right indexed from zero. Cells are listed from top-to-bottom, left-to-right, indexed from zero. All valid payloads and responses must use well-formed JSON. “cells” is returned as follows: “cells”: [[<nine values from top-left>], [<nine values from top-middle>], …]

End Points

POST /games?difficulty=<difficulty>
Creates a new game and associated board

   Parameters: 
   difficulty: easy | medium | hard | hell

   Body: none

   Status code: 201 Created

   Response: ID (integer) of newly created game
   {"id":<id>}
   
   {"id": 728134}

   Errors:
   
   {{{errors}}}

GET /games/<id>/cells
Returns the current cells for the specified game

   Parameters: 
   none

   Body: none

   Status code: 200 OK

   Response: Cells
   {"id":<id>}
   
   {"id": 728134}

   Errors:
   
   {{{errors}}}

PUT /games/<id>/cells/<boxIndex>/<cellIndex>
Place specified value at in game at boxIndex, cellIndex

   Parameters: 
   none


   Body: value (null for removing value)


   Status code: 200 OK


   Response: {"board":[
     {"cells":[{"value":<value>},{"value":<value>},...,{"value":<value>}]},
     ...
     {"cells":[{"value":<value>},{"value":<value>},...,{"value":<value>}]}
  ]}
   

   {"board":[
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
       {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]}
    ]}


   Errors:
   

   {{{errors}}}

JSON Encoding[edit]

JSON Decoding[edit]

import Foundation

let json = 
#"""
    {"board":[
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]},
        {"cells":[{"value":0},{"value":1},{"value":2},{"value":3},{"value":4},{"value":5},{"value":6},{"value":7},{"value":8}]}
     ]}
 """#
let decoder = JSONDecoder()

guard let data = json.data(using: .utf8), 
      let board: Board = try? decoder.decode(Board.self, from: data) else {
    fatalError("Failed to decode json into board.")
}
dump(board)

// Structure definitions
struct Cell: Codable {
    let value: Int?
}
struct Box: Codable {
     let cells: [Cell]
  
     init() {
         var cells = [Cell]()
         for cellIndex in 0 ..< 9 {
             cells.append(Cell(value: cellIndex))
         }
         self.cells = cells
     }
}

struct Board: Codable {
     let board: [Box]
  
     init() {
         var board = [Box]()
         for _ in 0 ..< 9 {
             board.append(Box())
         }
         self.board = board
     }
}

Issue Request from Client to Server[edit]

import Foundation                                                                                                                                                                                                                           
import FoundationNetworking                                                                                                                                                                                                                 
 
// Form the request                                                                                                                                                                                                                                           
var request = URLRequest(url: URL(string: "https://language-server.codermerlin.com/now")!)                                                                                                                                                  
request.httpMethod = "GET"

// Execute synchronously (uses extension in code below)                                                                                                                                                                                                                 
let (data, response, error) = URLSession.shared.syncRequest(with: request)
if let data = data,                                                                                                                                                                          
   let string = String(data: data, encoding: .utf8) {                                                                                                                                     
   print(string)                                                                                                                                                                            
} else if let error = error {
    print("Error: \(error)")
} else {
    print("An unexpected error occurred.")
}

// Reference: https://stackoverflow.com/questions/26784315/can-i-somehow-do-a-synchronous-http-request-via-nsurlsession-in-swift
extension URLSession {
   func syncRequest(with request: URLRequest) -> (Data?, URLResponse?, Error?) {
      var data: Data?
      var response: URLResponse?
      var error: Error?
      
      let dispatchGroup = DispatchGroup()
      let task = dataTask(with: request) {
         data = $0
         response = $1
         error = $2
         dispatchGroup.leave()
      }
      dispatchGroup.enter()
      task.resume()
      dispatchGroup.wait()
      
      return (data, response, error)
   }  
}

@@ Line 72: / Line 72: @@
 // Structure definitions
+struct Position: Codable {
+    let boxIndex: Int
+    let cellIndex: Int
+}
 struct Cell: Codable {
+    let position: Position
      let value: Int?
 }
@@ Line 78: / Line 84: @@
       let cells: [Cell]
-      init() {
+      init(boxIndex: Int) {
           var cells = [Cell]()
           for cellIndex in 0 ..< 9 {
-              cells.append(Cell(value: cellIndex))
+              cells.append(Cell(position: Position(boxIndex: boxIndex, cellIndex: cellIndex), value: cellIndex))
           }
           self.cells = cells
@@ Line 92: / Line 98: @@
       init() {
           var board = [Box]()
-          for _ in 0 ..< 9 {
+          for boxIndex in 0 ..< 9 {
-              board.append(Box())
+              board.append(Box(boxIndex: boxIndex))
           }
           self.board = board