Work on board

Connect 4.xcworkspace/contents.xcworkspacedata

@@ -2,7 +2,7 @@
 <Workspace
    version = "1.0">
    <FileRef
-      location = "group:../CustomTypes">
+      location = "group:CustomTypes">
    </FileRef>
    <FileRef
       location = "group:CLI/CLI.xcodeproj">

CustomTypes/.gitignore

@@ -0,0 +1,8 @@
+.DS_Store
+/.build
+/Packages
+xcuserdata/
+DerivedData/
+.swiftpm/configuration/registries.json
+.swiftpm/xcode/package.xcworkspace/contents.xcworkspacedata
+.netrc

CustomTypes/Package.swift

@@ -0,0 +1,23 @@
+// swift-tools-version: 5.10
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+import PackageDescription
+
+let package = Package(
+    name: "CustomTypes",
+    products: [
+        // Products define the executables and libraries a package produces, making them visible to other packages.
+        .library(
+            name: "CustomTypes",
+            targets: ["CustomTypes"]),
+    ],
+    targets: [
+        // Targets are the basic building blocks of a package, defining a module or a test suite.
+        // Targets can depend on other targets in this package and products from dependencies.
+        .target(
+            name: "CustomTypes"),
+        .testTarget(
+            name: "CustomTypesTests",
+            dependencies: ["CustomTypes"]),
+    ]
+)

CustomTypes/Sources/CustomTypes/CustomTypes.swift

@@ -0,0 +1,2 @@
+// The Swift Programming Language
+// https://docs.swift.org/swift-book

CustomTypes/Tests/CustomTypesTests/CustomTypesTests.swift

@@ -0,0 +1,12 @@
+import XCTest
+@testable import CustomTypes
+
+final class CustomTypesTests: XCTestCase {
+    func testExample() throws {
+        // XCTest Documentation
+        // https://developer.apple.com/documentation/xctest
+
+        // Defining Test Cases and Test Methods
+        // https://developer.apple.com/documentation/xctest/defining_test_cases_and_test_methods
+    }
+}

Model/Sources/Model/Board.swift

@@ -1,14 +1,151 @@
 public struct Board {
 	var grid: [[Piece?]]
     
-    public init(width: Int, height: Int) throws {
-        // guard width > 0, height > 0 else {
-        //     // TODO: Swift std error?
-        // }
+    public var width: Int { return grid.count }
+    public var height: Int { return grid.first!.count }
+
+    public init?(width: Int, height: Int) {
         self.init(grid: Array(repeating: Array(repeating: nil, count: height), count: width))
 	}
 
-	public init(grid: [[Piece?]]) {
+	public init?(grid: [[Piece?]]) {
+        guard !grid.isEmpty, !grid.first!.isEmpty else {
+            return nil
+        }
+        
         self.grid = grid
 	}
+    
+    private func checkBounds(_ column: Int, _ row: Int) {
+        precondition(column >= 0 && column < self.width && row >= 0 && row < self.height, "Coordinates out of bounds")
+    }
+    
+    subscript(column: Int, row: Int) -> Piece? {
+        get {
+            checkBounds(column, row)
+            return grid[column][row]
+        }
+        
+        set {
+            checkBounds(column, row)
+            grid[column][row] = newValue
+        }
+    }
+    
+    public func countPieces() -> Int {
+        var count = 0;
+        
+        for column in grid {
+            for piece in column {
+                if piece != nil {
+                    count += 1
+                }
+            }
+        }
+        
+        return count
+    }
+    
+    public func countPieces(of_type type: Piece) -> Int {
+        var count = 0
+        
+        for column in grid {
+            for piece in column {
+                if piece == type {
+                    count += 1
+                }
+            }
+        }
+        
+        return count
+    }
+    
+    public mutating func insert(piece: Piece, side: Side = .Top, offset: Int, pushing push: Bool = false) -> Bool {
+        precondition(offset >= 0, "Offset out of bounds")
+        
+        switch side {
+        case .Top:
+            precondition(offset < self.width, "Offset (column) out of bounds")
+            
+            if self.grid[offset].first! != nil {
+                if (!push) {
+                    return false
+                }
+                
+                Board.shiftDown(column: &self.grid[offset])
+            }
+            
+            self.grid[offset][0] = piece
+            
+            return true
+        case .Left:
+            precondition(offset < self.height, "Offset (row) out of bounds")
+            
+            if self.grid.first![offset] != nil {
+                if (!push) {
+                    return false
+                }
+                
+                self.shiftLeft(row: offset)
+            }
+            
+            self.grid[0][offset] = piece
+            
+            return true
+        case .Bottom:
+            precondition(offset < self.width, "Offset (column) out of bounds")
+            
+            if self.grid[offset].last! != nil {
+                if (!push) {
+                    return false
+                }
+                
+                Board.shiftUp(column: &self.grid[offset])
+            }
+            
+            let lastIndex = self.grid[offset].count - 1
+            self.grid[offset][lastIndex] = piece
+            
+            return true
+        case .Right:
+            precondition(offset < self.height, "Offset (row) out of bounds")
+            
+            if self.grid.last![offset] != nil {
+                if (!push) {
+                    return false
+                }
+                
+                self.shiftLeft(row: offset)
+            }
+            
+            let lastIndex = self.grid[offset].count - 1
+            self.grid[offset][lastIndex] = piece
+            
+            return true
+        }
+    }
+    
+    private static func shiftDown(column: inout [Piece?]) {
+        for i in (1..<column.count).reversed() {
+            column[i] = column[i - 1]
+        }
+    }
+    
+    private static func shiftUp(column: inout [Piece?]) {
+        for i in 0..<(column.count - 1) {
+            column[i] = column[i + 1]
+        }
+    }
+    
+    private mutating func shiftLeft(row: Int) {
+        for i in 0..<(grid.count - 1) {
+            self.grid[i][row] = self.grid[i + 1][row]
+        }
+    }
+    
+    private mutating func shiftRight(row: Int) {
+        for i in 1..<grid.count {
+            self.grid[i - 1][row] = self.grid[i][row]
+        }
+    }
 }

Model/Sources/Model/Side.swift

@@ -0,0 +1,3 @@
+public enum Side {
+    case Top, Left, Bottom, Right
+}