Add the second variant of the todo-list

Author: radmitr

m05-arrays-and-collections/ToDoList/src/Main2.java

@@ -0,0 +1,65 @@
+import java.util.Arrays;
+import java.util.Scanner;
+
+// Task 5.2
+public class Main2 {
+
+    public static void main(String[] args) {
+        Scanner scanner = new Scanner(System.in);
+        ToDoList toDoList = new ToDoList();
+
+        while (true) {
+            UserInput userInput = parse(scanner.nextLine());
+            switch (userInput.getCommand()) {
+                case "LIST":
+                    System.out.println(toDoList.list());
+                    break;
+                case "ADD":
+                    toDoList.add(userInput.getIndex(), userInput.getTask());
+                    break;
+                case "EDIT":
+                    toDoList.edit(userInput.getIndex(), userInput.getTask());
+                    break;
+                case "DELETE":
+                    toDoList.delete(userInput.getIndex());
+                    break;
+            }
+        }
+    }
+
+    private static UserInput parse(String input) {
+        String[] split = input.split(" ");
+        if (split.length == 1) return new UserInput(input.toUpperCase(), null, null);
+        try {
+            return new UserInput(split[0].toUpperCase(), Integer.valueOf(split[1]), String.join(" ",
+                    Arrays.copyOfRange(split, 2, split.length)));
+        } catch (NumberFormatException e) {
+            return new UserInput(split[0].toUpperCase(), null, String.join(" ",
+                    Arrays.copyOfRange(split, 1, split.length)));
+        }
+    }
+
+    private static class UserInput {
+        private final String command;
+        private final Integer index;
+        private final String task;
+
+        public UserInput(String command, Integer index, String task) {
+            this.command = command;
+            this.index = index;
+            this.task = task;
+        }
+
+        public String getCommand() {
+            return command;
+        }
+
+        public Integer getIndex() {
+            return index;
+        }
+
+        public String getTask() {
+            return task;
+        }
+    }
+}

m05-arrays-and-collections/ToDoList/src/ToDoList.java

@@ -0,0 +1,37 @@
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class ToDoList {
+
+    private final List<String> todoList = new ArrayList<>();
+
+    public void add(String todo) {
+        todoList.add(todo);
+    }
+
+    public void add(Integer index, String todo) {
+        if (exist(index)) todoList.add(index, todo);
+        else add(todo);
+    }
+
+    public void edit(Integer index, String todo) {
+        if (exist(index)) todoList.set(index, todo);
+    }
+
+    public void delete(int index) {
+        if (exist(index)) todoList.remove(index);
+    }
+
+    public String list() {
+        return IntStream.range(0, todoList.size())
+                .mapToObj(i -> i + " - " + todoList.get(i))
+                .collect(Collectors.joining("\n"));
+    }
+
+    private boolean exist(Integer index) {
+        return index != null && index >= 0 && index < todoList.size();
+    }
+
+}