From b5ba7997e36408c09e3528b76fb27d045a746981 Mon Sep 17 00:00:00 2001
From: Moises Marquez <moises.marquez@minna.tech>
Date: Mon, 21 Mar 2022 19:51:19 +0100
Subject: [PATCH] Migration of todos to have completion status

---
 backend/daos/todosDao.js         | 13 +++++++++++
 backend/migrate-todos.js         | 24 ++++++++++++++++++++
 backend/services/todosService.js | 39 +++++++++++++++++++++++++++++++-
 backend/utils/models/todos.js    |  8 +++++++
 4 files changed, 83 insertions(+), 1 deletion(-)
 create mode 100644 backend/migrate-todos.js
 create mode 100644 backend/utils/models/todos.js

diff --git a/backend/daos/todosDao.js b/backend/daos/todosDao.js
index 12343994..0a2757a2 100644
--- a/backend/daos/todosDao.js
+++ b/backend/daos/todosDao.js
@@ -51,6 +51,19 @@ class TodosDao {
       throw new IoError('An error occurred when fetching the todos lists', {cause: err});
     }
   }
+
+  async getAllToDosLists() {
+    const dbConnect = mongoDbClient.getDb();
+
+    try {
+      return await this.mongoDbCollection(dbConnect)
+        .find({})
+        .toArray();
+    } catch (err) {
+      console.error(err.stack);
+      throw new IoError('An error occurred when fetching the todos lists', {cause: err});
+    }
+  }
 }
 
 module.exports = TodosDao;
\ No newline at end of file
diff --git a/backend/migrate-todos.js b/backend/migrate-todos.js
new file mode 100644
index 00000000..8439743b
--- /dev/null
+++ b/backend/migrate-todos.js
@@ -0,0 +1,24 @@
+const mongoDbClient = require("./database/mongoDbClient");
+const ToDosService = require("./services/todosService");
+
+mongoDbClient.connectToServer(async function (err) {
+  if (err) {
+    console.error(err);
+    process.exit();
+  }
+
+  const ToDosServiceInstance = new ToDosService();
+
+  // Naive migration of ToDos
+  await ToDosServiceInstance.migrateToDos();
+
+  const allNewToDosLists = await ToDosServiceInstance.getAllToDosLists();
+
+  const successfulMigration = allNewToDosLists.flatMap(todoList => todoList.todos).every(toDo => typeof toDo.task === 'string');
+
+  if (successfulMigration) {
+    console.log('successful migration');
+  } else {
+    console.log('something went wrong with the migration migration');
+  }
+});
\ No newline at end of file
diff --git a/backend/services/todosService.js b/backend/services/todosService.js
index 7568ae7f..f5f224bc 100644
--- a/backend/services/todosService.js
+++ b/backend/services/todosService.js
@@ -1,5 +1,6 @@
 const TodosDao = require('../daos/todosDao');
 const ULID = require("ulid");
+const {todoStatus} = require("../utils/models/todos");
 
 class TodosService {
   constructor () {
@@ -19,10 +20,46 @@ class TodosService {
   }
 
   updateToDosList(todoListId, newToDoListTitle, newToDoListToDos) {
-    const nonEmptyToDos = newToDoListToDos.filter(todo => todo.length > 0);
+    const nonEmptyToDos = newToDoListToDos.filter(todo => todo.task.length > 0);
 
     return this.ToDosDao.updateToDosList(todoListId, newToDoListTitle, nonEmptyToDos);
   }
+
+  getAllToDosLists() {
+    return this.ToDosDao.getAllToDosLists();
+  }
+
+  // Naive migration of data
+  async migrateToDos() {
+    const oldTodosLists = await this.getAllToDosLists();
+
+    console.log('oldTodosLists', oldTodosLists);
+
+    const newToDosLists = oldTodosLists.map(oldToDoList => ({
+      ...oldToDoList,
+      todos: oldToDoList.todos.map(oldToDo => ({
+        task: oldToDo,
+        status: todoStatus.Pending
+      }))
+    }));
+
+    console.log('newToDosLists', newToDosLists);
+
+    const futureMigratedToDosLists = newToDosLists.map(toDoList => {
+      return this.updateToDosList(toDoList.id, toDoList.title, toDoList.todos);
+    });
+
+    try {
+      return await Promise.all(futureMigratedToDosLists);
+    } catch {
+      console.log('An error occurred during the migration');
+      const futureOldToDosLists = oldTodosLists.map(toDoList => {
+        return this.updateToDosList(toDoList.id, toDoList.title, toDoList.todos);
+      });
+
+      return await Promise.all(futureOldToDosLists);
+    }
+  }
 }
 
 module.exports = TodosService;
\ No newline at end of file
diff --git a/backend/utils/models/todos.js b/backend/utils/models/todos.js
new file mode 100644
index 00000000..fca9b76d
--- /dev/null
+++ b/backend/utils/models/todos.js
@@ -0,0 +1,8 @@
+const ToDoStatus = {
+  Completed: 'Completed',
+  Pending: 'Pending'
+};
+
+module.exports = {
+  todoStatus: ToDoStatus
+}
\ No newline at end of file