require("dotenv").config();
const express = require('express');
const mongoose = require("mongoose")
const cors = require('cors');

const port = 3001;
const app = express();

app.use(express.json());
app.use(cors());

(async () => {
  try {
    mongoose.set("autoIndex", false);

    await mongoose.connect(process.env.MONGO_URI);
    console.log("✅ MongoDB Connected");

    await Task.syncIndexes();
    console.log("✅ Indexes created");

    app.listen(port, () => {
      console.log(`✅ To Do App listening on port ${port}`);
    });
  } catch (error) {
    console.error(`Startup Error! ${error}`);
  }
})();

// Task Schema
const taskSchema = new mongoose.Schema({
  title: { type: String, required: true },
  completed: { type: Boolean, required: true, default: false },
  description: { type: String, required: true },
  dueDate: { type: Date, required: true },
  dateCreated: { type: Date, required: true, default: new Date() }
})

taskSchema.index({ dueDate: 1 })
taskSchema.index({ dateCreated: 1 })

const Task = mongoose.model("Task", taskSchema);

app.get('/api/tasks', async (req, res) => {

  try {
    const { sortBy } = req.query; // ?sortBy=dueDate or ?sortBy=dateCreated
    let sortOption = {};

    if (sortBy === 'dueDate') {
        sortOption = { dueDate: 1 }; // Ascending
    } else if (sortBy === 'dateCreated') {
        sortOption = { dateCreated: 1 };
    }

    const tasks = await Task.find({}).sort(sortOption);

    if (!tasks) {
      return res.status(404).json({ message: "Tasks not found!" });
    }

    res.json(tasks);
  } catch (error) {
    console.error("Error:", error);
    res.status(500).json({ message: "Error grabbing tasks!" });

  } 
});


app.post('/api/tasks/todo', async (req, res) => {
  try {
    const { title, description, dueDate } = req.body;
    const taskData = { title, description, dueDate };
    const createTask = new Task(taskData);
    const newTask = await createTask.save();

    res.json({ task: newTask, message: "New task created successfully!" });

  } catch (error) {
    console.error("Error:", error);
    res.status(500).json({ message: "Error creating the task!" });
  }

});

// To 'complete' the task and move columns ↓   

app.patch('/api/tasks/complete/:id', async (req, res) => {
  try {
    const { completed } = req.body;
    const taskId = req.params.id;
    const completedTask = await Task.findByIdAndUpdate(taskId, { completed }, { new: true });

    if (!completedTask) {
      return res.status(404).json({ message: "Task not found!" });

    }
    res.json({ task: completedTask, message: "Task set to 'Complete'" });

  } catch (error) {
    console.error("Error:", error);
    res.status(500).json({ message: "Error completing the task!" });

  }
});

// To make the task 'not complete' and move columns ↓

app.patch('/api/tasks/notComplete/:id', async (req, res) => {

  try {
    const { completed } = req.body; 
    const taskId = req.params.id;
    const taskNotComplete = await Task.findByIdAndUpdate(taskId, { completed }, { new: true });

    if (!taskNotComplete) {
      return res.status(404).json({ message: "Task not found!" });
    }
    res.json({ task: taskNotComplete, message: "Task set to 'Not Complete'" });
  } catch (error) {
    console.error("Error:", error);
    res.status(500).json({ message: "Error making the task NOT complete!" });
  }
});

app.delete('/api/tasks/delete/:id', async (req, res) => {
  try {
    const taskId = req.params.id;
    const deletedTask = await Task.findByIdAndDelete(taskId);

    if (!deletedTask) {
      return res.status(404).json({ message: "Task not found!" });
    }

    res.json({ task: deletedTask, message: "Task deleted successfully!" });

  } catch (error) {
    console.error("Error:", error);
    res.status(500).json({ message: "Error deleting the task!" });

  }
});

// To edit exisiting task and update

app.put('/api/tasks/update/:id', async (req, res) => {

  try {
    const taskId = req.params.id;
    const { title, description, dueDate } = req.body;  // Extract data from front end request
    const taskData = { title, description, dueDate };
    const updatedTask = await Task.findByIdAndUpdate(taskId, taskData, { new: true });

    if (!updatedTask) {
        return res.status(404).json({ message: "Task not found!" });
    }

    res.json({ task: updatedTask, message: "Task updated successfully!" });

  } catch (error) {
    console.error('Error:', error);
    res.status(500).json({ message: "Error updating the task!" });

  }

});