const express = require("express");
const Course = require("../models/Course");

const router = express.Router();

router.get("/", async (req, res) => {
    try {
      const filter = {};
  
      if (req.query.department) filter.department = req.query.department;
      if (req.query.program) filter.program = req.query.program;
      if (req.query.semester) filter.semester = Number(req.query.semester); // Convert to number if needed
      if (req.query.scheme) filter.scheme = req.query.scheme;
  
      const courses = await Course.find(filter);
      res.json(courses);
    } catch (error) {
      console.error("Error fetching courses:", error);
      res.status(500).json({ error: "Failed to fetch courses" });
    }
  });
  

// Get course by ID
router.get("/:id", async (req, res) => {
  try {
    const course = await Course.findOne({ courseId: req.params.id });
    if (!course) {
      return res.status(404).json({ error: "Course not found" });
    }
    res.json(course);
  } catch (error) {
    console.error("Error fetching course:", error);
    res.status(500).json({ error: "Failed to fetch course" });
  }
});

// Update course status route
router.patch("/api/courses/:courseId", async (req, res) => {
  try {
    const { courseId } = req.params; // Extract courseId from params
    const { status } = req.body; // Extract status from body

    console.log("Request params:", req.params);
    console.log("Request body:", req.body);

    // Validate status
    if (!["submitted", "not submitted"].includes(status.toLowerCase())) {
      return res.status(400).json({ message: "Invalid status value" });
    }

    // Find and update the course by courseId
    const updatedCourse = await Course.findOneAndUpdate(
      { courseId }, // Query by courseId field
      { status: status.toLowerCase() }, // Set status (convert to lowercase)
      { new: true } // Return the updated document
    );

    if (!updatedCourse) {
      console.error("Course not found:", courseId);
      return res.status(404).json({ message: "Course not found" });
    }

    console.log("Updated course:", updatedCourse);
    res.status(200).json(updatedCourse);
  } catch (error) {
    console.error("Error updating course status:", error.message);
    res.status(500).json({ message: "Internal server error" });
  }
});


module.exports = router;