test.py

import unittest
import os
import io
import json
import datetime
from unittest.mock import patch, mock_open

# Import the modules being tested
from study_reminders.students_manager import StudentsManager
from study_reminders.students import Students
from study_reminders.reminder_generator import generate_reminder
from study_reminders.reminder_sender import send_reminder
from study_reminders.logger import log_reminder


# -------------------------------
# Tests for reminder-related functions
# -------------------------------
class TestReminderFunctions(unittest.TestCase):

    def test_generate_reminder(self):
        """Test that generate_reminder creates a proper message."""
        msg = generate_reminder("Alice", "Physics")
        self.assertIn("Alice", msg)
        self.assertIn("Physics", msg)
        self.assertTrue(msg.startswith("Hi"))

    def test_send_reminder_valid_email(self):
        """Test that send_reminder prints a message when email is valid."""
        with patch("builtins.print") as mock_print:
            send_reminder("alice@example.com", "Test Reminder")
            mock_print.assert_called_once()  # Ensure print was called once
            args = mock_print.call_args[0][0]  # Extract print text
            self.assertIn("Sending reminder", args)

    def test_send_reminder_missing_email(self):
        """Test that send_reminder raises an error if email is missing."""
        with self.assertRaises(ValueError):
            send_reminder("", "No email")

    def test_log_reminder_creates_entry(self):
        """Test that log_reminder writes correct log entry content."""
        student = {"name": "Alice"}
        reminder = "Study Physics"
        fake_file = io.StringIO()
        with patch("builtins.open", mock_open()) as mock_file:
            log_reminder(student, reminder)
            mock_file.assert_called_once()  # Ensure file was opened
            handle = mock_file()  # Get file handle
            written = handle.write.call_args[0][0]  # Get what was written
            # Check that log contains student name, reminder text, and a timestamp
            self.assertIn("Alice", written)
            self.assertIn("Study Physics", written)
            self.assertIn(str(datetime.datetime.now().year), written)


# -------------------------------
# Tests for StudentsManager class
# -------------------------------
class TestStudentsManager(unittest.TestCase):

    def setUp(self):
        """Prepare a fake students.json for testing."""
        fake_json = json.dumps([
            {"name": "Alice", "email": "a@a.com", "course": "Math", "preferred_time": "08:00"}
        ])
        # Patch the open_text function to return fake JSON data
        self.patcher = patch("study_reminders.students_manager.resources.open_text", mock_open(read_data=fake_json))
        self.mock_open_text = self.patcher.start()
        self.sm = StudentsManager()

    def tearDown(self):
        """Stop the patch after each test."""
        self.patcher.stop()

    def test_load_students(self):
        """Ensure that students.json is correctly loaded into memory."""
        students = self.sm.get_students()
        self.assertEqual(len(students), 1)
        self.assertEqual(students[0]['name'], "Alice")

    def test_add_student(self):
        """Test adding a new student and saving to JSON."""
        with patch("builtins.open", mock_open()) as mock_file:
            self.sm.add_student("Bob", "b@b.com", "Physics")
            # Verify new student was added
            self.assertTrue(any(s["name"] == "Bob" for s in self.sm.get_students()))
            mock_file.assert_called_once()  # Ensure JSON file was saved

    def test_remove_student(self):
        """Test removing an existing student."""
        with patch("builtins.open", mock_open()):
            self.sm.add_student("Charlie", "c@c.com", "Chemistry")
            self.sm.remove_student("Charlie")
            # Verify the student was removed
            self.assertFalse(any(s["name"] == "Charlie" for s in self.sm.get_students()))


# -------------------------------
# Tests for Students class (simpler student container)
# -------------------------------
class TestStudentsClass(unittest.TestCase):

    def test_add_and_remove_student(self):
        """Ensure Students class can add and remove students correctly."""
        s = Students()
        s.add_student("Alice", "alice@example.com", "Math")
        self.assertEqual(len(s.get_students()), 1)
        s.remove_student("Alice")
        self.assertEqual(len(s.get_students()), 0)


# -------------------------------
# Run all tests
# -------------------------------
if __name__ == "__main__":
    unittest.main()