import pytest

from django.core import mail

from todo.models import Task, Comment
from todo.utils import toggle_done, toggle_deleted, send_notify_mail, send_email_to_thread_participants


@pytest.fixture()
# Set up an in-memory mail server to receive test emails
def email_backend_setup(settings):
    settings.EMAIL_BACKEND = 'django.core.mail.backends.locmem.EmailBackend'


def test_toggle_done(todo_setup):
    """Utility function takes an array of POSTed IDs and changes their `completed` status.
    """
    u1_tasks = Task.objects.filter(created_by__username="u1")
    completed = u1_tasks.filter(completed=True)
    incomplete = u1_tasks.filter(completed=False)

    # Expected counts in fixture data
    assert u1_tasks.count() == 3
    assert incomplete.count() == 2
    assert completed.count() == 1

    # Mark incomplete tasks completed and check again
    toggle_done([t.id for t in incomplete])
    now_completed = u1_tasks.filter(created_by__username="u1", completed=True)
    assert now_completed.count() == 3

    # Mark all incomplete and check again
    toggle_done([t.id for t in now_completed])
    now_incomplete = u1_tasks.filter(created_by__username="u1", completed=False)
    assert now_incomplete.count() == 3


def test_toggle_deleted(todo_setup):
    """Unlike toggle_done, delete means delete, so it's not really a toggle.
    """
    u1_tasks = Task.objects.filter(created_by__username="u1")
    assert u1_tasks.count() == 3
    t1 = u1_tasks.first()
    t2 = u1_tasks.last()

    toggle_deleted([t1.id, t2.id, ])
    u1_tasks = Task.objects.filter(created_by__username="u1")
    assert u1_tasks.count() == 1


def test_send_notify_mail_not_me(todo_setup, django_user_model, email_backend_setup):
    """Assign a task to someone else, mail should be sent.
    TODO: Future tests could check for email contents.
    """

    u1 = django_user_model.objects.get(username="u1")
    u2 = django_user_model.objects.get(username="u2")

    task = Task.objects.filter(created_by=u1).first()
    task.assigned_to = u2
    task.save()
    send_notify_mail(task)
    assert len(mail.outbox) == 1


def test_send_notify_mail_myself(todo_setup, django_user_model, email_backend_setup):
    """Assign a task to myself, no mail should be sent.
    """

    u1 = django_user_model.objects.get(username="u1")
    task = Task.objects.filter(created_by=u1).first()
    task.assigned_to = u1
    task.save()
    send_notify_mail(task)
    assert len(mail.outbox) == 0


def test_send_email_to_thread_participants(todo_setup, django_user_model, email_backend_setup):
    """For a given task authored by one user, add comments by two other users.
    Notification email should be sent to all three users."""

    u1 = django_user_model.objects.get(username="u1")
    task = Task.objects.filter(created_by=u1).first()

    u3 = django_user_model.objects.create_user(username="u3", password="zzz", email="u3@example.com")
    u4 = django_user_model.objects.create_user(username="u4", password="zzz", email="u4@example.com")
    Comment.objects.create(author=u3, task=task, body="Hello", )
    Comment.objects.create(author=u4, task=task, body="Hello", )

    send_email_to_thread_participants(task, "test body", u1)
    assert len(mail.outbox) == 1  # One message to multiple recipients
    assert 'u1@example.com' in mail.outbox[0].recipients()
    assert 'u3@example.com' in mail.outbox[0].recipients()
    assert 'u4@example.com' in mail.outbox[0].recipients()