from django.contrib.auth.models import User
from django.test import TestCase

from exercise.models import Exercise
from generator.models import UserPreference
from generator.services.exercise_selector import ExerciseSelector
from registered_user.models import RegisteredUser


class TestSidePairIntegrity(TestCase):
    def setUp(self):
        django_user = User.objects.create_user(
            username='side_pair_user',
            password='testpass123',
        )
        registered_user = RegisteredUser.objects.create(
            user=django_user,
            first_name='Side',
            last_name='Pair',
        )
        self.preference = UserPreference.objects.create(
            registered_user=registered_user,
            days_per_week=4,
            fitness_level=2,
        )
        self.selector = ExerciseSelector(self.preference)

    def test_orphan_left_is_removed_and_replaced(self):
        left_only = Exercise.objects.create(
            name='Single Arm Row Left',
            side='Left',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper pull - horizontal, upper pull',
            muscle_groups='lats,upper back,biceps',
            difficulty_level='intermediate',
        )
        filler_a = Exercise.objects.create(
            name='Chest Supported Row',
            side='',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper pull - horizontal, upper pull',
            muscle_groups='lats,upper back,biceps',
            difficulty_level='intermediate',
        )
        filler_b = Exercise.objects.create(
            name='Face Pull',
            side='',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper pull, rear delt',
            muscle_groups='upper back,deltoids',
            difficulty_level='intermediate',
        )

        selected = [left_only]
        base_qs = Exercise.objects.filter(pk__in=[left_only.pk, filler_a.pk, filler_b.pk])
        enforced = self.selector._ensure_side_pair_integrity(selected, base_qs, count=1)

        self.assertEqual(len(enforced), 1)
        self.assertNotEqual(enforced[0].pk, left_only.pk)
        self.assertIn(
            enforced[0].pk,
            {filler_a.pk, filler_b.pk},
            'Orphan left-side movement should be replaced by a non-sided filler.',
        )

    def test_left_right_pair_is_preserved(self):
        left_ex = Exercise.objects.create(
            name='Single Arm Press Left',
            side='Left',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper push - vertical, upper push',
            muscle_groups='deltoids,triceps',
            difficulty_level='intermediate',
        )
        right_ex = Exercise.objects.create(
            name='Single Arm Press Right',
            side='Right',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper push - vertical, upper push',
            muscle_groups='deltoids,triceps',
            difficulty_level='intermediate',
        )

        enforced = self.selector._ensure_side_pair_integrity(
            [left_ex, right_ex],
            Exercise.objects.filter(pk__in=[left_ex.pk, right_ex.pk]),
            count=2,
        )
        enforced_ids = {ex.pk for ex in enforced}
        self.assertEqual(enforced_ids, {left_ex.pk, right_ex.pk})

    def test_left_arm_right_arm_pair_is_preserved(self):
        left_ex = Exercise.objects.create(
            name='Single Arm Row',
            side='left_arm',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper pull - horizontal, upper pull',
            muscle_groups='lats,upper back,biceps',
            difficulty_level='intermediate',
        )
        right_ex = Exercise.objects.create(
            name='Single Arm Row',
            side='right_arm',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper pull - horizontal, upper pull',
            muscle_groups='lats,upper back,biceps',
            difficulty_level='intermediate',
        )

        paired = self.selector._pair_sided_exercises(
            [left_ex],
            Exercise.objects.filter(pk__in=[left_ex.pk, right_ex.pk]),
        )
        paired_ids = {ex.pk for ex in paired}
        self.assertEqual(paired_ids, {left_ex.pk, right_ex.pk})

    def test_orphan_left_arm_is_removed(self):
        left_ex = Exercise.objects.create(
            name='Single Arm Row',
            side='left_arm',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper pull - horizontal, upper pull',
            muscle_groups='lats,upper back,biceps',
            difficulty_level='intermediate',
        )
        filler = Exercise.objects.create(
            name='Inverted Row',
            side='',
            is_reps=True,
            is_duration=False,
            is_weight=False,
            movement_patterns='upper pull - horizontal, upper pull',
            muscle_groups='lats,upper back,biceps',
            difficulty_level='intermediate',
        )

        enforced = self.selector._ensure_side_pair_integrity(
            [left_ex],
            Exercise.objects.filter(pk__in=[left_ex.pk, filler.pk]),
            count=1,
        )
        self.assertEqual(len(enforced), 1)
        self.assertEqual(enforced[0].pk, filler.pk)

    def test_try_hard_fetch_adds_opposite_side_partner_from_global_db(self):
        left_ex = Exercise.objects.create(
            name='Single Arm Lateral Raise Left',
            side='Left',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper push',
            muscle_groups='deltoids',
            difficulty_level='intermediate',
        )
        right_ex = Exercise.objects.create(
            name='Single Arm Lateral Raise Right',
            side='Right',
            is_reps=True,
            is_duration=False,
            is_weight=True,
            movement_patterns='upper push',
            muscle_groups='deltoids',
            difficulty_level='intermediate',
        )
        filler = Exercise.objects.create(
            name='Shoulder Tap',
            side='',
            is_reps=True,
            is_duration=False,
            is_weight=False,
            movement_patterns='upper push',
            muscle_groups='deltoids,core',
            difficulty_level='intermediate',
        )

        # base_qs intentionally does not include right_ex to validate global fallback.
        base_qs = Exercise.objects.filter(pk__in=[left_ex.pk, filler.pk])
        enforced = self.selector._ensure_side_pair_integrity(
            [left_ex, filler],
            base_qs,
            count=2,
        )
        enforced_ids = {ex.pk for ex in enforced}
        self.assertIn(left_ex.pk, enforced_ids)
        self.assertIn(right_ex.pk, enforced_ids)
        self.assertNotIn(filler.pk, enforced_ids)