"""
Tests for queue processor v2 core functionality.

Tests cover:
- Process queue loop
- Process user queue
- Start queued researches
"""

import threading
import time


class TestProcessQueueLoop:
    """Tests for the main queue processing loop."""

    def test_process_queue_loop_execution(self):
        """Queue loop executes when running."""
        running = True
        iterations = 0
        max_iterations = 3

        while running and iterations < max_iterations:
            iterations += 1
            if iterations >= max_iterations:
                running = False

        assert iterations == max_iterations

    def test_process_queue_loop_user_check_list_processing(self):
        """Queue loop processes user check list."""
        users_to_check = {"user1:session1", "user2:session2", "user3:session3"}
        processed_users = []

        for user_session in users_to_check:
            username, session_id = user_session.split(":", 1)
            processed_users.append(username)

        assert len(processed_users) == 3
        assert "user1" in processed_users

    def test_process_queue_loop_queue_empty_detection(self):
        """Queue loop detects empty queue."""
        queue_status = {"queued_tasks": 0, "active_tasks": 0}

        queue_empty = queue_status["queued_tasks"] == 0

        assert queue_empty

    def test_process_queue_loop_error_handling_in_loop(self):
        """Queue loop handles errors gracefully."""
        errors_caught = []

        try:
            raise Exception("Processing error")
        except Exception as e:
            errors_caught.append(str(e))
            # Loop continues after error

        assert len(errors_caught) == 1

    def test_process_queue_loop_thread_safety_concurrent_ops(self):
        """Queue loop is thread-safe."""
        users_to_check = set()
        lock = threading.Lock()

        def add_user(username):
            with lock:
                users_to_check.add(username)

        threads = []
        for i in range(10):
            t = threading.Thread(target=add_user, args=(f"user{i}",))
            threads.append(t)
            t.start()

        for t in threads:
            t.join()

        assert len(users_to_check) == 10

    def test_process_queue_loop_check_interval_timing(self):
        """Queue loop respects check interval."""
        check_interval = 0.1  # 100ms
        start_time = time.time()

        # Simulate one interval
        time.sleep(check_interval)

        elapsed = time.time() - start_time

        assert elapsed >= check_interval

    def test_process_queue_loop_stop_flag_respected(self):
        """Queue loop stops when flag is set."""
        running = True
        iterations = 0

        while running:
            iterations += 1
            if iterations == 3:
                running = False  # Stop flag

        assert iterations == 3

    def test_process_queue_loop_user_removal_during_processing(self):
        """Users are removed from check list when queue empty."""
        users_to_check = {"user1:session1", "user2:session2"}
        users_to_remove = []

        for user_session in users_to_check:
            # Simulate queue empty for user1
            if "user1" in user_session:
                users_to_remove.append(user_session)

        for user_session in users_to_remove:
            users_to_check.discard(user_session)

        assert len(users_to_check) == 1
        assert "user2:session2" in users_to_check

    def test_process_queue_loop_multiple_users_independence(self):
        """Multiple users are processed independently."""
        user_queues = {
            "user1": {"queued": 5, "active": 1},
            "user2": {"queued": 0, "active": 2},
            "user3": {"queued": 3, "active": 0},
        }

        users_with_work = [u for u, q in user_queues.items() if q["queued"] > 0]

        assert len(users_with_work) == 2
        assert "user2" not in users_with_work

    def test_process_queue_loop_database_error_recovery(self):
        """Queue loop recovers from database errors."""
        db_errors = 0
        max_retries = 3

        for _ in range(max_retries):
            try:
                # Simulate DB error
                raise Exception("Database error")
            except Exception:
                db_errors += 1
                # Continue processing

        assert db_errors == max_retries


class TestProcessUserQueue:
    """Tests for processing individual user queues."""

    def test_process_user_queue_password_retrieval(self):
        """Password is retrieved from session store."""
        session_passwords = {"user1:session1": "password123"}

        username = "user1"
        session_id = "session1"
        key = f"{username}:{session_id}"

        password = session_passwords.get(key)

        assert password == "password123"

    def test_process_user_queue_database_opening_error(self):
        """Database opening error is handled."""
        db_open_success = False

        if not db_open_success:
            # Keep checking - could be temporary
            keep_checking = True
        else:
            keep_checking = False

        assert keep_checking

    def test_process_user_queue_queue_status_retrieval(self):
        """Queue status is retrieved correctly."""
        queue_status = {"active_tasks": 2, "queued_tasks": 5}

        assert queue_status["active_tasks"] == 2
        assert queue_status["queued_tasks"] == 5

    def test_process_user_queue_available_slots_calculation(self):
        """Available slots are calculated correctly."""
        max_concurrent = 3
        active_tasks = 1

        available_slots = max_concurrent - active_tasks

        assert available_slots == 2

    def test_process_user_queue_return_value_queue_empty(self):
        """Returns True when queue is empty."""
        queued_tasks = 0

        queue_empty = queued_tasks == 0

        assert queue_empty

    def test_process_user_queue_return_value_queue_not_empty(self):
        """Returns False when queue has items."""
        queued_tasks = 5

        queue_empty = queued_tasks == 0

        assert not queue_empty

    def test_process_user_queue_session_expired_handling(self):
        """Session expired removes user from checking."""
        password = None  # Session expired

        if not password:
            remove_from_checking = True
        else:
            remove_from_checking = False

        assert remove_from_checking

    def test_process_user_queue_settings_manager_integration(self):
        """Settings manager is used for user settings."""
        settings = {
            "app.queue_mode": "direct",
            "app.max_concurrent_researches": 3,
        }

        queue_mode = settings.get("app.queue_mode", "direct")
        max_concurrent = settings.get("app.max_concurrent_researches", 3)

        assert queue_mode == "direct"
        assert max_concurrent == 3

    def test_process_user_queue_concurrent_access_safety(self):
        """User queue processing is thread-safe."""
        processing_users = set()
        lock = threading.Lock()

        def process_user(username):
            with lock:
                processing_users.add(username)
            time.sleep(0.01)
            with lock:
                processing_users.discard(username)

        threads = []
        for i in range(5):
            t = threading.Thread(target=process_user, args=(f"user{i}",))
            threads.append(t)
            t.start()

        for t in threads:
            t.join()

        assert len(processing_users) == 0

    def test_process_user_queue_transaction_rollback(self):
        """Transaction is rolled back on error."""
        transaction_committed = False
        transaction_rolled_back = False

        try:
            # Simulate error
            raise Exception("Transaction error")
            transaction_committed = True
        except Exception:
            transaction_rolled_back = True

        assert not transaction_committed
        assert transaction_rolled_back


class TestStartQueuedResearches:
    """Tests for starting queued researches."""

    def test_start_queued_researches_fetch_items(self):
        """Queued items are fetched correctly."""
        queued_items = [
            {"research_id": 1, "position": 1},
            {"research_id": 2, "position": 2},
            {"research_id": 3, "position": 3},
        ]

        fetched = queued_items[:2]  # Limit to available slots

        assert len(fetched) == 2

    def test_start_queued_researches_ordering_by_position(self):
        """Items are ordered by position."""
        queued_items = [
            {"research_id": 3, "position": 3},
            {"research_id": 1, "position": 1},
            {"research_id": 2, "position": 2},
        ]

        sorted_items = sorted(queued_items, key=lambda x: x["position"])

        assert sorted_items[0]["research_id"] == 1
        assert sorted_items[1]["research_id"] == 2
        assert sorted_items[2]["research_id"] == 3

    def test_start_queued_researches_processing_flag_set(self):
        """Processing flag is set before starting."""
        queued_research = {"is_processing": False}

        # Set flag
        queued_research["is_processing"] = True

        assert queued_research["is_processing"]

    def test_start_queued_researches_processing_flag_reset_on_error(self):
        """Processing flag is reset on error."""
        queued_research = {"is_processing": False}

        try:
            queued_research["is_processing"] = True
            raise Exception("Start error")
        except Exception:
            queued_research["is_processing"] = False

        assert not queued_research["is_processing"]

    def test_start_queued_researches_task_status_updates(self):
        """Task status is updated during processing."""
        statuses = []

        statuses.append("queued")
        statuses.append("processing")
        statuses.append("started")

        assert statuses == ["queued", "processing", "started"]

    def test_start_queued_researches_max_concurrent_limit(self):
        """Max concurrent limit is respected."""
        available_slots = 2
        queued_count = 5

        to_start = min(available_slots, queued_count)

        assert to_start == 2

    def test_start_queued_researches_empty_queue(self):
        """Empty queue returns without starting."""
        queued_items = []

        started_count = 0
        for item in queued_items:
            started_count += 1

        assert started_count == 0

    def test_start_queued_researches_all_slots_filled(self):
        """No starts when all slots filled."""
        available_slots = 0

        can_start = available_slots > 0

        assert not can_start

    def test_start_queued_researches_partial_start_on_error(self):
        """Partial starts are completed before error."""
        queued_items = [1, 2, 3, 4, 5]
        started = []

        for i, item in enumerate(queued_items):
            if i == 3:
                break  # Error on 4th item
            started.append(item)

        assert len(started) == 3

    def test_start_queued_researches_database_commit(self):
        """Database is committed after starting."""
        commit_count = 0

        # Each successful start commits
        for _ in range(3):
            commit_count += 1

        assert commit_count == 3


class TestQueueProcessorInitialization:
    """Tests for queue processor initialization."""

    def test_initialization_default_interval(self):
        """Default check interval is set."""
        default_interval = 10

        assert default_interval == 10

    def test_initialization_empty_sets(self):
        """User check set is empty on init."""
        users_to_check = set()

        assert len(users_to_check) == 0

    def test_initialization_pending_operations_dict(self):
        """Pending operations dict is empty on init."""
        pending_operations = {}

        assert len(pending_operations) == 0

    def test_initialization_locks_created(self):
        """Thread locks are created."""
        users_lock = threading.Lock()
        pending_lock = threading.Lock()

        assert users_lock is not None
        assert pending_lock is not None
