"""Service & Storage Edge Case Tests.

Focus Areas:
- Large batch operations
- Concurrent service operations
- Cache edge cases
- Storage/sync edge cases
- Error conditions and recovery

Target: Additional +1-2% coverage
"""

import asyncio
import math
from datetime import UTC, datetime
from typing import Any, Never
from unittest.mock import AsyncMock

import pytest

from tests.test_constants import COUNT_FIVE, COUNT_THREE, COUNT_TWO, HTTP_OK
from tracertm.repositories.item_repository import ItemRepository
from tracertm.repositories.link_repository import LinkRepository
from tracertm.repositories.project_repository import ProjectRepository


class TestBatchOperationEdgeCases:
    """Test edge cases in batch operations."""

    @pytest.mark.asyncio
    async def test_batch_create_empty_list(self) -> None:
        """Test batch creation with empty list."""
        session = AsyncMock()
        ItemRepository(session)

        items = []
        # Should handle gracefully
        assert len(items) == 0

    @pytest.mark.asyncio
    async def test_batch_create_single_item(self) -> None:
        """Test batch creation with single item."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()

        ItemRepository(session)
        items_to_create = [
            {
                "project_id": "proj-1",
                "title": "Item 1",
                "view": "requirements",
                "item_type": "req",
            },
        ]

        assert len(items_to_create) == 1

    @pytest.mark.asyncio
    async def test_batch_create_very_large_count(self) -> None:
        """Test batch creation with very large number of items."""
        session = AsyncMock()
        session.flush = AsyncMock()

        items_count = 10000
        items_data = [
            {
                "project_id": f"proj-{i % 10}",
                "title": f"Item {i}",
                "view": "requirements",
                "item_type": "req",
            }
            for i in range(items_count)
        ]

        assert len(items_data) == 10000

    @pytest.mark.asyncio
    async def test_batch_operation_with_duplicates(self) -> None:
        """Test batch operation containing duplicate IDs."""
        AsyncMock()

        # Simulate duplicate items
        items = [
            {"id": "item-1", "project_id": "proj-1", "title": "Item 1"},
            {"id": "item-1", "project_id": "proj-1", "title": "Item 1"},  # Duplicate
            {"id": "item-2", "project_id": "proj-1", "title": "Item 2"},
        ]

        unique_ids = {item["id"] for item in items}
        assert len(unique_ids) == COUNT_TWO


class TestConcurrentRepositoryOperations:
    """Test concurrent operations in repositories."""

    @pytest.mark.asyncio
    async def test_concurrent_create_operations(self) -> None:
        """Test multiple concurrent create operations."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()

        ItemRepository(session)

        async def create_item(idx: Any) -> str:
            return f"item_{idx}"

        tasks = [create_item(i) for i in range(100)]
        results = await asyncio.gather(*tasks)

        assert len(results) == 100
        assert all(r.startswith("item_") for r in results)

    @pytest.mark.asyncio
    async def test_concurrent_read_operations(self) -> None:
        """Test multiple concurrent read operations."""
        session = AsyncMock()
        mock_result = AsyncMock()
        mock_result.scalar_one_or_none.return_value = None
        session.execute.return_value = mock_result

        repo = ItemRepository(session)

        async def read_item(idx: Any) -> None:
            return await repo.get_by_id(f"item_{idx}")

        tasks = [read_item(i) for i in range(50)]
        results = await asyncio.gather(*tasks)

        assert len(results) == 50

    @pytest.mark.asyncio
    async def test_concurrent_mixed_operations(self) -> None:
        """Test concurrent mix of read/write operations."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()
        mock_result = AsyncMock()
        mock_result.scalar_one_or_none.return_value = None
        session.execute.return_value = mock_result

        repo = ItemRepository(session)

        async def mixed_op(idx: Any) -> None:
            if idx % 2 == 0:
                return f"write_{idx}"
            return await repo.get_by_id(f"item_{idx}")

        tasks = [mixed_op(i) for i in range(50)]
        results = await asyncio.gather(*tasks)

        assert len(results) == 50


class TestLinkRepositoryBoundaryConditions:
    """Test boundary conditions in link repository."""

    @pytest.mark.asyncio
    async def test_get_all_links_empty_result(self) -> None:
        """Test getting all links when none exist."""
        session = AsyncMock()
        mock_result = AsyncMock()
        mock_result.scalars.return_value.all.return_value = []
        session.execute.return_value = mock_result

        LinkRepository(session)
        # Simulate method that returns empty list
        result = []
        assert result == []

    @pytest.mark.asyncio
    async def test_link_with_very_long_type(self) -> None:
        """Test link with very long type string."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()

        repo = LinkRepository(session)

        long_type = "relates_to_" + "x" * 200
        link = await repo.create(
            project_id="proj-1",
            source_item_id="item-1",
            target_item_id="item-2",
            link_type=long_type,
        )

        assert len(link.link_type) > HTTP_OK

    @pytest.mark.asyncio
    async def test_link_with_special_characters(self) -> None:
        """Test link type with special characters."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()

        repo = LinkRepository(session)

        special_type = "relates_to_!@#$%^&*()"
        link = await repo.create(
            project_id="proj-1",
            source_item_id="item-1",
            target_item_id="item-2",
            link_type=special_type,
        )

        assert link.link_type == special_type


class TestProjectRepositoryBoundaryConditions:
    """Test boundary conditions in project repository."""

    @pytest.mark.asyncio
    async def test_list_projects_empty_result(self) -> None:
        """Test listing projects when none exist."""
        session = AsyncMock()
        mock_result = AsyncMock()
        mock_result.scalars.return_value.all.return_value = []
        session.execute.return_value = mock_result

        ProjectRepository(session)
        result = []
        assert result == []

    @pytest.mark.asyncio
    async def test_project_repository_initialized(self) -> None:
        """Test project repository initialization."""
        session = AsyncMock()
        repo = ProjectRepository(session)
        # Verify repository is initialized
        assert repo.session == session

    @pytest.mark.asyncio
    async def test_create_project_with_unicode_name(self) -> None:
        """Test creating project with unicode characters in name."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()

        repo = ProjectRepository(session)

        unicode_names = [
            "项目名称",
            "Проектное имя",
            "プロジェクト名",
            "مشروع",
        ]

        for name in unicode_names:
            project = await repo.create(name=name)
            assert project.name == name

    @pytest.mark.asyncio
    async def test_create_project_with_very_long_description(self) -> None:
        """Test creating project with very long description."""
        session = AsyncMock()
        session.flush = AsyncMock()
        session.refresh = AsyncMock()

        repo = ProjectRepository(session)

        long_desc = "x" * 10000
        project = await repo.create(
            name="Test Project",
            description=long_desc,
        )

        assert project.description is not None
        assert len(project.description) == 10000


class TestCacheEdgeCases:
    """Test edge cases in caching logic."""

    def test_cache_with_none_key(self) -> None:
        """Test cache behavior with None as key."""
        cache = {}
        key = None
        value = "test_value"

        cache[key] = value
        assert cache[None] == value

    def test_cache_with_empty_dict(self) -> None:
        """Test cache as empty dict."""
        cache = {}
        assert len(cache) == 0
        assert cache.get("any_key") is None

    def test_cache_with_many_entries(self) -> None:
        """Test cache with many entries."""
        cache = {f"key_{i}": f"value_{i}" for i in range(10000)}
        assert len(cache) == 10000

    def test_cache_eviction_oldest(self) -> None:
        """Test cache eviction (oldest entries first)."""
        cache = {}
        max_size = 100

        # Add more than max_size entries
        for i in range(150):
            cache[f"key_{i}"] = f"value_{i}"
            if len(cache) > max_size:
                # Remove oldest
                oldest_key = min(cache.keys())
                del cache[oldest_key]

        assert len(cache) <= max_size


class TestStorageSyncEdgeCases:
    """Test edge cases in storage synchronization."""

    @pytest.mark.asyncio
    async def test_sync_with_no_changes(self) -> None:
        """Test sync when there are no changes."""
        AsyncMock()
        changes = []

        # No changes to sync
        assert len(changes) == 0

    @pytest.mark.asyncio
    async def test_sync_with_conflicting_changes(self) -> None:
        """Test sync with conflicting changes."""
        AsyncMock()

        # Simulate conflicting changes
        local_changes = [{"id": "item-1", "title": "Local Title"}]
        remote_changes = [{"id": "item-1", "title": "Remote Title"}]

        # They differ
        assert local_changes[0]["title"] != remote_changes[0]["title"]

    @pytest.mark.asyncio
    async def test_sync_with_deleted_items(self) -> None:
        """Test sync handling deleted items."""
        AsyncMock()

        deleted_items = [
            {"id": "item-1", "deleted_at": datetime.now(UTC)},
            {"id": "item-2", "deleted_at": datetime.now(UTC)},
        ]

        assert len(deleted_items) == COUNT_TWO
        assert all("deleted_at" in item for item in deleted_items)

    @pytest.mark.asyncio
    async def test_sync_with_orphaned_links(self) -> None:
        """Test sync handling orphaned links (source or target deleted)."""
        AsyncMock()

        links = [
            {
                "id": "link-1",
                "source_id": "deleted_item",
                "target_id": "item-2",
            },
            {
                "id": "link-2",
                "source_id": "item-1",
                "target_id": "deleted_item",
            },
        ]

        assert len(links) == COUNT_TWO


class TestErrorHandlingEdgeCases:
    """Test edge cases in error handling."""

    @pytest.mark.asyncio
    async def test_repository_initialization(self) -> None:
        """Test repository initialization with session."""
        session = AsyncMock()
        repo = ItemRepository(session)
        # Verify repository is initialized
        assert repo.session == session

    @pytest.mark.asyncio
    async def test_constraint_violation_error_message(self) -> None:
        """Test constraint violation error message."""
        session = AsyncMock()
        session.flush.side_effect = ValueError("Unique constraint violated")

        repo = ItemRepository(session)
        # Error should propagate when flushing
        assert hasattr(repo, "create")

    @pytest.mark.asyncio
    async def test_constraint_violation_on_create(self) -> None:
        """Test constraint violation during creation."""
        session = AsyncMock()
        session.flush.side_effect = ValueError("Constraint violation")

        repo = ItemRepository(session)

        with pytest.raises(ValueError):
            await repo.create(
                project_id="proj-1",
                title="Test",
                view="requirements",
                item_type="req",
            )

    @pytest.mark.asyncio
    async def test_timeout_on_operation(self) -> None:
        """Test operation timeout."""
        AsyncMock()

        async def slow_operation() -> str:
            await asyncio.sleep(10)
            return "result"

        with pytest.raises(asyncio.TimeoutError):
            await asyncio.wait_for(slow_operation(), timeout=0.1)


class TestMetadataEdgeCases:
    """Test edge cases in metadata handling."""

    def test_metadata_with_reserved_keys(self) -> None:
        """Test metadata containing reserved field names."""
        metadata = {
            "id": "fake-id",
            "version": 999,
            "created_at": "not-a-date",
            "custom_field": "value",
        }

        assert "id" in metadata
        assert metadata["version"] == 999

    def test_metadata_with_special_key_names(self) -> None:
        """Test metadata with special characters in keys."""
        metadata = {
            "key.with.dots": "value",
            "key-with-dashes": "value",
            "key_with_underscores": "value",
            "key with spaces": "value",
            "key@with#special$chars": "value",
        }

        assert len(metadata) == COUNT_FIVE

    def test_metadata_with_mixed_types(self) -> None:
        """Test metadata with mixed value types."""
        metadata = {
            "string": "value",
            "number": 42,
            "float": math.pi,
            "bool": True,
            "null": None,
            "list": [1, 2, 3],
            "dict": {"nested": "value"},
        }

        assert len(metadata) == 7
        assert metadata["null"] is None

    def test_metadata_with_circular_reference(self) -> None:
        """Test metadata with circular references."""
        metadata = {"key": "value"}
        metadata["self"] = metadata  # Circular reference

        assert metadata["self"]["key"] == "value"


class TestDatabaseValueEdgeCases:
    """Test edge cases in database value handling."""

    def test_json_type_with_null_bytes(self) -> None:
        """Test JSON type handling null bytes."""
        # Should be stored as-is or escaped

    def test_json_type_with_very_large_data(self) -> None:
        """Test JSON type with very large data structure."""
        large_data = {f"key_{i}": "x" * 1000 for i in range(100)}
        # Simulate storing in JSON
        assert len(large_data) == 100

    def test_json_type_with_unicode_keys(self) -> None:
        """Test JSON with unicode keys."""
        unicode_data = {
            "键": "value",
            "キー": "value",
            "مفتاح": "value",
        }
        assert len(unicode_data) == COUNT_THREE

    def test_json_type_with_numeric_keys(self) -> None:
        """Test JSON with numeric keys."""
        numeric_data = {
            "1": "value",
            "999": "value",
            "-42": "value",
        }
        assert len(numeric_data) == COUNT_THREE


class TestTimestampEdgeCases:
    """Test edge cases in timestamp handling."""

    def test_timestamp_microsecond_precision(self) -> None:
        """Test timestamp with microsecond precision."""
        now = datetime.now(UTC)
        assert now.microsecond >= 0
        assert now.microsecond < 1_000_000

    def test_timestamp_epoch_zero(self) -> None:
        """Test timestamp at epoch (1970-01-01)."""
        epoch = datetime(1970, 1, 1, tzinfo=UTC)
        assert epoch.year == 1970
        assert epoch.month == 1
        assert epoch.day == 1

    def test_timestamp_year_2038(self) -> None:
        """Test timestamp at 2038 (Unix 32-bit limit)."""
        year_2038 = datetime(2038, 1, 19, tzinfo=UTC)
        assert year_2038.year == 2038

    def test_timestamp_far_future(self) -> None:
        """Test timestamp far in the future."""
        year_9999 = datetime(9999, 12, 31, tzinfo=UTC)
        assert year_9999.year == 9999

    def test_timestamp_comparison_edge_cases(self) -> None:
        """Test timestamp comparison with edge cases."""
        dt1 = datetime(2024, 1, 1, 0, 0, 0, tzinfo=UTC)
        dt2 = datetime(2024, 1, 1, 0, 0, 0, 1, tzinfo=UTC)  # 1 microsecond later

        assert dt1 < dt2


class TestAsyncEdgeCases:
    """Test edge cases in async operations."""

    @pytest.mark.asyncio
    async def test_async_operation_immediate_completion(self) -> None:
        """Test async operation that completes immediately."""

        async def immediate() -> str:
            return "result"

        result = await immediate()
        assert result == "result"

    @pytest.mark.asyncio
    async def test_async_operation_with_cancellation(self) -> None:
        """Test async operation with cancellation."""

        async def slow_operation() -> None:
            await asyncio.sleep(10)

        task = asyncio.create_task(slow_operation())
        task.cancel()

        with pytest.raises(asyncio.CancelledError):
            await task

    @pytest.mark.asyncio
    async def test_async_operation_exception_propagation(self) -> None:
        """Test exception propagation in async operations."""

        async def failing_operation() -> Never:
            msg = "Test error"
            raise ValueError(msg)

        with pytest.raises(ValueError, match="Test error"):
            await failing_operation()

    @pytest.mark.asyncio
    async def test_async_gather_with_empty_list(self) -> None:
        """Test asyncio.gather with empty task list."""
        tasks = []
        results = await asyncio.gather(*tasks)
        assert results == []

    @pytest.mark.asyncio
    async def test_async_gather_partial_failure(self) -> None:
        """Test asyncio.gather with some failures."""

        async def success() -> str:
            return "ok"

        async def failure() -> Never:
            msg = "error"
            raise ValueError(msg)

        tasks = [success(), failure(), success()]

        with pytest.raises(ValueError):
            await asyncio.gather(*tasks)
