"""Core functionality tests for DownloadManager."""

import asyncio
import os
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import AsyncMock

import pytest

from py.services.download_manager import DownloadManager
from py.services import download_manager
from py.services.service_registry import ServiceRegistry
from py.services.settings_manager import SettingsManager, get_settings_manager


@pytest.fixture(autouse=True)
def reset_download_manager():
    """Ensure each test operates on a fresh singleton."""
    DownloadManager._instance = None
    yield
    DownloadManager._instance = None


@pytest.fixture(autouse=True)
def isolate_settings(monkeypatch, tmp_path):
    """Point settings writes at a temporary directory to avoid touching real files."""
    manager = get_settings_manager()
    default_settings = manager._get_default_settings()
    default_settings.update(
        {
            "default_lora_root": str(tmp_path),
            "default_checkpoint_root": str(tmp_path / "checkpoints"),
            "default_embedding_root": str(tmp_path / "embeddings"),
            "download_path_templates": {
                "lora": "{base_model}/{first_tag}",
                "checkpoint": "{base_model}/{first_tag}",
                "embedding": "{base_model}/{first_tag}",
            },
            "base_model_path_mappings": {"BaseModel": "MappedModel"},
        }
    )
    monkeypatch.setattr(manager, "settings", default_settings)
    monkeypatch.setattr(SettingsManager, "_save_settings", lambda self: None)


@pytest.fixture(autouse=True)
def stub_metadata(monkeypatch):
    class _StubMetadata:
        def __init__(self, save_path: str):
            self.file_path = save_path
            self.sha256 = "sha256"
            self.file_name = Path(save_path).stem

    def _factory(save_path: str):
        return _StubMetadata(save_path)

    def _make_class():
        @staticmethod
        def from_civitai_info(_version_info, _file_info, save_path):
            return _factory(save_path)

        return type("StubMetadata", (), {"from_civitai_info": from_civitai_info})

    stub_class = _make_class()
    monkeypatch.setattr(download_manager, "LoraMetadata", stub_class)
    monkeypatch.setattr(download_manager, "CheckpointMetadata", stub_class)
    monkeypatch.setattr(download_manager, "EmbeddingMetadata", stub_class)


class DummyScanner:
    def __init__(self, exists: bool = False):
        self.exists = exists
        self.calls = []

    async def check_model_version_exists(self, version_id):
        self.calls.append(version_id)
        return self.exists


@pytest.fixture
def scanners(monkeypatch):
    lora_scanner = DummyScanner()
    checkpoint_scanner = DummyScanner()
    embedding_scanner = DummyScanner()

    monkeypatch.setattr(
        ServiceRegistry, "get_lora_scanner", AsyncMock(return_value=lora_scanner)
    )
    monkeypatch.setattr(
        ServiceRegistry,
        "get_checkpoint_scanner",
        AsyncMock(return_value=checkpoint_scanner),
    )
    monkeypatch.setattr(
        ServiceRegistry,
        "get_embedding_scanner",
        AsyncMock(return_value=embedding_scanner),
    )

    return SimpleNamespace(
        lora=lora_scanner,
        checkpoint=checkpoint_scanner,
        embedding=embedding_scanner,
    )


@pytest.fixture
def metadata_provider(monkeypatch):
    class DummyProvider:
        def __init__(self):
            self.calls = []

        async def get_model_version(self, model_id, model_version_id):
            self.calls.append((model_id, model_version_id))
            return {
                "id": 42,
                "model": {"type": "LoRA", "tags": ["fantasy"]},
                "baseModel": "BaseModel",
                "creator": {"username": "Author"},
                "files": [
                    {
                        "type": "Model",
                        "primary": True,
                        "downloadUrl": "https://example.invalid/file.safetensors",
                        "name": "file.safetensors",
                    }
                ],
            }

    provider = DummyProvider()
    monkeypatch.setattr(
        download_manager,
        "get_default_metadata_provider",
        AsyncMock(return_value=provider),
    )
    return provider


@pytest.fixture(autouse=True)
def noop_cleanup(monkeypatch):
    async def _cleanup(self, task_id):
        if task_id in self._active_downloads:
            self._active_downloads[task_id]["cleaned"] = True

    monkeypatch.setattr(DownloadManager, "_cleanup_download_record", _cleanup)


@pytest.mark.asyncio
async def test_download_requires_identifier():
    """Test that download fails when no identifier is provided."""
    manager = DownloadManager()
    result = await manager.download_from_civitai()
    assert result == {
        "success": False,
        "error": "Either model_id or model_version_id must be provided",
    }


@pytest.mark.asyncio
async def test_successful_download_uses_defaults(
    monkeypatch, scanners, metadata_provider, tmp_path
):
    """Test successful download with default settings."""
    manager = DownloadManager()

    captured = {}

    async def fake_execute_download(
        self,
        *,
        download_urls,
        save_dir,
        metadata,
        version_info,
        relative_path,
        progress_callback,
        model_type,
        download_id,
    ):
        captured.update(
            {
                "download_urls": download_urls,
                "save_dir": Path(save_dir),
                "relative_path": relative_path,
                "progress_callback": progress_callback,
                "model_type": model_type,
                "download_id": download_id,
                "metadata_path": metadata.file_path,
            }
        )
        return {"success": True}

    monkeypatch.setattr(
        DownloadManager, "_execute_download", fake_execute_download, raising=False
    )

    result = await manager.download_from_civitai(
        model_version_id=99,
        save_dir=str(tmp_path),
        use_default_paths=True,
        progress_callback=None,
        source=None,
    )

    assert result["success"] is True
    assert "download_id" in result
    assert manager._download_tasks == {}
    assert manager._active_downloads[result["download_id"]]["status"] == "completed"

    assert captured["relative_path"] == "MappedModel/fantasy"
    expected_dir = (
        Path(get_settings_manager().get("default_lora_root"))
        / "MappedModel"
        / "fantasy"
    )
    assert captured["save_dir"] == expected_dir
    assert captured["model_type"] == "lora"
    assert captured["download_urls"] == ["https://example.invalid/file.safetensors"]


@pytest.mark.asyncio
async def test_download_uses_active_mirrors(
    monkeypatch, scanners, metadata_provider, tmp_path
):
    """Test that active mirrors are used when available."""
    manager = DownloadManager()

    metadata_with_mirrors = {
        "id": 42,
        "model": {"type": "LoRA", "tags": ["fantasy"]},
        "baseModel": "BaseModel",
        "creator": {"username": "Author"},
        "files": [
            {
                "type": "Model",
                "primary": True,
                "downloadUrl": "https://example.invalid/file.safetensors",
                "mirrors": [
                    {
                        "url": "https://mirror.example/file.safetensors",
                        "deletedAt": None,
                    },
                    {
                        "url": "https://mirror.example/old.safetensors",
                        "deletedAt": "2024-01-01",
                    },
                ],
                "name": "file.safetensors",
            }
        ],
    }

    metadata_provider.get_model_version = AsyncMock(return_value=metadata_with_mirrors)

    captured = {}

    async def fake_execute_download(
        self,
        *,
        download_urls,
        save_dir,
        metadata,
        version_info,
        relative_path,
        progress_callback,
        model_type,
        download_id,
    ):
        captured["download_urls"] = download_urls
        return {"success": True}

    monkeypatch.setattr(
        DownloadManager, "_execute_download", fake_execute_download, raising=False
    )

    result = await manager.download_from_civitai(
        model_version_id=99,
        save_dir=str(tmp_path),
        use_default_paths=True,
        progress_callback=None,
        source=None,
    )

    assert result["success"] is True
    assert captured["download_urls"] == ["https://mirror.example/file.safetensors"]


@pytest.mark.asyncio
async def test_download_aborts_when_version_exists(
    monkeypatch, scanners, metadata_provider
):
    """Test that download aborts when version already exists."""
    scanners.lora.exists = True

    manager = DownloadManager()

    execute_mock = AsyncMock(return_value={"success": True})
    monkeypatch.setattr(DownloadManager, "_execute_download", execute_mock)

    result = await manager.download_from_civitai(model_version_id=101, save_dir="/tmp")

    assert result["success"] is False
    assert result["error"] == "Model version already exists in lora library"
    assert "download_id" in result
    assert execute_mock.await_count == 0


@pytest.mark.asyncio
async def test_download_handles_metadata_errors(monkeypatch, scanners):
    """Test that download handles metadata fetch failures gracefully."""
    async def failing_provider(*_args, **_kwargs):
        return None

    monkeypatch.setattr(
        download_manager,
        "get_default_metadata_provider",
        AsyncMock(
            return_value=SimpleNamespace(get_model_version=AsyncMock(return_value=None))
        ),
    )

    manager = DownloadManager()

    result = await manager.download_from_civitai(model_version_id=5, save_dir="/tmp")

    assert result["success"] is False
    assert result["error"] == "Failed to fetch model metadata"
    assert "download_id" in result


@pytest.mark.asyncio
async def test_download_rejects_unsupported_model_type(monkeypatch, scanners):
    """Test that unsupported model types are rejected."""
    class Provider:
        async def get_model_version(self, *_args, **_kwargs):
            return {
                "model": {"type": "Unsupported", "tags": []},
                "files": [],
            }

    monkeypatch.setattr(
        download_manager,
        "get_default_metadata_provider",
        AsyncMock(return_value=Provider()),
    )

    manager = DownloadManager()

    result = await manager.download_from_civitai(model_version_id=5, save_dir="/tmp")

    assert result["success"] is False
    assert result["error"].startswith("Model type")


def test_embedding_relative_path_replaces_spaces():
    """Test that embedding paths replace spaces with underscores."""
    manager = DownloadManager()

    version_info = {
        "baseModel": "Base Model",
        "model": {"tags": ["tag with space"]},
        "creator": {"username": "Author Name"},
    }

    relative_path = manager._calculate_relative_path(version_info, "embedding")

    assert relative_path == "Base_Model/tag_with_space"


def test_relative_path_supports_model_and_version_placeholders():
    """Test that relative path supports {model_name} and {version_name} placeholders."""
    manager = DownloadManager()
    settings_manager = get_settings_manager()
    settings_manager.settings["download_path_templates"]["lora"] = (
        "{model_name}/{version_name}"
    )

    version_info = {
        "baseModel": "BaseModel",
        "name": "Version One",
        "model": {"name": "Fancy Model", "tags": []},
    }

    relative_path = manager._calculate_relative_path(version_info, "lora")

    assert relative_path == "Fancy Model/Version One"


def test_relative_path_sanitizes_model_and_version_placeholders():
    """Test that relative path sanitizes special characters in placeholders."""
    manager = DownloadManager()
    settings_manager = get_settings_manager()
    settings_manager.settings["download_path_templates"]["lora"] = (
        "{model_name}/{version_name}"
    )

    version_info = {
        "baseModel": "BaseModel",
        "name": "Version:One?",
        "model": {"name": "Fancy:Model*", "tags": []},
    }

    relative_path = manager._calculate_relative_path(version_info, "lora")

    assert relative_path == "Fancy_Model/Version_One"


def test_distribute_preview_to_entries_moves_and_copies(tmp_path):
    """Test that preview distribution moves file to first entry and copies to others."""
    manager = DownloadManager()
    preview_file = tmp_path / "bundle.webp"
    preview_file.write_bytes(b"image-data")

    entries = [
        SimpleNamespace(file_path=str(tmp_path / "model-one.safetensors")),
        SimpleNamespace(file_path=str(tmp_path / "model-two.safetensors")),
    ]

    targets = manager._distribute_preview_to_entries(str(preview_file), entries)

    assert targets == [
        str(tmp_path / "model-one.webp"),
        str(tmp_path / "model-two.webp"),
    ]
    assert not preview_file.exists()
    assert Path(targets[0]).read_bytes() == b"image-data"
    assert Path(targets[1]).read_bytes() == b"image-data"


def test_distribute_preview_to_entries_keeps_existing_file(tmp_path):
    """Test that existing preview files are not overwritten."""
    manager = DownloadManager()
    existing_preview = tmp_path / "model-one.webp"
    existing_preview.write_bytes(b"preview")

    entries = [
        SimpleNamespace(file_path=str(tmp_path / "model-one.safetensors")),
        SimpleNamespace(file_path=str(tmp_path / "model-two.safetensors")),
    ]

    targets = manager._distribute_preview_to_entries(str(existing_preview), entries)

    assert targets[0] == str(existing_preview)
    assert Path(targets[1]).read_bytes() == b"preview"