"""Every module must be extensible without editing the kit.

These tests pin the extension points that let a pip-installed consumer add
storage backends, pipeline steps, an invoice builder, or a 2FA method purely
through settings/registries, and confirm the public import surface.
"""

import io

import pytest
from django.core.exceptions import ImproperlyConfigured

pytestmark = pytest.mark.django_db


# --- fakes referenced by dotted path from settings --------------------------


class FakeStorage:
    def __init__(self, config):
        self.config = config
        self.saved = {}

    def save(self, name, content):
        self.saved[name] = content.read()
        return name

    def open(self, name, mode="rb"):
        return io.BytesIO(self.saved[name])

    def exists(self, name):
        return name in self.saved

    def url(self, name):
        return f"/fake/{name}"

    def delete(self, name):
        self.saved.pop(name, None)

    def generate_signed_url(self, name, expiry_seconds=3600):
        return f"/fake/{name}?signed=1"


class RecordingExecutor:
    def execute(self, execution):
        execution.status = "completed"
        execution.save(update_fields=["status"])
        return execution


def fake_invoice_builder(invoice):
    return b"%PDF-1.4 custom-builder"


class FakeTwoFactorService:
    def generate_secret(self):
        return "FAKESECRET"


class TestPublicImportSurface:
    def test_app_packages_expose_public_names(self):
        from infrasynth.audit import ModelChangeLog
        from infrasynth.billing import EntitlementService, Plan
        from infrasynth.features import FeatureService
        from infrasynth.files import FileService, get_storage_backend
        from infrasynth.gates import GatePermission
        from infrasynth.notifications import NotificationService
        from infrasynth.scheduler import TaskService
        from infrasynth.security import AuthorizationService, HybridPermission
        from infrasynth.shared import Result
        from infrasynth.tenancy import TenantManager
        from infrasynth.webhooks import EventRegistry
        from infrasynth.workflows import WorkflowEngine

        assert all(
            x is not None
            for x in (
                ModelChangeLog,
                EntitlementService,
                Plan,
                FeatureService,
                FileService,
                get_storage_backend,
                NotificationService,
                TaskService,
                AuthorizationService,
                HybridPermission,
                Result,
                TenantManager,
                EventRegistry,
                WorkflowEngine,
                GatePermission,
            )
        )

    def test_unknown_attribute_raises(self):
        import infrasynth.security as security

        with pytest.raises(AttributeError):
            security.ThisDoesNotExist


class TestStorageExtension:
    def test_custom_backend_via_settings_class(self, settings):
        settings.INFRASYNTH_FILES = {
            **settings.INFRASYNTH_FILES,
            "STORAGE_BACKENDS": {
                **settings.INFRASYNTH_FILES.get("STORAGE_BACKENDS", {}),
                "fake": {"CLASS": "tests.test_extensibility.FakeStorage", "REGION": "x"},
            },
        }
        storage = get_backend("fake")
        assert isinstance(storage, FakeStorage)
        assert storage.config.get("REGION") == "x"

    def test_custom_backend_via_registry(self):
        from infrasynth.files.storage import register_storage_backend

        register_storage_backend("factory-made", FakeStorage)
        assert isinstance(get_backend("factory-made"), FakeStorage)

    def test_unknown_backend_raises(self):
        from infrasynth.files.storage import get_storage_backend

        with pytest.raises(ImproperlyConfigured):
            get_storage_backend("does-not-exist")


class TestPipelineExtension:
    def test_registered_step_is_used(self, settings, user, media_root):
        from django.core.files.uploadedfile import SimpleUploadedFile

        from infrasynth.files.models import PipelineExecution, ProcessingPipeline
        from infrasynth.files.processing import PipelineExecutor, pipeline_step
        from infrasynth.files.services import FileService

        calls = []

        @pipeline_step("test.tag")
        def tag_step(data, mime_type, params):
            calls.append(params)
            return data, mime_type

        uploaded = FileService().upload(
            SimpleUploadedFile("a.txt", b"hello", content_type="text/plain"),
            filename="a.txt",
            user=user,
        )
        pipeline = ProcessingPipeline.objects.create(
            name="Tag", slug="tag", steps=[{"type": "test.tag", "params": {"k": "v"}}]
        )
        execution = PipelineExecution.objects.create(file=uploaded, pipeline=pipeline)
        PipelineExecutor().execute(execution)

        execution.refresh_from_db()
        assert execution.status == PipelineExecution.Status.COMPLETED
        assert calls == [{"k": "v"}]

    def test_executor_is_swappable(self, settings):
        from infrasynth.files.processing import get_pipeline_executor

        settings.INFRASYNTH_FILES = {
            **settings.INFRASYNTH_FILES,
            "PIPELINE_EXECUTOR": "tests.test_extensibility.RecordingExecutor",
        }
        assert isinstance(get_pipeline_executor(), RecordingExecutor)


class TestInvoiceBuilderExtension:
    def test_builder_is_swappable(self, settings):
        from infrasynth.billing.invoice_generator import get_invoice_pdf_builder

        settings.INFRASYNTH_BILLING = {
            **settings.INFRASYNTH_BILLING,
            "INVOICE_PDF_BUILDER": "tests.test_extensibility.fake_invoice_builder",
        }
        assert get_invoice_pdf_builder()(object()) == b"%PDF-1.4 custom-builder"


class TestTwoFactorExtension:
    def test_service_is_swappable(self, settings):
        from infrasynth.security.two_factor.services import get_two_factor_service

        settings.INFRASYNTH_SECURITY = {
            **settings.INFRASYNTH_SECURITY,
            "TWO_FACTOR_SERVICE": "tests.test_extensibility.FakeTwoFactorService",
        }
        assert get_two_factor_service().generate_secret() == "FAKESECRET"


def get_backend(name):
    from infrasynth.files.storage import get_storage_backend

    return get_storage_backend(name)