import itertools
import sys
from collections.abc import Callable
from functools import cached_property, partial
from typing import Any

from mypy.build import PRI_MED, PRI_MYPY
from mypy.modulefinder import mypy_path
from mypy.nodes import MypyFile, TypeInfo
from mypy.options import Options
from mypy.plugin import (
    AnalyzeTypeContext,
    AttributeContext,
    ClassDefContext,
    DynamicClassDefContext,
    FunctionContext,
    MethodContext,
    Plugin,
    ReportConfigContext,
)
from mypy.types import Type as MypyType

from mypy_django_plugin.config import DjangoPluginConfig
from mypy_django_plugin.django.context import DjangoContext
from mypy_django_plugin.exceptions import UnregisteredModelError
from mypy_django_plugin.lib import fullnames, helpers
from mypy_django_plugin.transformers import (
    choices,
    fields,
    forms,
    init_create,
    manytomany,
    manytoone,
    meta,
    orm_lookups,
    querysets,
    settings,
)
from mypy_django_plugin.transformers.auth import get_user_model
from mypy_django_plugin.transformers.functional import resolve_str_promise_attribute
from mypy_django_plugin.transformers.managers import (
    add_as_manager_to_queryset_class,
    create_new_manager_class_from_from_queryset_method,
    reparametrize_any_manager_hook,
    resolve_manager_method,
)
from mypy_django_plugin.transformers.models import (
    MetaclassAdjustments,
    handle_annotated_type,
    process_model_class,
    set_auth_user_model_boolean_fields,
)
from mypy_django_plugin.transformers.request import check_querydict_is_mutable


class NewSemanalDjangoPlugin(Plugin):
    def __init__(self, options: Options) -> None:
        super().__init__(options)
        self.plugin_config = DjangoPluginConfig(options.config_file)
        # Add paths from MYPYPATH env var
        sys.path.extend(mypy_path())
        # Add paths from mypy_path config option
        sys.path.extend(options.mypy_path)
        self.django_context = DjangoContext(self.plugin_config.django_settings_module)

    def _get_current_form_bases(self) -> dict[str, int]:
        model_info = self._get_typeinfo_or_none(fullnames.BASEFORM_CLASS_FULLNAME)
        if model_info:
            bases = helpers.get_django_metadata_bases(model_info, "baseform_bases")
            bases[fullnames.BASEFORM_CLASS_FULLNAME] = 1
            bases[fullnames.FORM_CLASS_FULLNAME] = 1
            bases[fullnames.MODELFORM_CLASS_FULLNAME] = 1
            return bases
        return {}

    def _get_typeinfo_or_none(self, class_name: str) -> TypeInfo | None:
        sym = self.lookup_fully_qualified(class_name)
        if sym is not None and isinstance(sym.node, TypeInfo):
            return sym.node
        return None

    def _new_dependency(self, module: str, priority: int = PRI_MYPY) -> tuple[int, str, int]:
        fake_lineno = -1
        return (priority, module, fake_lineno)

    def get_additional_deps(self, file: MypyFile) -> list[tuple[int, str, int]]:
        # for settings
        if file.fullname == "django.conf" and self.django_context.django_settings_module:
            return [self._new_dependency(self.django_context.django_settings_module, PRI_MED)]

        # for values / values_list
        if file.fullname == "django.db.models":
            return [self._new_dependency("typing"), self._new_dependency("django_stubs_ext")]

        # for `get_user_model()`
        if file.fullname == "django.contrib.auth" or file.fullname in {"django.http", "django.http.request"}:
            auth_user_model_name = self.django_context.settings.AUTH_USER_MODEL
            try:
                auth_user_module = self.django_context.apps_registry.get_model(auth_user_model_name).__module__
            except LookupError:
                # get_user_model() model app is not installed
                return []
            return [self._new_dependency(auth_user_module), self._new_dependency("django_stubs_ext")]

        # ensure that all mentions to='someapp.SomeModel' are loaded with corresponding related Fields
        defined_model_classes = self.django_context.model_modules.get(file.fullname)
        if not defined_model_classes:
            return []
        deps = set()

        for model_class in defined_model_classes.values():
            for field in itertools.chain(
                # forward relations
                self.django_context.get_model_related_fields(model_class),
                # reverse relations - `related_objects` is private API (according to docstring)
                model_class._meta.related_objects,
            ):
                try:
                    related_model_cls = self.django_context.get_field_related_model_cls(field)  # type: ignore[arg-type]
                except UnregisteredModelError:
                    continue
                related_model_module = related_model_cls.__module__
                if related_model_module != file.fullname:
                    deps.add(self._new_dependency(related_model_module))

        return [
            *deps,
            # For `QuerySet.annotate`
            self._new_dependency("django_stubs_ext"),
            # For `TypedModelMeta` lookup in model transformers
            self._new_dependency("django_stubs_ext.db.models"),
            # For `Manager.from_queryset`
            self._new_dependency("django.db.models.query"),
        ]

    def get_function_hook(self, fullname: str) -> Callable[[FunctionContext], MypyType] | None:
        info = self._get_typeinfo_or_none(fullname)
        if info:
            if info.has_base(fullnames.FIELD_FULLNAME):
                return partial(fields.transform_into_proper_return_type, django_context=self.django_context)

            if helpers.is_model_type(info):
                return partial(init_create.typecheck_model_init, django_context=self.django_context)

            if info.has_base(fullnames.BASE_MANAGER_CLASS_FULLNAME):
                return querysets.determine_proper_manager_type

            if info.has_base(fullnames.PREFETCH_CLASS_FULLNAME):
                return partial(querysets.specialize_prefetch_type, django_context=self.django_context)

        return None

    @cached_property
    def manager_and_queryset_method_hooks(self) -> dict[str, Callable[[MethodContext], MypyType]]:
        typecheck_filtering_method = partial(orm_lookups.typecheck_queryset_filter, django_context=self.django_context)
        return {
            "values": partial(querysets.extract_proper_type_queryset_values, django_context=self.django_context),
            "values_list": partial(
                querysets.extract_proper_type_queryset_values_list, django_context=self.django_context
            ),
            "alias": partial(querysets.extract_proper_type_queryset_annotate, django_context=self.django_context),
            "annotate": partial(querysets.extract_proper_type_queryset_annotate, django_context=self.django_context),
            "create": partial(init_create.typecheck_model_create, django_context=self.django_context),
            "acreate": partial(init_create.typecheck_model_acreate, django_context=self.django_context),
            "filter": typecheck_filtering_method,
            "get": typecheck_filtering_method,
            "aget": typecheck_filtering_method,
            "exclude": typecheck_filtering_method,
            "prefetch_related": partial(
                querysets.extract_prefetch_related_annotations, django_context=self.django_context
            ),
            "select_related": partial(querysets.validate_select_related, django_context=self.django_context),
            "bulk_update": partial(
                querysets.validate_bulk_update, django_context=self.django_context, method="bulk_update"
            ),
            "abulk_update": partial(
                querysets.validate_bulk_update, django_context=self.django_context, method="abulk_update"
            ),
        }

    def get_method_hook(self, fullname: str) -> Callable[[MethodContext], MypyType] | None:
        class_fullname, _, method_name = fullname.rpartition(".")
        # Methods called very often -- short circuit for minor speed up
        if method_name == "__init_subclass__" or fullname.startswith("builtins."):
            return None

        if class_fullname.endswith("QueryDict"):
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.QUERYDICT_CLASS_FULLNAME):
                return check_querydict_is_mutable

        elif method_name == "__get__":
            hooks = {
                fullnames.MANYTOMANY_FIELD_FULLNAME: manytomany.refine_many_to_many_related_manager,
                fullnames.MANY_TO_MANY_DESCRIPTOR: manytomany.refine_many_to_many_related_manager,
                fullnames.REVERSE_MANY_TO_ONE_DESCRIPTOR: manytoone.refine_many_to_one_related_manager,
            }
            return hooks.get(class_fullname)

        if method_name in self.manager_and_queryset_method_hooks:
            info = self._get_typeinfo_or_none(class_fullname)
            if info and helpers.has_any_of_bases(
                info, [fullnames.QUERYSET_CLASS_FULLNAME, fullnames.MANAGER_CLASS_FULLNAME]
            ):
                return self.manager_and_queryset_method_hooks[method_name]
        elif method_name == "get_field":
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.OPTIONS_CLASS_FULLNAME):
                return partial(meta.return_proper_field_type_from_get_field, django_context=self.django_context)

        return None

    def get_customize_class_mro_hook(self, fullname: str) -> Callable[[ClassDefContext], None] | None:
        info = self._get_typeinfo_or_none(fullname)
        if info and info.has_base(fullnames.BASE_MANAGER_CLASS_FULLNAME):
            return reparametrize_any_manager_hook
        return None

    def get_metaclass_hook(self, fullname: str) -> Callable[[ClassDefContext], None] | None:
        if fullname == fullnames.MODEL_METACLASS_FULLNAME:
            return partial(MetaclassAdjustments.adjust_model_class, plugin_config=self.plugin_config)
        return None

    def get_base_class_hook(self, fullname: str) -> Callable[[ClassDefContext], None] | None:
        # Base class is a Model class definition
        info = self._get_typeinfo_or_none(fullname)
        if info and helpers.is_model_type(info):
            return partial(process_model_class, django_context=self.django_context)

        # Base class is a Form class definition
        if fullname in self._get_current_form_bases():
            return forms.transform_form_class

        # Base class is a QuerySet class definition
        if info and info.has_base(fullnames.QUERYSET_CLASS_FULLNAME):
            return add_as_manager_to_queryset_class
        return None

    def get_attribute_hook(self, fullname: str) -> Callable[[AttributeContext], MypyType] | None:
        class_name, _, attr_name = fullname.rpartition(".")

        # Lookup of a settings variable
        if class_name == fullnames.DUMMY_SETTINGS_BASE_CLASS:
            return partial(
                settings.get_type_of_settings_attribute,
                django_context=self.django_context,
                plugin_config=self.plugin_config,
            )

        info = self._get_typeinfo_or_none(class_name)

        # Lookup of the '.is_superuser' attribute
        if info and info.has_base(fullnames.PERMISSION_MIXIN_CLASS_FULLNAME) and attr_name == "is_superuser":
            return partial(set_auth_user_model_boolean_fields, django_context=self.django_context)

        # Lookup of the 'user.is_staff' or 'user.is_active' attribute
        if info and info.has_base(fullnames.ABSTRACT_USER_MODEL_FULLNAME) and attr_name in ("is_staff", "is_active"):
            return partial(set_auth_user_model_boolean_fields, django_context=self.django_context)

        # Lookup of a method on a dynamically generated manager class
        # i.e. a manager class only existing while mypy is running, not collected from the AST
        if (
            info
            and info.has_base(fullnames.BASE_MANAGER_CLASS_FULLNAME)
            and "from_queryset_manager" in helpers.get_django_metadata(info)
        ):
            return resolve_manager_method

        if info and info.has_base(fullnames.STR_PROMISE_FULLNAME):
            return resolve_str_promise_attribute

        if info and (
            (
                info.has_base(fullnames.CHOICES_TYPE_METACLASS_FULLNAME)
                and attr_name in {"choices", "labels", "values", "__empty__"}
            )
            or (info.has_base(fullnames.CHOICES_CLASS_FULLNAME) and attr_name in {"label", "value"})
        ):
            return choices.transform_into_proper_attr_type

        return None

    def get_type_analyze_hook(self, fullname: str) -> Callable[[AnalyzeTypeContext], MypyType] | None:
        if fullname in fullnames.ANNOTATED_TYPES_FULLNAMES:
            return partial(handle_annotated_type, fullname=fullname)
        if fullname == "django.contrib.auth.models._User":
            return partial(get_user_model, django_context=self.django_context)
        return None

    def get_dynamic_class_hook(self, fullname: str) -> Callable[[DynamicClassDefContext], None] | None:
        # Create a new manager class definition when a manager's '.from_queryset' classmethod is called
        class_name, _, method_name = fullname.rpartition(".")
        if method_name == "from_queryset":
            info = self._get_typeinfo_or_none(class_name)
            if info and info.has_base(fullnames.BASE_MANAGER_CLASS_FULLNAME):
                return create_new_manager_class_from_from_queryset_method
        return None

    def report_config_data(self, ctx: ReportConfigContext) -> dict[str, Any]:
        # Cache would be cleared if any settings do change.
        extra_data = {
            "AUTH_USER_MODEL": self.django_context.settings.AUTH_USER_MODEL,
        }
        return self.plugin_config.to_json(extra_data)


def plugin(version: str) -> type[NewSemanalDjangoPlugin]:
    return NewSemanalDjangoPlugin