import sys
from functools import partial
from typing import Callable, Dict, List, Optional, Tuple

from django.db.models.fields.related import RelatedField
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,
)
from mypy.types import Type as MypyType

import mypy_django_plugin.transformers.orm_lookups
from mypy_django_plugin.config import DjangoPluginConfig
from mypy_django_plugin.django.context import DjangoContext
from mypy_django_plugin.lib import fullnames, helpers
from mypy_django_plugin.transformers import fields, forms, init_create, meta, querysets, request, settings
from mypy_django_plugin.transformers.managers import (
    create_new_manager_class_from_from_queryset_method,
    resolve_manager_method,
)
from mypy_django_plugin.transformers.models import (
    handle_annotated_type,
    process_model_class,
    set_auth_user_model_boolean_fields,
)
from mypy_django_plugin.transformers.request import check_querydict_is_mutable


def transform_model_class(ctx: ClassDefContext, django_context: DjangoContext) -> None:
    sym = ctx.api.lookup_fully_qualified_or_none(fullnames.MODEL_CLASS_FULLNAME)

    if sym is not None and isinstance(sym.node, TypeInfo):
        helpers.get_django_metadata(sym.node)["model_bases"][ctx.cls.fullname] = 1
    else:
        if not ctx.api.final_iteration:
            ctx.api.defer()
            return

    process_model_class(ctx, django_context)


def transform_form_class(ctx: ClassDefContext) -> None:
    sym = ctx.api.lookup_fully_qualified_or_none(fullnames.BASEFORM_CLASS_FULLNAME)
    if sym is not None and isinstance(sym.node, TypeInfo):
        helpers.get_django_metadata(sym.node)["baseform_bases"][ctx.cls.fullname] = 1

    forms.make_meta_nested_class_inherit_from_any(ctx)


def add_new_manager_base_hook(ctx: ClassDefContext) -> None:
    helpers.add_new_manager_base(ctx.api, ctx.cls.fullname)


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_queryset_bases(self) -> Dict[str, int]:
        model_sym = self.lookup_fully_qualified(fullnames.QUERYSET_CLASS_FULLNAME)
        if model_sym is not None and isinstance(model_sym.node, TypeInfo):
            return helpers.get_django_metadata(model_sym.node).setdefault(
                "queryset_bases", {fullnames.QUERYSET_CLASS_FULLNAME: 1}
            )
        else:
            return {}

    def _get_current_manager_bases(self) -> Dict[str, int]:
        model_sym = self.lookup_fully_qualified(fullnames.MANAGER_CLASS_FULLNAME)
        if model_sym is not None and isinstance(model_sym.node, TypeInfo):
            return helpers.get_django_metadata(model_sym.node).setdefault(
                "manager_bases", {fullnames.MANAGER_CLASS_FULLNAME: 1}
            )
        else:
            return {}

    def _get_current_model_bases(self) -> Dict[str, int]:
        model_sym = self.lookup_fully_qualified(fullnames.MODEL_CLASS_FULLNAME)
        if model_sym is not None and isinstance(model_sym.node, TypeInfo):
            return helpers.get_django_metadata(model_sym.node).setdefault(
                "model_bases", {fullnames.MODEL_CLASS_FULLNAME: 1}
            )
        else:
            return {}

    def _get_current_form_bases(self) -> Dict[str, int]:
        model_sym = self.lookup_fully_qualified(fullnames.BASEFORM_CLASS_FULLNAME)
        if model_sym is not None and isinstance(model_sym.node, TypeInfo):
            return helpers.get_django_metadata(model_sym.node).setdefault(
                "baseform_bases",
                {
                    fullnames.BASEFORM_CLASS_FULLNAME: 1,
                    fullnames.FORM_CLASS_FULLNAME: 1,
                    fullnames.MODELFORM_CLASS_FULLNAME: 1,
                },
            )
        else:
            return {}

    def _get_typeinfo_or_none(self, class_name: str) -> Optional[TypeInfo]:
        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) -> Tuple[int, str, int]:
        return 10, module, -1

    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)]

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

        # for `get_user_model()`
        if self.django_context.settings:
            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)]

        # ensure that all mentioned 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:
            # forward relations
            for field in self.django_context.get_model_fields(model_class):
                if isinstance(field, RelatedField):
                    related_model_cls = self.django_context.get_field_related_model_cls(field)
                    if related_model_cls is None:
                        continue
                    related_model_module = related_model_cls.__module__
                    if related_model_module != file.fullname:
                        deps.add(self._new_dependency(related_model_module))
            # reverse relations
            # `related_objects` is private API (according to docstring)
            for relation in model_class._meta.related_objects:  # type: ignore[attr-defined]
                related_model_cls = self.django_context.get_field_related_model_cls(relation)
                related_model_module = related_model_cls.__module__
                if related_model_module != file.fullname:
                    deps.add(self._new_dependency(related_model_module))
        return list(deps) + [
            # for QuerySet.annotate
            self._new_dependency("django_stubs_ext"),
            # For BaseManager.from_queryset
            self._new_dependency("django.db.models.query"),
        ]

    def get_function_hook(self, fullname: str) -> Optional[Callable[[FunctionContext], MypyType]]:
        if fullname == "django.contrib.auth.get_user_model":
            return partial(settings.get_user_model_hook, django_context=self.django_context)

        manager_bases = self._get_current_manager_bases()
        if fullname in manager_bases:
            return querysets.determine_proper_manager_type

        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_subclass_info(info, self.django_context):
                return partial(init_create.redefine_and_typecheck_model_init, django_context=self.django_context)
        return None

    def get_method_hook(self, fullname: str) -> Optional[Callable[[MethodContext], MypyType]]:
        class_fullname, _, method_name = fullname.rpartition(".")
        # It is looked up very often, specialcase this method for minor speed up
        if method_name == "__init_subclass__":
            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 partial(check_querydict_is_mutable, django_context=self.django_context)

        elif method_name == "get_form_class":
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.FORM_MIXIN_CLASS_FULLNAME):
                return forms.extract_proper_type_for_get_form_class

        elif method_name == "get_form":
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.FORM_MIXIN_CLASS_FULLNAME):
                return forms.extract_proper_type_for_get_form

        manager_classes = self._get_current_manager_bases()

        if method_name == "values":
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.QUERYSET_CLASS_FULLNAME) or class_fullname in manager_classes:
                return partial(querysets.extract_proper_type_queryset_values, django_context=self.django_context)

        elif method_name == "values_list":
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.QUERYSET_CLASS_FULLNAME) or class_fullname in manager_classes:
                return partial(querysets.extract_proper_type_queryset_values_list, django_context=self.django_context)

        elif method_name == "annotate":
            info = self._get_typeinfo_or_none(class_fullname)
            if info and info.has_base(fullnames.QUERYSET_CLASS_FULLNAME) or class_fullname in manager_classes:
                return partial(querysets.extract_proper_type_queryset_annotate, django_context=self.django_context)

        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)

        elif class_fullname in manager_classes and method_name == "create":
            return partial(init_create.redefine_and_typecheck_model_create, django_context=self.django_context)
        elif class_fullname in manager_classes and method_name in {"filter", "get", "exclude"}:
            return partial(
                mypy_django_plugin.transformers.orm_lookups.typecheck_queryset_filter,
                django_context=self.django_context,
            )

        return None

    def get_base_class_hook(self, fullname: str) -> Optional[Callable[[ClassDefContext], None]]:
        # Base class is a Model class definition
        if (
            fullname in self.django_context.all_registered_model_class_fullnames
            or fullname in self._get_current_model_bases()
        ):
            return partial(transform_model_class, django_context=self.django_context)

        # Base class is a Manager class definition
        if fullname in self._get_current_manager_bases():
            return add_new_manager_base_hook

        # Base class is a Form class definition
        if fullname in self._get_current_form_bases():
            return transform_form_class
        return None

    def get_attribute_hook(self, fullname: str) -> Optional[Callable[[AttributeContext], MypyType]]:
        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)

        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 'request.user' attribute
        if info and info.has_base(fullnames.HTTPREQUEST_CLASS_FULLNAME) and attr_name == "user":
            return partial(request.set_auth_user_model_as_type_for_request_user, 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

        return None

    def get_type_analyze_hook(self, fullname: str) -> Optional[Callable[[AnalyzeTypeContext], MypyType]]:
        if fullname in (
            "typing.Annotated",
            "typing_extensions.Annotated",
            "django_stubs_ext.annotations.WithAnnotations",
        ):
            return partial(handle_annotated_type, django_context=self.django_context)

    def get_dynamic_class_hook(self, fullname: str) -> Optional[Callable[[DynamicClassDefContext], None]]:
        # Create a new manager class definition when a manager's '.from_queryset' classmethod is called
        if fullname.endswith("from_queryset"):
            class_name, _, _ = fullname.rpartition(".")
            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 plugin(version):
    return NewSemanalDjangoPlugin