# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
# Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt

"""Handle diagram generation options for class diagram or default diagrams."""

from typing import Any, Optional

import astroid
from astroid import nodes

from pylint.pyreverse.diagrams import ClassDiagram, PackageDiagram
from pylint.pyreverse.inspector import Project
from pylint.pyreverse.utils import LocalsVisitor

# diagram generators ##########################################################


class DiaDefGenerator:
    """Handle diagram generation options."""

    def __init__(self, linker, handler):
        """Common Diagram Handler initialization."""
        self.config = handler.config
        self._set_default_options()
        self.linker = linker
        self.classdiagram = None  # defined by subclasses

    def get_title(self, node):
        """Get title for objects."""
        title = node.name
        if self.module_names:
            title = f"{node.root().name}.{title}"
        return title

    def _set_option(self, option):
        """Activate some options if not explicitly deactivated."""
        # if we have a class diagram, we want more information by default;
        # so if the option is None, we return True
        if option is None:
            return bool(self.config.classes)
        return option

    def _set_default_options(self):
        """Set different default options with _default dictionary."""
        self.module_names = self._set_option(self.config.module_names)
        all_ancestors = self._set_option(self.config.all_ancestors)
        all_associated = self._set_option(self.config.all_associated)
        anc_level, association_level = (0, 0)
        if all_ancestors:
            anc_level = -1
        if all_associated:
            association_level = -1
        if self.config.show_ancestors is not None:
            anc_level = self.config.show_ancestors
        if self.config.show_associated is not None:
            association_level = self.config.show_associated
        self.anc_level, self.association_level = anc_level, association_level

    def _get_levels(self):
        """Help function for search levels."""
        return self.anc_level, self.association_level

    def show_node(self, node):
        """True if builtins and not show_builtins."""
        if self.config.show_builtin:
            return True
        return node.root().name != "builtins"

    def add_class(self, node):
        """Visit one class and add it to diagram."""
        self.linker.visit(node)
        self.classdiagram.add_object(self.get_title(node), node)

    def get_ancestors(self, node, level):
        """Return ancestor nodes of a class node."""
        if level == 0:
            return
        for ancestor in node.ancestors(recurs=False):
            if not self.show_node(ancestor):
                continue
            yield ancestor

    def get_associated(self, klass_node, level):
        """Return associated nodes of a class node."""
        if level == 0:
            return
        for association_nodes in list(klass_node.instance_attrs_type.values()) + list(
            klass_node.locals_type.values()
        ):
            for node in association_nodes:
                if isinstance(node, astroid.Instance):
                    node = node._proxied
                if not (isinstance(node, nodes.ClassDef) and self.show_node(node)):
                    continue
                yield node

    def extract_classes(self, klass_node, anc_level, association_level):
        """Extract recursively classes related to klass_node."""
        if self.classdiagram.has_node(klass_node) or not self.show_node(klass_node):
            return
        self.add_class(klass_node)

        for ancestor in self.get_ancestors(klass_node, anc_level):
            self.extract_classes(ancestor, anc_level - 1, association_level)

        for node in self.get_associated(klass_node, association_level):
            self.extract_classes(node, anc_level, association_level - 1)


class DefaultDiadefGenerator(LocalsVisitor, DiaDefGenerator):
    """Generate minimum diagram definition for the project :

    * a package diagram including project's modules
    * a class diagram including project's classes
    """

    def __init__(self, linker, handler):
        DiaDefGenerator.__init__(self, linker, handler)
        LocalsVisitor.__init__(self)

    def visit_project(self, node: Project) -> None:
        """Visit a pyreverse.utils.Project node.

        create a diagram definition for packages
        """
        mode = self.config.mode
        if len(node.modules) > 1:
            self.pkgdiagram: Optional[PackageDiagram] = PackageDiagram(
                f"packages {node.name}", mode
            )
        else:
            self.pkgdiagram = None
        self.classdiagram = ClassDiagram(f"classes {node.name}", mode)

    def leave_project(self, _: Project) -> Any:
        """Leave the pyreverse.utils.Project node.

        return the generated diagram definition
        """
        if self.pkgdiagram:
            return self.pkgdiagram, self.classdiagram
        return (self.classdiagram,)

    def visit_module(self, node: nodes.Module) -> None:
        """Visit an astroid.Module node.

        add this class to the package diagram definition
        """
        if self.pkgdiagram:
            self.linker.visit(node)
            self.pkgdiagram.add_object(node.name, node)

    def visit_classdef(self, node: nodes.ClassDef) -> None:
        """Visit an astroid.Class node.

        add this class to the class diagram definition
        """
        anc_level, association_level = self._get_levels()
        self.extract_classes(node, anc_level, association_level)

    def visit_importfrom(self, node: nodes.ImportFrom) -> None:
        """Visit astroid.ImportFrom  and catch modules for package diagram."""
        if self.pkgdiagram:
            self.pkgdiagram.add_from_depend(node, node.modname)


class ClassDiadefGenerator(DiaDefGenerator):
    """Generate a class diagram definition including all classes related to a
    given class
    """

    def class_diagram(self, project, klass):
        """Return a class diagram definition for the given klass and its
        related klasses
        """

        self.classdiagram = ClassDiagram(klass, self.config.mode)
        if len(project.modules) > 1:
            module, klass = klass.rsplit(".", 1)
            module = project.get_module(module)
        else:
            module = project.modules[0]
            klass = klass.split(".")[-1]
        klass = next(module.ilookup(klass))

        anc_level, association_level = self._get_levels()
        self.extract_classes(klass, anc_level, association_level)
        return self.classdiagram


# diagram handler #############################################################


class DiadefsHandler:
    """Get diagram definitions from user (i.e. xml files) or generate them."""

    def __init__(self, config):
        self.config = config

    def get_diadefs(self, project, linker):
        """Get the diagram's configuration data.

        :param project:The pyreverse project
        :type project: pyreverse.utils.Project
        :param linker: The linker
        :type linker: pyreverse.inspector.Linker(IdGeneratorMixIn, LocalsVisitor)

        :returns: The list of diagram definitions
        :rtype: list(:class:`pylint.pyreverse.diagrams.ClassDiagram`)
        """

        #  read and interpret diagram definitions (Diadefs)
        diagrams = []
        generator = ClassDiadefGenerator(linker, self)
        for klass in self.config.classes:
            diagrams.append(generator.class_diagram(project, klass))
        if not diagrams:
            diagrams = DefaultDiadefGenerator(linker, self).visit(project)
        for diagram in diagrams:
            diagram.extract_relationships()
        return diagrams
