"""
GTSAM Copyright 2010-2020, Georgia Tech Research Corporation,
Atlanta, Georgia 30332-0415
All Rights Reserved

See LICENSE for the license information

Parser classes and rules for parsing C++ classes.

Author: Duy Nguyen Ta, Fan Jiang, Matthew Sklar, Varun Agrawal, and Frank Dellaert
"""

from typing import List, Union

from pyparsing import Optional, ZeroOrMore

from .function import ArgumentList, ReturnType
from .template import Template
from .tokens import (CLASS, COLON, CONST, IDENT, LBRACE, LPAREN, RBRACE,
                     RPAREN, SEMI_COLON, STATIC, VIRTUAL)
from .type import Type, Typename


class Method:
    """
    Rule to parse a method in a class.

    E.g.
    ```
    class Hello {
        void sayHello() const;
    };
    ```
    """
    rule = (
        Optional(Template.rule("template"))  #
        + ReturnType.rule("return_type")  #
        + IDENT("name")  #
        + LPAREN  #
        + ArgumentList.rule("args_list")  #
        + RPAREN  #
        + Optional(CONST("is_const"))  #
        + SEMI_COLON  # BR
    ).setParseAction(lambda t: Method(t.template, t.name, t.return_type, t.
                                      args_list, t.is_const))

    def __init__(self,
                 template: str,
                 name: str,
                 return_type: ReturnType,
                 args: ArgumentList,
                 is_const: str,
                 parent: Union[str, "Class"] = ''):
        self.template = template
        self.name = name
        self.return_type = return_type
        self.args = args
        self.is_const = is_const

        self.parent = parent

    def __repr__(self) -> str:
        return "Method: {} {} {}({}){}".format(
            self.template,
            self.return_type,
            self.name,
            self.args,
            self.is_const,
        )


class StaticMethod:
    """
    Rule to parse all the static methods in a class.

    E.g.
    ```
    class Hello {
        static void changeGreeting();
    };
    ```
    """
    rule = (
        STATIC  #
        + ReturnType.rule("return_type")  #
        + IDENT("name")  #
        + LPAREN  #
        + ArgumentList.rule("args_list")  #
        + RPAREN  #
        + SEMI_COLON  # BR
    ).setParseAction(
        lambda t: StaticMethod(t.name, t.return_type, t.args_list))

    def __init__(self,
                 name: str,
                 return_type: ReturnType,
                 args: ArgumentList,
                 parent: Union[str, "Class"] = ''):
        self.name = name
        self.return_type = return_type
        self.args = args

        self.parent = parent

    def __repr__(self) -> str:
        return "static {} {}{}".format(self.return_type, self.name, self.args)

    def to_cpp(self) -> str:
        """Generate the C++ code for wrapping."""
        return self.name


class Constructor:
    """
    Rule to parse the class constructor.
    Can have 0 or more arguments.
    """
    rule = (
        IDENT("name")  #
        + LPAREN  #
        + ArgumentList.rule("args_list")  #
        + RPAREN  #
        + SEMI_COLON  # BR
    ).setParseAction(lambda t: Constructor(t.name, t.args_list))

    def __init__(self,
                 name: str,
                 args: ArgumentList,
                 parent: Union["Class", str] = ''):
        self.name = name
        self.args = args

        self.parent = parent

    def __repr__(self) -> str:
        return "Constructor: {}".format(self.name)


class Property:
    """
    Rule to parse the variable members of a class.

    E.g.
    ```
    class Hello {
        string name;  // This is a property.
    };
    ````
    """
    rule = (
        Type.rule("ctype")  #
        + IDENT("name")  #
        + SEMI_COLON  #
    ).setParseAction(lambda t: Property(t.ctype, t.name))

    def __init__(self, ctype: Type, name: str, parent=''):
        self.ctype = ctype
        self.name = name
        self.parent = parent

    def __repr__(self) -> str:
        return '{} {}'.format(self.ctype.__repr__(), self.name)


def collect_namespaces(obj):
    """
    Get the chain of namespaces from the lowest to highest for the given object.

    Args:
        obj: Object of type Namespace, Class or InstantiatedClass.
    """
    namespaces = []
    ancestor = obj.parent
    while ancestor and ancestor.name:
        namespaces = [ancestor.name] + namespaces
        ancestor = ancestor.parent
    return [''] + namespaces


class Class:
    """
    Rule to parse a class defined in the interface file.

    E.g.
    ```
    class Hello {
        ...
    };
    ```
    """
    class MethodsAndProperties:
        """
        Rule for all the methods and properties within a class.
        """
        rule = ZeroOrMore(Constructor.rule ^ StaticMethod.rule ^ Method.rule
                          ^ Property.rule).setParseAction(
                              lambda t: Class.MethodsAndProperties(t.asList()))

        def __init__(self, methods_props: List[Union[Constructor, Method,
                                                     StaticMethod, Property]]):
            self.ctors = []
            self.methods = []
            self.static_methods = []
            self.properties = []
            for m in methods_props:
                if isinstance(m, Constructor):
                    self.ctors.append(m)
                elif isinstance(m, Method):
                    self.methods.append(m)
                elif isinstance(m, StaticMethod):
                    self.static_methods.append(m)
                elif isinstance(m, Property):
                    self.properties.append(m)

    _parent = COLON + Typename.rule("parent_class")
    rule = (
        Optional(Template.rule("template"))  #
        + Optional(VIRTUAL("is_virtual"))  #
        + CLASS  #
        + IDENT("name")  #
        + Optional(_parent)  #
        + LBRACE  #
        + MethodsAndProperties.rule("methods_props")  #
        + RBRACE  #
        + SEMI_COLON  # BR
    ).setParseAction(lambda t: Class(
        t.template,
        t.is_virtual,
        t.name,
        t.parent_class,
        t.methods_props.ctors,
        t.methods_props.methods,
        t.methods_props.static_methods,
        t.methods_props.properties,
    ))

    def __init__(
        self,
        template: Template,
        is_virtual: str,
        name: str,
        parent_class: list,
        ctors: List[Constructor],
        methods: List[Method],
        static_methods: List[StaticMethod],
        properties: List[Property],
        parent: str = '',
    ):
        self.template = template
        self.is_virtual = is_virtual
        self.name = name
        if parent_class:
            self.parent_class = Typename.from_parse_result(parent_class)
        else:
            self.parent_class = ''

        self.ctors = ctors
        self.methods = methods
        self.static_methods = static_methods
        self.properties = properties
        self.parent = parent
        # Make sure ctors' names and class name are the same.
        for ctor in self.ctors:
            if ctor.name != self.name:
                raise ValueError("Error in constructor name! {} != {}".format(
                    ctor.name, self.name))

        for ctor in self.ctors:
            ctor.parent = self
        for method in self.methods:
            method.parent = self
        for static_method in self.static_methods:
            static_method.parent = self
        for _property in self.properties:
            _property.parent = self

    def namespaces(self) -> list:
        """Get the namespaces which this class is nested under as a list."""
        return collect_namespaces(self)

    def __repr__(self):
        return "Class: {self.name}".format(self=self)