import warnings
from xml.etree import ElementTree as ET

from ast_parser.gaz_unparser import GazUnparser
from ast_parser.general_unparser import GeneralUnparser
from constants import *


def to_python_type(ty):
    if ty == GAZ_INT_KEY:
        return "int"
    elif ty == GAZ_BOOL_KEY:
        return "bool"
    elif ty == GAZ_FLOAT_KEY:
        return "float"
    elif ty == GAZ_CHAR_KEY:
        return "str"
    elif ty == GAZ_STRING_KEY:
        return "str"
    else:
        raise Exception("Unknown type: " + ty)


def to_python_op(param):
    if param == "negation" or param == "subtraction":
        return "-"
    elif param == "addition":
        return "+"
    elif param == "multiplication":
        return "*"
    elif param == "division":
        return "/"
    elif param == "modulus":
        return "%"
    elif param == "power":
        return "**"
    elif param == "equality":
        return "=="
    elif param == "inequality":
        return "!="
    elif param == "less-than":
        return "<"
    elif param == "less-than-or-equal":
        return "<="
    elif param == "greater-than":
        return ">"
    elif param == "greater-than-or-equal":
        return ">="
    else:
        warnings.warn("Warning, unknown operator: " + param)
        return param


class PythonUnparser(GeneralUnparser):
    def __init__(self, ast: ET.Element, debug=False):
        super().__init__(ast, debug,
                         endline='\n',
                         outstream_begin_delimiter="print(",
                         outstream_end_delimiter=", end='')",
                         function_return_type_indicator_predicate="->",
                         loop_start_delimiter="while ",
                         loop_end_delimiter=":",
                         conditional_case_delimiter="elif ",
                         conditional_start_delimiter="if ",
                         conditional_else_delimiter="else:",
                         conditional_end_delimiter=":",
                         block_start_delimiter="",
                         block_end_delimiter="",
                         strip_conditionals=True)

    def format_variable(self, mut, ty, name, declaration: bool = False):
        if declaration:
            return "{}: {}".format(name, ty)
        else:
            return "{}".format(name)

    def translate_value(self, val):
        return str(val)

    def translate_op(self, param):
        return to_python_op(param)

    def translate_type(self, ty):
        return to_python_type(ty)

    def function_declaration(self, xml_tag, args, name, return_type):
        return "def {}{} {}:".format(
            name,
            args,
            return_type,
        )

    def format_single_arg(self, ty, name):
        return "{}: {}".format(name, ty)