from string import ascii_letters, digits
from rply import LexerGenerator

VALID_CHARACTERS = ascii_letters+"_"+digits

KEYWORD_TOKENS = [("KEYWORD_"+i.upper(), i) for i in [
    "hello",
    "goodbye",
    "maybe",
    "do",
    "if",
    "because",
    "until",
    "define",
    "as",
    "variable",
    "return",
    "argument",
    "set",
    "skip",
    "else"
]]

BUILTIN_TOKENS = [("BUILTIN", i) for i in [
    "print",
    "input",
    "random"
]]

DATA_TOKENS = [
    ("DATA_STRING", r"\'.*?\'"),
    ("DATA_INT", r"\d+"),
    ("DATA_FLOAT", r"\d+(\.\d+)")
]

SYMBOL_TOKENS = [
    ("SYMBOL_OR", r"\\\/"),
    ("SYMBOL_AND", r"\/\\"),
    ("SYMBOL_SET", r"\-\>"),
    ("SYMBOL_TILDE", r"\~"),
    ("SYMBOL_LPARENS", r"\("),
    ("SYMBOL_RPARENS", r"\)"),
    ("SYMBOL_LBRACKET", r"\["),
    ("SYMBOL_RBRACKET", r"\]"),
    ("SYMBOL_LCURL", r"\{"),
    ("SYMBOL_RCURL", r"\}"),
    ("SYMBOL_PLUS", r"\+"),
    ("SYMBOL_MINUS", r"\-"),
    ("SYMBOL_TIMES", r"\*"),
    ("SYMBOL_DIVIDE", r"\/"),
#    ("SYMBOL_COMMA", r"\,"),
#    ("SYMBOL_COLON", r"\:"),
    ("SYMBOL_SEMICOLON", r"\;"),
    ("SYMBOL_PIPE", r"\|"),
    ("SYMBOL_QUOTE", r"\""),
    ("SYMBOL_LT", r"\<"),
    ("SYMBOL_GT", r"\>"),
    ("SYMBOL_EQUALS", r"\="),
#    ("SYMBOL_DOLLAR", r"\$")
]

ALL_TOKENS = (
    KEYWORD_TOKENS +
    BUILTIN_TOKENS +
    DATA_TOKENS +
    SYMBOL_TOKENS +
    [("ARG", r"\#\d+")] +
    [("ID", f"[{VALID_CHARACTERS}]+")]
)


class Lexer():
    def __init__(self):
        self.lexer = LexerGenerator()

    def _add_tokens(self):
        for token in ALL_TOKENS:
            self.lexer.add(*token)
        self.lexer.ignore(r"[\s\n]+|//.*\n")

    def get_lexer(self):
        self._add_tokens()
        return self.lexer.build()