# Copyright 2022 Mattia Giambirtone & All Contributors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import strformat
import strutils


type
  TokenType* {.pure.} = enum
    ## Token types enumeration

    # Booleans
    True, False,

    # Other singleton types
    Infinity, NotANumber, Nil

    # Control flow statements
    If, Else,

    # Looping statements
    While, For,

    # Keywords
    Fun, Break, Lambda,
    Continue, Var, Const, Is,
    Return, Async, Class, Import, From,
    IsNot, Raise, Assert, Del, Await,
    Foreach, Yield, Static, Dynamic,
    Private, Public, As, Of, Defer, Try,
    Except, Finally

    # Basic types

    Integer, Float, String, Identifier,
    Binary, Octal, Hex

    # Brackets, parentheses and other
    # symbols

    LeftParen, RightParen, # ()
    LeftBrace, RightBrace, # {}
    LeftBracket, RightBracket, # []
    Dot, Semicolon, Colon, Comma, # . ; : ,
    Plus, Minus, Slash, Asterisk, # + - / *
    Percentage, DoubleAsterisk, # % **
    Caret, Pipe, Ampersand, Tilde, # ^ | & ~
    Equal, GreaterThan, LessThan, # = > <
    LessOrEqual, GreaterOrEqual, # >= <=
    NotEqual, RightShift, LeftShift, # != >> <<
    LogicalAnd, LogicalOr, LogicalNot, FloorDiv, # and or not //
    InplaceAdd, InplaceSub, InplaceDiv, # += -= /=
    InplaceMod, InplaceMul, InplaceXor, # %= *= ^=
    InplaceAnd, InplaceOr, # &= |=
    DoubleEqual, InplaceFloorDiv, InplacePow, # == //= **=
    InplaceRightShift, InplaceLeftShift

    # Miscellaneous

    EndOfFile


  Token* = ref object
    ## A token object
    kind*: TokenType
    lexeme*: string
    line*: int
    pos*: tuple[start, stop: int]


proc `$`*(self: Token): string =
  if self != nil:
    result = &"Token(kind={self.kind}, lexeme={$(self.lexeme)}, line={self.line}, pos=({self.pos.start}, {self.pos.stop}))"
  else:
    result = "nil"