from __future__ import print_function

import os
import sys

GREEN = '\033[32m'
YELLOW = '\033[33m'
RED = '\033[31m'
EXIT = '\033[0m'

INFO = 'info'
WARNING = 'warning'
ERROR = 'error'

LEVEL_COLOR_MAP = {
    INFO: GREEN,
    WARNING: YELLOW,
    ERROR: RED
}


class Sender(object):
    def __init__(self, prefix=None):
        self._prefix = prefix

    def format(self, msg, level):
        """ Escapes a message with a color assigned based on its level. Informational messages
        are green, warnings are yellow, and errors are red. The given prefix is prepended to the
        message for namespace identification. If $TERM is not set, no color escape sequences are
        added.

        Args:
            msg: Given message
            level: stderr 'level' priority. Must be INFO, WARNING, or ERROR.
            prefix: Given namespace of the project calling this library.
        """
        msg = level.upper() + ': ' + self._prefix + ' ' + msg

        if os.getenv('TERM'):
            msg = LEVEL_COLOR_MAP[level] + msg + EXIT

        return msg

    def write(self, msg, level):
        """ Prints a message to stderr with a color assigned based on its level. Informational
        messages are green, warnings are yellow, and errors are red. The given prefix is prepended
        to the message for namespace identification. If $TERM is not set, no color escape sequences
        are added.

        Args:
            msg: Given message
            level: stderr 'level' priority. Must be INFO, WARNING, or ERROR.
            prefix: Given namespace of the project calling this library.
        """
        print(self.format(msg, level), file=sys.stderr)

    def info(self, msg, **kwargs):
        self.write(msg, INFO, **kwargs)

    def warning(self, msg, **kwargs):
        self.write(msg, WARNING, **kwargs)

    def error(self, msg, **kwargs):
        self.write(msg, ERROR, **kwargs)

    def format_error(self, msg, **kwargs):
        return self.format(msg, ERROR, **kwargs)
