import subprocess
from subprocess import CalledProcessError, PIPE, STDOUT
import sys

class Shell(object):
    """An advanced shell, with the ability to do dry-run and log commands"""
    def __init__(self, logger = False, dry = False):
        """ `logger`    The logger
            `dry`       Whether or not to not run any commands, and just print"""
        self.logger = logger
        self.dry = dry
    def call(self, *args):
        if self.dry or self.logger:
            self.logger.info("$ " + ' '.join(args))
        if self.dry: return
        proc = None
        if self.logger:
            if hasattr(self.logger, "verbose"):
                proc = subprocess.Popen(args, stdout=sys.stdout, stderr=sys.stderr)
            else:
                proc = subprocess.Popen(args, stdout=PIPE, stderr=STDOUT)
        else:
            proc = subprocess.Popen(args)
        stdout, _ = proc.communicate()
        if self.logger and stdout: self.logger.info(stdout)
        if proc.returncode:
            raise CalledProcessError(proc.returncode, args)