import subprocess as subproc
import os

from mubench import CALLBACKS_DIR
from mubench.lang import Language
from mubench.exceptions import ExecutionFailure
from mubench.util import expandenv


class Python(Language):
    name = 'python'
    src_ext = 'py'
    compiled = False
    default_exec = 'python'

    @classmethod
    def check_runner(cls, rc, lc, env):
        # python interpreter
        python = rc.get('exec', cls.default_exec)
        rc['exec'] = expandenv(python, env)

        # PYTHOPATH
        pythonpath = env.get('PYTHONPATH', '')
        callback_dir = CALLBACKS_DIR / 'python'
        pythonpath = '%(callback_dir)s:%(pythonpath)s' % locals()
        env['PYTHONPATH'] = pythonpath

        return rc

    @classmethod
    def run(cls, target, task):
        rc = task.runner_conf
        bmc = task.benchmark_conf

        cmd = []
        cmd.append(rc['exec'])

        cmd.append(target)

        # first & second argument: callback class name and parameter string
        cmd.append(task.callback_conf['name'])
        cmd.append(task.callback_conf['param'])

        # third argument: iterations
        cmd.append(bmc['iterations'])

        cmd.extend(bmc['args'])

        # place callback module on PYTHONPATH
        env = os.environ.copy()
        pythonpath = env.get('PYTHONPATH', '')
        callback_dir = CALLBACKS_DIR / 'python'
        pythonpath = '%(callback_dir)s:%(pythonpath)s' % locals()
        env['PYTHONPATH'] = pythonpath

        return cls.run_in_subproc(cmd, os.environ)