#(c) 2013-2014 by Authors
#This file is a part of Ragout program.
#Released under the BSD license (see LICENSE file)

"""
This module executes overlap native binary
which reconstructs overlap graph from contigs
"""

import os
import logging
import subprocess

from ragout.shared import config
from ragout.shared.utils import which

logger = logging.getLogger()

OVERLAP_EXEC = "ragout-overlap"

class OverlapException(Exception):
    pass

def check_binary():
    """
    Checks if the native binary is available and runnable
    """
    binary = which(OVERLAP_EXEC)
    if not binary:
        logger.error("\"{0}\" native module not found".format(OVERLAP_EXEC))
        return False

    try:
        devnull = open(os.devnull, "w")
        subprocess.check_call([OVERLAP_EXEC, "--help"], stderr=devnull)
    except subprocess.CalledProcessError as e:
        logger.error("Some error inside native {0} module: {1}"
                     .format(OVERLAP_EXEC, e))
        return False

    return True


def make_overlap_graph(contigs_file, dot_file):
    """
    Builds assembly graph and outputs it in "dot" format
    """
    cmdline = [OVERLAP_EXEC, contigs_file, dot_file,
               str(config.vals["overlap"]["min_overlap"]),
               str(config.vals["overlap"]["max_overlap"])]
    if config.vals["overlap"]["detect_kmer"]:
        cmdline.append("--detect-kmer")

    logger.info("Building assembly graph")
    proc = subprocess.Popen(cmdline, stderr=subprocess.PIPE)
    for line in iter(proc.stderr.readline, ""):
        logger.debug(line.strip())
    ret_code = proc.wait()
    if ret_code:
        raise OverlapException("Error building overlap graph: Non-zero return "
                               "code when calling {0} "
                               "module: {1}".format(OVERLAP_EXEC, ret_code))