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

"""
This module runs Sibelia
"""

import os
import sys
import shutil
import subprocess
import copy
import logging

from ragout.shared import utils
from ragout.shared import config
from .synteny_backend import SyntenyBackend, BackendException

logger = logging.getLogger()

SIBELIA_EXEC = "Sibelia"
SIBELIA_WORKDIR = "sibelia-workdir"
SIBELIA_MAX_INPUT = 100 * 1024 * 1024

try:
    SIBELIA_INSTALL = os.environ["SIBELIA_INSTALL"]
    os.environ["PATH"] += os.pathsep + SIBELIA_INSTALL
except:
    pass


class SibeliaBackend(SyntenyBackend):
    def __init__(self):
        SyntenyBackend.__init__(self)

    def run_backend(self, recipe, output_dir, overwrite):
        files = {}
        work_dir = os.path.join(output_dir, SIBELIA_WORKDIR)
        if overwrite and os.path.isdir(work_dir):
            shutil.rmtree(work_dir)

        if os.path.isdir(work_dir):
            #using existing results
            logger.warning("Using existing Sibelia results from previous run")
            logger.warning("Use --overwrite to force alignment")
            for block_size in self.blocks:
                block_dir = os.path.join(work_dir, str(block_size))
                coords_file = os.path.join(block_dir, "blocks_coords.txt")
                if not os.path.isfile(coords_file):
                    raise BackendException("Exitsing results are incompatible "
                                           "with input recipe")
                files[block_size] = os.path.abspath(coords_file)

        else:
            chr2genome, total_size = _get_sequence_info(recipe)
            if total_size > SIBELIA_MAX_INPUT:
                logger.warning("Total size of input ({0}MB) is more "
                               "than 100MB. Processing could take a "
                               "very long time. It is recommended to use "
                               "some other synteny backend for your data."
                               .format(total_size / 1024 / 1024))

            os.mkdir(work_dir)
            for block_size in self.blocks:
                block_dir = os.path.join(work_dir, str(block_size))
                perm_file = os.path.join(block_dir, "genomes_permutations.txt")
                coords_file = os.path.join(block_dir, "blocks_coords.txt")

                if not os.path.isdir(block_dir):
                    os.mkdir(block_dir)

                all_fasta = [p["fasta"] for p in recipe["genomes"].values()]
                _run_sibelia(all_fasta, block_size, block_dir)
                _postprocess_coords(chr2genome, coords_file)
                _postprocess_perms(chr2genome, perm_file)
                files[block_size] = coords_file

        return files


def _check_installation():
    return bool(utils.which(SIBELIA_EXEC))

if _check_installation():
    logger.debug("Sibelia is installed")
    SyntenyBackend.register_backend("sibelia", SibeliaBackend())
else:
    logger.debug("Sibelia is not installed")


def _get_sequence_info(recipe):
    """
    Reads fasta files and constructs a correspondence table
    between sequence name and genome name. Also returns
    the total size of input in nucleotides
    """
    chr2genome = {}
    for gen_name, gen_params in recipe["genomes"].items():
        if "fasta" not in gen_params:
            raise BackendException("FASTA file for '{0}' is not "
                                    "specified".format(gen_name))

        if not os.path.exists(gen_params["fasta"]):
            raise BackendException("Can't open '{0}'"
                                   .format(gen_params["fasta"]))

        total_size = 0
        with open(gen_params["fasta"], "r") as f:
            for line in f:
                line = line.strip()
                if line.startswith(">"):
                    chr_name = line.strip()[1:].split(" ")[0]
                    if chr_name in chr2genome:
                        raise BackendException("Some fasta files contain "
                                               "sequences with similar names")
                    chr2genome[chr_name] = gen_name

                else:
                    total_size += len(line)

    return chr2genome, total_size


def _postprocess_perms(chr2genome, file):
    """
    Converts Sibelia's permutation file to UCSC naming convention:
    genome.chromosome
    """
    new_file = file + "_new"
    with open(file, "r") as fin, open(new_file, "w") as fout:
        for line in fin:
            line = line.strip()
            if line.startswith(">"):
                chr_name = line[1:]
                fout.write(">{0}.{1}\n".format(chr2genome[chr_name], chr_name))
            else:
                fout.write(line + "\n")
    os.remove(file)
    os.rename(new_file, file)


def _postprocess_coords(chr2genome, file):
    """
    Converts Sibelia's blocks_coords file to UCSC naming convention:
    genome.chromosome
    """
    new_file = file + "_new"
    with open(file, "r") as fin, open(new_file, "w") as fout:
        header = True
        for line in fin:
            line = line.strip()

            if header:
                if line.startswith("Seq_id"):
                    fout.write(line + "\n")
                    continue
                if line.startswith("-"):
                    fout.write(line + "\n")
                    header = False
                    continue

                chr_id, chr_size, seq_name = line.split("\t")
                fout.write("{0}\t{1}\t{2}.{3}\n".format(chr_id, chr_size,
                                                        chr2genome[seq_name],
                                                        seq_name))
            else:
                fout.write(line + "\n")

    os.remove(file)
    os.rename(new_file, file)


def _make_stagefile(stages, out_file):
    assert len(stages)

    with open(out_file, "w") as f:
        f.write("{0}\n".format(len(stages)))
        for stage_k, stage_d in stages:
            f.write("{0} {1}\n".format(stage_k, stage_d))


def _run_sibelia(fasta_files, block_size, out_dir):
    logger.info("Running Sibelia with block size " + str(block_size))
    if not utils.which(SIBELIA_EXEC):
        raise BackendException("Sibelia is not installed")

    stagefile = os.path.join(out_dir, "stagefile.txt")
    _make_stagefile(config.vals["sibelia"], stagefile)

    devnull = open(os.devnull, "w")
    cmdline = [SIBELIA_EXEC, "--nopostprocess", "--stagefile", stagefile,
               "--minblocksize", str(block_size), "--outdir", out_dir]
    cmdline.extend(fasta_files)
    subprocess.check_call(cmdline, stdout=devnull)

    os.remove(stagefile)
    os.remove(os.path.join(out_dir, "d3_blocks_diagram.html"))
    shutil.rmtree(os.path.join(out_dir, "circos"))