# Copyright 2021 DeepMind Technologies Limited
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#            http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""A Python wrapper for hmmsearch - search profile against a sequence db."""

import os
import subprocess
from typing import Optional, Sequence

from absl import logging
from fastfold.data import parsers
from fastfold.data.tools import hmmbuild
from fastfold.data.tools import utils


class Hmmsearch(object):
    """Python wrapper of the hmmsearch binary."""

    def __init__(self,
        *,
        binary_path: str,
        hmmbuild_binary_path: str,
        database_path: str,
        n_cpu: int=8,
        flags: Optional[Sequence[str]] = None
    ):
        """Initializes the Python hmmsearch wrapper.

        Args:
            binary_path: The path to the hmmsearch executable.
            hmmbuild_binary_path: The path to the hmmbuild executable. Used to build
                an hmm from an input a3m.
            database_path: The path to the hmmsearch database (FASTA format).
            flags: List of flags to be used by hmmsearch.

        Raises:
            RuntimeError: If hmmsearch binary not found within the path.
        """
        self.binary_path = binary_path
        self.hmmbuild_runner = hmmbuild.Hmmbuild(binary_path=hmmbuild_binary_path)
        self.database_path = database_path
        self.n_cpu = n_cpu
        if flags is None:
            # Default hmmsearch run settings.
            flags = ['--F1', '0.1',
                             '--F2', '0.1',
                             '--F3', '0.1',
                             '--incE', '100',
                             '-E', '100',
                             '--domE', '100',
                             '--incdomE', '100']
        self.flags = flags

        if not os.path.exists(self.database_path):
            logging.error('Could not find hmmsearch database %s', database_path)
            raise ValueError(f'Could not find hmmsearch database {database_path}')

    @property
    def output_format(self) -> str:
        return 'sto'

    @property
    def input_format(self) -> str:
        return 'sto'

    def query(self, msa_sto: str, output_dir: Optional[str] = None) -> str:
        """Queries the database using hmmsearch using a given stockholm msa."""
        hmm = self.hmmbuild_runner.build_profile_from_sto(
            msa_sto,
            model_construction='hand'
        )
        return self.query_with_hmm(hmm, output_dir)

    def query_with_hmm(self, 
        hmm: str, 
        output_dir: Optional[str] = None
    ) -> str:
        """Queries the database using hmmsearch using a given hmm."""
        with utils.tmpdir_manager() as query_tmp_dir:
            hmm_input_path = os.path.join(query_tmp_dir, 'query.hmm')
            output_dir = query_tmp_dir if output_dir is None else output_dir
            out_path = os.path.join(output_dir, 'hmm_output.sto')
            with open(hmm_input_path, 'w') as f:
                f.write(hmm)

            cmd = [
                    self.binary_path,
                    '--noali',    # Don't include the alignment in stdout.
                    '--cpu', str(self.n_cpu)
            ]
            # If adding flags, we have to do so before the output and input:
            if self.flags:
                cmd.extend(self.flags)
            cmd.extend([
                    '-A', out_path,
                    hmm_input_path,
                    self.database_path,
            ])

            logging.info('Launching sub-process %s', cmd)
            process = subprocess.Popen(
                    cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
            with utils.timing(
                    f'hmmsearch ({os.path.basename(self.database_path)}) query'):
                stdout, stderr = process.communicate()
                retcode = process.wait()

            if retcode:
                raise RuntimeError(
                        'hmmsearch failed:\nstdout:\n%s\n\nstderr:\n%s\n' % (
                                stdout.decode('utf-8'), stderr.decode('utf-8')))

            with open(out_path) as f:
                out_msa = f.read()

        return out_msa

    @staticmethod
    def get_template_hits(
        output_string: str,
        input_sequence: str
    ) -> Sequence[parsers.TemplateHit]:
        """Gets parsed template hits from the raw string output by the tool."""
        template_hits = parsers.parse_hmmsearch_sto(
            output_string,
            input_sequence,
        )
        return template_hits
