# Copyright 2012 by Wibowo Arindrarto.  All rights reserved.
# This file is part of the Biopython distribution and governed by your
# choice of the "Biopython License Agreement" or the "BSD 3-Clause License".
# Please see the LICENSE file that should have been included as part of this
# package.
"""Bio.SearchIO parser for HMMER table output format."""

from itertools import chain

from Bio.Alphabet import generic_protein
from Bio.SearchIO._index import SearchIndexer
from Bio.SearchIO._model import QueryResult, Hit, HSP, HSPFragment


__all__ = ("Hmmer3TabParser", "Hmmer3TabIndexer", "Hmmer3TabWriter")


class Hmmer3TabParser:
    """Parser for the HMMER table format."""

    def __init__(self, handle):
        """Initialize the class."""
        self.handle = handle
        self.line = self.handle.readline()

    def __iter__(self):
        """Iterate over Hmmer3TabParser, yields query results."""
        header_mark = "#"
        # read through the header if it exists
        while self.line.startswith(header_mark):
            self.line = self.handle.readline()
        # if we have result rows, parse it
        if self.line:
            yield from self._parse_qresult()

    def _parse_row(self):
        """Return a dictionary of parsed row values (PRIVATE)."""
        cols = [x for x in self.line.strip().split(" ") if x]
        if len(cols) < 18:
            raise ValueError("Less columns than expected, only %i" % len(cols))
        # if len(cols) > 19, we have extra description columns
        # combine them all into one string in the 19th column
        cols[18] = " ".join(cols[18:])

        # assign parsed column data into qresult, hit, and hsp dicts
        qresult = {}
        qresult["id"] = cols[2]  # query name
        qresult["accession"] = cols[3]  # query accession
        hit = {}
        hit["id"] = cols[0]  # target name
        hit["accession"] = cols[1]  # target accession
        hit["evalue"] = float(cols[4])  # evalue (full sequence)
        hit["bitscore"] = float(cols[5])  # score (full sequence)
        hit["bias"] = float(cols[6])  # bias (full sequence)
        hit["domain_exp_num"] = float(cols[10])  # exp
        hit["region_num"] = int(cols[11])  # reg
        hit["cluster_num"] = int(cols[12])  # clu
        hit["overlap_num"] = int(cols[13])  # ov
        hit["env_num"] = int(cols[14])  # env
        hit["domain_obs_num"] = int(cols[15])  # dom
        hit["domain_reported_num"] = int(cols[16])  # rep
        hit["domain_included_num"] = int(cols[17])  # inc
        hit["description"] = cols[18]  # description of target
        hsp = {}
        hsp["evalue"] = float(cols[7])  # evalue (best 1 domain)
        hsp["bitscore"] = float(cols[8])  # score (best 1 domain)
        hsp["bias"] = float(cols[9])  # bias (best 1 domain)
        # strand is always 0, since HMMER now only handles protein
        frag = {}
        frag["hit_strand"] = frag["query_strand"] = 0
        frag["alphabet"] = generic_protein

        return {"qresult": qresult, "hit": hit, "hsp": hsp, "frag": frag}

    def _parse_qresult(self):
        """Return QueryResult objects (PRIVATE)."""
        # state values, determines what to do for each line
        state_EOF = 0
        state_QRES_NEW = 1
        state_QRES_SAME = 3
        # initial value dummies
        qres_state = None
        file_state = None
        prev_qid = None
        cur, prev = None, None
        # container for Hit objects, used to create QueryResult
        hit_list = []
        cur_qid = None
        while True:
            # store previous line's parsed values for all lines after the first
            if cur is not None:
                prev = cur
                prev_qid = cur_qid
            # only parse the result row if it's not EOF
            # NOTE: we are not parsing the extra '#' lines appended to the end
            # of hmmer31b1 tabular results since storing them in qresult
            # objects means we can not do a single-pass parsing
            if self.line and not self.line.startswith("#"):
                cur = self._parse_row()
                cur_qid = cur["qresult"]["id"]
            else:
                file_state = state_EOF
                # mock value for cur_qid, since we have nothing to parse
                cur_qid = None

            if prev_qid != cur_qid:
                qres_state = state_QRES_NEW
            else:
                qres_state = state_QRES_SAME

            if prev is not None:
                # since domain tab formats only have 1 Hit per line
                # we always create HSPFragment, HSP, and Hit per line
                prev_hid = prev["hit"]["id"]

                # create fragment and HSP and set their attributes
                frag = HSPFragment(prev_hid, prev_qid)
                for attr, value in prev["frag"].items():
                    setattr(frag, attr, value)
                hsp = HSP([frag])
                for attr, value in prev["hsp"].items():
                    setattr(hsp, attr, value)

                # create Hit and set its attributes
                hit = Hit([hsp])
                for attr, value in prev["hit"].items():
                    setattr(hit, attr, value)
                hit_list.append(hit)

                # create qresult and yield if we're at a new qresult or at EOF
                if qres_state == state_QRES_NEW or file_state == state_EOF:
                    qresult = QueryResult(hit_list, prev_qid)
                    for attr, value in prev["qresult"].items():
                        setattr(qresult, attr, value)
                    yield qresult
                    # if we're at EOF, break
                    if file_state == state_EOF:
                        break
                    hit_list = []

            self.line = self.handle.readline()


class Hmmer3TabIndexer(SearchIndexer):
    """Indexer class for HMMER table output."""

    _parser = Hmmer3TabParser
    # denotes column location for query identifier
    _query_id_idx = 2

    def __iter__(self):
        """Iterate over the file handle; yields key, start offset, and length."""
        handle = self._handle
        handle.seek(0)
        query_id_idx = self._query_id_idx
        qresult_key = None
        header_mark = b"#"
        split_mark = b" "
        # set line with initial mock value, to emulate header
        line = header_mark

        # read through header
        while line.startswith(header_mark):
            start_offset = handle.tell()
            line = handle.readline()

        # and index the qresults
        while True:
            end_offset = handle.tell()

            if not line:
                break

            cols = [x for x in line.strip().split(split_mark) if x]
            if qresult_key is None:
                qresult_key = cols[query_id_idx]
            else:
                curr_key = cols[query_id_idx]

                if curr_key != qresult_key:
                    adj_end = end_offset - len(line)
                    yield (qresult_key.decode(), start_offset, adj_end - start_offset)
                    qresult_key = curr_key
                    start_offset = adj_end

            line = handle.readline()
            if not line:
                yield (qresult_key.decode(), start_offset, end_offset - start_offset)
                break

    def get_raw(self, offset):
        """Return the raw bytes string of a QueryResult object from the given offset."""
        handle = self._handle
        handle.seek(offset)
        query_id_idx = self._query_id_idx
        qresult_key = None
        qresult_raw = b""
        split_mark = b" "

        while True:
            line = handle.readline()
            if not line:
                break
            cols = [x for x in line.strip().split(split_mark) if x]
            if qresult_key is None:
                qresult_key = cols[query_id_idx]
            else:
                curr_key = cols[query_id_idx]
                if curr_key != qresult_key:
                    break
            qresult_raw += line

        return qresult_raw


class Hmmer3TabWriter:
    """Writer for hmmer3-tab output format."""

    def __init__(self, handle):
        """Initialize the class."""
        self.handle = handle

    def write_file(self, qresults):
        """Write to the handle.

        Returns a tuple of how many QueryResult, Hit, and HSP objects were written.

        """
        handle = self.handle
        qresult_counter, hit_counter, hsp_counter, frag_counter = 0, 0, 0, 0

        try:
            first_qresult = next(qresults)
        except StopIteration:
            handle.write(self._build_header())
        else:
            # write header
            handle.write(self._build_header(first_qresult))
            # and then the qresults
            for qresult in chain([first_qresult], qresults):
                if qresult:
                    handle.write(self._build_row(qresult))
                    qresult_counter += 1
                    hit_counter += len(qresult)
                    hsp_counter += sum(len(hit) for hit in qresult)
                    frag_counter += sum(len(hit.fragments) for hit in qresult)

        return qresult_counter, hit_counter, hsp_counter, frag_counter

    def _build_header(self, first_qresult=None):
        """Return the header string of a HMMER table output (PRIVATE)."""
        # calculate whitespace required
        # adapted from HMMER's source: src/p7_tophits.c#L1083
        if first_qresult is not None:
            # qnamew = max(20, len(first_qresult.id))
            qnamew = 20  # why doesn't the above work?
            tnamew = max(20, len(first_qresult[0].id))
            qaccw = max(10, len(first_qresult.accession))
            taccw = max(10, len(first_qresult[0].accession))
        else:
            qnamew, tnamew, qaccw, taccw = 20, 20, 10, 10
        # Turn black code style off
        # fmt: off
        header = ("#%*s %22s %22s %33s\n"
                  % (tnamew + qnamew + taccw + qaccw + 2, "",
                     "--- full sequence ----", "--- best 1 domain ----",
                     "--- domain number estimation ----"))
        header += ("#%-*s %-*s %-*s %-*s %9s %6s %5s %9s %6s %5s %5s %3s "
                   "%3s %3s %3s %3s %3s %3s %s\n"
                   % (tnamew - 1, " target name",
                      taccw, "accession", qnamew, "query name", qaccw,
                      "accession", "  E-value", " score", " bias",
                      "  E-value", " score", " bias", "exp",
                      "reg", "clu", " ov", "env", "dom", "rep",
                      "inc", "description of target"))
        header += ("#%*s %*s %*s %*s %9s %6s %5s %9s %6s %5s %5s %3s %3s "
                   "%3s %3s %3s %3s %3s %s\n"
                   % (tnamew - 1, "-------------------",
                      taccw, "----------", qnamew, "--------------------", qaccw,
                      "----------", "---------", "------", "-----", "---------",
                      "------", "-----", "---", "---", "---", "---", "---", "---",
                      "---", "---", "---------------------"))
        # Turn black code style on
        # fmt: on
        return header

    def _build_row(self, qresult):
        """Return a string or one row or more of the QueryResult object (PRIVATE)."""
        rows = ""

        # calculate whitespace required
        # adapted from HMMER's source: src/p7_tophits.c#L1083
        qnamew = max(20, len(qresult.id))
        tnamew = max(20, len(qresult[0].id))
        qaccw = max(10, len(qresult.accession))
        taccw = max(10, len(qresult[0].accession))

        for hit in qresult:
            rows += (
                "%-*s %-*s %-*s %-*s %9.2g %6.1f %5.1f %9.2g %6.1f"
                " %5.1f %5.1f %3d %3d %3d %3d %3d %3d %3d %s\n"
                % (
                    tnamew,
                    hit.id,
                    taccw,
                    hit.accession,
                    qnamew,
                    qresult.id,
                    qaccw,
                    qresult.accession,
                    hit.evalue,
                    hit.bitscore,
                    hit.bias,
                    hit.hsps[0].evalue,
                    hit.hsps[0].bitscore,
                    hit.hsps[0].bias,
                    hit.domain_exp_num,
                    hit.region_num,
                    hit.cluster_num,
                    hit.overlap_num,
                    hit.env_num,
                    hit.domain_obs_num,
                    hit.domain_reported_num,
                    hit.domain_included_num,
                    hit.description,
                )
            )

        return rows


# if not used as a module, run the doctest
if __name__ == "__main__":
    from Bio._utils import run_doctest

    run_doctest()
