# Copyright 2007-2010 by Peter Cock.  All rights reserved.
# This code is part of the Biopython distribution and governed by its
# license.  Please see the LICENSE file that should have been included
# as part of this package.

from __future__ import print_function
from Bio._py3k import basestring

import os
import warnings

try:
    from StringIO import StringIO  # Python 2
    # Can't use cStringIO, quoting the documentation,
    #   "Unlike the StringIO module, this module is not able to accept
    #    Unicode strings that cannot be encoded as plain ASCII strings."
    # Therefore can't use from Bio._py3k import StringIO
except ImportError:
    from io import StringIO  # Python 3
from io import BytesIO

from Bio import BiopythonWarning, BiopythonParserWarning
from Bio import SeqIO
from Bio import AlignIO
from Bio.SeqRecord import SeqRecord
from Bio.Seq import Seq, UnknownSeq
from Bio import Alphabet
from Bio.Align import MultipleSeqAlignment

# TODO - Convert this to using unittest, and check desired warnings
# are issued. Used to do that by capturing warnings to stdout and
# verifying via the print-and-compare check. However, there was some
# frustrating cross-platform inconsistency I couldn't resolve.

protein_alphas = [Alphabet.generic_protein]
dna_alphas = [Alphabet.generic_dna]
rna_alphas = [Alphabet.generic_rna]
nucleotide_alphas = [Alphabet.generic_nucleotide,
                     Alphabet.Gapped(Alphabet.generic_nucleotide)]
no_alpha_formats = ["fasta", "clustal", "phylip", "phylip-relaxed",
                    "phylip-sequential", "tab", "ig",
                    "stockholm", "emboss", "fastq", "fastq-solexa",
                    "fastq-illumina", "qual"]
possible_unknown_seq_formats = ["qual", "genbank", "gb", "embl", "imgt"]

# List of formats including alignment only file formats we can read AND write.
# The list is initially hard coded to preserve the original order of the unit
# test output, with any new formats added since appended to the end.
test_write_read_alignment_formats = ["fasta", "clustal", "phylip", "stockholm",
                                     "phylip-relaxed"]
for format in sorted(SeqIO._FormatToWriter):
    if format not in test_write_read_alignment_formats:
        test_write_read_alignment_formats.append(format)
for format in sorted(AlignIO._FormatToWriter):
    if format not in test_write_read_alignment_formats:
        test_write_read_alignment_formats.append(format)
test_write_read_alignment_formats.remove("gb")  # an alias for genbank
test_write_read_alignment_formats.remove("fastq-sanger")  # an alias for fastq

# test_files is a list of tuples containing:
# - string:  file format
# - boolean: alignment (requires all seqs be same length)
# - string:  relative filename
# - integer: number of sequences

test_files = [
    ("sff", False, 'Roche/E3MFGYR02_random_10_reads.sff', 10),
    # Following examples are also used in test_Clustalw.py
    ("clustal", True, 'Clustalw/cw02.aln', 2),
    ("clustal", True, 'Clustalw/opuntia.aln', 7),
    ("clustal", True, 'Clustalw/hedgehog.aln', 5),
    ("clustal", True, 'Clustalw/odd_consensus.aln', 2),
    # Following nucleic examples are also used in test_SeqIO_FastaIO.py
    ("fasta", False, 'Fasta/lupine.nu', 1),
    ("fasta", False, 'Fasta/elderberry.nu', 1),
    ("fasta", False, 'Fasta/phlox.nu', 1),
    ("fasta", False, 'Fasta/centaurea.nu', 1),
    ("fasta", False, 'Fasta/wisteria.nu', 1),
    ("fasta", False, 'Fasta/sweetpea.nu', 1),
    ("fasta", False, 'Fasta/lavender.nu', 1),
    # Following protein examples are also used in test_SeqIO_FastaIO.py
    ("fasta", False, 'Fasta/aster.pro', 1),
    ("fasta", False, 'Fasta/loveliesbleeding.pro', 1),
    ("fasta", False, 'Fasta/rose.pro', 1),
    ("fasta", False, 'Fasta/rosemary.pro', 1),
    # Following examples are also used in test_BioSQL_SeqIO.py
    ("fasta", False, 'Fasta/f001', 1),  # Protein
    ("fasta", False, 'Fasta/f002', 3),  # DNA
    # ("fasta", False, 'Fasta/f003', 2),  # Protein with comments
    ("fasta", False, 'Fasta/fa01', 2),  # Protein with gaps
    # Following are also used in test_SeqIO_features.py, see also NC_005816.gb
    ("fasta", False, 'GenBank/NC_005816.fna', 1),
    ("fasta", False, 'GenBank/NC_005816.ffn', 10),
    ("fasta", False, 'GenBank/NC_005816.faa', 10),
    ("fasta", False, 'GenBank/NC_000932.faa', 85),
    ("tab", False, 'GenBank/NC_005816.tsv', 10),  # FASTA -> Tabbed
    # Following examples are also used in test_GFF.py
    ("fasta", False, 'GFF/NC_001802.fna', 1),  # upper case
    ("fasta", False, 'GFF/NC_001802lc.fna', 1),  # lower case
    ("fasta", True, 'GFF/multi.fna', 3),  # Trivial nucleotide alignment
    # Following example is also used in test_registry.py
    ("fasta", False, 'Registry/seqs.fasta', 2),  # contains blank line
    # Following example is also used in test_Nexus.py
    ("nexus", True, 'Nexus/test_Nexus_input.nex', 9),
    # Following examples are also used in test_SwissProt.py
    ("swiss", False, 'SwissProt/sp001', 1),
    ("swiss", False, 'SwissProt/sp002', 1),
    ("swiss", False, 'SwissProt/sp003', 1),
    ("swiss", False, 'SwissProt/sp004', 1),
    ("swiss", False, 'SwissProt/sp005', 1),
    ("swiss", False, 'SwissProt/sp006', 1),
    ("swiss", False, 'SwissProt/sp007', 1),
    ("swiss", False, 'SwissProt/sp008', 1),
    ("swiss", False, 'SwissProt/sp009', 1),
    ("swiss", False, 'SwissProt/sp010', 1),
    ("swiss", False, 'SwissProt/sp011', 1),
    ("swiss", False, 'SwissProt/sp012', 1),
    ("swiss", False, 'SwissProt/sp013', 1),
    ("swiss", False, 'SwissProt/sp014', 1),
    ("swiss", False, 'SwissProt/sp015', 1),
    ("swiss", False, 'SwissProt/sp016', 1),
    # Following example is also used in test_registry.py
    ("swiss", False, 'Registry/EDD_RAT.dat', 1),
    # Following examples are also used in test_Uniprot.py
    ("uniprot-xml", False, 'SwissProt/uni001', 1),
    ("uniprot-xml", False, 'SwissProt/uni002', 3),
    ("uniprot-xml", False, 'SwissProt/Q13639.xml', 1),
    ("swiss", False, 'SwissProt/Q13639.txt', 1),
    ("uniprot-xml", False, 'SwissProt/H2CNN8.xml', 1),
    ("swiss", False, "SwissProt/H2CNN8.txt", 1),
    # Following examples are also used in test_GenBank.py
    ("genbank", False, 'GenBank/noref.gb', 1),
    ("genbank", False, 'GenBank/cor6_6.gb', 6),
    ("genbank", False, 'GenBank/iro.gb', 1),
    ("genbank", False, 'GenBank/pri1.gb', 1),
    ("genbank", False, 'GenBank/arab1.gb', 1),
    ("genbank", False, 'GenBank/protein_refseq.gb', 1),  # Old version
    ("genbank", False, 'GenBank/protein_refseq2.gb', 1),  # Revised version
    ("genbank", False, 'GenBank/extra_keywords.gb', 1),
    ("genbank", False, 'GenBank/one_of.gb', 1),
    ("genbank", False, 'GenBank/NT_019265.gb', 1),  # contig, no sequence
    ("genbank", False, 'GenBank/origin_line.gb', 1),
    ("genbank", False, 'GenBank/blank_seq.gb', 1),
    ("genbank", False, 'GenBank/dbsource_wrap.gb', 1),
    ("genbank", False, 'GenBank/NC_005816.gb', 1),  # See also AE017046.embl
    ("genbank", False, 'GenBank/NC_000932.gb', 1),
    # Odd LOCUS line from Vector NTI
    ("genbank", False, 'GenBank/pBAD30.gb', 1),
    # The next example is a truncated copy of gbvrl1.seq from
    # ftp://ftp.ncbi.nih.gov/genbank/gbvrl1.seq.gz
    # This includes an NCBI header, and the first three records:
    ("genbank", False, 'GenBank/gbvrl1_start.seq', 3),
    # Following files are also used in test_GFF.py
    ("genbank", False, 'GFF/NC_001422.gbk', 1),
    # Generated with Entrez.efetch("protein", id="16130152",
    # rettype="gbwithparts")
    ("genbank", False, 'GenBank/NP_416719.gbwithparts', 1),
    # GenPept file with nasty bond locations,
    ("genbank", False, 'GenBank/1MRR_A.gp', 1),
    # Following files are currently only used here or in test_SeqIO_index.py:
    ("embl", False, 'EMBL/epo_prt_selection.embl', 9),  # proteins
    ("embl", False, 'EMBL/patents.embl', 4),  # more proteins, but no seq
    ("embl", False, 'EMBL/TRBG361.embl', 1),
    ("embl", False, 'EMBL/DD231055_edited.embl', 1),
    ("embl", False, 'EMBL/DD231055_edited2.embl', 1),  # Partial ID line
    ("embl", False, 'EMBL/SC10H5.embl', 1),  # Pre 2006 style ID line
    ("embl", False, 'EMBL/U87107.embl', 1),  # Old ID line with SV line
    ("embl", False, 'EMBL/AAA03323.embl', 1),  # 2008, PA line but no AC
    ("embl", False, 'EMBL/AE017046.embl', 1),  # See also NC_005816.gb
    ("embl", False, 'EMBL/Human_contigs.embl', 2),  # contigs, no sequences
    # wrapped locations and unspecified type
    ("embl", False, 'EMBL/location_wrap.embl', 1),
    # features over indented for EMBL
    ("embl", False, 'EMBL/A04195.imgt', 1),
    # features over indented for EMBL
    ("imgt", False, 'EMBL/A04195.imgt', 1),
    ("stockholm", True, 'Stockholm/simple.sth', 2),
    ("stockholm", True, 'Stockholm/funny.sth', 6),
    # Following PHYLIP files are currently only used here and in test_AlignIO.py,
    # and are mostly from Joseph Felsenstein's PHYLIP v3.6 documentation:
    ("phylip", True, 'Phylip/reference_dna.phy', 6),
    ("phylip", True, 'Phylip/reference_dna2.phy', 6),
    ("phylip", True, 'Phylip/hennigian.phy', 10),
    ("phylip", True, 'Phylip/horses.phy', 10),
    ("phylip", True, 'Phylip/random.phy', 10),
    ("phylip", True, 'Phylip/interlaced.phy', 3),
    ("phylip", True, 'Phylip/interlaced2.phy', 4),
    # Following are EMBOSS simple or pairs format alignments
    ("emboss", True, 'Emboss/alignret.txt', 4),
    ("emboss", False, 'Emboss/needle.txt', 10),
    ("emboss", True, 'Emboss/water.txt', 2),
    # Following PHD (PHRAP) sequencing files are also used in test_Phd.py
    ("phd", False, 'Phd/phd1', 3),
    ("phd", False, 'Phd/phd2', 1),
    ("phd", False, 'Phd/phd_solexa', 2),
    ("phd", False, 'Phd/phd_454', 1),
    # Following ACE assembly files are also used in test_Ace.py
    ("ace", False, 'Ace/contig1.ace', 2),
    ("ace", False, 'Ace/consed_sample.ace', 1),
    ("ace", False, 'Ace/seq.cap.ace', 1),
    # Following IntelliGenetics / MASE files are also used in
    # test_intelligenetics.py
    ("ig", False, 'IntelliGenetics/TAT_mase_nuc.txt', 17),
    ("ig", True, 'IntelliGenetics/VIF_mase-pro.txt', 16),
    # This next file is a MASE alignment but sequence O_ANT70 is shorter than
    # the others (so as an alignment will fail).  Perhaps MASE doesn't
    # write trailing gaps?
    ("ig", False, 'IntelliGenetics/vpu_nucaligned.txt', 9),
    # Following NBRD-PIR files are used in test_nbrf.py
    ("pir", False, 'NBRF/B_nuc.pir', 444),
    ("pir", False, 'NBRF/Cw_prot.pir', 111),
    ("pir", False, 'NBRF/DMA_nuc.pir', 4),
    ("pir", False, 'NBRF/DMB_prot.pir', 6),
    ("pir", True, 'NBRF/clustalw.pir', 2),
    # Following quality files are also used in the Bio.SeqIO.QualityIO
    # doctests:
    ("fasta", True, 'Quality/example.fasta', 3),
    ("qual", False, 'Quality/example.qual', 3),
    ("fastq", True, 'Quality/example.fastq', 3),  # Unix new lines
    ("fastq", True, 'Quality/example_dos.fastq', 3),  # DOS/Windows new lines
    ("fastq", True, 'Quality/tricky.fastq', 4),
    ("fastq", False, 'Quality/sanger_faked.fastq', 1),
    ("fastq", False, 'Quality/sanger_93.fastq', 1),
    ("fastq-illumina", False, 'Quality/illumina_faked.fastq', 1),
    ("fastq-solexa", False, 'Quality/solexa_faked.fastq', 1),
    ("fastq-solexa", True, 'Quality/solexa_example.fastq', 5),
    # Following examples are also used in test_SeqXML.py
    ("seqxml", False, 'SeqXML/dna_example.xml', 4),
    ("seqxml", False, 'SeqXML/rna_example.xml', 5),
    ("seqxml", False, 'SeqXML/protein_example.xml', 5),
    # Following examples are also used in test_SeqIO_AbiIO.py
    ("abi", False, 'Abi/310.ab1', 1),
    ("abi", False, 'Abi/3100.ab1', 1),
    ("abi", False, 'Abi/3730.ab1', 1),
]


class ForwardOnlyHandle(object):
    """Mimic a network handle without seek and tell methods etc."""

    def __init__(self, handle):
        self._handle = handle

    def __iter__(self):
        return iter(self._handle)

    def read(self, length=None):
        if length is None:
            return self._handle.read()
        else:
            return self._handle.read(length)

    def readline(self):
        return self._handle.readline()

    def close(self):
        return self._handle.close()


def compare_record(record_one, record_two):
    """This is meant to be a strict comparison for exact agreement..."""
    assert isinstance(record_one, SeqRecord)
    assert isinstance(record_two, SeqRecord)
    assert record_one.seq is not None
    assert record_two.seq is not None
    if record_one.id != record_two.id:
        return False
    if record_one.name != record_two.name:
        return False
    if record_one.description != record_two.description:
        return False
    if len(record_one) != len(record_two):
        return False
    if isinstance(record_one.seq, UnknownSeq) \
            and isinstance(record_two.seq, UnknownSeq):
        # Jython didn't like us comparing the string of very long UnknownSeq
        # object (out of heap memory error)
        if record_one.seq._character != record_two.seq._character:
            return False
    elif str(record_one.seq) != str(record_two.seq):
        return False
    # TODO - check features and annotation (see code for BioSQL tests)
    for key in set(record_one.letter_annotations).intersection(
            record_two.letter_annotations):
        if record_one.letter_annotations[key] != \
           record_two.letter_annotations[key]:
            return False
    return True


def record_summary(record, indent=" "):
    """Returns a concise summary of a SeqRecord object as a string"""
    if record.id == record.name:
        answer = "%sID and Name='%s',\n%sSeq='" % (indent, record.id, indent)
    else:
        answer = "%sID = '%s', Name='%s',\n%sSeq='" % (
            indent, record.id, record.name, indent)
    if record.seq is None:
        answer += "None"
    else:
        if len(record.seq) > 50:
            answer += str(record.seq[:40]) + "..." + str(record.seq[-7:])
        else:
            answer += str(record.seq)
        answer += "', length=%i" % (len(record.seq))
    return answer


def col_summary(col_text):
    if len(col_text) < 65:
        return col_text
    else:
        return col_text[:60] + "..." + col_text[-5:]


def alignment_summary(alignment, index=" "):
    """Returns a concise summary of an Alignment object as a string"""
    answer = []
    alignment_len = alignment.get_alignment_length()
    rec_count = len(alignment)
    for i in range(min(5, alignment_len)):
        answer.append(index + col_summary(alignment[:, i])
                            + " alignment column %i" % i)
    if alignment_len > 5:
        i = alignment_len - 1
        answer.append(index + col_summary("|" * rec_count)
                            + " ...")
        answer.append(index + col_summary(alignment[:, i])
                            + " alignment column %i" % i)
    return "\n".join(answer)


def check_simple_write_read(records, indent=" "):
    # print(indent+"Checking we can write and then read back these records")
    for format in test_write_read_alignment_formats:
        if format not in possible_unknown_seq_formats \
                and isinstance(records[0].seq, UnknownSeq) \
                and len(records[0].seq) > 100:
            # Skipping for speed.  Some of the unknown sequences are
            # rather long, and it seems a bit pointless to record them.
            continue
        print(indent + "Checking can write/read as '%s' format" % format)

        # Going to write to a handle...
        if format in SeqIO._BinaryFormats:
            handle = BytesIO()
        else:
            handle = StringIO()

        try:
            with warnings.catch_warnings():
                # e.g. data loss
                warnings.simplefilter("ignore", BiopythonWarning)
                c = SeqIO.write(
                    sequences=records, handle=handle, format=format)
            assert c == len(records)
        except (TypeError, ValueError) as e:
            # This is often expected to happen, for example when we try and
            # write sequences of different lengths to an alignment file.
            if "len()" in str(e):
                # Python 2.4.3,
                # >>> len(None)
                # ...
                # TypeError: len() of unsized object
                #
                # Python 2.5.2,
                # >>> len(None)
                # ...
                # TypeError: object of type 'NoneType' has no len()
                print("Failed: Probably len() of None")
            else:
                print(indent + "Failed: %s" % str(e))
            if records[0].seq.alphabet.letters is not None:
                assert format != t_format, \
                    "Should be able to re-write in the original format!"
            # Carry on to the next format:
            continue

        handle.flush()
        handle.seek(0)
        # Now ready to read back from the handle...
        try:
            records2 = list(SeqIO.parse(handle=handle, format=format))
        except ValueError as e:
            # This is BAD.  We can't read our own output.
            # I want to see the output when called from the test harness,
            # run_tests.py (which can be funny about new lines on Windows)
            handle.seek(0)
            raise ValueError("%s\n\n%s\n\n%s"
                             % (str(e), repr(handle.read()), repr(records)))

        assert len(records2) == t_count
        for r1, r2 in zip(records, records2):
            # Check the bare minimum (ID and sequence) as
            # many formats can't store more than that.
            assert len(r1) == len(r2)

            # Check the sequence
            if format in ["gb", "genbank", "embl", "imgt"]:
                # The GenBank/EMBL parsers will convert to upper case.
                if isinstance(r1.seq, UnknownSeq) \
                        and isinstance(r2.seq, UnknownSeq):
                    # Jython didn't like us comparing the string of very long
                    # UnknownSeq object (out of heap memory error)
                    assert r1.seq._character.upper() == r2.seq._character
                else:
                    assert str(r1.seq).upper() == str(r2.seq)
            elif format == "qual":
                assert isinstance(r2.seq, UnknownSeq)
                assert len(r2) == len(r1)
            else:
                assert str(r1.seq) == str(r2.seq)
            # Beware of different quirks and limitations in the
            # valid character sets and the identifier lengths!
            if format in ["phylip", "phylip-sequential"]:
                assert r1.id.replace("[", "").replace("]", "")[:10] == r2.id, \
                    "'%s' vs '%s'" % (r1.id, r2.id)
            elif format == "phylip-relaxed":
                assert r1.id.replace(" ", "").replace(':', '|') == r2.id, \
                    "'%s' vs '%s'" % (r1.id, r2.id)
            elif format == "clustal":
                assert r1.id.replace(" ", "_")[:30] == r2.id, \
                    "'%s' vs '%s'" % (r1.id, r2.id)
            elif format == "stockholm":
                assert r1.id.replace(" ", "_") == r2.id, \
                    "'%s' vs '%s'" % (r1.id, r2.id)
            elif format == "fasta":
                assert r1.id.split()[0] == r2.id
            else:
                assert r1.id == r2.id, \
                    "'%s' vs '%s'" % (r1.id, r2.id)

        if len(records) > 1:
            # Try writing just one record (passing a SeqRecord, not a list)
            if format in SeqIO._BinaryFormats:
                handle = BytesIO()
            else:
                handle = StringIO()
            SeqIO.write(records[0], handle, format)
            assert handle.getvalue() == records[0].format(format)


# Check parsers can cope with an empty file
for t_format in SeqIO._FormatToIterator:
    if t_format in SeqIO._BinaryFormats or \
       t_format in ("uniprot-xml", "pdb-seqres", "pdb-atom"):
        # Not allowed empty SFF files.
        continue
    handle = StringIO()
    records = list(SeqIO.parse(handle, t_format))
    assert len(records) == 0

for (t_format, t_alignment, t_filename, t_count) in test_files:
    if t_format in SeqIO._BinaryFormats:
        mode = "rb"
    else:
        mode = "r"

    print("Testing reading %s format file %s" % (t_format, t_filename))
    assert os.path.isfile(t_filename), t_filename

    with warnings.catch_warnings():
        # e.g. BiopythonParserWarning: Dropping bond qualifier in feature
        # location
        warnings.simplefilter("ignore", BiopythonParserWarning)

        # Try as an iterator using handle
        h = open(t_filename, mode)
        records = list(SeqIO.parse(handle=h, format=t_format))
        h.close()
        assert len(records) == t_count, \
            "Found %i records but expected %i" % (len(records), t_count)

        # Try using the iterator with a for loop, and a filename not handle
        records2 = []
        for record in SeqIO.parse(t_filename, format=t_format):
            records2.append(record)
        assert len(records2) == t_count

        # Try using the iterator with the next() method
        records3 = []
        h = open(t_filename, mode)
        seq_iterator = SeqIO.parse(handle=h, format=t_format)
        while True:
            try:
                record = next(seq_iterator)
            except StopIteration:
                break
            assert record is not None, "Should raise StopIteration not return None"
            records3.append(record)
        h.close()

        # Try a mixture of next() and list (a torture test!)
        h = open(t_filename, mode)
        seq_iterator = SeqIO.parse(handle=h, format=t_format)
        try:
            record = next(seq_iterator)
        except StopIteration:
            record = None
        if record is not None:
            records4 = [record]
            records4.extend(list(seq_iterator))
        else:
            records4 = []
        assert len(records4) == t_count
        h.close()

        # Try a mixture of next() and for loop (a torture test!)
        # with a forward-only-handle
        if t_format == "abi":
            # Temp hack
            h = open(t_filename, mode)
        else:
            h = ForwardOnlyHandle(open(t_filename, mode))
        seq_iterator = SeqIO.parse(h, format=t_format)
        try:
            record = next(seq_iterator)
        except StopIteration:
            record = None
        if record is not None:
            records5 = [record]
            for record in seq_iterator:
                records5.append(record)
        else:
            records5 = []
        assert len(records5) == t_count
        h.close()

    for i in range(t_count):
        record = records[i]

        # Check returned expected object type
        assert isinstance(record, SeqRecord)
        if t_format in possible_unknown_seq_formats:
            assert isinstance(record.seq, Seq) or \
                isinstance(record.seq, UnknownSeq)
        else:
            assert isinstance(record.seq, Seq)
        assert isinstance(record.id, basestring)
        assert isinstance(record.name, basestring)
        assert isinstance(record.description, basestring)
        assert record.id != ""

        if "accessions" in record.annotations:
            accs = record.annotations["accessions"]
            # Check for blanks, or entries with leading/trailing spaces
            for acc in accs:
                assert acc and acc == acc.strip(), \
                    "Bad accession in annotations: %s" % repr(acc)
            assert len(set(accs)) == len(accs), \
                "Repeated accession in annotations: %s" % repr(accs)
        for ref in record.dbxrefs:
            assert ref and ref == ref.strip(), \
                "Bad cross reference in dbxrefs: %s" % repr(ref)
        assert len(record.dbxrefs) == len(record.dbxrefs), \
            "Repeated cross reference in dbxrefs: %s" % repr(record.dbxrefs)

        # Check the lists obtained by the different methods agree
        assert compare_record(record, records2[i])
        assert compare_record(record, records3[i])
        assert compare_record(record, records4[i])
        assert compare_record(record, records5[i])

        if i < 3:
            print(record_summary(record))
    # Only printed the only first three records: 0,1,2
    if t_count > 4:
        print(" ...")
    if t_count > 3:
        print(record_summary(records[-1]))

    # Check Bio.SeqIO.read(...)
    if t_count == 1:
        record = SeqIO.read(t_filename, format=t_format)
        assert isinstance(record, SeqRecord)
    else:
        try:
            record = SeqIO.read(t_filename, t_format)
            assert False, "Bio.SeqIO.read(...) should have failed"
        except ValueError:
            # Expected to fail
            pass

    # Check alphabets
    for record in records:
        base_alpha = Alphabet._get_base_alphabet(record.seq.alphabet)
        if isinstance(base_alpha, Alphabet.SingleLetterAlphabet):
            if t_format in no_alpha_formats:
                # Too harsh?
                assert base_alpha == Alphabet.single_letter_alphabet
        else:
            base_alpha = None
    if base_alpha is None:
        good = []
        bad = []
        given_alpha = None
    elif isinstance(base_alpha, Alphabet.ProteinAlphabet):
        good = protein_alphas
        bad = dna_alphas + rna_alphas + nucleotide_alphas
    elif isinstance(base_alpha, Alphabet.RNAAlphabet):
        good = nucleotide_alphas + rna_alphas
        bad = protein_alphas + dna_alphas
    elif isinstance(base_alpha, Alphabet.DNAAlphabet):
        good = nucleotide_alphas + dna_alphas
        bad = protein_alphas + rna_alphas
    elif isinstance(base_alpha, Alphabet.NucleotideAlphabet):
        good = nucleotide_alphas
        bad = protein_alphas
    else:
        assert t_format in no_alpha_formats, "Got %s from %s file" \
            % (repr(base_alpha), t_format)
        good = protein_alphas + dna_alphas + rna_alphas + nucleotide_alphas
        bad = []
    for given_alpha in good:
        # These should all work...
        given_base = Alphabet._get_base_alphabet(given_alpha)
        for record in SeqIO.parse(t_filename, t_format, given_alpha):
            base_alpha = Alphabet._get_base_alphabet(record.seq.alphabet)
            assert isinstance(base_alpha, given_base.__class__)
            assert base_alpha == given_base
        if t_count == 1:
            h = open(t_filename, mode)
            record = SeqIO.read(h, t_format, given_alpha)
            h.close()
            assert isinstance(base_alpha, given_base.__class__)
            assert base_alpha == given_base
    for given_alpha in bad:
        # These should all fail...
        h = open(t_filename, mode)
        try:
            print(next(SeqIO.parse(h, t_format, given_alpha)))
            h.close()
            assert False, "Forcing wrong alphabet, %s, should fail (%s)" \
                % (repr(given_alpha), t_filename)
        except ValueError:
            # Good - should fail
            pass
        h.close()
    del good, bad, given_alpha, base_alpha

    if t_alignment:
        print("Testing reading %s format file %s as an alignment"
              % (t_format, t_filename))

        alignment = MultipleSeqAlignment(SeqIO.parse(
            handle=t_filename, format=t_format))
        assert len(alignment) == t_count

        alignment_len = alignment.get_alignment_length()

        # Check the record order agrees, and double check the
        # sequence lengths all agree too.
        for i in range(t_count):
            assert compare_record(records[i], alignment[i])
            assert len(records[i].seq) == alignment_len

        print(alignment_summary(alignment))

    # Some alignment file formats have magic characters which mean
    # use the letter in this position in the first sequence.
    # They should all have been converted by the parser, but if
    # not reversing the record order might expose an error.  Maybe.
    records.reverse()
    check_simple_write_read(records)

print("Finished tested reading files")
