#!/usr/bin/env python
"""
Runs SRMA on a SAM/BAM file;
TODO: more documentation

usage: srma_wrapper.py [options]

See below for options
"""

import optparse
import os
import shutil
import subprocess
import sys
import tempfile


def stop_err(msg):
    sys.stderr.write('%s\n' % msg)
    sys.exit()


def parseRefLoc(refLoc, refUID):
    for line in open(refLoc):
        if not line.startswith('#'):
            fields = line.strip().split('\t')
            if len(fields) >= 3:
                if fields[0] == refUID:
                    return fields[1]
    return None


def __main__():
    parser = optparse.OptionParser()
    parser.add_option('-r', '--ref', dest='ref', help='The reference genome to index and use')
    parser.add_option('-u', '--refUID', dest='refUID', help='The pre-index reference genome unique Identifier')
    parser.add_option('-i', '--input', dest='input', help='The SAM/BAM input file')
    parser.add_option('-I', '--inputIndex', dest='inputIndex', help='The SAM/BAM input index file')
    parser.add_option('-o', '--output', dest='output', help='The SAM/BAM output file')
    parser.add_option('-O', '--offset', dest='offset', help='The alignment offset')
    parser.add_option('-Q', '--minMappingQuality', dest='minMappingQuality', help='The minimum mapping quality')
    parser.add_option('-P', '--minAlleleProbability', dest='minAlleleProbability', help='The minimum allele probability conditioned on coverage (for the binomial quantile).')
    parser.add_option('-C', '--minAlleleCoverage', dest='minAlleleCoverage', help='The minimum haploid coverage for the consensus')
    parser.add_option('-R', '--range', dest='range', help='A range to examine')
    parser.add_option('-c', '--correctBases', dest='correctBases', help='Correct bases ')
    parser.add_option('-q', '--useSequenceQualities', dest='useSequenceQualities', help='Use sequence qualities ')
    parser.add_option('-M', '--maxHeapSize', dest='maxHeapSize', help='The maximum number of nodes on the heap before re-alignment is ignored')
    parser.add_option('-s', '--fileSource', dest='fileSource', help='Whether to use a previously indexed reference sequence or one from history (indexed or history)')
    parser.add_option('-p', '--params', dest='params', help='Parameter setting to use (pre_set or full)')
    parser.add_option('-j', '--jarBin', dest='jarBin', default='', help='The path to where jars are stored')
    parser.add_option('-f', '--jarFile', dest='jarFile', help='The file name of the jar file to use')
    (options, args) = parser.parse_args()

    # make temp directory for srma
    tmp_dir = tempfile.mkdtemp()
    buffsize = 1048576

    # set up reference filenames
    reference_filepath_name = None
    # need to create SRMA dict and Samtools fai files for custom genome
    if options.fileSource == 'history':
        try:
            reference_filepath = tempfile.NamedTemporaryFile(dir=tmp_dir, suffix='.fa')
            reference_filepath_name = reference_filepath.name
            reference_filepath.close()
            dict_filepath_name = reference_filepath_name.replace('.fa', '.dict')
            os.symlink(options.ref, reference_filepath_name)
            # create fai file using Samtools
            index_fai_cmd = 'samtools faidx %s' % reference_filepath_name
            try:
                tmp = tempfile.NamedTemporaryFile(dir=tmp_dir).name
                tmp_stderr = open(tmp, 'wb')
                proc = subprocess.Popen(args=index_fai_cmd, shell=True, cwd=tmp_dir, stderr=tmp_stderr.fileno())
                returncode = proc.wait()
                tmp_stderr.close()
                # get stderr, allowing for case where it's very large
                tmp_stderr = open(tmp, 'rb')
                stderr = ''
                try:
                    while True:
                        stderr += tmp_stderr.read(buffsize)
                        if not stderr or len(stderr) % buffsize != 0:
                            break
                except OverflowError:
                    pass
                tmp_stderr.close()
                if returncode != 0:
                    raise Exception(stderr)
            except Exception as e:
                # clean up temp dir
                if os.path.exists(tmp_dir):
                    shutil.rmtree(tmp_dir)
                stop_err('Error creating Samtools index for custom genome file: %s\n' % str(e))
            # create dict file using SRMA
            dict_cmd = 'java -cp "%s" net.sf.picard.sam.CreateSequenceDictionary R=%s O=%s' % (os.path.join(options.jarBin, options.jarFile), reference_filepath_name, dict_filepath_name)
            try:
                tmp = tempfile.NamedTemporaryFile(dir=tmp_dir).name
                tmp_stderr = open(tmp, 'wb')
                proc = subprocess.Popen(args=dict_cmd, shell=True, cwd=tmp_dir, stderr=tmp_stderr.fileno())
                returncode = proc.wait()
                tmp_stderr.close()
                # get stderr, allowing for case where it's very large
                tmp_stderr = open(tmp, 'rb')
                stderr = ''
                try:
                    while True:
                        stderr += tmp_stderr.read(buffsize)
                        if not stderr or len(stderr) % buffsize != 0:
                            break
                except OverflowError:
                    pass
                tmp_stderr.close()
                if returncode != 0:
                    raise Exception(stderr)
            except Exception as e:
                # clean up temp dir
                if os.path.exists(tmp_dir):
                    shutil.rmtree(tmp_dir)
                stop_err('Error creating index for custom genome file: %s\n' % str(e))
        except Exception as e:
            # clean up temp dir
            if os.path.exists(tmp_dir):
                shutil.rmtree(tmp_dir)
            stop_err('Problem handling SRMA index (dict file) for custom genome file: %s\n' % str(e))
    # using built-in dict/index files
    else:
        if options.ref:
            reference_filepath_name = options.ref
        else:
            reference_filepath_name = parseRefLoc(options.refLocation, options.refUID)
    if reference_filepath_name is None:
        raise ValueError('A valid genome reference was not provided.')

    # set up aligning and generate aligning command options
    if options.params == 'pre_set':
        srma_cmds = ''
    else:
        ranges = 'null'
        if options.range == 'None':
            range = 'null'
        else:
            range = options.range
        srma_cmds = "OFFSET=%s MIN_MAPQ=%s MINIMUM_ALLELE_PROBABILITY=%s MINIMUM_ALLELE_COVERAGE=%s RANGES=%s RANGE=%s CORRECT_BASES=%s USE_SEQUENCE_QUALITIES=%s MAX_HEAP_SIZE=%s" % (options.offset, options.minMappingQuality, options.minAlleleProbability, options.minAlleleCoverage, ranges, range, options.correctBases, options.useSequenceQualities, options.maxHeapSize)

    srma_cmds = "%s VALIDATION_STRINGENCY=LENIENT" % srma_cmds

    # perform alignments
    buffsize = 1048576
    try:
        # symlink input bam and index files due to the naming conventions required by srma here
        input_bam_filename = os.path.join(tmp_dir, '%s.bam' % os.path.split(options.input)[-1])
        os.symlink(options.input, input_bam_filename)
        input_bai_filename = "%s.bai" % os.path.splitext(input_bam_filename)[0]
        os.symlink(options.inputIndex, input_bai_filename)

        # create a temp output name, ending in .bam due to required naming conventions? unkown if required
        output_bam_filename = os.path.join(tmp_dir, "%s.bam" % os.path.split(options.output)[-1])
        # generate commandline
        java_opts = ''
        if '_JAVA_OPTIONS' not in os.environ:
            java_opts = '-Xmx2048m'
        cmd = 'java %s -jar %s I=%s O=%s R=%s %s' % (java_opts, os.path.join(options.jarBin, options.jarFile), input_bam_filename, output_bam_filename, reference_filepath_name, srma_cmds)
        # need to nest try-except in try-finally to handle 2.4
        try:
            try:
                tmp = tempfile.NamedTemporaryFile(dir=tmp_dir).name
                tmp_stderr = open(tmp, 'wb')
                proc = subprocess.Popen(args=cmd, shell=True, cwd=tmp_dir, stderr=tmp_stderr.fileno())
                returncode = proc.wait()
                tmp_stderr.close()
                # get stderr, allowing for case where it's very large
                tmp_stderr = open(tmp, 'rb')
                stderr = ''
                try:
                    while True:
                        stderr += tmp_stderr.read(buffsize)
                        if not stderr or len(stderr) % buffsize != 0:
                            break
                except OverflowError:
                    pass
                tmp_stderr.close()
                if returncode != 0:
                    raise Exception(stderr)
            except Exception as e:
                raise Exception('Error executing SRMA. ' + str(e))
            # move file from temp location (with .bam name) to provided path
            shutil.move(output_bam_filename, options.output)
            # check that there are results in the output file
            if os.path.getsize(options.output) <= 0:
                raise Exception('The output file is empty. You may simply have no matches, or there may be an error with your input file or settings.')
        except Exception as e:
            stop_err('The re-alignment failed.\n' + str(e))
    finally:
        # clean up temp dir
        if os.path.exists(tmp_dir):
            shutil.rmtree(tmp_dir)


if __name__ == "__main__":
    __main__()