import sys
import re
import datetime

_MARKER = re.compile(r'^------\s*\[{0,1}') # deal with our generated markers
_ISO8601 = re.compile(r'^(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})T'
                      r'(?P<hour>\d{2}):(?P<minute>\d{2}):(?P<second>\d{2})')

class Record:
    def __init__(self, message, file, begin):
        self.message = message
        self.file = file
        self.begin = begin

    def __cmp__(self, other):
        return cmp(self.timeof(), other.timeof())

    def rewind(self):
        self.file.seek(self.begin)

    def tostr(self):
        result = '------ [%s]\n' % self.file.name
        result += self.message + '\n'
        return result

    def timeof(self):
        message = self.message
        match = _ISO8601.match(message)
        if not match:
            raise ValueError, message
        L = []
        for name in ('year', 'month', 'day', 'hour', 'minute', 'second'):
            L.append(int(match.group(name)))
        return datetime.datetime(*L)

def main(files):
    while 1:
        heads = []
        for file in files[:]: # we need to mutate this
            record = next_record(file)
            if record is None:
                files.remove(file) # file done
                continue
            heads.append(record)

        if not heads:
            break
        
        heads.sort()
        latest = heads.pop(0)
        sys.stdout.write(latest.tostr())
        for record in heads: # rewind files that didn't have the latest record
            record.rewind()
    
def next_record(f):
    begin = f.tell()
    # read (garbage) until past marker
    line = ''
    while not _MARKER.match(line):
        line = f.readline()
        if not line:
            break
    message = ''
    while 1:
        line = f.readline()
        if not line:
            # we've reached the end of the file
            break
        if _MARKER.match(line):
            # we found the beginning of the next record, rewind and stop
            f.seek(-len(line), 1)
            break
        message += line
    if message:
        return Record(message, f, begin)

def test(f):
    # test derived file, making sure that records are saved in ascending order
    last = datetime.datetime(1969, 1, 1)
    while 1:
        record = next_record(f)
        if record is None:
            break
        timeof = record.timeof()
        if timeof < last:
            raise ValueError, record.tostr()
        last = timeof

## if __name__ == '__main__':
##     test(open(sys.argv[1], 'r'))

if __name__ == '__main__':
    main([open(x, 'r') for x in sys.argv[1:]])