# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


__copyright__ = "Copyright (C) 2005 Canonical Ltd."
__author__ = "Martin Pool <mbp@canonical.com>"


"""Messages and logging for bazaar-ng

Nothing is actually logged unless you call bzrlib.open_tracefile().
"""


import sys, os

######################################################################
# messages and logging

global _tracefile, _starttime
_tracefile = None

# used to have % (os.environ['USER'], time.time(), os.getpid()), 'w')
_starttime = None

# If false, notes also go to stdout; should replace this with --silent
# at some point.
silent = False


# fix this if we ever fork within python
_mypid = os.getpid()
_logprefix = '[%d] ' % _mypid


def _write_trace(msg):
    if _tracefile:
        _tracefile.write(_logprefix + msg + '\n')


def warning(msg):
    sys.stderr.write('bzr: warning: ' + msg + '\n')
    _write_trace('warning: ' + msg)


mutter = _write_trace


def note(msg):
    b = '* ' + str(msg) + '\n'
    if not silent:
        sys.stderr.write(b)
    _write_trace('note: ' + msg)


def log_error(msg):
    sys.stderr.write(msg + '\n')
    _write_trace(msg)


def _rollover_trace_maybe(trace_fname):
    import stat
    try:
        size = os.stat(trace_fname)[stat.ST_SIZE]
        if size <= 4 << 20:
            return
        old_fname = trace_fname + '.old'

        try:
            # must remove before rename on windows
            os.remove(old_fname)
        except OSError:
            pass

        try:
            # might fail if in use on windows
            os.rename(trace_fname, old_fname)
        except OSError:
            pass
    except OSError:
        return



def open_tracefile(argv=[], tracefilename='~/.bzr.log'):
    # Messages are always written to here, so that we have some
    # information if something goes wrong.  In a future version this
    # file will be removed on successful completion.
    global _starttime, _tracefile
    import stat, codecs

    _starttime = os.times()[4]

    trace_fname = os.path.join(os.path.expanduser(tracefilename))
    _rollover_trace_maybe(trace_fname)

    # buffering=1 means line buffered
    try:
        _tracefile = codecs.open(trace_fname, 'at', 'utf8', buffering=1)
        t = _tracefile

        if os.fstat(t.fileno())[stat.ST_SIZE] == 0:
            t.write("\nthis is a debug log for diagnosing/reporting problems in bzr\n")
            t.write("you can delete or truncate this file, or include sections in\n")
            t.write("bug reports to bazaar-ng@lists.canonical.com\n\n")

        import bzrlib
        _write_trace('bzr %s invoked on python %s (%s)'
                     % (bzrlib.__version__,
                        '.'.join(map(str, sys.version_info)),
                        sys.platform))

        _write_trace('  arguments: %r' % argv)
        _write_trace('  working dir: ' + os.getcwdu())
    except IOError, e:
        warning("failed to open trace file: %s" % (e))

def close_trace():
    times = os.times()
    mutter("finished, %.3fu/%.3fs cpu, %.3fu/%.3fs cum, %.3f elapsed"
           % (times[:4] + ((times[4] - _starttime),)))



def log_exception():
    """Log the last exception into the trace file."""
    import cgitb
    s = cgitb.text(sys.exc_info())
    for l in s.split('\n'):
        _write_trace(l)