#!/usr/bin/python
"""\
@file template_verifier.py
@brief Message template compatibility verifier.

$LicenseInfo:firstyear=2007&license=viewergpl$

Copyright (c) 2007-2008, Linden Research, Inc.

Second Life Viewer Source Code
The source code in this file ("Source Code") is provided by Linden Lab
to you under the terms of the GNU General Public License, version 2.0
("GPL"), unless you have obtained a separate licensing agreement
("Other License"), formally executed by you and Linden Lab.  Terms of
the GPL can be found in doc/GPL-license.txt in this distribution, or
online at http://secondlifegrid.net/programs/open_source/licensing/gplv2

There are special exceptions to the terms and conditions of the GPL as
it is applied to this Source Code. View the full text of the exception
in the file doc/FLOSS-exception.txt in this software distribution, or
online at http://secondlifegrid.net/programs/open_source/licensing/flossexception

By copying, modifying or distributing this software, you acknowledge
that you have read and understood your obligations described above,
and agree to abide by those obligations.

ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
COMPLETENESS OR PERFORMANCE.
$/LicenseInfo$
"""

"""template_verifier is a script which will compare the
current repository message template with the "master" message template, accessible
via http://secondlife.com/app/message_template/master_message_template.msg
If [FILE] is specified, it will be checked against the master template.
If [FILE] [FILE] is specified, two local files will be checked against
each other.
"""

import sys
import os.path

# Look for indra/lib/python in all possible parent directories ...
# This is an improvement over the setup-path.py method used previously:
#  * the script may blocated anywhere inside the source tree
#  * it doesn't depend on the current directory
#  * it doesn't depend on another file being present.

root = os.path.abspath(__file__)
# always insert the directory of the script in the search path
dir = os.path.dirname(root)
if dir not in sys.path:
    sys.path.insert(0, dir)

# Now go look for indra/lib/python in the parent dies
while root != os.path.sep:
    root = os.path.dirname(root)
    dir = os.path.join(root, 'indra', 'lib', 'python')
    if os.path.isdir(dir):
        if dir not in sys.path:
            sys.path.insert(0, dir)
        break
else:
    print >>sys.stderr, "This script is not inside a valid installation."
    sys.exit(1)

import optparse
import os
import urllib

from indra.ipc import compatibility
from indra.ipc import tokenstream
from indra.ipc import llmessage

def getstatusall(command):
    """ Like commands.getstatusoutput, but returns stdout and 
    stderr separately(to get around "killed by signal 15" getting 
    included as part of the file).  Also, works on Windows."""
    (input, out, err) = os.popen3(command, 't')
    status = input.close() # send no input to the command
    output = out.read()
    error = err.read()
    status = out.close()
    status = err.close() # the status comes from the *last* pipe that is closed
    return status, output, error

def getstatusoutput(command):
    status, output, error = getstatusall(command)
    return status, output


def die(msg):
    print >>sys.stderr, msg
    sys.exit(1)

MESSAGE_TEMPLATE = 'message_template.msg'

PRODUCTION_ACCEPTABLE = (compatibility.Same, compatibility.Newer)
DEVELOPMENT_ACCEPTABLE = (
    compatibility.Same, compatibility.Newer,
    compatibility.Older, compatibility.Mixed)	

MAX_MASTER_AGE = 60 * 60 * 4   # refresh master cache every 4 hours

def retry(times, function, *args, **kwargs):
    for i in range(times):
        try:
            return function(*args, **kwargs)
        except Exception, e:
            if i == times - 1:
                raise e  # we retried all the times we could

def compare(base_parsed, current_parsed, mode):
    """Compare the current template against the base template using the given
    'mode' strictness:

    development: Allows Same, Newer, Older, and Mixed
    production: Allows only Same or Newer

    Print out information about whether the current template is compatible
    with the base template.

    Returns a tuple of (bool, Compatibility)
    Return True if they are compatible in this mode, False if not.
    """

    compat = current_parsed.compatibleWithBase(base_parsed)
    if mode == 'production':
        acceptable = PRODUCTION_ACCEPTABLE
    else:
        acceptable = DEVELOPMENT_ACCEPTABLE

    if type(compat) in acceptable:
        return True, compat
    return False, compat

def fetch(url):
    if url.startswith('file://'):
        # just open the file directly because urllib is dumb about these things
        file_name = url[len('file://'):]
        return open(file_name).read()
    else:
        # *FIX: this doesn't throw an exception for a 404, and oddly enough the sl.com 404 page actually gets parsed successfully
        return ''.join(urllib.urlopen(url).readlines())   

def cache_master(master_url):
    """Using the url for the master, updates the local cache, and returns an url to the local cache."""
    master_cache = local_master_cache_filename()
    master_cache_url = 'file://' + master_cache
    # decide whether to refresh the master cache based on its age
    import time
    if (os.path.exists(master_cache)
        and time.time() - os.path.getmtime(master_cache) < MAX_MASTER_AGE):
        return master_cache_url  # our cache is fresh
    # new master doesn't exist or isn't fresh
    print "Refreshing master cache from %s" % master_url
    def get_and_test_master():
        new_master_contents = fetch(master_url)
        llmessage.parseTemplateString(new_master_contents)
        return new_master_contents
    try:
        new_master_contents = retry(3, get_and_test_master)
    except IOError, e:
        # the refresh failed, so we should just soldier on
        print "WARNING: unable to download new master, probably due to network error.  Your message template compatibility may be suspect."
        print "Cause: %s" % e
        return master_cache_url
    try:
        tmpname = '%s.%d' % (master_cache, os.getpid())
        mc = open(tmpname, 'wb')
        mc.write(new_master_contents)
        mc.close()
        try:
            os.rename(tmpname, master_cache)
        except OSError:
            # We can't rename atomically on top of an existing file on
            # Windows.  Unlinking the existing file will fail if the
            # file is being held open by a process, but there's only
            # so much working around a lame I/O API one can take in
            # a single day.
            os.unlink(master_cache)
            os.rename(tmpname, master_cache)
    except IOError, e:
        print "WARNING: Unable to write master message template to %s, proceeding without cache." % master_cache
        print "Cause: %s" % e
        return master_url
    return master_cache_url

def local_template_filename():
    """Returns the message template's default location relative to template_verifier.py:
    ./messages/message_template.msg."""
    d = os.path.dirname(os.path.realpath(__file__))
    return os.path.join(d, 'messages', MESSAGE_TEMPLATE)

def getuser():
    try:
        # Unix-only.
        import getpass
        return getpass.getuser()
    except ImportError:
        import win32api
        return win32api.GetUserName()

def local_master_cache_filename():
    """Returns the location of the master template cache (which is in the system tempdir)
    <temp_dir>/master_message_template_cache.msg"""
    import tempfile
    d = tempfile.gettempdir()
    user = getuser()
    return os.path.join(d, 'master_message_template_cache.%s.msg' % user)


def run(sysargs):
    parser = optparse.OptionParser(
        usage="usage: %prog [FILE] [FILE]",
        description=__doc__)
    parser.add_option(
        '-m', '--mode', type='string', dest='mode',
        default='development',
        help="""[development|production] The strictness mode to use
while checking the template; see the wiki page for details about
what is allowed and disallowed by each mode:
http://wiki.secondlife.com/wiki/Template_verifier.py
""")
    parser.add_option(
        '-u', '--master_url', type='string', dest='master_url',
        default='http://secondlife.com/app/message_template/master_message_template.msg',
        help="""The url of the master message template.""")
    parser.add_option(
        '-c', '--cache_master', action='store_true', dest='cache_master',
        default=False,  help="""Set to true to attempt use local cached copy of the master template.""")

    options, args = parser.parse_args(sysargs)

    if options.mode == 'production':
        options.cache_master = False

    # both current and master supplied in positional params
    if len(args) == 2:
        master_filename, current_filename = args
        print "master:", master_filename
        print "current:", current_filename
        master_url = 'file://%s' % master_filename
        current_url = 'file://%s' % current_filename
    # only current supplied in positional param
    elif len(args) == 1:
        master_url = None
        current_filename = args[0]
        print "master:", options.master_url 
        print "current:", current_filename
        current_url = 'file://%s' % current_filename
    # nothing specified, use defaults for everything
    elif len(args) == 0:
        master_url  = None
        current_url = None
    else:
        die("Too many arguments")

    if master_url is None:
        master_url = options.master_url
        
    if current_url is None:
        current_filename = local_template_filename()
        print "master:", options.master_url
        print "current:", current_filename
        current_url = 'file://%s' % current_filename

    # retrieve the contents of the local template and check for syntax
    current = fetch(current_url)
    current_parsed = llmessage.parseTemplateString(current)

    if options.cache_master:
        # optionally return a url to a locally-cached master so we don't hit the network all the time
        master_url = cache_master(master_url)

    def parse_master_url():
        master = fetch(master_url)
        return llmessage.parseTemplateString(master)
    try:
        master_parsed = retry(3, parse_master_url)
    except (IOError, tokenstream.ParseError), e:
        if options.mode == 'production':
            raise e
        else:
            print "WARNING: problems retrieving the master from %s."  % master_url
            print "Syntax-checking the local template ONLY, no compatibility check is being run."
            print "Cause: %s\n\n" % e
            return 0
        
    acceptable, compat = compare(
        master_parsed, current_parsed, options.mode)

    def explain(header, compat):
        print header
        # indent compatibility explanation
        print '\n\t'.join(compat.explain().split('\n'))

    if acceptable:
        explain("--- PASS ---", compat)
    else:
        explain("*** FAIL ***", compat)
        return 1

if __name__ == '__main__':
    sys.exit(run(sys.argv[1:]))