# Copyright (C) 2006 Novell Inc.  All rights reserved.
# This program is free software; it may be used, copied, modified
# and distributed under the terms of the GNU General Public Licence,
# either version 2, or (at your option) any later version.

"""Read osc configuration and store it in a dictionary

This module reads and parses ~/.oscrc. The resulting configuration is stored
for later usage in a dictionary named 'config'. 

If information is missing, it asks the user questions.

After reading the config, urllib2 is initialized.

The configuration dictionary could look like this:

{'apisrv': 'https://api.opensuse.org/',
 'user': 'joe',
 'api_host_options': {'api.opensuse.org': {'user': 'joe', 'pass': 'secret'},
                      'apitest.opensuse.org': {'user': 'joe', 'pass': 'secret',
                                               'http_headers':(('Host','api.suse.de'),
                                                               ('User','faye'))},
                      'foo.opensuse.org': {'user': 'foo', 'pass': 'foo'}},
 'build-cmd': '/usr/bin/build',
 'build-root': '/abuild/oscbuild-%(repo)s-%(arch)s',
 'packagecachedir': '/var/cache/osbuild',
 'su-wrapper': 'sudo',
 }

"""

import OscConfigParser
from osc import oscerr

try:
    import gobject
    gobject.set_application_name('osc')
    import gnomekeyring
    GNOME_KEYRING = gnomekeyring.is_available()
except:
    GNOME_KEYRING = False

# being global to this module, this dict can be accessed from outside
# it will hold the parsed configuration
config = { }

DEFAULTS = { 'apiurl': 'https://api.opensuse.org',
             'user': 'your_username',
             'pass': 'your_password',
             'packagecachedir': '/var/tmp/osbuild-packagecache',
             'su-wrapper': 'su -c',

             # build type settings
             'build-cmd': '/usr/bin/build',
             'build-type' : '', # may be empty for chroot, kvm or xen
             'build-root': '/var/tmp/build-root',
             'build-device': '', # required for VM builds
             'build-memory' : '',# required for VM builds
             'build-swap' : '',  # optional for VM builds

             'debug': '0',
             'http_debug': '0',
             'traceback': '0',
             'post_mortem': '0',
             'gnome_keyring': '1',
             'cookiejar': '~/.osc_cookiejar',
             # enable project tracking by default
             'do_package_tracking': '1',
             # default for osc build
             'extra-pkgs': 'vim gdb strace',
             # default platform
             'build_platform': 'openSUSE_Factory',
}
boolean_opts = ['debug', 'do_package_tracking', 'http_debug', 'post_mortem', 'traceback']

new_conf_template = """
[general]

# URL to access API server, e.g. %(apiurl)s
# you also need a section [%(apiurl)s] with the credentials
apiurl = %(apiurl)s

# Downloaded packages are cached here. Must be writable by you.
#packagecachedir = %(packagecachedir)s

# Wrapper to call build as root (sudo, su -, ...)
#su-wrapper = %(su-wrapper)s

# rootdir to setup the chroot environment
# can contain %%(repo)s, %%(arch)s, %%(project)s and %%(package)s for replacement, e.g.
# /srv/oscbuild/%%(repo)s-%%(arch)s or
# /srv/oscbuild/%%(repo)s-%%(arch)s-%%(project)s-%%(package)s
#build-root = %(build-root)s

# extra packages to install when building packages locally (osc build)
# this corresponds to osc build's -x option and can be overridden with that
# -x '' can also be given on the command line to override this setting, or
# you can have an empty setting here.
#extra-pkgs = vim gdb strace

# build platform is used if the platform argument is omitted to osc build
#build_platform = openSUSE_Factory

# show info useful for debugging 
#debug = 1
    
# show HTTP traffic useful for debugging 
#http_debug = 1
    
# jump into the debugger in case of errors
#post_mortem = 1
    
# print call traces in case of errors
#traceback = 1
    
# use GNOME keyring for credentials if available
#gnome_keyring = 0
    
[%(apiurl)s]
user = %(user)s
pass = %(pass)s
# set aliases for this apiurl
# aliases = foo, bar
# email used in .changes, unless the one from osc meta prj <user> will be used
# email = 
# additional headers to pass to a request, e.g. for special authentication
#http_headers = Host: foofoobar,
#       User: mumblegack
# Force using of keyring for this API
#keyring = 1
"""


account_not_configured_text ="""
Your user account / password are not configured yet.
You will be asked for them below, and they will be stored in
%s for future use.
"""

config_incomplete_text = """

Your configuration file %s is not complete.
Make sure that it has a [general] section.
(You can copy&paste the below. Some commented defaults are shown.)

"""

config_missing_apiurl_text = """
the apiurl \'%s\' does not exist in the config file. Please enter
your credentials for this apiurl.
"""

cookiejar = None

def parse_apisrv_url(scheme, apisrv):
    import urlparse
    if apisrv.startswith('http://') or apisrv.startswith('https://'):
        return urlparse.urlsplit(apisrv)[0:2]
    elif scheme != None:
        return scheme, apisrv
    else:
        from urllib2 import URLError
        msg = 'invalid apiurl \'%s\' (specify the protocol (http:// or https://))' % apisrv
        raise URLError(msg)

def urljoin(scheme, apisrv):
    return '://'.join([scheme, apisrv])

def get_apiurl_api_host_options(apiurl):
    """
    Returns all apihost specific options for the given apiurl, None if
    no such specific optiosn exist.
    """
    # FIXME: in A Better World (tm) there was a config object which
    # knows this instead of having to extract it from a url where it
    # had been mingled into before.  But this works fine for now.

    apiurl = urljoin(*parse_apisrv_url(None, apiurl))
    try:
        return config['api_host_options'][apiurl]
    except KeyError:
        raise oscerr.ConfigMissingApiurl('missing credentials for apiurl: \'%s\'' % apiurl,
                                         '', apiurl)

def get_apiurl_usr(apiurl):
    """
    returns the user for this host - if this host does not exist in the
    internal api_host_options the default user is returned.
    """
    # FIXME: maybe there should be defaults not just for the user but
    # for all apihost specific options.  The ConfigParser class
    # actually even does this but for some reason we don't use it
    # (yet?).

    import sys
    try:
        return get_apiurl_api_host_options(apiurl)['user']
    except KeyError:
        print >>sys.stderr, 'no specific section found in config file for host of [\'%s\'] - using default user: \'%s\'' \
            % (apiurl, config['user'])
        return config['user']

def init_basicauth(config):
    """initialize urllib2 with the credentials for Basic Authentication"""

    from osc.core import __version__
    import os, urllib2
    import cookielib

    global cookiejar

    # HTTPS proxy is not supported by urllib2. It only leads to an error
    # or, at best, a warning.
    # https://bugzilla.novell.com/show_bug.cgi?id=214983
    # https://bugzilla.novell.com/show_bug.cgi?id=298378
    if 'https_proxy' in os.environ:
        del os.environ['https_proxy']
    if 'HTTPS_PROXY' in os.environ:
        del os.environ['HTTPS_PROXY']

    if config['http_debug']:
        # brute force
        def urllib2_debug_init(self, debuglevel=0):
            self._debuglevel = 1
        urllib2.AbstractHTTPHandler.__init__ = urllib2_debug_init

    authhandler = urllib2.HTTPBasicAuthHandler( \
        urllib2.HTTPPasswordMgrWithDefaultRealm())

    cookie_file = os.path.expanduser(config['cookiejar'])
    cookiejar = cookielib.LWPCookieJar(cookie_file)
    try: 
        cookiejar.load(ignore_discard=True)
    except IOError:
        try:
            open(cookie_file, 'w').close()
            os.chmod(cookie_file, 0600)
        except:
            #print 'Unable to create cookiejar file: \'%s\'. Using RAM-based cookies.' % cookie_file
            cookiejar = cookielib.CookieJar()

    opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cookiejar), authhandler)
    urllib2.install_opener(opener)

    opener.addheaders = [('User-agent', 'osc/%s' % __version__)]

    # with None as first argument, it will always use this username/password
    # combination for urls for which arg2 (apisrv) is a super-url
    for host, auth in config['api_host_options'].iteritems():
        authhandler.add_password(None, host, auth['user'], auth['pass'])


def get_configParser(conffile=None, force_read=False):
    """
    Returns an ConfigParser() object. After its first invocation the
    ConfigParser object is stored in a method attribute and this attribute
    is returned unless you pass force_read=True.
    """
    import os
    conffile = conffile or os.environ.get('OSC_CONFIG', '~/.oscrc')
    conffile = os.path.expanduser(conffile)
    if force_read or not get_configParser.__dict__.has_key('cp'):
        get_configParser.cp = OscConfigParser.OscConfigParser(DEFAULTS)
        get_configParser.cp.read(conffile)
    return get_configParser.cp


def write_initial_config(conffile, entries, custom_template = ''):
    """
    write osc's intial configuration file. entries is a dict which contains values
    for the config file (e.g. { 'user' : 'username', 'pass' : 'password' } ).
    custom_template is an optional configuration template.
    """
    import os, StringIO, sys
    conf_template = custom_template or new_conf_template
    config = DEFAULTS.copy()
    config.update(entries)
    if config['gnome_keyring'] and GNOME_KEYRING:
        protocol, host = \
            parse_apisrv_url(None, config['apiurl'])
        gnomekeyring.set_network_password_sync(
            user = config['user'],
            password = config['pass'],
            protocol = protocol,
            server = host)
        config['user'] = ''
        config['pass'] = ''
    sio = StringIO.StringIO(conf_template.strip() % config)
    cp = OscConfigParser.OscConfigParser(DEFAULTS)
    cp.readfp(sio)

    file = None
    try:
        file = open(conffile, 'w')
    except IOError, e:
        raise oscerr.OscIOError(e, 'cannot open configfile \'%s\'' % conffile)
    try:
        try:
            os.chmod(conffile, 0600)
            cp.write(file, True)
        except IOError, e:
            raise oscerr.OscIOError(e, 'cannot write configfile \'s\'' % conffile)
    finally:
        if file: file.close()

def add_section(filename, url, user, passwd):
    """
    Add a section to config file for new api url.
    """
    global config
    cp = get_configParser(filename)
    try:
        cp.add_section(url)
    except OscConfigParser.ConfigParser.DuplicateSectionError:
        # Section might have existed, but was empty
        pass
    if config['gnome_keyring'] and GNOME_KEYRING:
        protocol, host = \
            parse_apisrv_url(None, url)
        gnomekeyring.set_network_password_sync(
            user = user,
            password = passwd,
            protocol = protocol,
            server = host)
        cp.set(url, 'keyring', '1')
    else:
        cp.set(url, 'user', user)
        cp.set(url, 'pass', passwd)
    file = open(filename, 'w')
    cp.write(file, True)
    if file: file.close()


def get_config(override_conffile = None, 
               override_apiurl = None,
               override_debug = None, 
               override_http_debug = None, 
               override_traceback = None,
               override_post_mortem = None,
               override_no_gnome_keyring = None):
    """do the actual work (see module documentation)"""
    import os
    import sys
    import re
    global config

    conffile = override_conffile or os.environ.get('OSC_CONFIG', '~/.oscrc')
    conffile = os.path.expanduser(conffile)

    if not os.path.exists(conffile):
        raise oscerr.NoConfigfile(conffile, \
                                  account_not_configured_text % conffile)

    # okay, we made sure that .oscrc exists

    cp = get_configParser(conffile)

    if not cp.has_section('general'):
        # FIXME: it might be sufficient to just assume defaults?
        msg = config_incomplete_text % conffile
        msg += new_conf_template % DEFAULTS
        raise oscerr.ConfigError(msg, conffile)

    config = dict(cp.items('general', raw=1))

    # backward compatibility
    if config.has_key('apisrv'):
        apisrv = config['apisrv'].lstrip('http://')
        apisrv = apisrv.lstrip('https://')
        scheme = config.get('scheme', 'https')
        config['apiurl'] = urljoin(scheme, apisrv)
    if config.has_key('apisrv') or config.has_key('scheme'):
        import warnings
        warnings.warn('Use of the \'scheme\' or \'apisrv\' config option is deprecated! ' \
                      'See README for migration details.',
                      DeprecationWarning)

    for i in boolean_opts:
        try:
            config[i] = cp.getboolean('general', i)
        except ValueError, e:
            raise oscerr.ConfigError('cannot parse \'%s\' setting: ' % i + str(e), conffile)

    config['packagecachedir'] = os.path.expanduser(config['packagecachedir'])

    re_clist = re.compile('[, ]+')
    config['extra-pkgs'] = [ i.strip() for i in re_clist.split(config['extra-pkgs'].strip()) if i ]
    if config['extra-pkgs'] == []: 
        config['extra-pkgs'] = None

    # collect the usernames, passwords and additional options for each api host
    api_host_options = {}

    # Regexp to split extra http headers into a dictionary
    # the text to be matched looks essentially looks this:
    # "Attribute1: value1, Attribute2: value2, ..."
    # there may be arbitray leading and intermitting whitespace.
    # the following regexp does _not_ support quoted commas within the value.
    http_header_regexp = re.compile(r"\s*(.*?)\s*:\s*(.*?)\s*(?:,\s*|\Z)")

    # override values which we were called with
    # This needs to be done before processing API sections as it might be already used there
    if override_no_gnome_keyring: 
        config['gnome_keyring'] = False

    aliases = {}
    for url in [ x for x in cp.sections() if x != 'general' ]:
        # backward compatiblity
        scheme, host = \
            parse_apisrv_url(config.get('scheme', 'https'), url)
        apiurl = urljoin(scheme, host)
        user = None
        # Read from gnome keyring if available
        if config['gnome_keyring'] and GNOME_KEYRING:
            try:
                gk_data = gnomekeyring.find_network_password_sync(
                    protocol = scheme,
                    server = host)
                password = gk_data[0]['password']
                user = gk_data[0]['user']
            except gnomekeyring.NoMatchError:
                # Fallback to file based auth.
                pass
        # Read credentials from config
        if user is None:
            #FIXME: this could actually be the ideal spot to take defaults
            #from the general section.
            user         = cp.get(url, 'user', raw=True) # need to set raw to prevent '%' expansion
            password     = cp.get(url, 'pass', raw=True) # especially on password!
            if cp.has_option(url, 'keyring') and cp.get(url, 'keyring'):
                # This APIURL was configured to use keyring by
                continue
        email        = ''
        if cp.has_option(url, 'email'):
            email    = cp.get(url, 'email')

        if cp.has_option(url, 'http_headers'):
            http_headers = cp.get(url, 'http_headers')
            http_headers = http_header_regexp.findall(http_headers)
        else:
            http_headers = []
        if cp.has_option(url, 'aliases'):
            for i in cp.get(url, 'aliases').split(','):
                key = i.strip()
                if key == '':
                    continue
                if aliases.has_key(key):
                    msg = 'duplicate alias entry: \'%s\' is already used for another apiurl' % key
                    raise oscerr.ConfigError(msg, conffile)
                aliases[key] = url

        api_host_options[apiurl] = { 'user': user,
                                     'pass': password,
                                     'http_headers': http_headers}
        if email:
            api_host_options[apiurl]['email'] = email

    # add the auth data we collected to the config dict
    config['api_host_options'] = api_host_options

    # override values which we were called with
    if override_debug: 
        config['debug'] = override_debug
    if override_http_debug:
        config['http_debug'] = override_http_debug
    if override_traceback:
        config['traceback'] = override_traceback
    if override_post_mortem:
        config['post_mortem'] = override_post_mortem
    if override_apiurl:
        apiurl = aliases.get(override_apiurl, override_apiurl)
        # check if apiurl is a valid url
        parse_apisrv_url(None, apiurl)
        config['apiurl'] = apiurl

    # XXX unless config['user'] goes away (and is replaced with a handy function, or 
    # config becomes an object, even better), set the global 'user' here as well,
    # provided that there _are_ credentials for the chosen apiurl:
    try:
        config['user'] = get_apiurl_usr(config['apiurl'])
    except oscerr.ConfigMissingApiurl, e:
        e.msg = config_missing_apiurl_text % config['apiurl']
        e.file = conffile
        raise e

    # finally, initialize urllib2 for to use the credentials for Basic Authentication
    init_basicauth(config)