"""configuration files"""

import grp
import os
import pwd
try:
    from hashlib import sha1 as sha
except ImportError:
    from sha import sha
import string

import curlwrapper
import logger
import tools
import xmlrpclib
from config import Config

# right after net
priority = 2

class conf_files:
    def __init__(self, noscripts=False):
        self.config = Config()
        self.noscripts = noscripts
        self.data = None

    def checksum(self, path):
        try:
            f = open(path)
            try: return sha(f.read()).digest()
            finally: f.close()
        except IOError: return None

    def system(self, cmd):
        if not self.noscripts and cmd:
            logger.verbose('conf_files: running command %s' % cmd)
            return tools.fork_as(None, os.system, cmd)
        else: return 0

    def update_conf_file(self, cf_rec):
        if not cf_rec['enabled']: return
        dest = cf_rec['dest']
        err_cmd = cf_rec['error_cmd']
        mode = string.atoi(cf_rec['file_permissions'], base=8)
        try:
            uid = pwd.getpwnam(cf_rec['file_owner'])[2]
        except:
            logger.log('conf_files: cannot find user %s -- %s not updated'%(cf_rec['file_owner'],dest))
            return
        try:
            gid = grp.getgrnam(cf_rec['file_group'])[2]
        except:
            logger.log('conf_files: cannot find group %s -- %s not updated'%(cf_rec['file_group'],dest))
            return
        url = 'https://%s/%s' % (self.config.PLC_BOOT_HOST, cf_rec['source'])
        # set node_id at the end of the request - hacky
        if tools.node_id():
            if url.find('?') >0: url += '&'
            else:                url += '?'
            url += "node_id=%d"%tools.node_id()
        else:
            logger.log('conf_files: %s -- WARNING, cannot add node_id to request'%dest)
        try:
            logger.verbose("conf_files: retrieving URL=%s"%url)
            contents = curlwrapper.retrieve(url, self.config.cacert)
        except xmlrpclib.ProtocolError,e:
            logger.log('conf_files: failed to retrieve %s from %s, skipping' % (dest, url))
            return
        if not cf_rec['always_update'] and sha(contents).digest() == self.checksum(dest):
            return
        if self.system(cf_rec['preinstall_cmd']):
            self.system(err_cmd)
            if not cf_rec['ignore_cmd_errors']: return
        logger.log('conf_files: installing file %s from %s' % (dest, url))
        try: os.makedirs(os.path.dirname(dest))
        except OSError: pass
        tools.write_file(dest, lambda f: f.write(contents), mode=mode, uidgid=(uid,gid))
        if self.system(cf_rec['postinstall_cmd']): self.system(err_cmd)

    def run_once(self, data):
        if data.has_key("conf_files"):
            for f in data['conf_files']:
                try: self.update_conf_file(f)
                except: logger.log_exc("conf_files: failed to update conf_file")
        else:
            logger.log_missing_data("conf_files.run_once",'conf_files')


def start(): pass

def GetSlivers(data, config = None, plc = None):
    logger.log("conf_files: Running.")
    cf = conf_files()
    cf.run_once(data)
    logger.log("conf_files: Done.")

if __name__ == '__main__':
    import optparse
    parser = optparse.OptionParser()
    parser.add_option('-f', '--config', action='store', dest='config', default='/etc/planetlab/plc_config', help='PLC configuration file')
    parser.add_option('-k', '--session', action='store', dest='session', default='/etc/planetlab/session', help='API session key (or file)')
    parser.add_option('--noscripts', action='store_true', dest='noscripts', default=False, help='Do not run pre- or post-install scripts')
    (options, args) = parser.parse_args()

    # Load /etc/planetlab/plc_config
    config = Config(options.config)

    # Load /etc/planetlab/session
    if os.path.exists(options.session):
        session = file(options.session).read().strip()
    else:
        session = options.session

    # Initialize XML-RPC client
    from plcapi import PLCAPI
    plc = PLCAPI(config.plc_api_uri, config.cacert, auth = session)

    main = conf_files(options.noscripts)
    data = plc.GetSlivers()
    main.run_once(data)