#!/usr/bin/python
#
# Copyright (C) 2015  Custodia Project Contributors - see LICENSE file

try:
    from ConfigParser import RawConfigParser
except ImportError:
    from configparser import RawConfigParser
from custodia.httpd.server import LocalHTTPServer
import importlib
import os
import six
import sys


def source_config():
    cfgfile = None
    if (len(sys.argv) > 1):
        cfgfile = sys.argv[-1]
    elif os.path.isfile('custodia.conf'):
        cfgfile = 'custodia.conf'
    elif os.path.isfile('/etc/custodia/custodia.conf'):
        cfgfile = '/etc/custodia/custodia.conf'
    else:
        raise IOError("Configuration file not found")
    return cfgfile

def attach_store(typename, plugins, stores):
    for name, c in six.iteritems(plugins):
        if getattr(c, 'store_name', None) is None:
            continue
        try:
            c.store = stores[c.store_name]
        except KeyError:
            raise ValueError('[%s%s] references unexisting store '
                             '"%s"' % (typename, name, c.store_name))

CONFIG_SPECIALS = ['authenticators', 'authorizers', 'consumers', 'stores']

def parse_config(cfgfile):
    parser = RawConfigParser()
    parser.optionxform = str
    files = parser.read(cfgfile)
    if len(files) == 0:
        raise IOError("Failed to read config file")

    config = dict()
    for s in CONFIG_SPECIALS:
        config[s] = dict()
    for s in parser.sections():
        if s == 'global':
            for opt, val in parser.items(s):
                if opt in CONFIG_SPECIALS:
                    raise ValueError('"%s" is an invalid '
                                     '[global] option' % opt)
                config[opt] = val
            continue

        if s.startswith('/'):
            menu = 'consumers'
            name = s
        else:
            if s.startswith('auth:'):
                menu = 'authenticators'
                name = s[5:]
            elif s.startswith('authz:'):
                menu = 'authorizers'
                name = s[6:]
            elif s.startswith('store:'):
                menu = 'stores'
                name = s[6:]
            else:
                raise ValueError('Invalid section name [%s].\n' % s)

        if not parser.has_option(s, 'handler'):
            raise ValueError('Invalid section, missing "handler"')

        handler = None
        hconf = None
        for opt, val in parser.items(s):
            if opt == 'handler':
                try:
                    module, classname = val.rsplit('.', 1)
                    m = importlib.import_module(module)
                    handler = getattr(m, classname)
                except Exception as e:  # pylint: disable=broad-except
                    raise ValueError('Invalid format for "handler" option '
                                     '[%r]' % e)

            else:
                if hconf is None:
                    hconf = dict()
                hconf[opt] = val
        config[menu][name] = handler(hconf)

    # Attach stores to other plugins
    attach_store('auth:', config['authenticators'], config['stores'])
    attach_store('authz:', config['authorizers'], config['stores'])
    attach_store('', config['consumers'], config['stores'])

    return config

if __name__ == '__main__':
    cfgfile = source_config()
    config = parse_config(cfgfile)

    if 'server_socket' in config:
        address = config['server_socket']
    else:
        address = os.path.join(os.getcwd(), 'server_socket')
    httpd = LocalHTTPServer(address, config)
    httpd.serve()