#!/usr/bin/env python3

import collections
import getpass
import io
import yaml
import json
import urllib.request, urllib.parse, urllib.error
import os
import inspect
import sys
from bson.son import SON
import kpov_util
import random
import argparse
import locale
import readline

locale.setlocale(locale.LC_ALL, ['C', 'utf8'])
readline.set_completer_delims(readline.get_completer_delims().replace('/', ''))
readline.parse_and_bind('tab: complete')

# SERVER_URL = "http://localhost/kpov_judge/"
#SERVER_URL = "http://kpov.fri.uni-lj.si/kpov_judge/"
#TASK_URL = SERVER_URL + '{task_id}/task.py'

TASK_URL = "file://" + os.getcwd() + '/tasks'
PARAMS_FILE = os.path.expanduser("~/.kpov_params.yaml")
DEFAULT_LANGUAGE = 'si'

"""get the parameters for a task either from the user
or from a file."""
def get_params(params, meta, param_name_list=None, language=None):
    if param_name_list is None:
        param_name_list = list(meta.keys())
    if language is None:
        language = params.get('language', DEFAULT_LANGUAGE)
    for name in param_name_list:
        if name not in meta:
            pass
        m = meta.get(name, {})
        try:
            description = m['descriptions'][language]
        except KeyError:
            description = name
        init = params.get(name) or ''
        try:
            if name == 'password':
                s = getpass.getpass('{}: '.format(description))
            else:
                s = input('{} [{}]: '.format(description, init))
            if s and m.get('w', True):
                params[name] = s
            elif name not in params:
                params[name] = None
        except EOFError:
            print()
    return params

def add_meta_to_argparser(argparser, meta, defaults = {}):
    language = defaults.get('language', DEFAULT_LANGUAGE)
    for k, v in meta.items():
        try:
            desc = v['descriptions'][language].encode("utf-8")
        except:
            desc = k
        argparser.add_argument('--'+k, nargs='?', help=desc, type=str, default=defaults.get(k, None))

def http_auth(url, username, password):
    password_mgr = urllib.request.HTTPPasswordMgrWithDefaultRealm()
    password_mgr.add_password(None, url, username, password)
    handler = urllib.request.HTTPBasicAuthHandler(password_mgr)
    opener = urllib.request.build_opener(handler)
    # Install the opener. Now all calls to urllib2.urlopen use our opener.
    urllib.request.install_opener(opener)

def load_task(stream):
    # the stream should definitions for the functions task(…),
    # task_check and gen_params, and a dictionary params_meta
    source = stream.read()
    d = {}
    exec(compile(source, 'task.py', 'exec'), globals(), d)
    return d['task'], d['task_check'], d['params_meta'], d['gen_params']

def locate_task(params, argparser, quiet=False):
    # first the URL where all tasks are stored
    url_meta = {
        'task_url': {'descriptions': {'si': 'URL z nalogami', 'en': 'Root URL for all tasks'}}
    }
    if 'task_url' not in params:
        params['task_url'] = TASK_URL
    add_meta_to_argparser(argparser, meta = url_meta, defaults = params)
    args, unknown_args = argparser.parse_known_args()
    params['task_url'] = args.task_url
    if not quiet:
        params = get_params(params, url_meta)
    # then the student's ID (and password if neccessarry)
    fetch_params_meta = collections.OrderedDict({
            'username': {'descriptions': {'si': 'Uporabniško ime', 'en': 'Username'}},
    })
    if params['task_url'] is not None and (
            params['task_url'].startswith('http')):
        fetch_params_meta['password'] = {'descriptions': {'si': 'Geslo', 'en': 'Password'}, }
    # and finally, the name of the task
    fetch_params_meta['task_name'] = {'descriptions': {'si': 'Ime naloge', 'en': 'Task name'}, }
    add_meta_to_argparser(argparser, meta = fetch_params_meta, defaults = params)
    args, unknown_args = argparser.parse_known_args()
    # update params with the now known args
    for k, v in fetch_params_meta.items():
        params[k] = vars(args).get(k, params.get(k, None))
    if not quiet:
        params = get_params(params, fetch_params_meta)
    return params

def load_params(filename):
    try:
        with open(filename) as f:
            return yaml.load(f)
    except:
        return {}
 
if __name__ == '__main__':
    # get the parameters needed to get to the task, such as the URLs, the name of the task and optionally an ID from the student
    # start with the the parameters needed for the dialog gui to work
    argparser = argparse.ArgumentParser(conflict_handler='resolve', add_help=False,
        description='Get task parameters')
    argparser.add_argument('-h', '--help', action='store_true')
    argparser.add_argument('-q', '--quiet', action='store_true',
        help='disable prompts')
    argparser.add_argument('-g', '--generate_params', action='store_true',
        help='generate initial values for the task parameters')
    argparser.add_argument('-pf','--params_file', nargs='?', default=PARAMS_FILE,
        help='a local file containing saved param values')
    basic_args, unknown_args = argparser.parse_known_args()

    # get default parameters including language
    params = load_params(basic_args.params_file)
    argparser.add_argument('-l', '--language', nargs='?',
        default=params.get('language', DEFAULT_LANGUAGE),
        help='the language used')
    basic_args, unknown_args = argparser.parse_known_args()
    params['language'] = basic_args.language

    # continue with the parameters needed to get the task
    params = locate_task(params, argparser, quiet=basic_args.quiet)
    # TODO: if the task name is missing or invalid, try to get a list of tasks 
    # get task source and generate params if neccessarry
    try:
        task_url = params['task_url']
        task_name = params['task_name']
        if task_url.startswith('http'):
            http_auth(task_url, params['username'], params['password'])
        print()
        print("Fetching {task_url}/{task_name}/task.py…".format(**params))
        source = urllib.request.urlopen("{task_url}/{task_name}/task.py".format(**params))
        task, task_check, task_params_meta, gen_params = load_task(source)
    except Exception as e:
        import traceback
        traceback.print_exc()
        print()
        for k, v in params.items():
            if k != 'password':
                print('{}: {}'.format(k, v))
        print()
        if basic_args.help:
            argparser.print_help()
        else:
            argparser.print_usage()
        with open(basic_args.params_file, 'w') as f:
            yaml.dump(params, f)
        exit(1)

    # get task parameters
    params['task_params'] = params.get('task_params', dict())
    params['task_params'][params['task_name']] = params['task_params'].get(params['task_name'], dict())
    task_params = params['task_params'][params['task_name']]
    if basic_args.generate_params:
	#prejema lahko samo stringe in ne številk (potrebno je str(int)
        # print ("params before: {} {}".format(params, task_params))
        task_params.update(gen_params(params['username'], task_params_meta))
        # print ("params after: {} {}".format(params, task_params))
    if task_url.startswith('http'):
        response = urllib.request.urlopen('{task_url}/{task_name}/params.json'.format(**params))
        web_task_params = json.load(io.TextIOWrapper(response))
        task_params.update(web_task_params)
    params_argparser = argparse.ArgumentParser(parents=[argparser], conflict_handler='resolve', add_help=True)
    add_meta_to_argparser(params_argparser, task_params_meta, defaults=task_params)
    args = vars(params_argparser.parse_args())
    for k in task_params_meta:
        if k in args and args[k] is not None:
            task_params[k] = args[k]
    if not basic_args.quiet:
        task_params = get_params(task_params, task_params_meta, language=params['language'])
    if basic_args.help:
        print(params_argparser.format_help())
        exit(0)

    # run task.task()
    public_params = dict()
    for k in inspect.getargs(task.__code__)[0]:
        public_params[k] = task_params[k]
    params['task_params'][params['task_name']] = task_params
    # save parameters for the next run
    with open(basic_args.params_file, 'w') as f:
        # print "dumping", params
        yaml.dump(params, f)

    try:
        print()
        print('Running task… ', end='')
        task_result = task(**public_params)
        print('Checking task… ', end='')
        score, hints = task_check(task_result, task_params)
        print('Done!')
        print('Score: {}'.format(score))
        print('Hints:')
        for hint in hints:
            print(hint)
    except Exception as e:
        import traceback
        traceback.print_exc()