# Grading Views

import logging
import urllib
import re

from django.conf import settings
from django.views.decorators.cache import cache_control
from mitxmako.shortcuts import render_to_response
from django.core.urlresolvers import reverse

from student.models import unique_id_for_user
from courseware.courses import get_course_with_access

from controller_query_service import ControllerQueryService
from xmodule.grading_service_module import GradingServiceError
import json
from .staff_grading import StaffGrading
from student.models import unique_id_for_user

import open_ended_util
import open_ended_notifications

from xmodule.modulestore.django import modulestore
from xmodule.modulestore import search

from django.http import HttpResponse, Http404, HttpResponseRedirect

log = logging.getLogger(__name__)

template_imports = {'urllib': urllib}

controller_url = open_ended_util.get_controller_url()
controller_qs = ControllerQueryService(controller_url)

"""
Reverses the URL from the name and the course id, and then adds a trailing slash if
it does not exist yet

"""


def _reverse_with_slash(url_name, course_id):
    ajax_url = _reverse_without_slash(url_name, course_id)
    if not ajax_url.endswith('/'):
        ajax_url += '/'
    return ajax_url


def _reverse_without_slash(url_name, course_id):
    ajax_url = reverse(url_name, kwargs={'course_id': course_id})
    return ajax_url

DESCRIPTION_DICT = {
            'Peer Grading': "View all problems that require peer assessment in this particular course.",
            'Staff Grading': "View ungraded submissions submitted by students for the open ended problems in the course.",
            'Problems you have submitted': "View open ended problems that you have previously submitted for grading.",
            'Flagged Submissions': "View submissions that have been flagged by students as inappropriate."
    }
ALERT_DICT = {
            'Peer Grading': "New submissions to grade",
            'Staff Grading': "New submissions to grade",
            'Problems you have submitted': "New grades have been returned",
            'Flagged Submissions': "Submissions have been flagged for review"
    }


@cache_control(no_cache=True, no_store=True, must_revalidate=True)
def staff_grading(request, course_id):
    """
    Show the instructor grading interface.
    """
    course = get_course_with_access(request.user, course_id, 'staff')

    ajax_url = _reverse_with_slash('staff_grading', course_id)

    return render_to_response('instructor/staff_grading.html', {
        'course': course,
        'course_id': course_id,
        'ajax_url': ajax_url,
        # Checked above
        'staff_access': True, })


@cache_control(no_cache=True, no_store=True, must_revalidate=True)
def peer_grading(request, course_id):
    '''
    Show a peer grading interface
    '''

    course = get_course_with_access(request.user, course_id, 'load')
    course_id_parts = course.id.split("/")
    course_id_norun = "/".join(course_id_parts[0:2])
    pg_location = "i4x://" + course_id_norun + "/peergrading/init"

    base_course_url  = reverse('courses')
    try:
        problem_url_parts = search.path_to_location(modulestore(), course.id, pg_location)
        problem_url = generate_problem_url(problem_url_parts, base_course_url)

        return HttpResponseRedirect(problem_url)
    except:
        error_message = "Error with initializing peer grading.  Centralized module does not exist.  Please contact course staff."
        log.exception(error_message + "Current course is: {0}".format(course_id))
        return HttpResponse(error_message)


def generate_problem_url(problem_url_parts, base_course_url):
    """
    From a list of problem url parts generated by search.path_to_location and a base course url, generates a url to a problem
    @param problem_url_parts: Output of search.path_to_location
    @param base_course_url: Base url of a given course
    @return: A path to the problem
    """
    problem_url = base_course_url + "/"
    for z in xrange(0, len(problem_url_parts)):
        part = problem_url_parts[z]
        if part is not None:
            if z == 1:
                problem_url += "courseware/"
            problem_url += part + "/"
    return problem_url


@cache_control(no_cache=True, no_store=True, must_revalidate=True)
def student_problem_list(request, course_id):
    '''
    Show a student problem list
    '''
    course = get_course_with_access(request.user, course_id, 'load')
    student_id = unique_id_for_user(request.user)

    # call problem list service
    success = False
    error_text = ""
    problem_list = []
    base_course_url  = reverse('courses')

    #try:
    problem_list_json = controller_qs.get_grading_status_list(course_id, unique_id_for_user(request.user))
    problem_list_dict = json.loads(problem_list_json)
    success = problem_list_dict['success']
    if 'error' in problem_list_dict:
        error_text = problem_list_dict['error']
        problem_list = []
    else:
        problem_list = problem_list_dict['problem_list']

    for i in xrange(0, len(problem_list)):
        problem_url_parts = search.path_to_location(modulestore(), course.id, problem_list[i]['location'])
        problem_url = generate_problem_url(problem_url_parts, base_course_url)
        problem_list[i].update({'actual_url': problem_url})

    """
    except GradingServiceError:
        error_text = "Error occured while contacting the grading service"
        success = False
    # catch error if if the json loads fails
    except ValueError:
        error_text = "Could not get problem list"
        success = False
    """

    ajax_url = _reverse_with_slash('open_ended_problems', course_id)

    return render_to_response('open_ended_problems/open_ended_problems.html', {
        'course': course,
        'course_id': course_id,
        'ajax_url': ajax_url,
        'success': success,
        'problem_list': problem_list,
        'error_text': error_text,
        # Checked above
        'staff_access': False, })


@cache_control(no_cache=True, no_store=True, must_revalidate=True)
def flagged_problem_list(request, course_id):
    '''
    Show a student problem list
    '''
    course = get_course_with_access(request.user, course_id, 'staff')
    student_id = unique_id_for_user(request.user)

    # call problem list service
    success = False
    error_text = ""
    problem_list = []
    base_course_url  = reverse('courses')

    try:
        problem_list_json = controller_qs.get_flagged_problem_list(course_id)
        problem_list_dict = json.loads(problem_list_json)
        success = problem_list_dict['success']
        if 'error' in problem_list_dict:
            error_text = problem_list_dict['error']
            problem_list = []
        else:
            problem_list = problem_list_dict['flagged_submissions']

    except GradingServiceError:
        error_text = "Error occured while contacting the grading service"
        success = False
    # catch error if if the json loads fails
    except ValueError:
        error_text = "Could not get problem list"
        success = False

    ajax_url = _reverse_with_slash('open_ended_flagged_problems', course_id)
    context = {
            'course': course,
            'course_id': course_id,
            'ajax_url': ajax_url,
            'success': success,
            'problem_list': problem_list,
            'error_text': error_text,
            # Checked above
            'staff_access': True,
    }
    return render_to_response('open_ended_problems/open_ended_flagged_problems.html', context)


@cache_control(no_cache=True, no_store=True, must_revalidate=True)
def combined_notifications(request, course_id):
    """
    Gets combined notifications from the grading controller and displays them
    """
    course = get_course_with_access(request.user, course_id, 'load')
    user = request.user
    notifications = open_ended_notifications.combined_notifications(course, user)
    response = notifications['response']
    notification_tuples = open_ended_notifications.NOTIFICATION_TYPES

    notification_list = []
    for response_num in xrange(0, len(notification_tuples)):
        tag = notification_tuples[response_num][0]
        if tag in response:
            url_name = notification_tuples[response_num][1]
            human_name = notification_tuples[response_num][2]
            url = _reverse_without_slash(url_name, course_id)
            has_img = response[tag]

            # check to make sure we have descriptions and alert messages
            if human_name in DESCRIPTION_DICT:
                description = DESCRIPTION_DICT[human_name]
            else:
                description = ""

            if human_name in ALERT_DICT:
                alert_message = ALERT_DICT[human_name]
            else:
                alert_message = ""

            notification_item = {
                'url': url,
                'name': human_name,
                'alert': has_img,
                'description': description,
                'alert_message': alert_message
            }
            notification_list.append(notification_item)

    ajax_url = _reverse_with_slash('open_ended_notifications', course_id)
    combined_dict = {
        'error_text': "",
        'notification_list': notification_list,
        'course': course,
        'success': True,
        'ajax_url': ajax_url,
    }

    return render_to_response('open_ended_problems/combined_notifications.html',
        combined_dict
    )


@cache_control(no_cache=True, no_store=True, must_revalidate=True)
def take_action_on_flags(request, course_id):
    """
    Takes action on student flagged submissions.
    Currently, only support unflag and ban actions.
    """
    if request.method != 'POST':
        raise Http404


    required = ['submission_id', 'action_type', 'student_id']
    for key in required:
        if key not in request.POST:
            return HttpResponse(json.dumps({'success': False, 'error': 'Missing key {0}'.format(key)}),
                mimetype="application/json")

    p = request.POST
    submission_id = p['submission_id']
    action_type = p['action_type']
    student_id = p['student_id']
    student_id = student_id.strip(' \t\n\r')
    submission_id = submission_id.strip(' \t\n\r')
    action_type = action_type.lower().strip(' \t\n\r')
    try:
        response = controller_qs.take_action_on_flags(course_id, student_id, submission_id, action_type)
        return HttpResponse(response, mimetype="application/json")
    except GradingServiceError:
        log.exception("Error saving calibration grade, submission_id: {0}, submission_key: {1}, grader_id: {2}".format(submission_id, submission_key, grader_id))
        return _err_response('Could not connect to grading service')