# -*- coding: utf-8 -*-
# Copyright (c) 2015, Frappe Technologies and contributors
# For lice

from __future__ import unicode_literals, division
import frappe
from frappe import _

class OverlapError(frappe.ValidationError): pass

def validate_overlap_for(doc, doctype, fieldname, value=None):
	"""Checks overlap for specified field.

	:param fieldname: Checks Overlap for this field
	"""

	existing = get_overlap_for(doc, doctype, fieldname, value)
	if existing:
		frappe.throw(_("This {0} conflicts with {1} for {2} {3}").format(doc.doctype, existing.name,
			doc.meta.get_label(fieldname) if not value else fieldname , value or doc.get(fieldname)), OverlapError)

def get_overlap_for(doc, doctype, fieldname, value=None):
	"""Returns overlaping document for specified field.

	:param fieldname: Checks Overlap for this field
	"""

	existing = frappe.db.sql("""select name, from_time, to_time from `tab{0}`
		where `{1}`=%(val)s and schedule_date = %(schedule_date)s and
		(
			(from_time > %(from_time)s and from_time < %(to_time)s) or
			(to_time > %(from_time)s and to_time < %(to_time)s) or
			(%(from_time)s > from_time and %(from_time)s < to_time) or
			(%(from_time)s = from_time and %(to_time)s = to_time))
		and name!=%(name)s and docstatus!=2""".format(doctype, fieldname),
		{
			"schedule_date": doc.schedule_date,
			"val": value or doc.get(fieldname),
			"from_time": doc.from_time,
			"to_time": doc.to_time,
			"name": doc.name or "No Name"
		}, as_dict=True)

	return existing[0] if existing else None


def validate_duplicate_student(students):
	unique_students= []
	for stud in students:
		if stud.student in unique_students:
			frappe.throw(_("Student {0} - {1} appears Multiple times in row {2} & {3}")
				.format(stud.student, stud.student_name, unique_students.index(stud.student)+1, stud.idx))
		else:
			unique_students.append(stud.student)

@frappe.whitelist()
def evaluate_quiz(quiz_response, **kwargs):
	"""LMS Function: Evaluates a simple multiple choice quiz.  It recieves arguments from `www/lms/course.js` as dictionary using FormData[1].


	:param quiz_response: contains user selected choices for a quiz in the form of a string formatted as a dictionary. The function uses `json.loads()` to convert it to a python dictionary.
	[1]: https://developer.mozilla.org/en-US/docs/Web/API/FormData
	"""
	import json
	quiz_response = json.loads(quiz_response)
	quiz_name = kwargs.get('quiz')
	course_name = kwargs.get('course')
	enrollment = get_course_enrollment(course_name, frappe.session.user)
	try:
		quiz = frappe.get_doc("Quiz", quiz_name)
		answers, score = quiz.evaluate(quiz_response, enrollment, quiz_name)
		add_quiz_activity(enrollment, quiz_name, score, answers, quiz_response)
		return score
	except frappe.DoesNotExistError:
		frappe.throw("Quiz {0} does not exist".format(quiz_name))
		return None


def add_quiz_activity(enrollment, quiz, score, answers, quiz_response):
	print(quiz, answers, score)
	if not enrollment:
		frappe.throw("The user is not enrolled for the course {course}".format(course=course))
	activity = frappe.get_doc({
		"doctype": "Quiz Activity",
		"enrollment": enrollment.name,
		"quiz": quiz,
		"score": score,
		"date": frappe.utils.datetime.datetime.now()
		})
	for question in quiz_response.keys():
		activity.append("result",
			{
			"question": question,
			"selected_option": quiz_response[question],
			"quiz_result": 'Correct' if answers[question] else 'Wrong'
			})
	activity.save()
	frappe.db.commit()

@frappe.whitelist()
def add_activity(content_type, content, course, program):
	enrollment = get_course_enrollment(course, frappe.session.user)
	if check_activity_exists(enrollment['name'], content_type, content):
		pass
	else:
		course_actvity = frappe.get_doc({
			"doctype": "Course Activity",
			"enrollment": enrollment['name'],
			"content_type": content_type,
			"content": content,
			"date": frappe.utils.datetime.datetime.now()
			})
		course_actvity.save()
		frappe.db.commit()

def check_activity_exists(enrollment, content_type, content):
	activity = frappe.get_list("Course Activity", filters={"enrollment": enrollment, "content_type": content_type, "content": content})
	if activity:
		return True
	else:
		return False


def get_program():
	program_list = frappe.get_list("Program", filters={"is_published": is_published})
	if program_list:
		return program_list
	else:
		return None

def get_featured_programs():
	featured_programs_name = frappe.get_list("Program", filters={"is_published": True, "is_featured": True})
	featured_list = [frappe.get_doc("Program", program["name"]) for program in featured_programs_name]
	if featured_list:
		return featured_list
	else:
		return None

@frappe.whitelist()
def add_course_enrollment(course, email):
	student_id = get_student_id(email)
	if not get_course_enrollment(course, email):
		enrollment = frappe.get_doc({
			"doctype": "Course Enrollment",
			"student": student_id,
			"course": course,
			"enrollment_date": frappe.getdate()
		})
		enrollment.save()
		frappe.db.commit()
		return enrollment

def get_course_enrollment(course, email):
	student_id = get_student_id(email)
	try:
		return frappe.get_list("Course Enrollment", filters={'course':course, 'student':student_id})[0]
	except IndexError:
		frappe.throw("The user is not enrolled for the course {course}".format(course=course))
		return None

def get_student_id(email=None):
	"""Returns student user name, example EDU-STU-2018-00001 (Based on the naming series).

	:param user: a user email address
	"""
	try:
		return frappe.get_all('Student', filters={'student_email_id': email}, fields=['name'])[0].name
	except IndexError:
		frappe.throw("Student with email {0} does not exist".format(email))
		return None