import frappe
from frappe.core.doctype.user.user import User
from frappe.utils import cint
import hashlib
import random
import re
from frappe import _

class CustomUser(User):

    def validate(self):
        super(CustomUser, self).validate()
        self.validate_username_characters()

    def validate_username_characters(self):
        if len(self.username):
            underscore_condition = self.username[0] == "_" or self.username[-1] == "_"
        else:
            underscore_condition = ''

        if self.is_new():
            if not self.username:
                self.username = self.get_username_from_first_name()

            if self.username.find(" "):
                self.username.replace(" ", "")

            if not re.match("^[A-Za-z0-9_]*$", self.username) or underscore_condition:
                self.username = self.remove_illegal_characters()

            if len(self.username) < 4:
                self.username = self.email.replace("@", "").replace(".", "")

            while self.username_exists():
                self.username = self.remove_illegal_characters() + str(random.randint(0, 99))

        else:
            if not self.username:
                frappe.throw(_("Username already exists."))

            if not re.match("^[A-Za-z0-9_]*$", self.username):
                frappe.throw(_("Username can only contain alphabets, numbers and underscore."))

            if underscore_condition:
                frappe.throw(_("First and Last character of username cannot be Underscore(_)."))

            if len(self.username) < 4:
                frappe.throw(_("Username cannot be less than 4 characters"))

    def get_username_from_first_name(self):
        return frappe.scrub(self.first_name) + str(random.randint(0, 99))

    def remove_illegal_characters(self):
        return re.sub("[^\w]+", "", self.username).strip("_")

    def get_authored_courses(self) -> int:
        """Returns the number of courses authored by this user.
        """
        return frappe.get_all(
            'LMS Course', {
                'instructor': self.name,
                'is_published': True
        })

    def get_palette(self):
        """
        Returns a color unique to each member for Avatar """

        palette = [
            ['--orange-avatar-bg', '--orange-avatar-color'],
            ['--pink-avatar-bg', '--pink-avatar-color'],
            ['--blue-avatar-bg', '--blue-avatar-color'],
            ['--green-avatar-bg', '--green-avatar-color'],
            ['--dark-green-avatar-bg', '--dark-green-avatar-color'],
            ['--red-avatar-bg', '--red-avatar-color'],
            ['--yellow-avatar-bg', '--yellow-avatar-color'],
            ['--purple-avatar-bg', '--purple-avatar-color'],
            ['--gray-avatar-bg', '--gray-avatar-color0']
        ]

        encoded_name = str(self.full_name).encode("utf-8")
        hash_name = hashlib.md5(encoded_name).hexdigest()
        idx = cint((int(hash_name[4:6], 16) + 1) / 5.33)
        return palette[idx % 8]

    def get_batch_count(self) -> int:
        """Returns the number of batches authored by this user.
        """
        return frappe.db.count(
            'LMS Batch Membership', {
                'member': self.name,
                'member_type': 'Mentor'
            })

    def get_user_reviews(self):
        """ Returns the reviews created by user """
        return frappe.get_all("LMS Course Review",
                {
                    "owner": self.name
                })

    def get_course_membership(self, member_type=None):
        """ Returns all memberships of the user  """
        filters = {
            "member": self.name
        }
        if member_type:
            filters["member_type"] = member_type

        return frappe.get_all("LMS Batch Membership", filters, ["name", "course"])

    def get_mentored_courses(self):
        """ Returns all courses mentored by this user """
        mentored_courses = []
        mapping = frappe.get_all("LMS Course Mentor Mapping",
                    {
                        "mentor": self.name,
                    },
                    ["name", "course"]
                )

        for map in mapping:
            if frappe.db.get_value("LMS Course", map.course, "is_published"):
                mentored_courses.append(map)

        return mentored_courses

    def get_enrolled_courses(self):
        in_progress = []
        completed = []
        memberships = self.get_course_membership("Student");
        for membership in memberships:
            course = frappe.get_doc("LMS Course", membership.course)
            progress = course.get_course_progress(member=self.name)
            if progress < 100:
                in_progress.append(course)
            else:
                completed.append(course)

        return {
            "in_progress": in_progress,
            "completed": completed
        }