from django.contrib.postgres.fields import ArrayField
from django.db import models
from django.utils import timezone
from simple_history.models import HistoricalRecords

from .constants import *


class User(models.Model):
    email = models.EmailField(primary_key=True, blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    id = models.CharField(blank=False, max_length=25, db_index=True)
    user_type = ArrayField(models.CharField(blank=False, max_length=10), size=4, default=list, blank=False)
    last_login_time = models.DateTimeField(default=timezone.now)
    history = HistoricalRecords()

    class Meta:
        verbose_name_plural = "User"
        unique_together = ('email', 'id')


class Student(models.Model):
    id = models.CharField(blank=False, max_length=15, primary_key=True)
    roll_no = models.CharField(blank=False, max_length=15, unique=True)
    name = models.CharField(blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    batch = models.CharField(max_length=10, choices=BATCH_CHOICES, blank=False)
    branch = models.CharField(choices=BRANCH_CHOICES, blank=False, max_length=10)
    phone_number = models.PositiveBigIntegerField(blank=True, default=None, null=True)
    resumes = ArrayField(models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=10,
                         default=list, blank=True)
    cpi = models.DecimalField(decimal_places=2, max_digits=4)
    can_apply_placements = models.BooleanField(default=True, verbose_name='Placement_Registered')
    can_apply_internship = models.BooleanField(default=True, verbose_name='Internship Registered') #added for internship
    changed_by = models.ForeignKey(User, blank=True, on_delete=models.RESTRICT, default=None, null=True)
    degree = models.CharField(choices=DEGREE_CHOICES, blank=False, max_length=10, default=DEGREE_CHOICES[0][0])
    history = HistoricalRecords(user_model=User)

    def __str__(self):
        return str(self.roll_no)

    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None


class Admin(models.Model):
    id = models.CharField(blank=False, max_length=15, primary_key=True)
    name = models.CharField(blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    changed_by = models.ForeignKey(User, blank=True, on_delete=models.RESTRICT, default=None, null=True)
    history = HistoricalRecords(user_model=User)

    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None


def two_day_after_today():
    # round off to nearest day
    return timezone.now().replace(hour=0, minute=0, second=0, microsecond=0) + timezone.timedelta(days=2)


class Placement(models.Model):
    id = models.CharField(blank=False, primary_key=True, max_length=15)
    # Company Details
    company_name = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT)
    address = models.CharField(blank=False, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT)
    company_type = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT)
    nature_of_business = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    type_of_organisation = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="", blank=False)
    website = models.CharField(blank=True, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    company_details = models.CharField(max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default=None, null=True, blank=True)
    company_details_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=5,
        default=list, blank=True)
    is_company_details_pdf = models.BooleanField(blank=False, default=False)
    contact_person_name = models.CharField(blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    phone_number = models.PositiveBigIntegerField(blank=False)
    email = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    city = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    state = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    country = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    pin_code = models.IntegerField(blank=False, default=None, null=True)
    city_type = models.CharField(blank=False, max_length=15, choices=OFFER_CITY_TYPE)
    # Job Details
    designation = models.CharField(blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT, default=None, null=True)
    description = models.CharField(blank=False, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default=None, null=True)
    job_location = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    description_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=5, default=list,
        blank=True)
    is_description_pdf = models.BooleanField(blank=False, default=False)
    compensation_CTC = models.IntegerField(blank=False, default=None, null=True)  # Job - Per Year
    compensation_gross = models.IntegerField(blank=False, default=None, null=True)
    compensation_take_home = models.IntegerField(blank=False, default=None, null=True)
    compensation_bonus = models.IntegerField(blank=True, default=None, null=True)
    compensation_details_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=5,
        default=list, blank=True)
    is_compensation_details_pdf = models.BooleanField(blank=False, default=False)
    bond_details = models.CharField(blank=True, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT)
    selection_procedure_rounds = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=10,
        default=list, blank=True)
    selection_procedure_details = models.CharField(blank=True, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT)
    selection_procedure_details_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT),
        size=5, default=list, blank=True)
    is_selection_procedure_details_pdf = models.BooleanField(blank=False, default=False)
    tier = models.CharField(blank=False, choices=TIERS, max_length=10, default=None, null=True)
    tentative_date_of_joining = models.DateField(blank=False, verbose_name="Tentative Date", default=timezone.now)
    allowed_batch = ArrayField(
        models.CharField(max_length=10, choices=BATCH_CHOICES),
        size=TOTAL_BATCHES,
        default=list
    )
    btech_allowed = models.BooleanField(blank=False, default=False)
    btech_allowed_branch = ArrayField(
        models.CharField(choices=BRANCH_CHOICES, blank=False, max_length=10),
        size=TOTAL_BRANCHES,
        default=list
    )
    mtech_allowed = models.BooleanField(blank=False, default=False)
    mtech_allowed_branch = ArrayField(
        models.CharField(choices=BRANCH_CHOICES, blank=False, max_length=10),
        size=TOTAL_BRANCHES,
        default=list
    )
    ms_allowed = models.BooleanField(blank=False, default=False)
    ms_allowed_branch = ArrayField(
        models.CharField(choices=BRANCH_CHOICES, blank=False, max_length=10),
        size=TOTAL_BRANCHES,
        default=list
    )
    phd_allowed = models.BooleanField(blank=False, default=False)
    phd_allowed_branch = ArrayField(
        models.CharField(choices=BRANCH_CHOICES, blank=False, max_length=10),
        size=TOTAL_BRANCHES,
        default=list
    )
    tentative_no_of_offers = models.IntegerField(blank=False, default=None, null=True)
    other_requirements = models.CharField(blank=True, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default="")
    additional_info = ArrayField(models.CharField(blank=True, max_length=JNF_TEXTMEDIUM_MAX_CHARACTER_COUNT), size=15,
                                 default=list, blank=True)
    email_verified = models.BooleanField(blank=False, default=False)
    offer_accepted = models.BooleanField(blank=False, default=None, null=True)
    deadline_datetime = models.DateTimeField(blank=False, verbose_name="Deadline Date", default=two_day_after_today)
    created_at = models.DateTimeField(blank=False, default=None, null=True)
    updated_at = models.DateTimeField(blank=False, default=None, null=True)
    changed_by = models.ForeignKey(User, on_delete=models.RESTRICT, blank=True, null=True)
    history = HistoricalRecords(user_model=User)

    def format(self):
        if self.company_name is not None:
            self.company_name = self.company_name.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.company_type is not None:
            self.company_type = self.company_type.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.company_details is not None:
            self.company_details = self.company_details.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.address is not None:
            self.address = self.address.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.nature_of_business is not None:
            self.nature_of_business = self.nature_of_business.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.type_of_organisation is not None:
            self.type_of_organisation = self.type_of_organisation.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.website is not None:
            self.website = self.website.strip()[:JNF_TEXT_MAX_CHARACTER_COUNT]
        if self.contact_person_name is not None:
            self.contact_person_name = self.contact_person_name.strip()[:JNF_TEXT_MAX_CHARACTER_COUNT]
        if self.email is not None:
            self.email = self.email.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.city is not None:
            self.city = self.city.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.state is not None:
            self.state = self.state.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.country is not None:
            self.country = self.country.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.city_type is not None:
            self.city_type = self.city_type.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.designation is not None:
            self.designation = self.designation.strip()[:JNF_TEXT_MAX_CHARACTER_COUNT]
        if self.description is not None:
            self.description = self.description.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.job_location is not None:
            self.job_location = self.job_location.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.selection_procedure_details is not None:
            self.selection_procedure_details = self.selection_procedure_details.strip()[
                                               :JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.bond_details is not None:
            self.bond_details = self.bond_details.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.other_requirements is not None:
            self.other_requirements = self.other_requirements.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.additional_info is not None:
            self.additional_info = [info.strip()[:JNF_TEXTMEDIUM_MAX_CHARACTER_COUNT] for info in
                                    list(self.additional_info)]

    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None

    def save(self, *args, **kwargs):
        ''' On save, add timestamps '''
        if not self.created_at:
            self.created_at = timezone.now()
        self.format()
        self.updated_at = timezone.now()
        return super(Placement, self).save(*args, **kwargs)

    def __str__(self):
        return self.company_name + " - " + self.designation


class PlacementApplication(models.Model):
    id = models.CharField(blank=False, primary_key=True, max_length=15)
    placement = models.ForeignKey(Placement, blank=False, on_delete=models.RESTRICT, default=None, null=True)
    student = models.ForeignKey(Student, blank=False, on_delete=models.CASCADE)
    resume = models.CharField(max_length=JNF_TEXT_MAX_CHARACTER_COUNT, blank=False, null=True, default=None)
    additional_info = models.JSONField(blank=True, null=True, default=None)
    selected = models.BooleanField(null=True, default=None, blank=True)
    offer_accepted = models.BooleanField(null=True, default=None, blank=True) # True if offer accepted, False if rejected, None if not yet decided
    applied_at = models.DateTimeField(blank=False, default=None, null=True)
    updated_at = models.DateTimeField(blank=False, default=None, null=True)
    changed_by = models.ForeignKey(User, blank=False, on_delete=models.RESTRICT, default=None, null=True)
    history = HistoricalRecords(user_model=User)

    def save(self, *args, **kwargs):
        ''' On save, add timestamps '''
        if not self.applied_at:
            self.applied_at = timezone.now()
        self.updated_at = timezone.now()

        return super(PlacementApplication, self).save(*args, **kwargs)

    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None

    class Meta:
        verbose_name_plural = "Placement Applications"
        unique_together = ('placement_id', 'student_id')

    def __str__(self):
        return self.placement.company_name + " - " + self.student.name


class PrePlacementOffer(models.Model):
    id = models.AutoField(primary_key=True)
    student = models.ForeignKey(Student, on_delete=models.CASCADE, blank=False)
    company = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="",
                               verbose_name="Company Name")
    compensation = models.IntegerField(blank=False)  # Job - Per Year
    compensation_details = models.CharField(blank=True, max_length=200)
    tier = models.CharField(blank=False, choices=TIERS, max_length=10)
    designation = models.CharField(blank=False, max_length=100, default=None, null=True)
    accepted = models.BooleanField(default=None, null=True)
    changed_by = models.ForeignKey(User, blank=False, on_delete=models.RESTRICT, default=None, null=True)
    history = HistoricalRecords(user_model=User)

    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None

class Internship(models.Model):
    id = models.CharField(blank=False, primary_key=True, max_length=15) #unique id for each internship
    # Company Details
    company_name = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT)
    website = models.CharField(blank=True, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    is_company_details_pdf = models.BooleanField(blank=False, default=False)
    company_details_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=5,
        default=list, blank=True)
    company_details = models.CharField(max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default=None, null=True, blank=True)
    #Company Address
    address = models.CharField(blank=False, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT)
    city = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    city_type = models.CharField(blank=True, max_length=15, choices=OFFER_CITY_TYPE)
    state = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    country = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    pin_code = models.IntegerField(blank=False, default=None, null=True)
    company_type = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT)
    nature_of_business = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    #Internship Details
    is_description_pdf = models.BooleanField(blank=False, default=False)
    description_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=5, default=list,
        blank=True)
    designation = models.CharField(blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT, default="")
    description = models.CharField(blank=False, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default=None, null=True)
    location = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    season = ArrayField(
        models.CharField(choices=SEASON_CHOICES, max_length=10, blank=False),
        size=INF_TOTAL_SEASONS,
        default=list
    )
    interning_period_from = models.DateField(blank=False, default=None, null=True)
    interning_period_to = models.DateField(blank=False, default=None, null=True)
    is_work_from_home = models.BooleanField(blank=False, default=False)
    allowed_branch = ArrayField(
        models.CharField(choices=BRANCH_CHOICES, blank=False, max_length=10),
        size=TOTAL_BRANCHES,
        default=list
    )
    allowed_batch = ArrayField(
        models.CharField(max_length=10, choices=BATCH_CHOICES),
        size=TOTAL_BATCHES,
        default=list
    )
    sophomore_eligible = models.BooleanField(blank=False, default=False)
    rs_eligible = models.BooleanField(blank=False, default=False)
    tentative_no_of_offers = models.IntegerField(blank=False, default=None, null=True)
    is_stipend_description_pdf = models.BooleanField(blank=False, default=False)
    stipend_description_pdf_names=ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=5, default=list,
        blank=True)
    stipend=models.IntegerField(blank=False, default=None, null=True)
    facilities_provided=ArrayField(
        models.CharField(null=True,  choices=INF_FACILITIES_PROVIDED, max_length=20),
        size=INF_TOTAL_FACILITIES,
        default=list,
        blank=True
    )
    additional_info = ArrayField(models.CharField(blank=True, max_length=JNF_TEXTMEDIUM_MAX_CHARACTER_COUNT), size=15,
                                 default=list, blank=True)
    offer_accepted = models.BooleanField(blank=False, default=None, null=True)
    deadline_datetime = models.DateTimeField(blank=False, verbose_name="Deadline Date", default=two_day_after_today)

    additional_facilities = models.CharField(blank=True, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default=None, null=True)
    academic_requirements = models.CharField(blank=True, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT, default=None, null=True)
    # selection process
    selection_procedure_rounds = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT), size=10,
        default=list, blank=True)
    selection_procedure_details = models.CharField(blank=True, max_length=JNF_TEXTAREA_MAX_CHARACTER_COUNT)
    selection_procedure_details_pdf_names = ArrayField(
        models.CharField(null=True, default=None, max_length=JNF_TEXT_MAX_CHARACTER_COUNT),
        size=5, default=list, blank=True)
    is_selection_procedure_details_pdf = models.BooleanField(blank=False, default=False)
    #contact details of company person
    contact_person_name = models.CharField(blank=False, max_length=JNF_TEXT_MAX_CHARACTER_COUNT)
    phone_number = models.PositiveBigIntegerField(blank=False)
    email = models.EmailField(blank=False)
    # contact_person_designation = models.CharField(blank=False, max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, default="")
    # telephone_number = models.PositiveBigIntegerField(blank=True, default=None, null=True)
    email_verified = models.BooleanField(blank=False, default=False)
    #history
    created_at = models.DateTimeField(blank=False, default=None, null=True)
    updated_at = models.DateTimeField(blank=False, default=None, null=True)
    changed_by = models.ForeignKey(User, on_delete=models.RESTRICT, blank=True, null=True)
    history = HistoricalRecords(user_model=User)

    
    def format(self):
        if self.company_name is not None:
            self.company_name = self.company_name.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.company_type is not None:
            self.company_type = self.company_type.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.company_details is not None:
            self.company_details = self.company_details.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.address is not None:
            self.address = self.address.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.nature_of_business is not None:
            self.nature_of_business = self.nature_of_business.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.website is not None:
            self.website = self.website.strip()[:JNF_TEXT_MAX_CHARACTER_COUNT]
        if self.contact_person_name is not None:
            self.contact_person_name = self.contact_person_name.strip()[:JNF_TEXT_MAX_CHARACTER_COUNT]
        if self.city is not None:
            self.city = self.city.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.state is not None:
            self.state = self.state.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.country is not None:
            self.country = self.country.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.city_type is not None:
            self.city_type = self.city_type.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        if self.selection_procedure_details is not None:
            self.selection_procedure_details = self.selection_procedure_details.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.description is not None:
            self.description = self.description.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.additional_facilities is not None:
            self.additional_facilities = self.additional_facilities.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.academic_requirements is not None:
            self.academic_requirements = self.academic_requirements.strip()[:JNF_TEXTAREA_MAX_CHARACTER_COUNT]
        if self.additional_info is not None:
            self.additional_info = [info.strip()[:JNF_TEXTMEDIUM_MAX_CHARACTER_COUNT] for info in
                                   list(self.additional_info)]
        # if self.contact_person_designation is not None:
        #     self.contact_person_designation = self.contact_person_designation.strip()[:JNF_SMALLTEXT_MAX_CHARACTER_COUNT]
        
    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None
            
    def save(self, *args, **kwargs):
        ''' On save, add timestamps '''
        if not self.created_at:
            self.created_at = timezone.now()
        self.format()
        self.updated_at = timezone.now()
        return super(Internship, self).save(*args, **kwargs)
    
    def __str__(self):
        return self.company_name + " - " + self.designation
    

class InternshipApplication(models.Model):
    id = models.CharField(blank=False, primary_key=True, max_length=15)
    internship = models.ForeignKey(Internship, blank=False, on_delete=models.RESTRICT, default=None, null=True)
    student = models.ForeignKey(Student, blank=False, on_delete=models.CASCADE)
    resume = models.CharField(max_length=JNF_TEXT_MAX_CHARACTER_COUNT, blank=False, null=True, default=None)
    additional_info = models.JSONField(blank=True, null=True, default=None)
    selected = models.BooleanField(null=True, default=None, blank=True)
    offer_accepted = models.BooleanField(null=True, default=None, blank=True) # True if offer accepted, False if rejected, None if not yet decided
    stipend = models.IntegerField(blank=True, default=None, null=True)
    applied_at = models.DateTimeField(blank=False, default=None, null=True)
    updated_at = models.DateTimeField(blank=False, default=None, null=True)
    changed_by = models.ForeignKey(User, blank=False, on_delete=models.RESTRICT, default=None, null=True)
    history = HistoricalRecords(user_model=User)

    def save(self, *args, **kwargs):
        ''' On save, add timestamps '''
        if not self.applied_at:
            self.applied_at = timezone.now()
        self.updated_at = timezone.now()

        return super(InternshipApplication, self).save(*args, **kwargs)

    @property
    def _history_user(self):
        return self.changed_by

    @_history_user.setter
    def _history_user(self, value):
        if isinstance(value, User):
            self.changed_by = value
        else:
            self.changed_by = None

    class Meta:
        verbose_name_plural = "Internship Applications"
        unique_together = ('internship_id', 'student_id')

    def __str__(self):
        return self.internship.company_name + " - " + self.student.name


class Contributor(models.Model):
    id = models.AutoField(primary_key=True)
    name = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="")
    email = models.EmailField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="", unique=True)
    github_id = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="", unique=True)
    linkedin = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, unique=True, null=True)
    commits = models.IntegerField(blank=False, default=0)
    image = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="", null=True)

    def __str__(self):
        return self.name
    

class Issues(models.Model):
    id = models.AutoField(primary_key=True)
    title = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="")
    description = models.CharField(max_length=200, blank=False, default="")
    #opening=(models.ForeignKey(Placement, on_delete=models.CASCADE, blank=False) or models.ForeignKey(Internship, on_delete=models.CASCADE, blank=False))
    opening_id=models.CharField(blank=False,  max_length=15, default=None, null=True)
    opening_type=models.CharField(choices=[('Placement','Placement'),('Internship','Internship')], blank=False, max_length=15, default=PLACEMENT)
    #status = models.CharField(max_length=JNF_SMALLTEXT_MAX_CHARACTER_COUNT, blank=False, default="")
    student=models.ForeignKey(Student, on_delete=models.CASCADE, blank=False)
    created_at = models.DateTimeField(blank=False, default=None, null=True)
    updated_at = models.DateTimeField(blank=False, default=None, null=True)
    changed_by = models.ForeignKey(User, on_delete=models.RESTRICT, blank=True, null=True)
    history = HistoricalRecords(user_model=User)

    def save(self, *args, **kwargs):
        ''' On save, add timestamps '''
        if not self.created_at:
            self.created_at = timezone.now()
        self.updated_at = timezone.now()

        return super(Issues, self).save(*args, **kwargs)

    def __str__(self):
        return self.title + " - " + self.student.name
    class Meta:
        verbose_name_plural = "Issues"