from datetime import datetime

from pytask.taskapp.models import Profile, Task, Comment, Claim, Map

from pytask.taskapp.utilities.task import getTask

from pytask.taskapp.utilities.request import create_request

from pytask.taskapp.utilities.helper import get_key

from pytask.taskapp.utilities.notification import create_notification

def publishTask(task, rem_mentors=True, rem_comments=True):

    """ set the task status to open """

    if task.sub_type == 'D':

        deps, subs = task.map_subs.all(), []

    else:

        subs, deps = task.map_subs.all(), []

    if subs or any(map(lambda t:t.status!="CM",deps)):

        task.status = "LO"

    else:

        task.status = "OP"

    if rem_mentors:

        task.mentors.clear()

        task.mentors.add(task.created_by)

    if rem_comments:

        task.comment_set.update(is_deleted=True)

        task.comment_set.update(deleted_by=task.created_by)

    task.published_datetime = datetime.now()

    task.save()

    pending_requests = task.request_task.filter(is_valid=True, is_replied=False)

    pending_requests.update(is_valid=False)

    return task

def addSubTask(main_task, sub_task):

    """ add the task to subs attribute of the task and update its status.

    sub task can be added only if a task is in UP/OP/LO state.

    """

    ## Shall modify after talking to pr about subtasks

    ## I think i might even remove the concept of subtasks

    main_task.sub_type = "S"

    main_task.save()

    try:

        mapobj = Map.objects.get(main=main_task)

    except Map.DoesNotExist:

        mapobj = Map()

        mapobj.main = main_task

        mapobj.save()

    mapobj.subs.add(sub_task)

    mapobj.save()

    sub_tasks = getTask(main_task.id).subs

    if main_task.status == "OP":

        if any(map(lambda t:t.status!="CM",sub_tasks)):

            main_task.status = "LO"

        else:

            "CM"

    main_task.save()

def addDep(main_task, dependency):

    """ add the dependency task to deps attribute of the task.

    update the status of main_task accordingly.

    note that deps can be added only if task is in UP/OP/LO state.

    And also if the task doesn't have any subs.

    """

    main_task.sub_type = "D"

    main_task.save()

    try:

        mapobj = Map.objects.get(main=main_task)

    except Map.DoesNotExist:

        mapobj = Map()

        mapobj.main = main_task

        mapobj.save()

    mapobj.subs.add(dependency)

    mapobj.save()

    deps = getTask(main_task.id).deps

    if main_task.status in ["OP", "LO"]: 

        if all(map(lambda t:t.status=="CM",deps)):

            main_task.status = "OP"

        else:

            main_task.status = "LO"

    main_task.save()

def reqMentor(task, mentor, req_by):

    """ create a request object with role as MT.

    """

    create_request(sent_by=req_by, role="MT", sent_to=mentor, task=task) 

def addMentor(task,mentor):

    """ add the mentor to mentors list of the task """

    task.mentors.add(mentor)

    task.save()

    return task     

def createTask(title,desc,created_by,credits):

    """ creates a bare minimum task with title, description and credits.

    the creator of the task will be assigned as a mentor for the task.

    """

    while True:

        id = get_key()

        try:

            task = Task.objects.get(id__iexact=id)

            continue

        except Task.DoesNotExist:

            break

    try:

        task = Task.objects.get(title__iexact=title)

        return None

    except:

        task = Task(title=title)

    task.id = id 

    task.desc = desc

    task.created_by = created_by

    task.credits = credits

    task.creation_datetime = datetime.now()

    task.published_datetime = datetime.now()

    task.save()

    return task

def addClaim(task, message, user):

    """ add claim data to the database if it does not exist 

    and also update the claimed users field of the task.

    """

    task.claimed_users.add(user)

    task.save()

    claim = Claim()

    claim.message = message

    claim.task = task

    claim.user = user

    claim.creation_datetime = datetime.now()

    claim.save()

def assignTask(task, user, assigned_by):

    """ check for the status of task and assign it to the particular user """

    if task.status in ['OP', 'WR']:

        task.assigned_users.add(user)

        task.claimed_users.remove(user)

        task.status = "WR"

    task.save()

def updateTask(task, title=None, desc=None, credits=None, tags_field=None):

    """ update the property accordingly.

    while updating title, check for uniqueness of title.

    return None if any error. 

    """

    if title:

        try:

            task.title = title

            task.save()

        except Task.IntegrityError:

            return None

    if desc:task.desc = desc

    if credits:task.credits = credits

    if tags_field:task.tags_field = tags_field

    task.save()

    return task

def removeTask(main_task, sub_task):

    """ get the corresponding map object and remove the sub_task.

    """

    mapobj = Map.objects.get(main=main_task)

    mapobj.subs.remove(sub_task)

    mapobj.save()

    """ right now, just remove the user from the list of assigned_users.

    """

    main_task.assigned_users.remove(rem_user)

    main_task.save()

def assignCredits(task, given_by, given_to, points):

    """ make a proper request object.

    """

    create_request(sent_by=given_by, role="PY", task=task, receiving_user=given_to, pynts=points ) 

def completeTask(task, marked_by):

    """ set the status of task as completed.

    We dont have to inform parent tasks.

    That part is taken care by getTask method.

    """

    task.status = "CM"

    task.save()

    pending_requests = task.request_task.filter(is_replied=False)

    pending_requests.update(is_valid=False)

    ## generate notification appropriately using marked_by

    ## we also have to mark unread requests as invalid

    for a_user in task.assigned_users.all():

        create_notification(role="CM", sent_to=a_user, sent_from=marked_by, task=task)

    for a_user in task.claimed_users.all():

        create_notification(role="CM", sent_to=a_user, sent_from=marked_by, task=task)

    for a_mentor in task.mentors.all():

        create_notification(role="CM", sent_to=a_mentor, sent_from=marked_by, task=task)

def closeTask(task, closed_by, reason=None):

    """ set the status of task as CD.

    generate notifications accordingly.

    """

    task.status = "CD"

    task.save()

    pending_requests = task.request_task.filter(is_replied=False)

    pending_requests.update(is_valid=False)

    ## generate notifications here

    for a_user in task.assigned_users.all():

        create_notification(role="CD", sent_to=a_user, sent_from=closed_by, task=task, remarks=reason)

    for a_user in task.claimed_users.all():

        create_notification(role="CD", sent_to=a_user, sent_from=closed_by, task=task, remarks=reason)

    for a_mentor in task.mentors.all():

        create_notification(role="CD", sent_to=a_mentor, sent_from=closed_by, task=task, remarks=reason)