from datetime import datetime

from django.http import HttpResponse

from django.shortcuts import render_to_response, redirect

from pytask.taskapp.models import User, Task, Comment, Claim

from pytask.taskapp.forms.task import TaskCreateForm, AddMentorForm, AssignTaskForm

from pytask.taskapp.events.task import createTask, addMentor, publishTask, addSubTask, addClaim, assignTask, getTask

from pytask.taskapp.views.user import show_msg

## everywhere if there is no task, django should display 500 message.. but take care of that in sensitive views like add mentor and all

## do not create su user thro syncdb

def browse_tasks(request):

    """ display all the tasks """

    user = request.user

    task_list = Task.objects.order_by('id').reverse()

    context = {'user':user,

               'task_list':task_list,

               }

    return render_to_response('task/browse.html', context)

def view_task(request, tid):

    """ get the task depending on its tid and display accordingly if it is a get.

    check for authentication and add a comment if it is a post request.

    """

    task_url = "/task/view/tid=%s"%tid

    user = request.user

    task = getTask(tid)

    comments = Comment.objects.filter(task=task)

    mentors = task.mentors.all()

    errors = []

    is_guest = True if not user.is_authenticated() else False

    is_mentor = True if user in task.mentors.all() else False

    context = {'user':user,

               'task':task,

               'comments':comments,

               'mentors':mentors,

               'is_guest':is_guest,

               'is_mentor':is_mentor,

               'errors':errors,

               }

    if request.method == 'POST':

        if not is_guest:

            data = request.POST["data"]

            task = getTask(tid)

            new_comment = Comment(task=task, data=data, created_by=user, creation_datetime=datetime.now())

            new_comment.save()

            return redirect(task_url)

        else:

            errors.append("You must be logged in to post a comment")

            return render_to_response('task/view.html', context)

    else:

        return render_to_response('task/view.html', context)

def create_task(request):

    """ check for rights and create a task if applicable.

    if user cannot create a task, redirect to homepage.

    """

    user = request.user

    is_guest = True if not user.is_authenticated() else False

    if not is_guest:

        user_profile = user.get_profile()

        can_create_task = False if user_profile.rights == "CT" else True

        if can_create_task:

            if request.method == "POST":

                form = TaskCreateForm(request.POST)

                if form.is_valid():

                    data = form.cleaned_data

                    title = data['title']

                    desc = data['desc']

                    credits = data['credits']

                    publish = data['publish']

                    task = createTask(title,desc,user,credits)

                    if not task:

                        error_msg = "Another task with the same title exists"

                        return render_to_response('task/create.html',{'form':form, 'error_msg':error_msg})

                    addMentor(task, user)

                    if publish: publishTask(task)    

                    task_url = '/task/view/tid=%s'%task.id

                    return redirect(task_url)

                else:

                    return render_to_response('task/create.html',{'form':form})

            else:

                form = TaskCreateForm()

                return render_to_response('task/create.html',{'form':form})

        else:

            return show_msg('You are not authorised to create a task.')

    else:

        return show_msg('You are not authorised to create a task.')

def add_mentor(request, tid):

    """ check if the current user has the rights to edit the task and add him.

    if user is not authenticated, redirect him to concerned page. """

    task_url = "/task/view/tid=%s"%tid

    user = request.user

    task = getTask(tid)

    errors = []

    is_guest = True if not user.is_authenticated() else False

    if (not is_guest) and user in task.mentors.all():

        ## now iam going for a brute force method

        user_list = list(User.objects.all())

        for mentor in task.mentors.all():

            user_list.remove(mentor)

        for a_user in task.claimed_users.all():

            user_list.remove(a_user)

        non_mentors = ((_.id,_.username) for _ in user_list)

        ## code till must be made elegant and not brute force like above

        form = AddMentorForm(non_mentors)

        if request.method == "POST":

            uid = request.POST['mentor']

            new_mentor = User.objects.get(id=uid)

            addMentor(task, new_mentor)

            return redirect(task_url)

        else:

            return render_to_response('task/addmentor.html', {'form':form, 'errors':errors})

    else:

        return show_msg('You are not authorised to add mentors for this task', task_url, 'view the task')

def add_tasks(request, tid):

    """ first display tasks which can be subtasks for the task and do the rest.

    """

    task_url = "/task/view/tid=%s"%tid

    user = request.user

    task = getTask(tid)

    errors = []

    is_guest = True if not user.is_authenticated() else False

    if (not is_guest) and user in task.mentors.all():

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

            if request.method == "POST":

                ## first decide if adding subs and deps can be in same page

                ## only exclude tasks with status deleted

                pass

            else:

                ## write a form just like add mentor and get the form here

                pass

        else:

            errors = ["The task cannot be added subtasks or dependencies in this state"]

#            return render_to_response('task/add.html', {'form':form, 'errors':errors})

            return show_msg('The task cannot be added subtasks or dependencies now', task_url, 'view the task')

    else:

        return show_msg('You are not authorised to add subtasks or dependencies for this task', task_url, 'view the task')

def claim_task(request, tid):

    """ display a list of claims for get and display submit only if claimable """

    ## create claims model and create a new database with required tables for it

    ## see if that "one to n" or "n to one" relationship has a special field

    task_url = "/task/view/tid=%s"%tid

    claim_url = "/task/claim/tid=%s"%tid

    errors = []

    user = request.user

    task = getTask(tid)

    claims = Claim.objects.filter(task=task)

    is_guest = True if not user.is_authenticated() else False

    if user in task.mentors.all():

        is_mentor = True 

    else:

         is_mentor = False

    task_claimable = True if task.status in ["OP", "RE", "CL"] else False

    user_can_claim = True if  task_claimable and not ( is_guest or is_mentor ) and ( user not in task.claimed_users.all() )  else False

    task_claimed = True if task.status == "CL" else False

    context = {'is_mentor':is_mentor,

               'task':task,

               'claims':claims,

               'user_can_claim':user_can_claim,

               'task_claimable':task_claimable,

               'task_claimed':task_claimed,

               'errors':errors}

    if not is_guest:

        if request.method == "POST":

            claim_proposal = request.POST['message']

            if claim_proposal:

                addClaim(task, claim_proposal, user)

                return redirect(claim_url)

            else:

                errors.append('Please fill up proposal in the field below')

                return render_to_response('task/claim.html', context)

        else:

            return render_to_response('task/claim.html', context)

    else:

        return show_msg('You are not logged in to view claims for this task', task_url, 'view the task')

def assign_task(request, tid):

    """ first get the status of the task and then assign it to one of claimed users

    generate list of claimed users by passing it as an argument to a function.

    """

    task_url = "/task/view/tid=%s"%tid

    user = request.user

    task = getTask(tid)

    is_guest = True if not user.is_authenticated() else False

    is_mentor = True if user in task.mentors.all() else False

    task_claimed = True if task.status == "CL" else False

    if (not is_guest) and is_mentor:

        if task_claimed:

            user_list = ((user.id,user.username) for user in task.claimed_users.all())

            form = AssignTaskForm(user_list)

            if request.method == "POST":

                uid = request.POST['user']

                assigned_user = User.objects.get(id=uid)

                assignTask(task, assigned_user)

                return redirect(task_url)

            else:

                return render_to_response('task/assign.html',{'form':form})

        elif task.status == "AS":

            return show_msg('The task is already assigned', task_url, 'view the task')

        elif task.status == "OP":

            return show_msg('No one has still claimed the task', task_url, 'view the task')

        else:

            return show_msg('The task status is %s. how can you assign it now'%task.status, task_url, 'view the task')

    else:

        return show_msg('You are not authorised to perform this action', task_url, 'view the task')

def edit_task(request, tid):

    """ see what are the attributes that can be edited depending on the current status

    and then give the user fields accordingly.

    """

    return None