from django.contrib.auth.decorators import login_required
from django.db.models import Sum
from django.http import HttpRequest, JsonResponse
from django.shortcuts import render
from django.utils.translation import gettext_lazy as _

from compensation.forms.forms import NewCompensationForm, EditCompensationForm
from compensation.forms.modalForms import NewStateModalForm, NewDeadlineModalForm, NewActionModalForm
from compensation.models import Compensation, CompensationState, CompensationAction, CompensationDocument
from compensation.tables import CompensationTable
from intervention.models import Intervention
from konova.contexts import BaseContext
from konova.decorators import *
from konova.forms import RemoveModalForm, SimpleGeomForm, NewDocumentForm
from konova.utils.documents import get_document, remove_document
from konova.utils.message_templates import FORM_INVALID, IDENTIFIER_REPLACED
from konova.utils.user_checks import in_group


@login_required
@any_group_check
def index_view(request: HttpRequest):
    """
    Renders the index view for compensation

    Args:
        request (HttpRequest): The incoming request

    Returns:
        A rendered view
    """
    template = "generic_index.html"
    compensations = Compensation.objects.filter(
        deleted=None,  # only show those which are not deleted individually
        intervention__deleted=None,  # and don't show the ones whose intervention has been deleted
    )
    table = CompensationTable(
        request=request,
        queryset=compensations
    )
    context = {
        "table": table,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
@default_group_required
@shared_access_required(Intervention, "intervention_id")
def new_view(request: HttpRequest, intervention_id: str = None):
    """
    Renders a view for a new compensation creation

    Args:
        request (HttpRequest): The incoming request

    Returns:

    """
    template = "compensation/new/view.html"
    data_form = NewCompensationForm(request.POST or None, intervention_id=intervention_id)
    geom_form = SimpleGeomForm(request.POST or None, read_only=False)
    if request.method == "POST":
        if data_form.is_valid() and geom_form.is_valid():
            generated_identifier = data_form.cleaned_data.get("identifier", None)
            comp = data_form.save(request.user, geom_form)
            if generated_identifier != comp.identifier:
                messages.info(
                    request,
                    IDENTIFIER_REPLACED.format(
                        generated_identifier,
                        comp.identifier
                    )
                )
            messages.success(request, _("Compensation {} added").format(comp.identifier))
            return redirect("compensation:open", id=comp.id)
        else:
            messages.error(request, FORM_INVALID)
    else:
        # For clarification: nothing in this case
        pass
    context = {
        "form": data_form,
        "geom_form": geom_form,
        "url": reverse("compensation:new-id")
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
def new_id_view(request: HttpRequest):
    """ JSON endpoint

    Provides fetching of free identifiers for e.g. AJAX calls

    """
    tmp = Compensation()
    identifier = tmp.generate_new_identifier()
    while Compensation.objects.filter(identifier=identifier).exists():
        identifier = tmp.generate_new_identifier()
    return JsonResponse(
        data={
            "identifier": identifier
        }
    )


@login_required
@default_group_required
def edit_view(request: HttpRequest, id: str):
    """
    Renders a view for editing compensations

    Args:
        request (HttpRequest): The incoming request

    Returns:

    """
    template = "compensation/new/view.html"
    # Get object from db
    comp = get_object_or_404(Compensation, id=id)
    # Create forms, initialize with values from db/from POST request
    data_form = EditCompensationForm(request.POST or None, instance=comp)
    geom_form = SimpleGeomForm(request.POST or None, read_only=False, instance=comp)
    if request.method == "POST":
        if data_form.is_valid() and geom_form.is_valid():
            # The data form takes the geom form for processing, as well as the performing user
            comp = data_form.save(request.user, geom_form)
            messages.success(request, _("Compensation {} edited").format(comp.identifier))
            return redirect("compensation:open", id=comp.id)
        else:
            messages.error(request, FORM_INVALID)
    else:
        # For clarification: nothing in this case
        pass
    context = {
        "form": data_form,
        "geom_form": geom_form,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
@any_group_check
def open_view(request: HttpRequest, id: str):
    """ Renders a detail view for a compensation

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id

    Returns:

    """
    template = "compensation/detail/compensation/view.html"
    comp = get_object_or_404(Compensation, id=id)
    geom_form = SimpleGeomForm(instance=comp)
    _user = request.user
    is_data_shared = comp.intervention.is_shared_with(_user)

    # Order states according to surface
    before_states = comp.before_states.all().order_by("-surface")
    after_states = comp.after_states.all().order_by("-surface")

    # Precalculate logical errors between before- and after-states
    # Sum() returns None in case of no states, so we catch that and replace it with 0 for easier handling
    sum_before_states = before_states.aggregate(Sum("surface"))["surface__sum"] or 0
    sum_after_states = after_states.aggregate(Sum("surface"))["surface__sum"] or 0
    diff_states = abs(sum_before_states - sum_after_states)

    context = {
        "obj": comp,
        "geom_form": geom_form,
        "has_access": is_data_shared,
        "before_states": before_states,
        "after_states": after_states,
        "sum_before_states": sum_before_states,
        "sum_after_states": sum_after_states,
        "diff_states": diff_states,
        "is_default_member": in_group(_user, DEFAULT_GROUP),
        "is_zb_member": in_group(_user, ZB_GROUP),
        "is_ets_member": in_group(_user, ETS_GROUP),
        "LANIS_LINK": comp.get_LANIS_link(),
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
def log_view(request: HttpRequest, id: str):
    """ Renders a log view using modal

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id

    Returns:

    """
    comp = get_object_or_404(Compensation, id=id)
    template = "modal/modal_generic.html"
    body_template = "log.html"

    context = {
        "modal_body_template": body_template,
        "log": comp.log.all(),
        "modal_title": _("Log"),
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
def remove_view(request: HttpRequest, id: str):
    """ Renders a modal view for removing the compensation

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id

    Returns:

    """
    comp = get_object_or_404(Compensation, id=id)
    form = RemoveModalForm(request.POST or None, instance=comp, user=request.user)
    return form.process_request(
        request=request,
        msg_success=_("Compensation removed"),
        redirect_url=reverse("compensation:index"),
    )


@login_required
def new_document_view(request: HttpRequest, id: str):
    """ Renders a form for uploading new documents

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id to which the new document will be related
    Returns:

    """
    comp = get_object_or_404(Compensation, id=id)
    form = NewDocumentForm(request.POST or None, request.FILES or None, instance=comp, user=request.user)
    return form.process_request(
        request,
        msg_success=_("Document added")
    )


@login_required
def get_document_view(request: HttpRequest, doc_id: str):
    """ Returns the document as downloadable file

    Wraps the generic document fetcher function from konova.utils.

    Args:
        request (HttpRequest): The incoming request
        doc_id (str): The document id

    Returns:

    """
    doc = get_object_or_404(CompensationDocument, id=doc_id)
    return get_document(doc)


@login_required
def remove_document_view(request: HttpRequest, doc_id: str):
    """ Removes the document from the database and file system

    Wraps the generic functionality from konova.utils.

    Args:
        request (HttpRequest): The incoming request
        doc_id (str): The document id

    Returns:

    """
    doc = get_object_or_404(CompensationDocument, id=doc_id)
    return remove_document(
        request,
        doc
    )


@login_required
def state_new_view(request: HttpRequest, id: str):
    """ Renders a form for adding new states for a compensation

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id to which the new state will be related

    Returns:

    """
    comp = get_object_or_404(Compensation, id=id)
    form = NewStateModalForm(request.POST or None, instance=comp, user=request.user)
    return form.process_request(
        request,
        msg_success=_("State added")
    )


@login_required
def action_new_view(request: HttpRequest, id: str):
    """ Renders a form for adding new actions for a compensation

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id to which the new state will be related

    Returns:

    """
    comp = get_object_or_404(Compensation, id=id)
    form = NewActionModalForm(request.POST or None, instance=comp, user=request.user)
    return form.process_request(
        request,
        msg_success=_("Action added")
    )


@login_required
def deadline_new_view(request: HttpRequest, id: str):
    """ Renders a form for adding new states for a compensation

    Args:
        request (HttpRequest): The incoming request
        id (str): The compensation's id to which the new state will be related

    Returns:

    """
    comp = get_object_or_404(Compensation, id=id)
    form = NewDeadlineModalForm(request.POST or None, instance=comp, user=request.user)
    return form.process_request(
        request,
        msg_success=_("Deadline added")
    )


@login_required
def state_remove_view(request: HttpRequest, id: str):
    """ Renders a form for removing a compensation state

    Args:
        request (HttpRequest): The incoming request
        id (str): The state's id

    Returns:

    """
    state = get_object_or_404(CompensationState, id=id)
    form = RemoveModalForm(request.POST or None, instance=state, user=request.user)
    return form.process_request(
        request,
        msg_success=_("State removed")
    )


@login_required
def action_remove_view(request: HttpRequest, id: str):
    """ Renders a form for removing a compensation action

    Args:
        request (HttpRequest): The incoming request
        id (str): The action's id

    Returns:

    """
    action = get_object_or_404(CompensationAction, id=id)
    form = RemoveModalForm(request.POST or None, instance=action, user=request.user)
    return form.process_request(
        request,
        msg_success=_("Action removed")
    )