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, \
    NewCompensationDocumentForm
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
from konova.utils.documents import get_document, remove_document
from konova.utils.generators import generate_qr_code
from konova.utils.message_templates import FORM_INVALID, IDENTIFIER_REPLACED, DATA_UNSHARED_EXPLANATION, \
    CHECKED_RECORDED_RESET
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/form/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:detail", id=comp.id)
        else:
            messages.error(request, FORM_INVALID, extra_tags="danger",)
    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
@default_group_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
@shared_access_required(Compensation, "id")
def edit_view(request: HttpRequest, id: str):
    """
    Renders a view for editing compensations

    Args:
        request (HttpRequest): The incoming request

    Returns:

    """
    template = "compensation/form/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():
            # Preserve state of intervention recorded/checked to determine whether the user must be informed or not
            # about a change of the recorded/checked state
            intervention_recorded = comp.intervention.recorded is not None
            intervention_checked = comp.intervention.checked is not None

            # The data form takes the geom form for processing, as well as the performing user
            comp = data_form.save(request.user, geom_form)
            if intervention_recorded or intervention_checked:
                messages.info(request, CHECKED_RECORDED_RESET)
            messages.success(request, _("Compensation {} edited").format(comp.identifier))
            return redirect("compensation:detail", id=comp.id)
        else:
            messages.error(request, FORM_INVALID, extra_tags="danger",)
    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 detail_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().prefetch_related("biotope_type").order_by("-surface")
    after_states = comp.after_states.all().prefetch_related("biotope_type").order_by("-surface")
    actions = comp.actions.all().prefetch_related("action_type")

    # 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)

    if not is_data_shared:
        messages.info(request, DATA_UNSHARED_EXPLANATION)

    context = {
        "obj": comp,
        "geom_form": geom_form,
        "has_access": is_data_shared,
        "actions": actions,
        "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
@default_group_required
@shared_access_required(Compensation, "id")
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
@default_group_required
@shared_access_required(Compensation, "id")
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
@default_group_required
@shared_access_required(Compensation, "id")
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 = NewCompensationDocumentForm(request.POST or None, request.FILES or None, instance=comp, user=request.user)
    return form.process_request(
        request,
        msg_success=_("Document added")
    )


@login_required
@default_group_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)
    user = request.user
    instance = doc.instance
    # File download only possible if related instance is shared with user
    if not instance.users.filter(id=user.id):
        messages.info(
            request,
            DATA_UNSHARED
        )
        return redirect("compensation:detail", id=instance.id)
    return get_document(doc)


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

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

    Returns:

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


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

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

    Returns:

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


def report_view(request: HttpRequest, id: str):
    """ Renders the public report view

    Args:
        request (HttpRequest): The incoming request
        id (str): The id of the intervention

    Returns:

    """
    # Reuse the compensation report template since compensations are structurally identical
    template = "compensation/report/compensation/report.html"
    comp = get_object_or_404(Compensation, id=id)

    # If intervention is not recorded (yet or currently) we need to render another template without any data
    if not comp.intervention.recorded:
        template = "report/unavailable.html"
        return render(request, template, {})

    # Prepare data for map viewer
    geom_form = SimpleGeomForm(
        instance=comp
    )
    qrcode_img = generate_qr_code(
        request.build_absolute_uri(reverse("compensation:report", args=(id,))),
        10
    )
    qrcode_img_lanis = generate_qr_code(
        comp.get_LANIS_link(),
        7
    )
    # Order states by surface
    before_states = comp.before_states.all().order_by("-surface").prefetch_related("biotope_type")
    after_states = comp.after_states.all().order_by("-surface").prefetch_related("biotope_type")
    actions = comp.actions.all().prefetch_related("action_type")

    context = {
        "obj": comp,
        "qrcode": qrcode_img,
        "qrcode_lanis": qrcode_img_lanis,
        "has_access": False,  # disables action buttons during rendering
        "before_states": before_states,
        "after_states": after_states,
        "geom_form": geom_form,
        "actions": actions,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)