from django.contrib import messages
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, get_object_or_404, redirect
from django.urls import reverse
from django.utils.translation import gettext_lazy as _

from compensation.forms.modalForms import NewStateModalForm, NewActionModalForm, NewDeadlineModalForm, \
    RemoveCompensationActionModalForm, RemoveCompensationStateModalForm
from compensation.models import CompensationAction, CompensationState
from ema.forms import NewEmaForm, EditEmaForm, NewEmaDocumentModalForm
from ema.tables import EmaTable
from intervention.forms.modalForms import ShareModalForm
from konova.contexts import BaseContext
from konova.decorators import conservation_office_group_required, shared_access_required
from ema.models import Ema, EmaDocument
from konova.forms import RemoveModalForm, SimpleGeomForm, RecordModalForm, RemoveDeadlineModalForm, \
    EditDocumentModalForm
from konova.models import Deadline
from konova.settings import DEFAULT_GROUP, ZB_GROUP, ETS_GROUP
from konova.sub_settings.context_settings import TAB_TITLE_IDENTIFIER
from konova.utils.documents import get_document, remove_document
from konova.utils.generators import generate_qr_code
from konova.utils.message_templates import IDENTIFIER_REPLACED, FORM_INVALID, DATA_UNSHARED, DATA_UNSHARED_EXPLANATION, \
    DOCUMENT_ADDED, COMPENSATION_STATE_REMOVED, COMPENSATION_STATE_ADDED, COMPENSATION_ACTION_REMOVED, \
    COMPENSATION_ACTION_ADDED, DEADLINE_ADDED, DEADLINE_REMOVED, DOCUMENT_EDITED
from konova.utils.user_checks import in_group


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

    Args:
        request (HttpRequest): The incoming request

    Returns:

    """
    template = "generic_index.html"
    emas = Ema.objects.filter(
        deleted=None,
    ).order_by(
        "-modified"
    )
    table = EmaTable(
        request,
        queryset=emas
    )
    context = {
        "table": table,
        TAB_TITLE_IDENTIFIER: _("EMAs - Overview"),
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
@conservation_office_group_required
def new_view(request: HttpRequest):
    """
    Renders a view for a new eco account creation

    Args:
        request (HttpRequest): The incoming request

    Returns:

    """
    template = "ema/form/view.html"
    data_form = NewEmaForm(request.POST or None)
    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)
            ema = data_form.save(request.user, geom_form)
            if generated_identifier != ema.identifier:
                messages.info(
                    request,
                    IDENTIFIER_REPLACED.format(
                        generated_identifier,
                        ema.identifier
                    )
                )
            messages.success(request, _("EMA {} added").format(ema.identifier))
            return redirect("ema:detail", id=ema.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,
        TAB_TITLE_IDENTIFIER: _("New EMA"),
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


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

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

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


@login_required
def detail_view(request: HttpRequest, id: str):
    """ Renders the detail view of an EMA

    Args:
        request (HttpRequest): The incoming request
        id (str): The EMA id

    Returns:

    """
    template = "ema/detail/view.html"
    ema = get_object_or_404(Ema, id=id, deleted=None)

    geom_form = SimpleGeomForm(instance=ema)
    parcels = ema.get_underlying_parcels()
    _user = request.user
    is_data_shared = ema.is_shared_with(_user)

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

    ema.set_status_messages(request)

    context = {
        "obj": ema,
        "geom_form": geom_form,
        "parcels": parcels,
        "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": ema.get_LANIS_link(),
        TAB_TITLE_IDENTIFIER: f"{ema.identifier} - {ema.title}",
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


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

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    template = "modal/modal_generic.html"
    body_template = "log.html"

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


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "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
    ema = get_object_or_404(Ema, id=id)
    # Create forms, initialize with values from db/from POST request
    data_form = EditEmaForm(request.POST or None, instance=ema)
    geom_form = SimpleGeomForm(request.POST or None, read_only=False, instance=ema)
    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
            ema = data_form.save(request.user, geom_form)
            messages.success(request, _("EMA {} edited").format(ema.identifier))
            return redirect("ema:detail", id=ema.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,
        TAB_TITLE_IDENTIFIER: _("Edit {}").format(ema.identifier),
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


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

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    form = RemoveModalForm(request.POST or None, instance=ema, request=request)
    return form.process_request(
        request=request,
        msg_success=_("EMA removed"),
        redirect_url=reverse("ema:index"),
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def record_view(request: HttpRequest, id: str):
    """ Renders a modal view for recording the EMA

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    msg_succ = _("{} unrecorded") if ema.recorded else _("{} recorded")
    form = RecordModalForm(request.POST or None, instance=ema, request=request)
    return form.process_request(
        request=request,
        msg_success=msg_succ.format("EMA"),
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def state_new_view(request: HttpRequest, id: str):
    """ Renders a form for adding new states for an EMA

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    form = NewStateModalForm(request.POST or None, instance=ema, request=request)
    return form.process_request(
        request,
        msg_success=COMPENSATION_STATE_ADDED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def action_new_view(request: HttpRequest, id: str):
    """ Renders a form for adding new actions for an EMA

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    form = NewActionModalForm(request.POST or None, instance=ema, request=request)
    return form.process_request(
        request,
        msg_success=COMPENSATION_ACTION_ADDED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def deadline_new_view(request: HttpRequest, id: str):
    """ Renders a form for adding new states for an EMA

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    form = NewDeadlineModalForm(request.POST or None, instance=ema, request=request)
    return form.process_request(
        request,
        msg_success=DEADLINE_ADDED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def document_new_view(request: HttpRequest, id: str):
    """ Renders a form for uploading new documents

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

    """
    ema = get_object_or_404(Ema, id=id)
    form = NewEmaDocumentModalForm(request.POST or None, request.FILES or None, instance=ema, request=request)
    return form.process_request(
        request,
        msg_success=DOCUMENT_ADDED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )


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

    Wraps the generic document fetcher function from konova.utils.

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    doc = get_object_or_404(EmaDocument, id=doc_id)
    return get_document(doc)


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def edit_document_view(request: HttpRequest, id: str, 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
        id (str): The EMA id
        doc_id (str): The document id

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    doc = get_object_or_404(EmaDocument, id=doc_id)
    form = EditDocumentModalForm(request.POST or None, request.FILES or None, instance=ema, document=doc, request=request)
    return form.process_request(
        request,
        DOCUMENT_EDITED,
        reverse("ema:detail", args=(id,)) + "#related_data"
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def remove_document_view(request: HttpRequest, id:str, 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
        id (str): The EMA id
        doc_id (str): The document id

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    doc = get_object_or_404(EmaDocument, id=doc_id)
    return remove_document(
        request,
        doc
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def state_remove_view(request: HttpRequest, id: str, state_id: str):
    """ Renders a form for removing an EMA state

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    state = get_object_or_404(CompensationState, id=state_id)
    form = RemoveCompensationStateModalForm(request.POST or None, instance=ema, state=state, request=request)
    return form.process_request(
        request,
        msg_success=COMPENSATION_STATE_REMOVED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def action_remove_view(request: HttpRequest, id: str, action_id: str):
    """ Renders a form for removing an EMA action

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    action = get_object_or_404(CompensationAction, id=action_id)
    form = RemoveCompensationActionModalForm(request.POST or None, instance=ema, action=action, request=request)
    return form.process_request(
        request,
        msg_success=COMPENSATION_ACTION_REMOVED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )


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 EMAs are structurally identical
    template = "ema/report/report.html"
    ema = get_object_or_404(Ema, id=id)

    tab_title = _("Report {}").format(ema.identifier)
    # If intervention is not recorded (yet or currently) we need to render another template without any data
    if not ema.is_ready_for_publish():
        template = "report/unavailable.html"
        context = {
            TAB_TITLE_IDENTIFIER: tab_title,
        }
        context = BaseContext(request, context).context
        return render(request, template, context)

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

    context = {
        "obj": ema,
        "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,
        "parcels": parcels,
        "actions": actions,
        TAB_TITLE_IDENTIFIER: tab_title,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
def share_view(request: HttpRequest, id: str, token: str):
    """ Performs sharing of an ema

    If token given in url is not valid, the user will be redirected to the dashboard

    Args:
        request (HttpRequest): The incoming request
        id (str): EMA's id
        token (str): Access token for EMA

    Returns:

    """
    user = request.user
    obj = get_object_or_404(Ema, id=id)
    # Check tokens
    if obj.access_token == token:
        # Send different messages in case user has already been added to list of sharing users
        if obj.is_shared_with(user):
            messages.info(
                request,
                _("{} has already been shared with you").format(obj.identifier)
            )
        else:
            messages.success(
                request,
                _("{} has been shared with you").format(obj.identifier)
            )
            obj.share_with(user)
        return redirect("ema:detail", id=id)
    else:
        messages.error(
            request,
            _("Share link invalid"),
            extra_tags="danger",
        )
        return redirect("home")


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def create_share_view(request: HttpRequest, id: str):
    """ Renders sharing form for an Ema

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

    Returns:

    """
    obj = get_object_or_404(Ema, id=id)
    form = ShareModalForm(request.POST or None, instance=obj, request=request)
    return form.process_request(
        request,
        msg_success=_("Share settings updated")
    )


@login_required
@conservation_office_group_required
@shared_access_required(Ema, "id")
def deadline_remove_view(request: HttpRequest, id: str, deadline_id: str):
    """ Renders a form for removing deadlines from a compensation

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

    Returns:

    """
    ema = get_object_or_404(Ema, id=id)
    deadline = get_object_or_404(Deadline, id=deadline_id)
    form = RemoveDeadlineModalForm(request.POST or None, instance=ema, deadline=deadline, request=request)
    return form.process_request(
        request,
        msg_success=DEADLINE_REMOVED,
        redirect_url=reverse("ema:detail", args=(id,)) + "#related_data"
    )