from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.http import HttpRequest
from django.shortcuts import render, redirect, get_object_or_404
from django.urls import reverse
from django.utils.translation import gettext_lazy as _

from compensation.models import Compensation
from konova.contexts import BaseContext
from konova.decorators import resolve_user_role, valid_process_role_required
from konova.forms import RemoveForm
from konova.utils.tables import ChoicesColumnForm
from process.enums import ProcessStateEnum
from process.forms import NewProcessForm, EditProcessForm
from process.models import Process
from process.settings import PROCESS_STATE_STRINGS
from process.tables import ProcessTable

# URL definitions
PROCESS_INDEX_URL = "process:index"


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

    Args:
        request (HttpRequest): The incoming request

    Returns:
        A rendered view
    """
    template = "generic_index.html"
    user = request.user
    processes = Process.get_role_objects(user)
    table = ProcessTable(
        request=request,
        queryset=processes
    )
    context = {
        "table": table,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


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

    Args:
        request (HttpRequest): The incoming request

    Returns:

    """
    template = "konova/form.html"
    form = NewProcessForm(request.POST or None)
    if request.method == "POST":
        if form.is_valid():
            process = form.save(request.user)
            intervention = process.intervention
            messages.info(request, _("A process is based on an intervention. Please fill in the missing data for this intervention"))
            return redirect("intervention:edit", id=intervention.id)
        else:
            messages.error(request, _("Invalid input"))
    else:
        # For clarification: Nothing to do here
        pass
    context = {
        "form": form,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


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

    Args:
        request (HttpRequest): The incoming request
        id (str): The uuid id as string

    Returns:

    """
    template = "process/open.html"
    process = get_object_or_404(Process, id=id)
    context = {
        "process": process,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
@resolve_user_role
def edit_view(request: HttpRequest, id: str):
    """ Renders an edit view for this process

    Args:
        request (HttpRequest): The incoming request
        id (str): The uuid id as string

    Returns:

    """
    template = "konova/form.html"
    process = get_object_or_404(Process, id=id)
    if request.method == "POST":
        form = EditProcessForm(request.POST or None, instance=process, user=request.user)
        if form.is_valid():
            process = form.save(request.user)
            messages.success(request, _("{} edited").format(process))
            return redirect("process:index")
        else:
            messages.error(request, _("Invalid input"))
    form = EditProcessForm(instance=process, user=request.user)
    context = {
        "form": form,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
def remove_view(request: HttpRequest, id: str):
    """ Renders a remove view for this process

    Args:
        request (HttpRequest): The incoming request
        id (str): The uuid id as string

    Returns:

    """
    template = "konova/form.html"
    process = get_object_or_404(Process, id=id)
    if request.method == "POST":
        form = RemoveForm(
            request.POST or None,
            object_to_remove=process,
            remove_post_url=reverse("process:remove", args=(id,)),
            cancel_url=reverse("process:index"),
        )
        if form.is_valid():
            confirmed = form.is_checked()
            if confirmed:
                process.deactivate()
                messages.success(request, _("Process {} removed").format(process))
            return redirect("process:index")
        else:
            messages.error(request, _("Invalid input"))

    form = RemoveForm(
        object_to_remove=process,
        remove_post_url=reverse("process:remove", args=(id,)),
        cancel_url=reverse("process:index"),
    )
    context = {
        "form": form,
    }
    context = BaseContext(request, context).context
    return render(request, template, context)


@login_required
def edit_status_view(request: HttpRequest, id: str):
    """ Changes only the status of a process

    Args:
        request (The incoming request):
        id ():

    Returns:

    """
    process = get_object_or_404(Process, id=id)
    old_state = process.state
    form = ChoicesColumnForm(request.POST or None, choices=ProcessStateEnum.as_choices(drop_empty_choice=True))
    if request.method == "POST":
        if form.is_valid():
            process.state = int(form.cleaned_data.get("select", -1))
            process.save()
            _from = PROCESS_STATE_STRINGS.get(old_state)
            _to = PROCESS_STATE_STRINGS.get(process.state)
            messages.info(request, _("{} status changed from {} to {}").format(process.intervention.title, _from, _to))
        else:
            messages.error(request, form.errors)
    return redirect("process:index")


@login_required
def add_compensation_view(request: HttpRequest, id: str):
    """ Adds a new compensation to a process

    Args:
        request (HttpRequest): The incoming request
        id (str): The process' id

    Returns:

    """
    process = get_object_or_404(Process, id=id)
    comp = Compensation()
    comp.process = process
    comp.save()
    messages.info(request, _("Please fill in the data for this compensation"))
    return redirect("compensation:edit", id=comp.id)
    #template = ""
    #context = {}
    #context = BaseContext(request, context).context
    #return render(request, template, context)