"""
Django views for interacting with Company app
"""


# -*- coding: utf-8 -*-
from __future__ import unicode_literals

from django.utils.translation import ugettext_lazy as _
from django.views.generic import DetailView, ListView

from django.urls import reverse
from django.core.files.base import ContentFile

from PIL import Image
import requests
import io

from InvenTree.views import AjaxUpdateView
from InvenTree.views import InvenTreeRoleMixin

from .models import Company
from .models import ManufacturerPart
from .models import SupplierPart


from .forms import CompanyImageDownloadForm


class CompanyIndex(InvenTreeRoleMixin, ListView):
    """ View for displaying list of companies
    """

    model = Company
    template_name = 'company/index.html'
    context_object_name = 'companies'
    paginate_by = 50
    permission_required = 'company.view_company'

    def get_context_data(self, **kwargs):

        ctx = super().get_context_data(**kwargs)

        # Provide custom context data to the template,
        # based on the URL we use to access this page

        lookup = {
            reverse('supplier-index'): {
                'title': _('Suppliers'),
                'button_text': _('New Supplier'),
                'filters': {'is_supplier': 'true'},
                'pagetype': 'suppliers',
            },
            reverse('manufacturer-index'): {
                'title': _('Manufacturers'),
                'button_text': _('New Manufacturer'),
                'filters': {'is_manufacturer': 'true'},
                'pagetype': 'manufacturers',
            },
            reverse('customer-index'): {
                'title': _('Customers'),
                'button_text': _('New Customer'),
                'filters': {'is_customer': 'true'},
                'pagetype': 'customers',
            }
        }

        default = {
            'title': _('Companies'),
            'button_text': _('New Company'),
            'filters': {},
            'pagetype': 'companies'
        }

        context = None

        for item in lookup:
            if self.request.path == item:
                context = lookup[item]
                break

        if context is None:
            context = default

        for key, value in context.items():
            ctx[key] = value

        return ctx

    def get_queryset(self):
        """ Retrieve the Company queryset based on HTTP request parameters.

        - supplier: Filter by supplier
        - customer: Filter by customer
        """
        queryset = Company.objects.all().order_by('name')

        if self.request.GET.get('supplier', None):
            queryset = queryset.filter(is_supplier=True)

        if self.request.GET.get('customer', None):
            queryset = queryset.filter(is_customer=True)

        return queryset


class CompanyDetail(DetailView):
    """ Detail view for Company object """
    context_obect_name = 'company'
    template_name = 'company/detail.html'
    queryset = Company.objects.all()
    model = Company
    permission_required = 'company.view_company'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)

        return ctx


class CompanyImageDownloadFromURL(AjaxUpdateView):
    """
    View for downloading an image from a provided URL
    """

    model = Company
    ajax_template_name = 'image_download.html'
    form_class = CompanyImageDownloadForm
    ajax_form_title = _('Download Image')

    def validate(self, company, form):
        """
        Validate that the image data are correct
        """
        # First ensure that the normal validation routines pass
        if not form.is_valid():
            return

        # We can now extract a valid URL from the form data
        url = form.cleaned_data.get('url', None)

        # Download the file
        response = requests.get(url, stream=True)

        # Look at response header, reject if too large
        content_length = response.headers.get('Content-Length', '0')

        try:
            content_length = int(content_length)
        except (ValueError):
            # If we cannot extract meaningful length, just assume it's "small enough"
            content_length = 0

        # TODO: Factor this out into a configurable setting
        MAX_IMG_LENGTH = 10 * 1024 * 1024

        if content_length > MAX_IMG_LENGTH:
            form.add_error('url', _('Image size exceeds maximum allowable size for download'))
            return

        self.response = response

        # Check for valid response code
        if not response.status_code == 200:
            form.add_error('url', _('Invalid response: {code}').format(code=response.status_code))
            return

        response.raw.decode_content = True

        try:
            self.image = Image.open(response.raw).convert()
            self.image.verify()
        except:
            form.add_error('url', _("Supplied URL is not a valid image file"))
            return

    def save(self, company, form, **kwargs):
        """
        Save the downloaded image to the company
        """
        fmt = self.image.format

        if not fmt:
            fmt = 'PNG'

        buffer = io.BytesIO()

        self.image.save(buffer, format=fmt)

        # Construct a simplified name for the image
        filename = f"company_{company.pk}_image.{fmt.lower()}"

        company.image.save(
            filename,
            ContentFile(buffer.getvalue()),
        )


class ManufacturerPartDetail(DetailView):
    """ Detail view for ManufacturerPart """
    model = ManufacturerPart
    template_name = 'company/manufacturer_part_detail.html'
    context_object_name = 'part'
    queryset = ManufacturerPart.objects.all()
    permission_required = 'purchase_order.view'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)

        return ctx


class SupplierPartDetail(DetailView):
    """ Detail view for SupplierPart """
    model = SupplierPart
    template_name = 'company/supplier_part_detail.html'
    context_object_name = 'part'
    queryset = SupplierPart.objects.all()
    permission_required = 'purchase_order.view'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)

        return ctx