import logging

import magic
from crispy_forms.helper import FormHelper
from crispy_forms.layout import Submit
from django import forms

from .models import ResourceCategory
from .models import ResourceType

logger = logging.getLogger(__name__)

ALLOWED_THUMBNAILS = 5
ALLOWED_PDFS = 20


class ResourceCreateForm(forms.Form):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.helper = FormHelper(self)
        self.helper.add_input(Submit("submit", "Submit"))

    error_css_class = "error"
    required_css_class = "required"

    name = forms.CharField(
        max_length=255,
        help_text="Concisely describe what the resource is, aiming for"
        " in 35-45 characters. "
        "eg: 'Fractions KS2 Worksheet and Answers.'",
    )
    description = forms.CharField(
        max_length=1000,
        widget=forms.Textarea,
        help_text="This is your opportunity to clearly explain what your resource "
        "is all "
        "about! It’s worth remembering that you are using the space to "
        "communicate to two "
        "different audiences. Firstly, think about what fellow teachers "
        "would like "
        "to know, such as exactly what the resource contains and how it "
        "could be used in the classroom. Secondly, the words you include "
        "on this page are also talking to internal and external search "
        "engines."
        " External search engines, like Google, show the first 155 characters "
        "of the resource description, so make sure you take advantage "
        "of these "
        "characters by using lots of relevant keywords as part of an "
        "enticing pitch.",
    )
    resource_type = forms.ModelChoiceField(queryset=ResourceType.objects.all())
    age_range = forms.ChoiceField(
        choices=[
            ("3-5", "3-5"),
            ("5-7", "5-7"),
            ("7-11", "7-11"),
            ("11-14", "11-14"),
            ("14-16", "14-16"),
            ("16+", "16+"),
            ("Age not applicable", "Age not applicable"),
        ],
        help_text="Try to be accurate in your choice of age range so that your resource "
        "shows up in the correct searches. (Although we don't have searches yet!)",
    )
    curriculum = forms.ChoiceField(
        choices=[
            ("No curriculum", "No curriculum"),
            ("English", "English"),
            ("Scottish", "Scottish"),
        ],
    )
    main_resource_category = forms.ModelChoiceField(
        queryset=ResourceCategory.objects.all(),
        help_text="Categorise your resource by subject so it shows up in the correct "
        "searches. It's a good idea to limit the number of subjects you select "
        "to one or two to make your resource easier to find.",
    )
    additional_resource_category = forms.ModelChoiceField(
        queryset=ResourceCategory.objects.all(),
        required=False,
    )
    pdf_files = forms.FileField(
        widget=forms.TextInput(
            attrs={
                "multiple": True,
                "type": "File",
                "required": True,
            },
        ),
        required=False,
        help_text="You can multi-select up to 20 .pdf files here.",
        label="PDF files",
    )
    thumbnail_files = forms.FileField(
        widget=forms.TextInput(
            attrs={
                "multiple": True,
                "type": "File",
                "required": True,
            },
        ),
        required=False,
        label="Cover images",
        help_text="Your cover image will be displayed in the search results and as "
        "the first image on your resource page in the preview function. "
        "It is important to add an eye catching cover image that gives "
        "other teachers an idea about what your resource contains. "
        "You can multi-select up to 5 .png or .jpg files here.",
    )
    pdf_files.widget.attrs.update({"class": "file_upload", "accept": ".pdf"})
    thumbnail_files.widget.attrs.update({"class": "file_upload", "accept": ".png,.jpg"})

    def clean_thumbnail_files(self):
        thumbnail_files = self.files.getlist("thumbnail_files")
        if not thumbnail_files:
            raise forms.ValidationError("Please select at least one thumbnail file.")
        acceptable = ["image/png", "image/jpeg"]
        for f in thumbnail_files:
            content_type = magic.from_buffer(f.file.read(), mime=True)
            f.file.seek(0)
            if content_type not in acceptable:
                raise forms.ValidationError("Please select only PNG or JPG files.")
        if len(thumbnail_files) > ALLOWED_THUMBNAILS:
            raise forms.ValidationError("Please select up to 5 files.")
        return thumbnail_files

    def clean_pdf_files(self):
        pdf_files = self.files.getlist("pdf_files")
        if not pdf_files:
            raise forms.ValidationError("Please select at least one PDF file.")
        acceptable = ["application/pdf"]
        for f in pdf_files:
            content_type = magic.from_buffer(f.file.read(), mime=True)
            f.file.seek(0)
            if content_type not in acceptable:
                raise forms.ValidationError("Please select only PDF files.")
        if len(pdf_files) > ALLOWED_PDFS:
            raise forms.ValidationError("Please select up to 20 PDF files.")
        return pdf_files