# -*- mode: python; coding: utf-8 -*-
# Copyright (C) 2017-2020 by BDE ENS Paris-Saclay
# SPDX-License-Identifier: GPL-3.0-or-later

import json
import os
import re
import unicodedata
import urllib.request

from django.db.models import QuerySet
from django.forms import ModelForm
from django.utils.translation import gettext_lazy as _

from .models import Auteur, BD
from .scraper import BedetequeScraper


def generate_side_identifier(title, authors, subtitle=None):
    if isinstance(authors, QuerySet):
        authors = list(authors)

    title_normalized = title.upper()
    title_normalized = title_normalized.replace('’', '\'')
    title_normalized = re.sub(r'^DE ', '', title_normalized)
    title_normalized = re.sub(r'^DES ', '', title_normalized)
    title_normalized = re.sub(r'^LE ', '', title_normalized)
    title_normalized = re.sub(r'^LA ', '', title_normalized)
    title_normalized = re.sub(r'^LES ', '', title_normalized)
    title_normalized = re.sub(r'^L\'', '', title_normalized)
    title_normalized = re.sub(r'^UN ', '', title_normalized)
    title_normalized = re.sub(r'^UNE ', '', title_normalized)
    title_normalized = re.sub(r'^THE ', '', title_normalized)
    title_normalized = re.sub(r'Œ', 'OE', title_normalized)
    title_normalized = title_normalized.replace(' ', '')
    title_normalized = ''.join(
        char
        for char in unicodedata.normalize(
            'NFKD', title_normalized.casefold())
        if all(not unicodedata.category(char).startswith(cat)
               for cat in {'M', 'P', 'Z', 'C'}) or char == ' '
    ).casefold().upper()
    title_normalized = re.sub("[^A-Z0-9$]", "", title_normalized)
    authors = authors.copy()

    def sort(author):
        return "{:042d}".format(-author.note) + author.name.split(" ")[-1] + ".{:042d}".format(author.pk)

    authors.sort(key=sort)
    primary_author = authors[0]
    author_name = primary_author.name.upper()
    if ',' not in author_name and ' ' in author_name:
        author_name = author_name.split(' ')[-1]
    author_name = ''.join(
        char for char in unicodedata.normalize('NFKD', author_name.casefold())
        if all(not unicodedata.category(char).startswith(cat) for cat in {'M', 'P', 'Z', 'C'}) or char == ' '
    ).casefold().upper()
    author_name = re.sub("[^A-Z]", "", author_name)
    side_identifier = "{:.3} {:.3}".format(author_name, title_normalized, )
    if subtitle:
        subtitle = re.sub(r'</span>', '', subtitle)
        subtitle = re.sub(r'<span.*>', '', subtitle)
        start = subtitle.split(' ')[0].replace('.', '')
        start = re.sub("^R?", "", start)

        if start.isnumeric():
            side_identifier += " {:0>2}".format(start, )

    # Normalize side identifier, in order to remove accents
    side_identifier = ''.join(char for char in unicodedata.normalize('NFKD', side_identifier.casefold())
                              if all(not unicodedata.category(char).startswith(cat) for cat in {'M', 'P', 'Z', 'C'})
                              or char == ' ').casefold().upper()

    return side_identifier


class MediaAdminForm(ModelForm):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        isbn_field = self.fields.get('isbn')
        if isbn_field:
            isbn_field.widget.template_name = "media/isbn_button.html"
            isbn_field.widget.attrs.update({'autofocus': 'autofocus'})
        side_identifier_field = self.fields.get('side_identifier')
        if side_identifier_field and self.instance and self.instance.pk:
            instance = self.instance
            title, authors, subtitle = instance.title, instance.authors.all(), None
            if hasattr(instance, "subtitle"):
                subtitle = instance.subtitle
            side_identifier_field.widget.attrs.update(
                {'data-generated-side-identifier': generate_side_identifier(title, authors, subtitle)})
            side_identifier_field.widget.template_name = "media/generate_side_identifier.html"

    def download_data_isbndb(self, isbn):
        api_url = "https://api2.isbndb.com/book/" + str(isbn) + "?Authorization=" + os.getenv("ISBNDB_KEY")
        req = urllib.request.Request(api_url)
        req.add_header("Authorization", os.getenv("ISBNDB_KEY"))
        with urllib.request.urlopen(req) as url:
            data = json.loads(url.read().decode())
        self.cleaned_data["title"] = data["title_long"]
        self.cleaned_data["published_date"] = data["date_published"][:10]
        self.cleaned_data["number_of_pages"] = data["pages"]
        self.cleaned_data["authors"] = \
            list(Auteur.objects.get_or_create(name=author_name)[0] for author_name in data["authors"])
        self.cleaned_data["external_url"] = data["image"]
        return True

    def download_data_bedeteque(self, isbn):
        """
        Download data from bedeteque
        :return True if success
        """
        scraper = BedetequeScraper()
        r = scraper.search_by_isbn(isbn)
        if not r:
            return False
        # If results, then take the most accurate
        data = scraper.scrap_bd_info(r[0])
        self.cleaned_data.update(data)
        return True

    def download_data_google(self, isbn):
        """
        Download data from google books
        :return True if success
        """
        api_url = "https://www.googleapis.com/books/v1/volumes?q=ISBN:{}"\
            .format(isbn)
        with urllib.request.urlopen(api_url) as url:
            data = json.loads(url.read().decode())

        if data and data['totalItems']:
            fetched_item = None
            for item in data['items']:
                for identifiers in item["volumeInfo"]["industryIdentifiers"]:
                    if identifiers["identifier"] == isbn:
                        fetched_item = item
                        break
                if fetched_item:
                    break
            if not fetched_item:
                return False
            # Fill the data
            self.parse_data_google(fetched_item)
            return True
        return False

    def parse_data_google(self, data):
        info = data['volumeInfo']
        self.cleaned_data['external_url'] = info['canonicalVolumeLink']
        if 'title' in info:
            self.cleaned_data['title'] = info['title']
        if 'subtitle' in data:
            self.cleaned_data['subtitle'] = info['subtitle']

        if 'pageCount' in info:
            self.cleaned_data['number_of_pages'] = \
                info['pageCount']
        elif not self.cleaned_data['number_of_pages']:
            self.cleaned_data['number_of_pages'] = 0

        if 'publishedDate' in info:
            if "-" not in info["publishedDate"]:
                info["publishedDate"] += "-01-01"
            elif len(info["publishedDate"]) == 7:
                info["publishedDate"] += "-01"
            self.cleaned_data['publish_date'] = info['publishedDate'][:10]

        if 'authors' not in self.cleaned_data \
                or not self.cleaned_data['authors']:
            self.cleaned_data['authors'] = list()

        if 'authors' in info:
            for author in info['authors']:
                author_obj = Auteur.objects.get_or_create(
                    name=author)[0]
                self.cleaned_data['authors'].append(author_obj)

        print(self.cleaned_data)

    def download_data_openlibrary(self, isbn):
        """
        Download data from openlibrary
        :return True if success
        """
        api_url = "https://openlibrary.org/api/books?bibkeys=ISBN:{}" \
                  "&format=json&jscmd=data".format(isbn)
        with urllib.request.urlopen(api_url) as url:
            data = json.loads(url.read().decode())

        if data and data['ISBN:' + isbn]:
            data = data['ISBN:' + isbn]
            if 'url' in data:
                # Fill the data
                self.parse_data_openlibrary(data)
                return True
        return False

    def parse_data_openlibrary(self, data):
        self.cleaned_data['external_url'] = data['url']
        if 'title' in data:
            self.cleaned_data['title'] = data['title']
        if 'subtitle' in data:
            self.cleaned_data['subtitle'] = data['subtitle']

        if 'number_of_pages' in data:
            self.cleaned_data['number_of_pages'] = \
                data['number_of_pages']
        elif not self.cleaned_data['number_of_pages']:
            self.cleaned_data['number_of_pages'] = 0

        if 'publish_date' in data:
            months = ['January', 'February', "March", "April", "Mai",
                      "June", "July", "August", "September",
                      "October", "November", "December"]
            split = data['publish_date'].replace(',', '').split(' ')
            if len(split) == 1:
                self.cleaned_data['publish_date'] = split[0] + "-01-01"
            else:
                month_to_number = dict(
                    Jan="01",
                    Feb="02",
                    Mar="03",
                    Apr="04",
                    May="05",
                    Jun="06",
                    Jul="07",
                    Aug="08",
                    Sep="09",
                    Oct="10",
                    Nov="11",
                    Dec="12",
                )
                if split[0][:3] in month_to_number:
                    self.cleaned_data['publish_date']\
                        = split[2] + "-" \
                        + month_to_number[split[0][:3]] + "-" + split[1]
                else:
                    self.cleaned_data['publish_date'] = "{}-{:02d}-{:02d}" \
                        .format(split[2], months.index(split[0])
                                + 1, int(split[1]), )

        if 'authors' not in self.cleaned_data \
                or not self.cleaned_data['authors']:
            self.cleaned_data['authors'] = list()

        if 'authors' in data:
            for author in data['authors']:
                author_obj = Auteur.objects.get_or_create(
                    name=author['name'])[0]
                self.cleaned_data['authors'].append(author_obj)

    def clean(self):
        """
        If user fetch ISBN data, then download data before validating the form
        """
        super().clean()

        if "_isbn" in self.data\
                or "_isbn_addanother" in self.data:
            isbn = self.cleaned_data.get('isbn')
            if "_isbn_addanother" in self.data:
                self.data = self.data.copy()
                self.data['_addanother'] = 42
                self.request.POST = self.data
            if isbn:
                scrap_result = self.download_data_isbndb(isbn)
                if not scrap_result:
                    # ISBN is present, try with bedeteque
                    scrap_result = self.download_data_bedeteque(isbn)
                    if not scrap_result:
                        # Try with Google
                        scrap_result = self.download_data_google(isbn)
                        if not scrap_result:
                            # Try with OpenLibrary
                            if not self.download_data_openlibrary(isbn):
                                self.add_error('isbn',
                                               _("This ISBN is not found."))
                                return self.cleaned_data

                if self.cleaned_data['title']:
                    self.cleaned_data['title'] = re.sub(
                        r'\(AUT\) ',
                        '',
                        self.cleaned_data['title']
                    )

                if self.cleaned_data['authors']:
                    side_identifier = generate_side_identifier(
                        self.cleaned_data["title"],
                        self.cleaned_data["authors"],
                        self.cleaned_data["subtitle"],
                    )

                    self.cleaned_data['side_identifier'] = side_identifier

        return self.cleaned_data

    def _clean_fields(self):
        for name, field in self.fields.items():
            # value_from_datadict() gets the data from the data dictionaries.
            # Each widget type knows how to retrieve its own data, because some
            # widgets split data over several HTML fields.
            if field.disabled:
                value = self.get_initial_for_field(field, name)
            else:
                value = field.widget.value_from_datadict(
                    self.data, self.files, self.add_prefix(name))
            from django.core.exceptions import ValidationError
            try:
                # We don't want to check a field when we enter an ISBN.
                if "isbn" not in self.data \
                        or not self.cleaned_data.get('isbn'):
                    value = field.clean(value)
                self.cleaned_data[name] = value
                if hasattr(self, 'clean_%s' % name):
                    value = getattr(self, 'clean_%s' % name)()
                    self.cleaned_data[name] = value
            except ValidationError as e:
                self.add_error(name, e)

    class Meta:
        model = BD
        fields = '__all__'