import requests
from bs4 import BeautifulSoup
from urllib.parse import urlencode

from django.core.management.base import BaseCommand

from utils import setting_handler
from journal import models as jm
from submission import models as sm
from metrics import models


def process_article(link, article):
    print("Processing article", end="... ")
    doi = link.doi.contents[0]
    volume = link.volume.contents[0] if link.volume else ""
    issue = link.issue.contents[0] if link.issue else ""
    issn = link.issn.contents[0] if link.issn else None

    defaults = {
        "year": link.year.contents[0],
        "journal_title": link.journal_title.contents[0],
        "article_title": link.article_title.contents[0],
        "volume": volume,
        "issue": issue,
        "journal_issn": issn,
    }

    models.ArticleLink.objects.get_or_create(
        article=article,
        doi=doi,
        object_type="article",
        defaults=defaults,
    )
    print("[ok]")


def process_book(link, article):
    print("Processing book", end="... ")
    doi = link.doi.contents[0]

    isbn_print = link.find("isbn", {"type": "print"})
    isbn_elec = link.find("isbn", {"type": "electronic"})

    title = link.volume_title.contents[0]

    defaults = {
        "year": link.year.contents[0],
        "title": title,
        "component_number": link.component_number.contents[0]
        if link.component_number
        else "",
        "isbn_print": isbn_print.contents[0] if isbn_print else "",
        "isbn_electronic": isbn_elec.contents[0] if isbn_elec else "",
    }
    models.BookLink.objects.get_or_create(
        article=article,
        doi=doi,
        object_type="book",
        defaults=defaults,
    )
    print("[ok]")


class Command(BaseCommand):
    """
    Pulls forward links from Crossref.
    """

    help = "Pulls forward links and creates altmetrics."

    def add_arguments(self, parser):
        """Adds arguments to Django's management command-line parser.

        :param parser: the parser to which the required arguments will be added
        :return: None
        """
        parser.add_argument("journal_code", nargs="?")
        parser.add_argument("date", default="2000-01-01", nargs="?")

    def handle(self, *args, **options):
        """Pulls forward links

        :param args: None
        :param options: None
        :return: None
        """
        date = options.get("date", "2000-01-01")
        journal_code = options.get("journal_code", None)

        if journal_code:
            journals = jm.Journal.objects.filter(code=journal_code)
        else:
            journals = jm.Journal.objects.all()

        for journal in journals:
            use_crossref = setting_handler.get_setting(
                "Identifiers",
                "use_crossref",
                journal,
            ).processed_value

            if use_crossref:
                usr = setting_handler.get_setting(
                    "Identifiers",
                    "crossref_username",
                    journal,
                ).value
                pwd = setting_handler.get_setting(
                    "Identifiers",
                    "crossref_password",
                    journal,
                ).value
                doi = setting_handler.get_setting(
                    "Identifiers",
                    "crossref_prefix",
                    journal,
                ).value

                payload = {
                    "usr": usr,
                    "pwd": pwd,
                    "doi": doi,
                    "startDate": date,
                }

                url = "https://doi.crossref.org/servlet/getForwardLinks?{}".format(
                    urlencode(payload)
                )

                print(url)

                print("Making request.", end="... ")
                r = requests.get(url)
                print("[ok]")

                print("Souping response", end="... ")
                soup = BeautifulSoup(r.text, "lxml")
                print("[ok]")

                print("Finding forward links", end="... ")
                forward_links = soup.find_all("forward_link")
                print("[ok]")

                print("Looping through links", end="... ")
                for link in forward_links:
                    type = link.doi.get("type")
                    doi = link.get("doi")

                    article = sm.Article.get_article(
                        journal,
                        "doi",
                        doi,
                    )

                    if article:
                        if type == "journal_article":
                            process_article(link, article)
                        elif type == "book_content":
                            process_book(link, article)
                        else:
                            print("Forward link type {} not supported".format(type))
                    else:
                        print("Article with doi {} not found.".format(doi))

                print(len(forward_links))