#!/usr/bin/env python3
"""
Functions for information retrieval of articles from the ACS journal JCIM

"""

__author__ = "Florian Jochens"
__email__ = "fj@andaco.de"
__status__ = "Production"
#__copyright__ = ""
#__credits__ = ["", "", "", ""]
#__license__ = ""
#__version__ = ""
#__maintainer__ = ""

from bs4 import BeautifulSoup as bs
import requests as req
import sys  
from pathlib import Path

class Publication:
    #_registry = []
    _citations = []
    
    def __init__(self, title, publication_date, contributors, doi_url, 
                 subjects, num_citations):
        #self._registry.append(self)
        self.title = title
        self.publication_date = publication_date
        self.contributors = contributors
        self.doi_url = doi_url
        self.subjects = subjects
        self.num_citations = num_citations

class Citation:
    def __init__(self, title, journal, contributors, doi_url):
        self.title = title
        self.journal = journal
        self.contributors = contributors
        self.doi_url = doi_url

def get_article_info(soup):
    header = soup.find('div', class_ = 'article_header-left pull-left')
    article_title = header.find('span', class_ = 'hlFld-Title').text
    publication_date = header.find('span', class_ = 'pub-date-value').text
    for link in header.find('div', class_ = 'article_header-doiurl'):
        doi_url = link.get('href')
    subs = header.find('div', class_ = 'article_header-taxonomy')
    subjects = []
    for sub in subs.find_all('a'):
        subjects.append(sub.get('title'))
    cons = header.find('ul', class_ = 'loa')
    contributors = []
    for con in cons.find_all('span', class_ = 'hlFld-ContribAuthor'):
        contributors.append(con.text)
    numc = header.find('div', class_ = 'articleMetrics_count')
    if not numc.a:
        num_citations = 0
    else:
        num_citations = numc.a.text

    pub = Publication(article_title, publication_date, contributors, doi_url,
                      subjects, num_citations)
    return pub

def get_download_url():
    export = soup.find('div', class_ = 'cit-download-dropdown_content')
    url = 'https://pubs.acs.org'
    for link in export.find_all('a'):
        if link.get('title') == 'Citation and references':
            url += link.get('href')     
    print(url)
    return url

def download(url): # Download citation and references file
    if url.find('='):
        filename = url.rsplit('=', 1)[1]
    path = Path(('./files/' + filename))
    if path.is_file():
        print("File already exists")
    else:
        print("File does not exist")

def get_citation_info(pub, num_citations, soup):
    pub._citations = []
    details = soup.find('ol', class_ = 'cited-content_cbyCitation')
    titles = [] 
    for title in details.find_all('span', 
            class_ = 'cited-content_cbyCitation_article-title'):
        titles.append(title.text.replace('.', ''))
    journal_names = []
    for name in details.find_all('span',
            class_ = 'cited-content_cbyCitation_journal-name'):
        journal_names.append(name.text)
    doi_urls = []
    for url in details.find_all('a'):
        doi_urls.append(url.get('href'))
    contributors = []
    for contrib in details.find_all('span', 
            class_ = 'cited-content_cbyCitation_article-contributors'):
        contributors.append(contrib.text)
    for i in range(0, int(num_citations)):
        pub._citations.append(Citation(titles[i], journal_names[i], 
                              contributors[i], doi_urls[i]))
def print_pub_info(pub):
    print(f'''Article title:    {pub.title}
Publication date: {pub.publication_date}
DOI-URL:          {pub.doi_url}

Subjects:''')
    print(*(pub.subjects), sep = ", ")
    print('\nContributors:')
    print(*(pub.contributors), sep = ", ")

    if int(pub.num_citations) > 0:
        if int(pub.num_citations) == 1:
            print(f'\nThis publication is cited by the following publication:\n')
        else:
            print(f'\nThis publication is cited by the following {pub.num_citations} publications:\n')
        for citation in pub._citations:
            print(f'''
    Title:        {citation.title}
    Journal:      {citation.journal}
    Contributors: {citation.contributors}
    DOI-URL:      {citation.doi_url}
            ''')
    else:
        print('\nThis publication is not cited by any other publication.')

def input(url):
    html_text = req.get(url).text
    soup = bs(html_text, 'html.parser')
    
    pub = get_article_info(soup)
    if int(pub.num_citations) > 0:
        get_citation_info(pub, int(pub.num_citations), soup)
    return pub

#if len(sys.argv) != 2:
#    sys.stderr.write('Usage: {} <url>\n'.format(sys.argv[0]))
#    exit(1)
#url = sys.argv[1]
#pub = input(url)
#print_pub_info(pub)