import logging
import os
import re
import configparser
from pathlib import Path
from werkzeug.security import check_password_hash

from flask import Flask, render_template, request, redirect, flash, safe_join, send_file
from flask_dropzone import Dropzone
from flask_migrate import Migrate, MigrateCommand
from flask_script import Manager
from flask_login import LoginManager, login_required, login_user, current_user, logout_user
from portal.model import db, RegisteredUser

import portal.base
import portal.solar
import portal.regular
import portal.predavanja


# TODO: Implement user registration.
# TODO: Integrate Shibboleth login.



# TODO: make logging level configurable
logging.basicConfig(level=logging.DEBUG, format='[APP LOGGER] %(asctime)s %(levelname)s: %(message)s')

######################
# Load configuration #
######################
config = configparser.ConfigParser()
config.read('config.ini')
config = config['DEFAULT']

MAIL_HOST = config['MAIL_HOST'] 
MAIL_LOGIN = config['MAIL_LOGIN']
MAIL_PASS = config['MAIL_PASS']
APP_SECRET_KEY = bytes.fromhex(config['APP_SECRET_KEY'])
SMTP_PORT = int(config['SMTP_PORT'])
IMAP_PORT = int(config['IMAP_PORT'])
MAX_UPLOAD_SIZE = int(config['MAX_UPLOAD_SIZE']) # Bytes
MAX_FILES_PER_UPLOAD = int(config['MAX_FILES_PER_UPLOAD'])
CONTRACT_CLIENT_CONTACT = config['CONTRACT_CLIENT_CONTACT']
MAIL_SUBJECT = config['MAIL_SUBJECT']
MAIL_BODY = config['MAIL_BODY']
MAIL_SUBJECT_PREDAVANJA = config['MAIL_SUBJECT_PREDAVANJA']
MAIL_BODY_PREDAVANJA = config['MAIL_BODY_PREDAVANJA']
SQL_CONN_STR = config['SQL_CONN_STR']
DESC_PREVODI = config['DESC_PREVODI']
DESC_GIGAFIDA = config['DESC_GIGAFIDA']
DESC_PREDAVANJA = config['DESC_PREDAVANJA']

if 'UPLOADS_DIR' in config:
    UPLOADS_DIR = Path(config['UPLOADS_DIR'])
else:
    UPLOADS_DIR = Path(__file__).resolve().parent / 'uploads'
if not UPLOADS_DIR.exists:
    UPLOADS_DIR.mkdir(parents=True)

# Override configs with environment variables, if set
if 'PORTALDS4DS1_MAIL_HOST' in os.environ:
    MAIL_HOST = os.environ['PORTALDS4DS1_MAIL_HOST']
if 'PORTALDS4DS1_MAIL_LOGIN' in os.environ:
    MAIL_LOGIN = os.environ['PORTALDS4DS1_MAIL_LOGIN']
if 'PORTALDS4DS1_MAIL_PASS' in os.environ:
    MAIL_PASS = os.environ['PORTALDS4DS1_MAIL_PASS']
if 'PORTALDS4DS1_APP_SECRET_KEY' in os.environ:
    APP_SECRET_KEY = bytes.fromhex(os.environ['PORTALDS4DS1_APP_SECRET_KEY'])
if 'PORTALDS4DS1_SMTP_PORT' in os.environ:
    SMTP_PORT = int(os.environ['PORTALDS4DS1_SMTP_PORT'])
if 'PORTALDS4DS1_IMAP_PORT' in os.environ:
    IMAP_PORT = int(os.environ['PORTALDS4DS1_IMAP_PORT'])
if 'PORTALDS4DS1_MAX_UPLOAD_SIZE' in os.environ:
    MAX_UPLOAD_SIZE = int(os.environ['PORTALDS4DS1_MAX_UPLOAD_SIZE'])
if 'PORTALDS4DS1_MAX_FILES_PER_UPLOAD' in os.environ:
    MAX_FILES_PER_UPLOAD = int(os.environ['PORTALDS4DS1_MAX_FILES_PER_UPLOAD'])
if 'PORTALDS4DS1_CONTRACT_CLIENT_CONTACT' in os.environ:
    CONTRACT_CLIENT_CONTACT = os.environ['PORTALDS4DS1_CONTRACT_CLIENT_CONTACT']
if 'PORTALDS4DS1_UPLOADS_DIR' in os.environ:
    UPLOADS_DIR = os.environ['PORTALDS4DS1_UPLOADS_DIR']
if 'PORTALDS4DS1_MAIL_SUBJECT' in os.environ:
    MAIL_SUBJECT = os.environ['PORTALDS4DS1_MAIL_SUBJECT']
if 'PORTALDS4DS1_MAIL_BODY' in os.environ:
    MAIL_BODY = os.environ['PORTALDS4DS1_MAIL_BODY']
if 'PORTALDS4DS1_MAIL_SUBJECT_PREDAVANJA' in os.environ:
    MAIL_SUBJECT_PREDAVANJA = os.environ['PORTALDS4DS1_MAIL_SUBJECT_PREDAVANJA']
if 'PORTALDS4DS1_MAIL_BODY_PREDAVANJA' in os.environ:
    MAIL_BODY_PREDAVANJA = os.environ['PORTALDS4DS1_MAIL_BODY_PREDAVANJA']
if 'PORTALDS4DS1_SQL_CONN_STR' in os.environ:
    SQL_CONN_STR = os.environ['PORTALDS4DS1_SQL_CONN_STR']
if 'PORTALDS4DS1_DESC_PREVODI' in os.environ:
    DESC_PREVODI = os.environ['PORTALDS4DS1_DESC_PREVODI']
if 'PORTALDS4DS1_DESC_GIGAFIDA' in os.environ:
    DESC_GIGAFIDA = os.environ['PORTALDS4DS1_DESC_GIGAFIDA']

ENABLED_CORPUSES = ['prevodi', 'gigafida', 'solar', 'predavanja']
CORPUSES_LOGIN_REQUIRED = ['solar']


######################

app = Flask(__name__)

app.config.update(
    SECRET_KEY = APP_SECRET_KEY,
    UPLOADED_PATH = UPLOADS_DIR,
    MAX_CONTENT_LENGTH = MAX_UPLOAD_SIZE,
    TEMPLATES_AUTO_RELOAD = True,
    SQLALCHEMY_DATABASE_URI = SQL_CONN_STR,
    SQLALCHEMY_ECHO = True
)
app.url_map.strict_slashes = False

# Run "python app.py db -?" to see more info about DB migrations.
manager = Manager(app)
db.init_app(app)
migrate = Migrate(app, db)
manager.add_command('db', MigrateCommand)

# Set up dropzone.js to serve all the stuff for "file dropping" on the web interface.
dropzone = Dropzone(app)

upload_handler_regular = portal.regular.UploadHandlerRegular(
        UPLOADS_DIR=UPLOADS_DIR,
        MAIL_HOST=MAIL_HOST,
        MAIL_LOGIN=MAIL_LOGIN,
        MAIL_PASS=MAIL_PASS,
        SMTP_PORT=SMTP_PORT,
        IMAP_PORT=IMAP_PORT,
        MAIL_SUBJECT=MAIL_SUBJECT,
        MAIL_BODY=MAIL_BODY,
        CONTRACT_CLIENT_CONTACT=CONTRACT_CLIENT_CONTACT,
        MAX_FILES_PER_UPLOAD=MAX_FILES_PER_UPLOAD
        )

upload_handler_solar = portal.solar.UploadHandlerSolar(
        UPLOADS_DIR=UPLOADS_DIR,
        MAIL_HOST=MAIL_HOST,
        MAIL_LOGIN=MAIL_LOGIN,
        MAIL_PASS=MAIL_PASS,
        SMTP_PORT=SMTP_PORT,
        IMAP_PORT=IMAP_PORT,
        MAIL_SUBJECT=MAIL_SUBJECT,
        MAIL_BODY=MAIL_BODY,
        CONTRACT_CLIENT_CONTACT=CONTRACT_CLIENT_CONTACT,
        MAX_FILES_PER_UPLOAD=MAX_FILES_PER_UPLOAD
        )

upload_handler_predavanja = portal.predavanja.UploadHandlerPredavanja(
        UPLOADS_DIR=UPLOADS_DIR,
        MAIL_HOST=MAIL_HOST,
        MAIL_LOGIN=MAIL_LOGIN,
        MAIL_PASS=MAIL_PASS,
        SMTP_PORT=SMTP_PORT,
        IMAP_PORT=IMAP_PORT,
        MAIL_SUBJECT=MAIL_SUBJECT_PREDAVANJA,
        MAIL_BODY=MAIL_BODY_PREDAVANJA,
        CONTRACT_CLIENT_CONTACT=CONTRACT_CLIENT_CONTACT,
        MAX_FILES_PER_UPLOAD=MAX_FILES_PER_UPLOAD
        )


# Use flask-login to manage user sessions where they are required.
login_manager = LoginManager(app)
login_manager.init_app(app)


@app.route('/')
def index():
    return render_template('index.html')


@app.route('/<corpus_name>')
def index_corpus(corpus_name):
    if corpus_name not in ENABLED_CORPUSES:
        return 'Korpus "{}" ne obstaja.'.format(corpus_name), 404

    if corpus_name == 'prevodi':
        description = DESC_PREVODI
    elif corpus_name == 'gigafida':
        description = DESC_GIGAFIDA
    elif corpus_name == 'predavanja':
        return render_template('basic-predavanja.html', description=DESC_PREDAVANJA, max_files=MAX_FILES_PER_UPLOAD)
    elif corpus_name == 'solar':
        if current_user.is_authenticated:
            return redirect('/solar/oddaja')
        return redirect('/solar/login')

    return render_template('basic.html', 
            corpus_name=corpus_name, description=description, max_files=MAX_FILES_PER_UPLOAD)


@login_manager.user_loader
def load_user(user_id):
    user = RegisteredUser.query.get(int(user_id))
    return user


@app.route('/solar/login')
def login_get():
    return render_template('login.html', corpus_name='solar', title='ŠOLAR')


@app.route('/<corpus_name>/login', methods=['POST'])
def login_post(corpus_name):
    if corpus_name not in ENABLED_CORPUSES or corpus_name not in CORPUSES_LOGIN_REQUIRED:
        return '', 404

    email = request.form.get('email')
    password = request.form.get('password')
    remember = True if request.form.get('remember') else False

    user = RegisteredUser.query.filter_by(email=email).first()

    if not user or not check_password_hash(user.pass_hash, password):
        flash('Napačni podatki za prijavo. Poskusite ponovno.')
        return redirect('/{}/login'.format(corpus_name))

    if not user.active:
        flash('Vaš uporabniški račun še ni bil aktiviran.')
        return redirect('/{}/login'.format(corpus_name))

    # Check if user is authorized to log into this corpus. Admins are an exception.
    if not portal.base.has_user_corpus_access(user.id, corpus_name):
        flash('Nimate dostopa do tega korpusa.')
        return redirect('/{}/login'.format(corpus_name))

    #portal.base.add_user_session(user.id)
    login_user(user, remember=remember)

    if corpus_name == 'solar':
        return redirect('/solar/oddaja')
    return '', 404


# TODO: Move solar stuff to seperate file using Flask blueprints.
# TODO: Better routing logic.

@app.route('/solar/logout')
@login_required
def logout():
    logout_user()
    return redirect('/solar/login')


@app.route('/solar/<path:text>')
@login_required
def solar(text):
    if not portal.base.has_user_corpus_access(current_user.id, 'solar'):
        return '', 404
    if text.startswith('oddaja/') or text == 'oddaja':
        return render_template('solar-oddaja.html')
    elif text.startswith('zgodovina/') or text == 'zgodovina':
        upload_items = portal.solar.get_upload_history(current_user.id)
        uploader_names = []
        institution_names = []
        for item in upload_items:
            uploader_names.append(portal.base.get_user_obj(current_user.id).name)
            institution = portal.base.get_institution_obj(item.institution)
            if not institution:
                institution_names.append(None)
            else:
                institution_names.append(institution.name)
        return render_template('solar-zgodovina.html', upload_history=upload_items, uploader_names=uploader_names,
                institution_names=institution_names)
    elif text.startswith('pogodbe/') or text == 'pogodbe':
        # Check for ownload contract request.
        match = re.match('^pogodbe/([a-z0-9_]+\.pdf)$', text)
        if match:
            filename = match.group(1)
            if len(filename) < 10:
                return '', 404
            prefix = filename[:2]
            suffix = filename[2:]

            safe_path = safe_join(str(upload_handler_solar.get_uploads_subdir('contracts')), prefix, suffix)
            try:
                return send_file(safe_path, as_attachment=True)
            except FileNotFoundError:
                return '', 404

        user_obj = portal.base.get_user_obj(current_user.get_id())
        institutions = portal.base.get_user_institutions(user_obj.id)
        contracts_students = []
        contract_school = []
        enable_upload_school_contract = False
        show_upload_form = False
        if len(institutions) > 0:
            show_upload_form = True
            institution = portal.base.get_user_institutions(user_obj.id)[0]
            contracts_students = portal.solar.get_institution_student_contracts(institution.id)
            contract_school = portal.solar.get_institution_contract(institution.id)

            if portal.base.is_institution_moderator(user_obj.id, institution.id):
                enable_upload_school_contract = True

        return render_template('solar-pogodbe.html', contracts_students=contracts_students,
                contract_school=contract_school, 
                enable_upload_school_contract=enable_upload_school_contract,
                show_upload_form=show_upload_form)
    elif text.startswith('admin/') or text == 'admin':
        solar_users = portal.base.get_all_active_users()
        solar_institutions = portal.solar.get_all_institutions()
        if current_user.role == 'admin':
            return render_template('solar-admin.html', users=solar_users, institutions=solar_institutions)
    return '', 404

@app.route('/solar/pogodbe', methods=['POST'])
@login_required
def solar_upload_contract():
    if not portal.base.has_user_corpus_access(current_user.id, 'solar'):
        return '', 404

    return upload_handler_solar.handle_contract_upload(request, current_user.get_id())


@app.route('/<corpus_name>/adduser', methods=['POST'])
@login_required
def solar_add_user(corpus_name):
    if not portal.base.is_admin(current_user.id):
        return '', 404
    if not corpus_name in ENABLED_CORPUSES:
        return '', 404

    name = request.form['name']
    email = request.form['email']
    password = request.form['password']

    if not name:
        return 'Prazno polje za ime.'
    if len(name) > 100:
        return 'Predolgo ime.'

    if not email:
        return 'Prazno polje za elektronsko pošto.'
    if len(email) > 100:
        return 'Predolgi email naslov'
    elif not re.search(portal.base.REGEX_EMAIL, email):
        return 'Email napačnega formata.'

    if not password:
        return 'Prazno polje za geslo.'
    if len(password) > 100:
        return 'Predolgo geslo.'

    portal.base.register_new_user(name, email, password)

    return 'Uporabnik je bil dodan.'


@app.route('/solar/deluser', methods=['POST'])
@login_required
def solar_del_user():
    # TODO: check if user is institution moderator for the added users institution or is an admin
    # TODO: delete from "user", "user_institution_mapping", update "institution_contract" set user to NULL
    return '', 404

@app.route('/<corpus_name>/addinstitution', methods=['POST'])
@login_required
def add_institution(corpus_name):
    if not portal.base.is_admin(current_user.id):
        return '', 404
    if not corpus_name in ENABLED_CORPUSES:
        return '', 404

    name = request.form['name']
    region = request.form['region']

    if not name:
        return 'Prazno polje za ime.'
    if len(name) > 100:
        return 'Predolgo ime.'

    if not region:
        return 'Prazno polje za regijo.'
    if len(region) > 100:
        return 'Predolgi niz za regijo.'

    institution_id = portal.base.add_institution(name, region)
    portal.base.grant_institution_corpus_access(institution_id, corpus_name)
    return 'Institucija je bila dodana.'

@app.route('/<corpus_name>/addusertoinstitution', methods=['POST'])
@login_required
def add_user_institution_mapping(corpus_name):
    if not portal.base.is_admin(current_user.id):
        return '', 404
    if not corpus_name in ENABLED_CORPUSES:
        return '', 404

    user_id = request.form['user_id']
    institution_id = request.form['institution_id']
    role = request.form['role']
    if role not in ['moderator', 'user']:
        return '', 404

    # TODO: remove this restriction
    if len(portal.base.get_user_institutions(user_id)) > 0:
        return 'Uporabnik je že dodeljen instituciji. Dodeljevanje večim institucijam '\
                'zaenkrat ni implementirano.'

    portal.base.add_user_to_institution(user_id, institution_id, role)
    return 'Uporabnik je bil dodeljen instituciji.'

@app.route('/<corpus_name>/delinstitution', methods=['POST'])
@login_required
def del_institution(corpus_name):
    # TODO: check if valid corpus_name
    # TODO: check if user is admin
    # TODO: delete cascade - institution, user_institution_mapping, corpus_access, institution_contract
    return '', 404


@app.route('/<corpus_name>/upload', methods=['POST'])
def handle_upload(corpus_name):
    if corpus_name not in ENABLED_CORPUSES:
        return '', 404
    
    if corpus_name == 'solar':
        if not current_user.is_authenticated:
            return '', 404
        if not portal.base.has_user_corpus_access(current_user.id, corpus_name):
            return '', 404
        return upload_handler_solar.handle_upload(request, current_user.get_id())
    elif corpus_name == 'predavanja':
        return upload_handler_predavanja.handle_upload(request)
    else:
        return upload_handler_regular.handle_upload(request, corpus_name)


if __name__ == '__main__':
    app.run(debug=True)