import logging
import re
from datetime import datetime

import portal.base
from portal.base import UploadHandler
from portal.model import UploadSolar


VALID_PROGRAMS = {'OS', 'SSG', 'MGP', 'ZG', 'NPI', 'SPI', 'SSI', 'PTI'}
VALID_SUBJECTS = {'slo', 'drug-jez', 'drug-druz', 'drug-narav', 'drug-strok', 'drug-izb'}
VALID_TEXT_TYPES = {'esej-spis', 'prakticno', 'solski-test', 'delo-v-razredu'}
VALID_GRAMMAR_CORRECTIONS = {'popr-ne', 'brez-popr', 'popr-da'}

MAXLEN_FORM = 150


class UploadHandlerSolar(UploadHandler):

    @staticmethod
    def store_metadata(upload_metadata, user_id):
        timestamp = datetime.fromtimestamp(upload_metadata['timestamp'])
        form_data = upload_metadata['form_data']
        file_hashes = upload_metadata['file_hashes_dict']
        sorted_f_hashes = list(file_hashes.values())
        sorted_f_hashes.sort()

        institution_id = UploadHandler.get_user_institution(user_id)

        try:
            model_obj = UploadSolar(
                        upload_user = user_id,
                        institution = institution_id,
                        upload_hash=upload_metadata['upload_id'],
                        timestamp=timestamp,
                        program=form_data['program'],
                        subject=form_data['predmet'],
                        subject_custom=form_data['predmet-custom'],
                        grade=form_data['letnik'],
                        text_type=form_data['vrsta'],
                        text_type_custom=form_data['vrsta-custom'],
                        school_year=form_data['solsko-leto'],
                        grammar_corrections=form_data['jezikovni-popravki'],
                        upload_file_hashes=sorted_f_hashes
                   )
            db.session.add(model_obj)
            db.session.commit()
        except Exception:
            traceback.print_exc()

    def handle_upload(self, request, user_id):
        err = portal.base.check_upload_request(request, self)
        if err:
            return err, 400

        err = self.check_form(request.form)
        if err:
            return err, 400

        # Parse request.
        upload_metadata = self.extract_upload_metadata('solar', request)

        logging.info('Upload from user "{}" with upload id "{}" supplied form data: {}'.format(
            user_id,
            upload_metadata['upload_id'],
            str(upload_metadata['form_data']
        )))

        # Store uploaded files to disk.
        self.store_datafiles(request.files, upload_metadata)

        # Store to database.
        self.store_metadata(upload_metadata, user_id)

        return 'Uspešno ste oddali datotek(e). Št. datotek: {}'.format(len(request.files))

    @staticmethod
    def check_form(form):
        program = form['program']
        predmet = form['predmet']
        letnik = int(form['letnik'])
        vrsta = form['vrsta']
        solsko_leto = form['solsko-leto']
        jezikovni_popravki = form['jezikovni-popravki']

        if program not in VALID_PROGRAMS:
            return 'Invalid program "{}"'.format(program)
        if predmet not in VALID_SUBJECTS:
            return 'Invalid subject "{}"'.format(premdet)
        if letnik < 1 or letnik > 9:
            return 'Invalid grade: {}'.format(letnik)
        if vrsta not in VALID_TEXT_TYPES:
            return 'Invalid text type "{}"'.format(vrsta)
        if not re.match('^\d{0,2}-\d{0,2}$', solsko_leto):
            return 'Invalid school year "{}"'.format(solsko_leto)
        if jezikovni_popravki not in VALID_GRAMMAR_CORRECTIONS:
            return 'Invalid text type "{}"'.format(jezikovni_popravki)

        for key, val in form.items():
            if len(val) > MAXLEN_FORM:
                return 'Value in form field "{}" exceeds max len of {}'.format(key, MAXLEN_FORM)