# -*- coding: utf-8 -*-

#  This file is part of the Calibre-Web (https://github.com/janeczku/calibre-web)
#    Copyright (C) 2020 pwr
#
#  This program is free software: you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program. If not, see <http://www.gnu.org/licenses/>.

import os
import re
from glob import glob
from shutil import copyfile
from markupsafe import escape

from sqlalchemy.exc import SQLAlchemyError
from flask_babel import lazy_gettext as N_

from cps.services.worker import CalibreTask
from cps import db
from cps import logger, config
from cps.subproc_wrapper import process_open
from flask_babel import gettext as _
from cps.kobo_sync_status import remove_synced_book
from cps.ub import init_db_thread

from cps.tasks.mail import TaskEmail
from cps import gdriveutils


log = logger.create()


class TaskConvert(CalibreTask):
    def __init__(self, file_path, book_id, task_message, settings, ereader_mail, user=None):
        super(TaskConvert, self).__init__(task_message)
        self.file_path = file_path
        self.book_id = book_id
        self.title = ""
        self.settings = settings
        self.ereader_mail = ereader_mail
        self.user = user

        self.results = dict()

    def run(self, worker_thread):
        self.worker_thread = worker_thread
        if config.config_use_google_drive:
            worker_db = db.CalibreDB(expire_on_commit=False, init=True)
            cur_book = worker_db.get_book(self.book_id)
            self.title = cur_book.title
            data = worker_db.get_book_format(self.book_id, self.settings['old_book_format'])
            df = gdriveutils.getFileFromEbooksFolder(cur_book.path,
                                                     data.name + "." + self.settings['old_book_format'].lower())
            if df:
                datafile = os.path.join(config.config_calibre_dir,
                                        cur_book.path,
                                        data.name + u"." + self.settings['old_book_format'].lower())
                if not os.path.exists(os.path.join(config.config_calibre_dir, cur_book.path)):
                    os.makedirs(os.path.join(config.config_calibre_dir, cur_book.path))
                df.GetContentFile(datafile)
                worker_db.session.close()
            else:
                error_message = _("%(format)s not found on Google Drive: %(fn)s",
                                  format=self.settings['old_book_format'],
                                  fn=data.name + "." + self.settings['old_book_format'].lower())
                worker_db.session.close()
                return error_message

        filename = self._convert_ebook_format()
        if config.config_use_google_drive:
            os.remove(self.file_path + u'.' + self.settings['old_book_format'].lower())

        if filename:
            if config.config_use_google_drive:
                # Upload files to gdrive
                gdriveutils.updateGdriveCalibreFromLocal()
                self._handleSuccess()
            if self.ereader_mail:
                # if we're sending to E-Reader after converting, create a one-off task and run it immediately
                # todo: figure out how to incorporate this into the progress
                try:
                    EmailText = N_("%(book)s send to E-Reader", book=escape(self.title))
                    worker_thread.add(self.user, TaskEmail(self.settings['subject'],
                                                           self.results["path"],
                                                           filename,
                                                           self.settings,
                                                           self.ereader_mail,
                                                           EmailText,
                                                           self.settings['body'],
                                                           internal=True)
                                      )
                except Exception as ex:
                    return self._handleError(str(ex))

    def _convert_ebook_format(self):
        error_message = None
        local_db = db.CalibreDB(expire_on_commit=False, init=True)
        file_path = self.file_path
        book_id = self.book_id
        format_old_ext = u'.' + self.settings['old_book_format'].lower()
        format_new_ext = u'.' + self.settings['new_book_format'].lower()

        # check to see if destination format already exists - or if book is in database
        # if it does - mark the conversion task as complete and return a success
        # this will allow send to E-Reader workflow to continue to work
        if os.path.isfile(file_path + format_new_ext) or\
                local_db.get_book_format(self.book_id, self.settings['new_book_format']):
            log.info("Book id %d already converted to %s", book_id, format_new_ext)
            cur_book = local_db.get_book(book_id)
            self.title = cur_book.title
            self.results['path'] = cur_book.path
            self.results['title'] = self.title
            new_format = local_db.session.query(db.Data).filter(db.Data.book == book_id)\
                .filter(db.Data.format == self.settings['new_book_format'].upper()).one_or_none()
            if not new_format:
                new_format = db.Data(name=os.path.basename(file_path),
                                     book_format=self.settings['new_book_format'].upper(),
                                     book=book_id, uncompressed_size=os.path.getsize(file_path + format_new_ext))
                try:
                    local_db.session.merge(new_format)
                    local_db.session.commit()
                except SQLAlchemyError as e:
                    local_db.session.rollback()
                    log.error("Database error: %s", e)
                    local_db.session.close()
                    self._handleError(N_("Oops! Database Error: %(error)s.", error=e))
                    return
                self._handleSuccess()
                local_db.session.close()
                return os.path.basename(file_path + format_new_ext)
        else:
            log.info("Book id %d - target format of %s does not exist. Moving forward with convert.",
                     book_id,
                     format_new_ext)

        if config.config_kepubifypath and format_old_ext == '.epub' and format_new_ext == '.kepub':
            check, error_message = self._convert_kepubify(file_path,
                                                          format_old_ext,
                                                          format_new_ext)
        else:
            # check if calibre converter-executable is existing
            if not os.path.exists(config.config_converterpath):
                self._handleError(N_("Calibre ebook-convert %(tool)s not found", tool=config.config_converterpath))
                return
            check, error_message = self._convert_calibre(file_path, format_old_ext, format_new_ext)

        if check == 0:
            cur_book = local_db.get_book(book_id)
            if os.path.isfile(file_path + format_new_ext):
                new_format = local_db.session.query(db.Data).filter(db.Data.book == book_id) \
                    .filter(db.Data.format == self.settings['new_book_format'].upper()).one_or_none()
                if not new_format:
                    new_format = db.Data(name=cur_book.data[0].name,
                                         book_format=self.settings['new_book_format'].upper(),
                                         book=book_id, uncompressed_size=os.path.getsize(file_path + format_new_ext))
                    try:
                        local_db.session.merge(new_format)
                        local_db.session.commit()
                        if self.settings['new_book_format'].upper() in ['KEPUB', 'EPUB', 'EPUB3']:
                            ub_session = init_db_thread()
                            remove_synced_book(book_id, True, ub_session)
                            ub_session.close()
                    except SQLAlchemyError as e:
                        local_db.session.rollback()
                        log.error("Database error: %s", e)
                        local_db.session.close()
                        self._handleError(error_message)
                        return
                self.results['path'] = cur_book.path
                self.title = cur_book.title
                self.results['title'] = self.title
                if not config.config_use_google_drive:
                    self._handleSuccess()
                return os.path.basename(file_path + format_new_ext)
            else:
                error_message = N_('%(format)s format not found on disk', format=format_new_ext.upper())
        local_db.session.close()
        log.info("ebook converter failed with error while converting book")
        if not error_message:
            error_message = N_('Ebook converter failed with unknown error')
        else:
            log.error(error_message)
        self._handleError(error_message)
        return

    def _convert_kepubify(self, file_path, format_old_ext, format_new_ext):
        quotes = [1, 3]
        command = [config.config_kepubifypath, (file_path + format_old_ext), '-o', os.path.dirname(file_path)]
        try:
            p = process_open(command, quotes)
        except OSError as e:
            return 1, N_("Kepubify-converter failed: %(error)s", error=e)
        self.progress = 0.01
        while True:
            nextline = p.stdout.readlines()
            nextline = [x.strip('\n') for x in nextline if x != '\n']
            for line in nextline:
                log.debug(line)
            if p.poll() is not None:
                break

        # ToD Handle
        # process returncode
        check = p.returncode

        # move file
        if check == 0:
            converted_file = glob(os.path.join(os.path.dirname(file_path), "*.kepub.epub"))
            if len(converted_file) == 1:
                copyfile(converted_file[0], (file_path + format_new_ext))
                os.unlink(converted_file[0])
            else:
                return 1, N_("Converted file not found or more than one file in folder %(folder)s",
                            folder=os.path.dirname(file_path))
        return check, None

    def _convert_calibre(self, file_path, format_old_ext, format_new_ext):
        try:
            # Linux py2.7 encode as list without quotes no empty element for parameters
            # linux py3.x no encode and as list without quotes no empty element for parameters
            # windows py2.7 encode as string with quotes empty element for parameters is okay
            # windows py 3.x no encode and as string with quotes empty element for parameters is okay
            # separate handling for windows and linux
            quotes = [1, 2]
            command = [config.config_converterpath, (file_path + format_old_ext),
                       (file_path + format_new_ext)]
            quotes_index = 3
            if config.config_calibre:
                parameters = config.config_calibre.split(" ")
                for param in parameters:
                    command.append(param)
                    quotes.append(quotes_index)
                    quotes_index += 1

            p = process_open(command, quotes, newlines=False)
        except OSError as e:
            return 1, N_("Ebook-converter failed: %(error)s", error=e)

        while p.poll() is None:
            nextline = p.stdout.readline()
            if isinstance(nextline, bytes):
                nextline = nextline.decode('utf-8', errors="ignore").strip('\r\n')
            if nextline:
                log.debug(nextline)
            # parse progress string from calibre-converter
            progress = re.search(r"(\d+)%\s.*", nextline)
            if progress:
                self.progress = int(progress.group(1)) / 100
                if config.config_use_google_drive:
                    self.progress *= 0.9

        # process returncode
        check = p.returncode
        calibre_traceback = p.stderr.readlines()
        error_message = ""
        for ele in calibre_traceback:
            ele = ele.decode('utf-8', errors="ignore").strip('\n')
            log.debug(ele)
            if not ele.startswith('Traceback') and not ele.startswith('  File'):
                error_message = N_("Calibre failed with error: %(error)s", error=ele)
        return check, error_message

    @property
    def name(self):
        return N_("Convert")

    def __str__(self):
        if self.ereader_mail:
            return "Convert {} {}".format(self.book_id, self.ereader_mail)
        else:
            return "Convert {}".format(self.book_id)

    @property
    def is_cancellable(self):
        return False