#!/usr/bin/env python


__license__   = 'GPL v3'
__copyright__ = '2010, Kovid Goyal <kovid@kovidgoyal.net>'
__docformat__ = 'restructuredtext en'

import os
import socket
import textwrap
import time
from collections import defaultdict
from functools import partial
from itertools import repeat
from threading import Thread

from qt.core import QDialog, QDialogButtonBox, QGridLayout, QIcon, QLabel, QLineEdit, QListWidget, QListWidgetItem, QPushButton, Qt

from calibre.constants import preferred_encoding
from calibre.customize.ui import available_input_formats, available_output_formats
from calibre.ebooks.metadata import authors_to_string
from calibre.gui2 import Dispatcher, config, error_dialog, gprefs, warning_dialog
from calibre.gui2.threaded_jobs import ThreadedJob
from calibre.library.save_to_disk import get_components
from calibre.utils.config import prefs, tweaks
from calibre.utils.icu import primary_sort_key
from calibre.utils.resources import get_image_path as I
from calibre.utils.smtp import compose_mail, extract_email_address, sendmail
from calibre.utils.smtp import config as email_config
from polyglot.binary import from_hex_unicode


class Worker(Thread):

    def __init__(self, func, args):
        Thread.__init__(self)
        self.daemon = True
        self.exception = self.tb = None
        self.func, self.args = func, args

    def run(self):
        # time.sleep(1000)
        try:
            self.func(*self.args)
        except Exception as e:
            import traceback
            self.exception = e
            self.tb = traceback.format_exc()
        finally:
            self.func = self.args = None


class Sendmail:

    MAX_RETRIES = 1
    TIMEOUT = 25 * 60  # seconds

    def __init__(self):
        self.calculate_rate_limit()
        self.last_send_time = time.time() - self.rate_limit

    def calculate_rate_limit(self):
        self.rate_limit = 1
        opts = email_config().parse()
        rh = opts.relay_host
        if rh:
            for suffix in tweaks['public_smtp_relay_host_suffixes']:
                if rh.lower().endswith(suffix):
                    self.rate_limit = tweaks['public_smtp_relay_delay']
                    break

    def __call__(self, attachment, aname, to, subject, text, log=None,
            abort=None, notifications=None):

        try_count = 0
        while True:
            if try_count > 0:
                log(f'\nRetrying in {self.rate_limit} seconds...\n')
            worker = Worker(self.sendmail,
                    (attachment, aname, to, subject, text, log))
            worker.start()
            start_time = time.time()
            while worker.is_alive():
                worker.join(0.2)
                if abort.is_set():
                    log('Sending aborted by user')
                    return
                if time.time() - start_time > self.TIMEOUT:
                    log('Sending timed out')
                    raise Exception(
                            f'Sending email {subject!r} to {to!r} timed out, aborting')
            if worker.exception is None:
                log('Email successfully sent')
                return
            log.error('\nSending failed...\n')
            log.debug(worker.tb)
            try_count += 1
            if try_count > self.MAX_RETRIES:
                raise worker.exception

    def sendmail(self, attachment, aname, to, subject, text, log):
        logged = False
        while time.time() - self.last_send_time <= self.rate_limit:
            if not logged and self.rate_limit > 0:
                log(f'Waiting {self.rate_limit} seconds before sending, to avoid being marked as spam.\nYou can control this delay via Preferences->Tweaks')
                logged = True
            time.sleep(1)
        try:
            opts = email_config().parse()
            from_ = opts.from_
            if not from_:
                from_ = 'calibre <calibre@'+socket.getfqdn()+'>'
            with open(attachment, 'rb') as f:
                msg = compose_mail(from_, to, text, subject, f, aname)
            efrom = extract_email_address(from_)
            eto = []
            for x in to.split(','):
                eto.append(extract_email_address(x.strip()))

            def safe_debug(*args, **kwargs):
                try:
                    return log.debug(*args, **kwargs)
                except Exception:
                    pass

            relay = opts.relay_host
            if relay and relay == 'smtp.live.com':
                # Microsoft changed the SMTP server
                relay = 'smtp-mail.outlook.com'

            sendmail(msg, efrom, eto, localhost=None,
                        verbose=1,
                        relay=relay,
                        username=opts.relay_username,
                        password=from_hex_unicode(opts.relay_password), port=opts.relay_port,
                        encryption=opts.encryption,
                        debug_output=safe_debug)
        finally:
            self.last_send_time = time.time()


gui_sendmail = Sendmail()


def is_for_kindle(to):
    return isinstance(to, str) and ('@kindle.com' in to or '@kindle.cn' in to or '@free.kindle.com' in to or '@free.kindle.cn' in to)


def send_mails(jobnames, callback, attachments, to_s, subjects,
                texts, attachment_names, job_manager):
    for name, attachment, to, subject, text, aname in zip(jobnames,
            attachments, to_s, subjects, texts, attachment_names):
        description = _('Email %(name)s to %(to)s') % dict(name=name, to=to)
        if isinstance(to, str) and (is_for_kindle(to) or '@pbsync.com' in to):
            # The PocketBook service is a total joke. It can't handle
            # non-ascii, filenames that are long enough to be split up, commas, and
            # the good lord alone knows what else. So use a random filename
            # containing only 22 English letters and numbers
            #
            # And since this email is only going to be processed by automated
            # services, make the subject+text random too as at least the amazon
            # service can't handle non-ascii text. I don't know what baboons
            # these companies employ to write their code. It's the height of
            # irony that they are called "tech" companies.
            # https://bugs.launchpad.net/calibre/+bug/1989282
            if not is_for_kindle(to):
                from calibre.utils.short_uuid import uuid4
                # Amazon nowadays reads metadata from attachment filename instead of
                # file internal metadata so don't nuke the filename.
                # https://www.mobileread.com/forums/showthread.php?t=349290
                aname = f'{uuid4()}.' + aname.rpartition('.')[-1]
            from calibre.utils.random_ua import random_english_text
            subject = random_english_text(min_words_per_sentence=3, max_words_per_sentence=9, max_num_sentences=1).rstrip('.')
            text = random_english_text()
        job = ThreadedJob('email', description, gui_sendmail, (attachment, aname, to,
                subject, text), {}, callback)
        job_manager.run_threaded_job(job)


def email_news(mi, remove, get_fmts, done, job_manager):
    opts = email_config().parse()
    accounts = [(account, [x.strip().lower() for x in x[0].split(',')])
            for account, x in opts.accounts.items() if x[1]]
    sent_mails = []
    for i, x in enumerate(accounts):
        account, fmts = x
        files = get_fmts(fmts)
        files = [f for f in files if f is not None]
        if not files:
            continue
        if opts.tags.get(account, False) and not ({t.strip() for t in opts.tags[account].split(',')} & set(mi.tags)):
            continue
        attachment = files[0]
        to_s = [account]
        subjects = [_('News:')+' '+mi.title]
        texts    = [_(
            'Attached is the %s periodical downloaded by calibre.') % (mi.title,)]
        attachment_names = [mi.title+os.path.splitext(attachment)[1]]
        attachments = [attachment]
        jobnames = [mi.title]
        do_remove = []
        if i == len(accounts) - 1:
            do_remove = remove
        send_mails(jobnames,
                Dispatcher(partial(done, remove=do_remove)),
                attachments, to_s, subjects, texts, attachment_names,
                job_manager)
        sent_mails.append(to_s[0])
    return sent_mails


plugboard_email_value = 'email'
plugboard_email_formats = ['epub', 'mobi', 'azw3']


class SelectRecipients(QDialog):  # {{{

    def __init__(self, parent=None):
        QDialog.__init__(self, parent)
        self._layout = l = QGridLayout(self)
        self.setLayout(l)
        self.setWindowIcon(QIcon(I('mail.png')))
        self.setWindowTitle(_('Select recipients'))
        self.recipients = r = QListWidget(self)
        l.addWidget(r, 0, 0, 1, -1)
        self.la = la = QLabel(_('Add a new recipient:'))
        la.setStyleSheet('QLabel { font-weight: bold }')
        l.addWidget(la, l.rowCount(), 0, 1, -1)

        self.labels = tuple(map(QLabel, (
            _('&Address'), _('A&lias'), _('&Formats'), _('&Subject'))))
        tooltips = (
            _('The email address of the recipient'),
            _('The optional alias (simple name) of the recipient'),
            _('Formats to email. The first matching one will be sent (comma separated list)'),
            _('The optional subject for email sent to this recipient'))

        for i, name in enumerate(('address', 'alias', 'formats', 'subject')):
            c = i % 2
            row = l.rowCount() - c
            self.labels[i].setText(str(self.labels[i].text()) + ':')
            l.addWidget(self.labels[i], row, (2*c))
            le = QLineEdit(self)
            le.setToolTip(tooltips[i])
            setattr(self, name, le)
            self.labels[i].setBuddy(le)
            l.addWidget(le, row, (2*c) + 1)
        self.formats.setText(prefs['output_format'].upper())
        self.add_button = b = QPushButton(QIcon(I('plus.png')), _('&Add recipient'), self)
        b.clicked.connect(self.add_recipient)
        l.addWidget(b, l.rowCount(), 0, 1, -1)

        self.bb = bb = QDialogButtonBox(QDialogButtonBox.StandardButton.Ok|QDialogButtonBox.StandardButton.Cancel)
        l.addWidget(bb, l.rowCount(), 0, 1, -1)
        bb.accepted.connect(self.accept)
        bb.rejected.connect(self.reject)
        self.setMinimumWidth(500)
        self.setMinimumHeight(400)
        self.resize(self.sizeHint())
        self.init_list()

    def add_recipient(self):
        to = str(self.address.text()).strip()
        if not to:
            return error_dialog(
                self, _('Need address'), _('You must specify an address'), show=True)
        from email.utils import parseaddr
        if not parseaddr(to)[-1] or '@' not in to:
            return error_dialog(
                self, _('Invalid email address'), _('The address {} is invalid').format(to), show=True)
        formats = ','.join([x.strip().upper() for x in str(self.formats.text()).strip().split(',') if x.strip()])
        if not formats:
            return error_dialog(
                self, _('Need formats'), _('You must specify at least one format to send'), show=True)
        opts = email_config().parse()
        if to in opts.accounts:
            return error_dialog(
                self, _('Already exists'), _('The recipient %s already exists') % to, show=True)
        acc = opts.accounts
        acc[to] = [formats, False, False]
        c = email_config()
        c.set('accounts', acc)
        alias = str(self.alias.text()).strip()
        if alias:
            opts.aliases[to] = alias
            c.set('aliases', opts.aliases)
        subject = str(self.subject.text()).strip()
        if subject:
            opts.subjects[to] = subject
            c.set('subjects', opts.subjects)
        self.create_item(alias or to, to, checked=True)

    def create_item(self, alias, key, checked=False):
        i = QListWidgetItem(alias, self.recipients)
        i.setFlags(Qt.ItemFlag.ItemIsEnabled | Qt.ItemFlag.ItemIsUserCheckable)
        i.setCheckState(Qt.CheckState.Checked if checked else Qt.CheckState.Unchecked)
        i.setData(Qt.ItemDataRole.UserRole, key)
        self.items.append(i)

    def init_list(self):
        opts = email_config().parse()
        self.items = []

        def sk(account):
            return primary_sort_key(opts.aliases.get(account) or account)

        for key in sorted(opts.accounts or (), key=sk):
            self.create_item(opts.aliases.get(key, key), key)

    def accept(self):
        if not self.ans:
            return error_dialog(self, _('No recipients'),
                                _('You must select at least one recipient'), show=True)
        QDialog.accept(self)

    @property
    def ans(self):
        opts = email_config().parse()
        ans = []
        for i in self.items:
            if i.checkState() == Qt.CheckState.Checked:
                to = str(i.data(Qt.ItemDataRole.UserRole) or '')
                fmts = tuple(x.strip().upper() for x in (opts.accounts[to][0] or '').split(','))
                subject = opts.subjects.get(to, '')
                ans.append((to, fmts, subject))
        return ans


def select_recipients(parent=None):
    d = SelectRecipients(parent)
    if d.exec() == QDialog.DialogCode.Accepted:
        return d.ans
    return ()
# }}}


class EmailMixin:  # {{{

    def __init__(self, *args, **kwargs):
        pass

    def send_multiple_by_mail(self, recipients, delete_from_library):
        ids = {self.library_view.model().id(r) for r in self.library_view.selectionModel().selectedRows()}
        if not ids:
            return
        db = self.current_db
        db_fmt_map = {book_id:set((db.formats(book_id, index_is_id=True) or '').upper().split(',')) for book_id in ids}
        ofmts = {x.upper() for x in available_output_formats()}
        ifmts = {x.upper() for x in available_input_formats()}
        bad_recipients = {}
        auto_convert_map = defaultdict(list)

        for to, fmts, subject in recipients:
            rfmts = set(fmts)
            ok_ids = {book_id for book_id, bfmts in db_fmt_map.items() if bfmts.intersection(rfmts)}
            convert_ids = ids - ok_ids
            self.send_by_mail(to, fmts, delete_from_library, subject=subject, send_ids=ok_ids, do_auto_convert=False)
            if not rfmts.intersection(ofmts):
                bad_recipients[to] = (convert_ids, True)
                continue
            outfmt = tuple(f for f in fmts if f in ofmts)[0]
            ok_ids = {book_id for book_id in convert_ids if db_fmt_map[book_id].intersection(ifmts)}
            bad_ids = convert_ids - ok_ids
            if bad_ids:
                bad_recipients[to] = (bad_ids, False)
            if ok_ids:
                auto_convert_map[outfmt].append((to, subject, ok_ids))

        if auto_convert_map:
            titles = {book_id for x in auto_convert_map.values() for data in x for book_id in data[2]}
            titles = {db.title(book_id, index_is_id=True) for book_id in titles}
            if self.auto_convert_question(
                _('Auto convert the following books before sending via email?'), list(titles)):
                for ofmt, data in auto_convert_map.items():
                    ids = {bid for x in data for bid in x[2]}
                    data = [(to, subject) for to, subject, x in data]
                    self.iactions['Convert Books'].auto_convert_multiple_mail(ids, data, ofmt, delete_from_library)

        if bad_recipients:
            det_msg = []
            titles = {book_id for x in bad_recipients.values() for book_id in x[0]}
            titles = {book_id:db.title(book_id, index_is_id=True) for book_id in titles}
            for to, (ids, nooutput) in bad_recipients.items():
                msg = _('This recipient has no valid formats defined') if nooutput else \
                        _('These books have no suitable input formats for conversion')
                det_msg.append(f'{to} - {msg}')
                det_msg.extend('\t' + titles[bid] for bid in ids)
                det_msg.append('\n')
            warning_dialog(self, _('Could not send'),
                           _('Could not send books to some recipients. Click "Show details" for more information'),
                           det_msg='\n'.join(det_msg), show=True)

    def send_by_mail(self, to, fmts, delete_from_library, subject='', send_ids=None,
            do_auto_convert=True, specific_format=None):
        ids = [self.library_view.model().id(r) for r in self.library_view.selectionModel().selectedRows()] if send_ids is None else send_ids
        if not ids or len(ids) == 0:
            return

        modified_metadata = []
        files, _auto_ids = self.library_view.model().get_preferred_formats_from_ids(
            ids, fmts, set_metadata=True, specific_format=specific_format, exclude_auto=do_auto_convert,
            use_plugboard=plugboard_email_value, plugboard_formats=plugboard_email_formats, modified_metadata=modified_metadata)
        if do_auto_convert:
            nids = list(set(ids).difference(_auto_ids))
            ids = [i for i in ids if i in nids]
        else:
            _auto_ids = []

        full_metadata = self.library_view.model().metadata_for(ids,
                get_cover=False)

        bad, remove_ids, jobnames = [], [], []
        texts, subjects, attachments, attachment_names = [], [], [], []
        for f, mi, id, newmi in zip(files, full_metadata, ids, modified_metadata):
            if not newmi:
                newmi = mi
            t = mi.title or _('Unknown')
            if f is None:
                bad.append(t)
            else:
                remove_ids.append(id)
                jobnames.append(t)
                attachments.append(f)
                if not subject:
                    subjects.append(_('E-book:')+ ' '+t)
                else:
                    components = get_components(subject, mi, id)
                    if not components:
                        components = [mi.title]
                    subjects.append(os.path.join(*components))
                a = authors_to_string(mi.authors or [_('Unknown')])
                texts.append(_('Attached, you will find the e-book') +
                        '\n\n' + t + '\n\t' + _('by') + ' ' + a + '\n\n' +
                        _('in the %s format.') %
                        os.path.splitext(f)[1][1:].upper())
                if mi.comments and gprefs['add_comments_to_email']:
                    from calibre.ebooks.metadata import fmt_sidx
                    from calibre.utils.html2text import html2text
                    if mi.series:
                        sidx=fmt_sidx(1.0 if mi.series_index is None else mi.series_index, use_roman=config['use_roman_numerals_for_series_number'])
                        texts[-1] += '\n\n' + _('{series_index} of {series}').format(series_index=sidx, series=mi.series)
                    texts[-1] += '\n\n' + _('About this book:') + '\n\n' + textwrap.fill(html2text(mi.comments))
                if is_for_kindle(to):
                    prefix = str(newmi.title or t)
                else:
                    prefix = f'{t} - {a}'
                if not isinstance(prefix, str):
                    prefix = prefix.decode(preferred_encoding, 'replace')
                attachment_names.append(prefix + os.path.splitext(f)[1])
        remove = remove_ids if delete_from_library else []

        to_s = list(repeat(to, len(attachments)))
        if attachments:
            send_mails(jobnames,
                    Dispatcher(partial(self.email_sent, remove=remove)),
                    attachments, to_s, subjects, texts, attachment_names,
                    self.job_manager)
            self.status_bar.show_message(_('Sending email to')+' '+to, 3000)

        auto = []
        if _auto_ids != []:
            for id in _auto_ids:
                if specific_format is None:
                    dbfmts = self.library_view.model().db.formats(id, index_is_id=True)
                    formats = [f.lower() for f in (dbfmts.split(',') if dbfmts else
                        [])]
                    if set(formats).intersection(available_input_formats()) and set(fmts).intersection(available_output_formats()):
                        auto.append(id)
                    else:
                        bad.append(self.library_view.model().db.title(id, index_is_id=True))
                elif specific_format in list(set(fmts).intersection(set(available_output_formats()))):
                    auto.append(id)
                else:
                    bad.append(self.library_view.model().db.title(id, index_is_id=True))

        if auto != []:
            format = specific_format if specific_format in list(set(fmts).intersection(set(available_output_formats()))) else None
            if not format:
                for fmt in fmts:
                    if fmt in list(set(fmts).intersection(set(available_output_formats()))):
                        format = fmt
                        break
            if format is None:
                bad += auto
            else:
                autos = [self.library_view.model().db.title(id, index_is_id=True) for id in auto]
                if self.auto_convert_question(
                    _('Auto convert the following books to %s before sending via '
                        'email?') % format.upper(), autos):
                    self.iactions['Convert Books'].auto_convert_mail(to, fmts, delete_from_library, auto, format, subject)

        if bad:
            bad = '\n'.join(f'{i}' for i in bad)
            d = warning_dialog(self, _('No suitable formats'),
                _('Could not email the following books '
                'as no suitable formats were found:'), bad)
            d.exec()

    def email_sent(self, job, remove=[]):
        if job.failed:
            self.job_exception(job, dialog_title=_('Failed to email book'))
            return

        self.status_bar.show_message(job.description + ' ' + _('sent'),
                    5000)
        if remove:
            try:
                next_id = self.library_view.next_id
                self.library_view.model().delete_books_by_id(remove)
                self.iactions['Remove Books'].library_ids_deleted2(remove,
                                                            next_id=next_id)
            except Exception:
                import traceback

                # Probably the user deleted the files, in any case, failing
                # to delete the book is not catastrophic
                traceback.print_exc()

    def email_news(self, id_):
        mi = self.library_view.model().db.get_metadata(id_,
                index_is_id=True)
        remove = [id_] if config['delete_news_from_library_on_upload'] \
                else []

        def get_fmts(fmts):
            files, auto = self.library_view.model().\
                    get_preferred_formats_from_ids([id_], fmts,
                            set_metadata=True,
                            use_plugboard=plugboard_email_value,
                            plugboard_formats=plugboard_email_formats)
            return files
        sent_mails = email_news(mi, remove,
                get_fmts, self.email_sent, self.job_manager)
        if sent_mails:
            self.status_bar.show_message(_('Sent news to')+' '+
                    ', '.join(sent_mails), 3000)

# }}}


if __name__ == '__main__':
    from qt.core import QApplication
    app = QApplication([])  # noqa: F841
    print(select_recipients())
