#! /usr/bin/env python
#
# RTEMS Tools Project (http://www.rtems.org/)
# Copyright 2019 Chris Johns (chrisj@rtems.org)
# All rights reserved.
#
# This file is part of the RTEMS Tools package in 'rtems-tools'.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#

#
# A tool to email a file. Taken from the mailer.py module in
# rtems-tools's toolkit.
#

from __future__ import print_function

import argparse
import smtplib
import socket
import sys

class error(Exception):
    def __init__(self, what):
        self.set_output('error: ' + what)
    def set_output(self, msg):
        self.msg = msg
    def __str__(self):
        return self.msg

class mail:
    def __init__(self, opts):
        self.opts = opts

    def from_address(self):

        def _clean(l):
            if '#' in l:
                l = l[:l.index('#')]
            if '\r' in l:
                l = l[:l.index('r')]
            if '\n' in l:
                l = l[:l.index('\n')]
            return l.strip()

        addr = self.opts.mail_from
        if addr is not None:
            return addr
        mailrc = None
        if 'MAILRC' in os.environ:
            mailrc = os.environ['MAILRC']
        if mailrc is None and 'HOME' in os.environ:
            mailrc = path.join(os.environ['HOME'], '.mailrc')
        if mailrc is not None and path.exists(mailrc):
            # set from="Joe Blow <joe@blow.org>"
            try:
                with open(mailrc, 'r') as mrc:
                    lines = mrc.readlines()
            except IOError as err:
                raise error('error reading: %s' % (mailrc))
            for l in lines:
                l = _clean(l)
                if 'from' in l:
                    fa = l[l.index('from') + len('from'):]
                    if '=' in fa:
                        addr = fa[fa.index('=') + 1:].replace('"', ' ').strip()
            if addr is not None:
                return addr
        if self._args_are_macros():
            addr = self.opts.defaults.get_value('%{_sbgit_mail}')
        else:
            raise error('no valid from address for mail')
        return addr

    def smtp_host(self):
        host = self.opts.smtp_host
        if host is not None:
            return host
        return 'localhost'

    def send(self, to_addr, subject, body):
        from_addr = self.from_address()
        msg = "From: %s\r\nTo: %s\r\nSubject: %s\r\n\r\n" % \
            (from_addr, to_addr, subject) + body
        try:
            s = smtplib.SMTP(self.smtp_host())
            s.sendmail(from_addr, [to_addr], msg)
        except smtplib.SMTPException as se:
            raise error('sending mail: %s' % (str(se)))
        except socket.error as se:
            raise error('sending mail: %s' % (str(se)))

    def send_file_as_body(self, to_addr, subject, name, intro = None):
        try:
            with open(name, 'r') as f:
                body = f.readlines()
        except IOError as err:
            raise error('error reading mail body: %s' % (name))
        if intro is not None:
            body = intro + body
        self.send(to_addr, subject, ''.join(body))

try:
    ec = 0
    notice = None

    args = argparse.ArgumentParser(prog = 'rtems-mailer',
                                   description = 'Tool to email a file to an specified SMTP host')
    args.add_argument('-s', '--subject',
                      help = 'Mail subject.',
                      type = str, required = True, default = None)
    args.add_argument('-t', '--to',
                      help = 'Mail to, comma separated list.',
                      type = str, required = True, default = None)
    args.add_argument('-f', '--from',
                      dest = 'mail_from',
                      help = 'Mail from.',
                      type = str, required = True, default = None)
    args.add_argument('-S', '--smtp-host',
                      help = 'SMTP host.',
                      type = str, default = None)
    args.add_argument('body',
                      help = 'Email body.',
                      type = str)

    opts = args.parse_args()

    m = mail(opts)
    for to in opts.to.split(','):
        m.send_file_as_body(to, opts.subject, opts.body)

except error as err:
    notice = str(err)
    ec = 1
except argparse.ArgumentError as ae:
    notice = str(ae)
    ec = 2
except KeyboardInterrupt:
    notice = 'abort: user terminated'
    ec = 3
except:
    raise
    notice = 'abort: unknown error'
    ec = 1
if notice is not None:
    print(notice, file = sys.stderr)
sys.exit(ec)