# -*- coding: utf-8 -*-
##############################################################################
#     OpenERP, Open Source Management Solution
#     Copyright (C) 2004-2009 Tiny SPRL (<http://tiny.be>). All Rights Reserved
#     Copyright 2015 Agile Business Group <http://www.agilebg.com>
#
#     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 socket
import os
import time
import datetime
import re
from openerp import models, fields, api, _
from openerp.exceptions import except_orm, Warning as UserError
from openerp import tools
from openerp.service import db
import logging
_logger = logging.getLogger(__name__)
try:
    import pysftp
except ImportError:
    _logger.debug('Can not import pysftp')


def execute(connector, method, *args):
    res = False
    try:
        res = getattr(connector, method)(*args)
    except socket.error as e:
        raise e
    return res


class DbBackup(models.Model):
    _name = 'db.backup'

    @api.model
    def _get_db_name(self):
        return self.env.cr.dbname

    name = fields.Char(
        string='Database', size=100, required=True,
        default=_get_db_name,
        help='Database you want to schedule backups for'
    )

    bkp_dir = fields.Char(
        string='Backup Directory', size=100,
        default='/odoo/backups',
        help='Absolute path for storing the backups',
        required=True
    )
    autoremove = fields.Boolean(
        string='Auto. Remove Backups',
        help=(
            "If you check this option you can choose to "
            "automaticly remove the backup after xx days"
        )
    )
    daystokeep = fields.Integer(
        string='Remove after x days',
        default=30,
        help=(
            "Choose after how many days the backup should be "
            "deleted. For example:\nIf you fill in 5 the backups "
            "will be removed after 5 days."
        ), required=True
    )
    sftpwrite = fields.Boolean(
        string='Write to external server with sftp',
        help=(
            "If you check this option you can specify the details "
            "needed to write to a remote server with SFTP."
        )
    )
    sftppath = fields.Char(
        string='Path external server',
        help=(
            "The location to the folder where the dumps should be "
            "written to. For example /odoo/backups/.\nFiles will then"
            " be written to /odoo/backups/ on your remote server."
        )
    )
    sftpip = fields.Char(
        string='IP Address SFTP Server',
        help=(
            "The IP address from your remote"
            " server. For example 192.168.0.1"
        )
    )
    sftpport = fields.Integer(
        string="SFTP Port",
        default=22,
        help="The port on the FTP server that accepts SSH/SFTP calls."
    )
    sftpusername = fields.Char(
        string='Username SFTP Server',
        help=(
            "The username where the SFTP connection "
            "should be made with. This is the user on the external server."
        )
    )
    sftppassword = fields.Char(
        string='Password User SFTP Server',
        help=(
            "The password from the user where the SFTP connection "
            "should be made with. This is the password from the user"
            " on the external server."
        )
    )
    daystokeepsftp = fields.Integer(
        string='Remove SFTP after x days',
        default=30,
        help=(
            "Choose after how many days the backup should be deleted "
            "from the FTP server. For example:\nIf you fill in 5 the "
            "backups will be removed after 5 days from the FTP server."
        )
    )
    sendmailsftpfail = fields.Boolean(
        string='Auto. E-mail on backup fail',
        help=(
            "If you check this option you can choose to automaticly"
            " get e-mailed when the backup to the external server failed."
        )
    )
    emailtonotify = fields.Char(
        string='E-mail to notify',
        help=(
            "Fill in the e-mail where you want to be"
            " notified that the backup failed on the FTP."
        )
    )
    lasterrorlog = fields.Text(
        string='E-mail to notify',
        help=(
            "Fill in the e-mail where you want to be"
            " notified that the backup failed on the FTP."
        )
    )

    @api.multi
    def _check_db_exist(self):
        for rec in self:
            db_list = db.exp_list(True)
            if rec.name in db_list:
                return True
            return False

    _constraints = [
        (
            _check_db_exist,
            _('Error ,No such database exists'), ['name']
        )
    ]

    @api.multi
    def test_sftp_connection(self):
        confs = self.search([])
        # Check if there is a success or fail and write messages
        messageTitle = ""
        messageContent = ""
        conn_success = False
        for rec in confs:
            try:
                conn_success = True
                ipHost = rec.sftpip
                portHost = rec.sftpport
                usernameLogin = rec.sftpusername
                passwordLogin = rec.sftppassword
                # Connect with external server over SFTP, so we know sure that
                # everything works.
                srv = pysftp.Connection(host=ipHost, username=usernameLogin,
                                        password=passwordLogin, port=portHost)
                srv.close()
                # We have a success.
                messageTitle = _("Connection Test Succeeded!")
                messageContent = _(
                    "Everything seems properly set up for FTP back-ups!")
            except Exception as e:
                conn_success = False
                messageTitle = _("Connection Test Failed!")
                if len(rec.sftpip) < 8:
                    messageContent += _(
                        "\nYour IP address seems to be too short.\n")
                messageContent += _("Here is what we got instead:\n")
        if not conn_success:
            raise except_orm(
                _(messageTitle), _(
                    messageContent + "%s") %
                tools.ustr(e))
        else:
            raise UserError(_(messageTitle), _(messageContent))

    @api.model
    def schedule_backup(self):

        for rec in self.search([]):
            if not os.path.isdir(rec.bkp_dir):
                os.makedirs(rec.bkp_dir)
            # Create name for dumpfile.
            bkp_file = '%s_%s.dump.zip' % (
                time.strftime('%d_%m_%Y_%H_%M_%S'),
                rec.name)
            file_path = os.path.join(rec.bkp_dir, bkp_file)
            fbk = open(file_path, 'wb')
            db.dump_db(rec.name, fbk)
            fbk.close()
            # Check if user wants to write to SFTP or not.
            if rec.sftpwrite is True:
                try:
                    # Store all values in variables
                    dir = rec.bkp_dir
                    pathToWriteTo = rec.sftppath
                    ipHost = rec.sftpip
                    portHost = rec.sftpport
                    usernameLogin = rec.sftpusername
                    passwordLogin = rec.sftppassword
                    # Connect with external server over SFTP
                    srv = pysftp.Connection(
                        host=ipHost,
                        username=usernameLogin,
                        password=passwordLogin,
                        port=portHost)
                    # Move to the correct directory on external server. If the
                    # user made a typo in his path with multiple slashes
                    # (/odoo//backups/) it will be fixed by this regex.
                    pathToWriteTo = re.sub('/+', '/', pathToWriteTo)
                    _logger.debug(
                        'Start to copy files..'
                    )
                    try:
                        srv.chdir(pathToWriteTo)
                    except IOError:
                        # Create directory and subdirs if they do not exist.
                        currentDir = ''
                        for dirElement in pathToWriteTo.split('/'):
                            currentDir += dirElement + '/'
                            try:
                                srv.chdir(currentDir)
                            except:
                                _logger.info(
                                    _(
                                        '(Part of the) path didn\'t exist. '
                                        'Creating it now at %s'
                                    ) % currentDir
                                )
                                # Make directory and then navigate into it
                                srv.mkdir(currentDir, mode=777)
                                srv.chdir(currentDir)
                                pass
                    srv.chdir(pathToWriteTo)
                    # Loop over all files in the directory.
                    for f in os.listdir(dir):
                        fullpath = os.path.join(dir, f)
                        if os.path.isfile(fullpath):
                            srv.put(fullpath)

                    # Navigate in to the correct folder.
                    srv.chdir(pathToWriteTo)
                    # Loop over all files in the directory from the back-ups.
                    # We will check the creation date of every back-up.
                    for file in srv.listdir(pathToWriteTo):
                        # Get the full path
                        fullpath = os.path.join(pathToWriteTo, file)
                        if srv.isfile(fullpath) and ".dump.zip" in file:
                            # Get the timestamp from the file on the external
                            # server
                            timestamp = srv.stat(fullpath).st_atime
                            createtime = (
                                datetime.datetime.fromtimestamp(timestamp)
                            )
                            now = datetime.datetime.now()
                            delta = now - createtime
                            # If the file is older than the daystokeepsftp (the
                            # days to keep that the user filled in on the Odoo
                            # form it will be removed.
                            if (
                                rec.daystokeepsftp > 0 and
                                delta.days >= rec.daystokeepsftp
                            ):
                                # Only delete files, no directories!
                                srv.unlink(file)
                    # Close the SFTP session.
                    srv.close()
                except Exception as e:
                    _logger.debug(
                        'Exception We couldn\'t back '
                        'up to the FTP server..'
                    )
                    # At this point the SFTP backup failed.
                    # We will now check if the user wants
                    # an e-mail notification about this.
                    if rec.sendmailsftpfail:
                        self.send_notification(rec, e)

            # Remove all old files (on local server)
            # in case this is configured..
            if rec.autoremove is True:
                try:
                    self.remove_folder(rec)
                except Exception as e:
                    _logger.debug(
                        'Exception when try to remove file'
                    )

        return True

    def send_notification(self, rec, e):
        try:
            ir_mail_server = self.env['ir.mail_server']
            message = (
                "Dear,\n\nThe backup for the server %s"
                " (IP: %s) failed.Please check"
                " the following details:\n\n"
                "IP address SFTP server: %s \nUsername: %s"
                "\nPassword: %s"
                "\n\nError details: %s \n\nWith kind regards"
            ) % (
                rec.host, rec.sftpip, rec.sftpip,
                rec.sftpusername, rec.sftppassword,
                tools.ustr(e)
            )
            msg = ir_mail_server.build_email(
                "auto_backup@%s.com" % rec.name,
                [rec.emailtonotify],
                "Backup from %s ( %s ) failed" % (
                    rec.host, rec.sftpip),
                message)
            ir_mail_server.send_email(msg)

        except Exception as e:
            _logger.debug(
                'Exception %s' % tools.ustr(e)
            )

    # This is done after the SFTP writing to prevent unusual behaviour:
    # If the user would set local back-ups to be kept 0 days and the SFTP
    # to keep backups xx days there wouldn't be any new back-ups added
    # to the SFTP.
    # If we'd remove the dump files before they're writen to the SFTP
    # there willbe nothing to write. Meaning that if an user doesn't want
    # to keep back-ups locally and only wants them on the SFTP
    # (NAS for example) there wouldn't be any writing to the
    # remote server if this if statement was before the SFTP write method
    # right above this comment.
    def remove_folder(self, rec):
        dir = rec.bkp_dir
        # Loop over all files in the directory.
        for f in os.listdir(dir):
            fullpath = os.path.join(dir, f)
            if os.path.isfile(fullpath) and ".dump.zip" in f:
                timestamp = os.stat(fullpath).st_ctime
                createtime = (
                    datetime.datetime.fromtimestamp(timestamp)
                )
                now = datetime.datetime.now()
                delta = now - createtime
                if delta.days >= rec.daystokeep:
                    _logger.debug(
                        'Remove local file...'
                    )
                    os.remove(fullpath)