# -*- coding: utf-8 -*-
# BSD 3-Clause License
#
# Apprise - Push Notification Library.
# Copyright (c) 2023, Chris Caron <lead2gold@gmail.com>
#
# 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.
#
# 3. Neither the name of the copyright holder nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
# 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.

# Signup @ https://www.sparkpost.com
#
# Ensure you've added a Senders Domain and have generated yourself an
# API Key at:
#   https://app.sparkpost.com/dashboard

# Note: For SMTP Access, your API key must have at least been granted the
#   'Send via SMTP' privileges.

# From here you can click on the domain you're interested in. You can acquire
# the API Key from here which will look something like:
#    1e1d479fcf1a87527e9411e083c700689fa1acdc
#
# Knowing this, you can buid your sparkpost url as follows:
#  sparkpost://{user}@{domain}/{apikey}
#  sparkpost://{user}@{domain}/{apikey}/{email}
#
# You can email as many addresses as you want as:
#  sparkpost://{user}@{domain}/{apikey}/{email1}/{email2}/{emailN}
#
#  The {user}@{domain} effectively assembles the 'from' email address
#  the email will be transmitted from.  If no email address is specified
#  then it will also become the 'to' address as well.
#
#  The {domain} must cross reference a domain you've set up with Spark Post
#
# API Documentation: https://developers.sparkpost.com/api/
# Specifically: https://developers.sparkpost.com/api/transmissions/
import requests
import base64
from json import loads
from json import dumps
from .NotifyBase import NotifyBase
from ..common import NotifyType
from ..common import NotifyFormat
from ..utils import is_email
from email.utils import formataddr
from ..utils import validate_regex
from ..utils import parse_emails
from ..utils import parse_bool
from ..AppriseLocale import gettext_lazy as _

# Provide some known codes SparkPost uses and what they translate to:
# Based on https://www.sparkpost.com/docs/tech-resources/extended-error-codes/
SPARKPOST_HTTP_ERROR_MAP = {
    400: 'A bad request was made to the server',
    401: 'Invalid User ID and/or Unauthorized User',
    403: 'Permission Denied; the provided API Key was not valid',
    404: 'There is a problem with the server query URI.',
    405: 'Invalid HTTP method',
    420: 'Sending limit reached.',
    422: 'Invalid data/format/type/length',
    429: 'To many requests per sec; rate limit',
}


class SparkPostRegion:
    """
    Regions
    """
    US = 'us'
    EU = 'eu'


# SparkPost APIs
SPARKPOST_API_LOOKUP = {
    SparkPostRegion.US: 'https://api.sparkpost.com/api/v1',
    SparkPostRegion.EU: 'https://api.eu.sparkpost.com/api/v1',
}

# A List of our regions we can use for verification
SPARKPOST_REGIONS = (
    SparkPostRegion.US,
    SparkPostRegion.EU,
)


class NotifySparkPost(NotifyBase):
    """
    A wrapper for SparkPost Notifications
    """

    # The default descriptive name associated with the Notification
    service_name = 'SparkPost'

    # The services URL
    service_url = 'https://sparkpost.com/'

    # Support attachments
    attachment_support = True

    # All notification requests are secure
    secure_protocol = 'sparkpost'

    # SparkPost advertises they allow 300 requests per minute.
    # 60/300 = 0.2
    request_rate_per_sec = 0.20

    # Words straight from their website:
    #    https://developers.sparkpost.com/api/#header-rate-limiting
    # These limits are dynamic, but as a general rule, wait 1 to 5 seconds
    # after receiving a 429 response before requesting again.

    # As a simple work around, this is what we will do... Wait X seconds
    # (defined below) before trying again when we get a 429 error
    sparkpost_retry_wait_sec = 5

    # The maximum number of times we'll retry to send our message when we've
    # reached a throttling situatin before giving up
    sparkpost_retry_attempts = 3

    # The maximum amount of emails that can reside within a single
    # batch transfer based on:
    #  https://www.sparkpost.com/docs/tech-resources/\
    #       smtp-rest-api-performance/#sending-via-the-transmission-rest-api
    default_batch_size = 2000

    # A URL that takes you to the setup/help of the specific protocol
    setup_url = 'https://github.com/caronc/apprise/wiki/Notify_sparkpost'

    # Default Notify Format
    notify_format = NotifyFormat.HTML

    # Define object templates
    templates = (
        '{schema}://{user}@{host}:{apikey}/',
        '{schema}://{user}@{host}:{apikey}/{targets}',
    )

    # Define our template tokens
    template_tokens = dict(NotifyBase.template_tokens, **{
        'user': {
            'name': _('User Name'),
            'type': 'string',
            'required': True,
        },
        'host': {
            'name': _('Domain'),
            'type': 'string',
            'required': True,
        },
        'apikey': {
            'name': _('API Key'),
            'type': 'string',
            'private': True,
            'required': True,
        },
        'targets': {
            'name': _('Target Emails'),
            'type': 'list:string',
        },
    })

    # Define our template arguments
    template_args = dict(NotifyBase.template_args, **{
        'name': {
            'name': _('From Name'),
            'type': 'string',
            'map_to': 'from_name',
        },
        'region': {
            'name': _('Region Name'),
            'type': 'choice:string',
            'values': SPARKPOST_REGIONS,
            'default': SparkPostRegion.US,
            'map_to': 'region_name',
        },
        'to': {
            'alias_of': 'targets',
        },
        'cc': {
            'name': _('Carbon Copy'),
            'type': 'list:string',
        },
        'bcc': {
            'name': _('Blind Carbon Copy'),
            'type': 'list:string',
        },
        'batch': {
            'name': _('Batch Mode'),
            'type': 'bool',
            'default': False,
        },
    })

    # Define any kwargs we're using
    template_kwargs = {
        'headers': {
            'name': _('Email Header'),
            'prefix': '+',
        },
        'tokens': {
            'name': _('Template Tokens'),
            'prefix': ':',
        },
    }

    def __init__(self, apikey, targets, cc=None, bcc=None, from_name=None,
                 region_name=None, headers=None, tokens=None, batch=None,
                 **kwargs):
        """
        Initialize SparkPost Object
        """
        super().__init__(**kwargs)

        # API Key (associated with project)
        self.apikey = validate_regex(apikey)
        if not self.apikey:
            msg = 'An invalid SparkPost API Key ' \
                  '({}) was specified.'.format(apikey)
            self.logger.warning(msg)
            raise TypeError(msg)

        # Validate our username
        if not self.user:
            msg = 'No SparkPost username was specified.'
            self.logger.warning(msg)
            raise TypeError(msg)

        # Acquire Email 'To'
        self.targets = list()

        # Acquire Carbon Copies
        self.cc = set()

        # Acquire Blind Carbon Copies
        self.bcc = set()

        # For tracking our email -> name lookups
        self.names = {}

        # Store our region
        try:
            self.region_name = self.template_args['region']['default'] \
                if region_name is None else region_name.lower()

            if self.region_name not in SPARKPOST_REGIONS:
                # allow the outer except to handle this common response
                raise
        except:
            # Invalid region specified
            msg = 'The SparkPost region specified ({}) is invalid.' \
                  .format(region_name)
            self.logger.warning(msg)
            raise TypeError(msg)

        # Get our From username (if specified)
        self.from_name = from_name

        # Get our from email address
        self.from_addr = '{user}@{host}'.format(user=self.user, host=self.host)

        if not is_email(self.from_addr):
            # Parse Source domain based on from_addr
            msg = 'Invalid ~From~ email format: {}'.format(self.from_addr)
            self.logger.warning(msg)
            raise TypeError(msg)

        self.headers = {}
        if headers:
            # Store our extra headers
            self.headers.update(headers)

        self.tokens = {}
        if tokens:
            # Store our template tokens
            self.tokens.update(tokens)

        # Prepare Batch Mode Flag
        self.batch = self.template_args['batch']['default'] \
            if batch is None else batch

        if targets:
            # Validate recipients (to:) and drop bad ones:
            for recipient in parse_emails(targets):
                result = is_email(recipient)
                if result:
                    self.targets.append(
                        (result['name'] if result['name'] else False,
                            result['full_email']))
                    continue

                self.logger.warning(
                    'Dropped invalid To email '
                    '({}) specified.'.format(recipient),
                )

        else:
            # If our target email list is empty we want to add ourselves to it
            self.targets.append(
                (self.from_name if self.from_name else False, self.from_addr))

        # Validate recipients (cc:) and drop bad ones:
        for recipient in parse_emails(cc):
            email = is_email(recipient)
            if email:
                self.cc.add(email['full_email'])

                # Index our name (if one exists)
                self.names[email['full_email']] = \
                    email['name'] if email['name'] else False
                continue

            self.logger.warning(
                'Dropped invalid Carbon Copy email '
                '({}) specified.'.format(recipient),
            )

        # Validate recipients (bcc:) and drop bad ones:
        for recipient in parse_emails(bcc):
            email = is_email(recipient)
            if email:
                self.bcc.add(email['full_email'])

                # Index our name (if one exists)
                self.names[email['full_email']] = \
                    email['name'] if email['name'] else False
                continue

            self.logger.warning(
                'Dropped invalid Blind Carbon Copy email '
                '({}) specified.'.format(recipient),
            )

    def __post(self, payload, retry):
        """
        Performs the actual post and returns the response

        """
        # Prepare our headers
        headers = {
            'User-Agent': self.app_id,
            'Accept': 'application/json',
            'Content-Type': 'application/json',
            'Authorization': self.apikey,
        }

        # Prepare our URL as it's based on our hostname
        url = '{}/transmissions/'.format(
            SPARKPOST_API_LOOKUP[self.region_name])

        # Some Debug Logging
        self.logger.debug('SparkPost POST URL: {} (cert_verify={})'.format(
            url, self.verify_certificate))

        if 'attachments' in payload['content']:
            # Since we print our payload; attachments make it a bit too noisy
            # we just strip out the data block to accomodate it
            log_payload = \
                {k: v for k, v in payload.items() if k != "content"}
            log_payload['content'] = \
                {k: v for k, v in payload['content'].items()
                 if k != "attachments"}
            log_payload['content']['attachments'] = \
                [{k: v for k, v in x.items() if k != "data"}
                 for x in payload['content']['attachments']]
        else:
            # No tidying is needed
            log_payload = payload

        self.logger.debug('SparkPost Payload: {}' .format(log_payload))

        wait = None

        # For logging output of success and errors; we get a head count
        # of our outbound details:
        verbose_dest = ', '.join(
            [x['address']['email'] for x in payload['recipients']]) \
            if len(payload['recipients']) <= 3 \
            else '{} recipients'.format(len(payload['recipients']))

        # Initialize our response object
        json_response = {}

        # Set ourselves a status code
        status_code = -1

        while 1:  # pragma: no branch

            # Always call throttle before any remote server i/o is made
            self.throttle(wait=wait)
            try:
                r = requests.post(
                    url,
                    data=dumps(payload),
                    headers=headers,
                    verify=self.verify_certificate,
                    timeout=self.request_timeout,
                )

                # A Good response (200) looks like this:
                #     "results": {
                #       "total_rejected_recipients": 0,
                #       "total_accepted_recipients": 1,
                #       "id": "11668787484950529"
                #        }
                #     }
                #
                # A Bad response looks like this:
                # {
                #   "errors": [
                #     {
                #       "description":
                #            "Unconfigured or unverified sending domain.",
                #       "code": "7001",
                #       "message": "Invalid domain"
                #     }
                #   ]
                # }
                #
                try:
                    # Update our status response if we can
                    json_response = loads(r.content)

                except (AttributeError, TypeError, ValueError):
                    # ValueError = r.content is Unparsable
                    # TypeError = r.content is None
                    # AttributeError = r is None

                    # We could not parse JSON response.
                    # We will just use the status we already have.
                    pass

                status_code = r.status_code

                payload['recipients'] = list()
                if status_code == requests.codes.ok:
                    self.logger.info(
                        'Sent SparkPost notification to {}.'.format(
                            verbose_dest))
                    return status_code, json_response

                # We had a problem if we get here
                status_str = \
                    NotifyBase.http_response_code_lookup(
                        status_code, SPARKPOST_API_LOOKUP)

                self.logger.warning(
                    'Failed to send SparkPost notification to {}: '
                    '{}{}error={}.'.format(
                        verbose_dest,
                        status_str,
                        ', ' if status_str else '',
                        status_code))

                self.logger.debug(
                    'Response Details:\r\n{}'.format(r.content))

                if status_code == requests.codes.too_many_requests and retry:
                    retry = retry - 1
                    if retry > 0:
                        wait = self.sparkpost_retry_wait_sec
                        continue

            except requests.RequestException as e:
                self.logger.warning(
                    'A Connection error occurred sending SparkPost '
                    'notification')
                self.logger.debug('Socket Exception: %s' % str(e))

            # Anything else and we're done
            return status_code, json_response

        # Our code will never reach here (outside of infinite while loop above)

    def send(self, body, title='', notify_type=NotifyType.INFO, attach=None,
             **kwargs):
        """
        Perform SparkPost Notification
        """

        if not self.targets:
            # There is no one to email; we're done
            self.logger.warning(
                'There are no Email recipients to notify')
            return False

        # Initialize our has_error flag
        has_error = False

        # Send in batches if identified to do so
        batch_size = 1 if not self.batch else self.default_batch_size

        reply_to = formataddr((self.from_name if self.from_name else False,
                               self.from_addr), charset='utf-8')

        payload = {
            "options": {
                # When set to True, an image is included with the email which
                # is used to detect if the user looked at the image or not.
                'open_tracking': False,

                # Track if links were clicked that were found within email
                'click_tracking': False,
            },
            "content": {
                "from": {
                    "name": self.from_name
                    if self.from_name else self.app_desc,
                    "email": self.from_addr,
                },

                # SparkPost does not allow empty subject lines or lines that
                # only contain whitespace; Since Apprise allows an empty title
                # parameter we swap empty title entries with the period
                "subject": title if title.strip() else '.',
                "reply_to": reply_to,
            }
        }

        if self.notify_format == NotifyFormat.HTML:
            payload['content']['html'] = body

        else:
            payload['content']['text'] = body

        if attach and self.attachment_support:
            # Prepare ourselves an attachment object
            payload['content']['attachments'] = []

            for attachment in attach:
                # Perform some simple error checking
                if not attachment:
                    # We could not access the attachment
                    self.logger.error(
                        'Could not access attachment {}.'.format(
                            attachment.url(privacy=True)))
                    return False

                self.logger.debug(
                    'Preparing SparkPost attachment {}'.format(
                        attachment.url(privacy=True)))

                try:
                    with open(attachment.path, 'rb') as fp:
                        # Prepare API Upload Payload
                        payload['content']['attachments'].append({
                            'name': attachment.name,
                            'type': attachment.mimetype,
                            'data': base64.b64encode(fp.read()).decode("ascii")
                        })

                except (OSError, IOError) as e:
                    self.logger.warning(
                        'An I/O error occurred while reading {}.'.format(
                            attachment.name if attachment else 'attachment'))
                    self.logger.debug('I/O Exception: %s' % str(e))
                    return False

        # Take a copy of our token dictionary
        tokens = self.tokens.copy()

        # Apply some defaults template values
        tokens['app_body'] = body
        tokens['app_title'] = title
        tokens['app_type'] = notify_type
        tokens['app_id'] = self.app_id
        tokens['app_desc'] = self.app_desc
        tokens['app_color'] = self.color(notify_type)
        tokens['app_url'] = self.app_url

        # Store our tokens if they're identified
        payload['substitution_data'] = self.tokens

        # Create a copy of the targets list
        emails = list(self.targets)

        for index in range(0, len(emails), batch_size):
            # Generate our email listing
            payload['recipients'] = list()

            # Initialize our cc list
            cc = (self.cc - self.bcc)

            # Initialize our bcc list
            bcc = set(self.bcc)

            # Initialize our headers
            headers = self.headers.copy()

            for addr in self.targets[index:index + batch_size]:
                entry = {
                    'address': {
                        'email': addr[1],
                    }
                }

                # Strip target out of cc list if in To
                cc = (cc - set([addr[1]]))

                # Strip target out of bcc list if in To
                bcc = (bcc - set([addr[1]]))

                if addr[0]:
                    entry['address']['name'] = addr[0]

                # Add our recipient to our list
                payload['recipients'].append(entry)

            if cc:
                # Handle our cc List
                for addr in cc:
                    entry = {
                        'address': {
                            'email': addr,
                            'header_to':
                                # Take the first email in the To
                                self.targets[index:index + batch_size][0][1],
                        },
                    }

                    if self.names.get(addr):
                        entry['address']['name'] = self.names[addr]

                    # Add our recipient to our list
                    payload['recipients'].append(entry)

                headers['CC'] = ','.join(cc)

            # Handle our bcc
            for addr in bcc:
                # Add our recipient to our list
                payload['recipients'].append({
                    'address': {
                        'email': addr,
                        'header_to':
                            # Take the first email in the To
                            self.targets[index:index + batch_size][0][1],
                    },
                })

            if headers:
                payload['content']['headers'] = headers

            # Send our message
            status_code, response = \
                self.__post(payload, self.sparkpost_retry_attempts)

            # Failed
            if status_code != requests.codes.ok:
                has_error = True

        return not has_error

    def url(self, privacy=False, *args, **kwargs):
        """
        Returns the URL built dynamically based on specified arguments.
        """

        # Define any URL parameters
        params = {
            'region': self.region_name,
            'batch': 'yes' if self.batch else 'no',
        }

        # Append our headers into our parameters
        params.update({'+{}'.format(k): v for k, v in self.headers.items()})

        # Append our template tokens into our parameters
        params.update({':{}'.format(k): v for k, v in self.tokens.items()})

        # Extend our parameters
        params.update(self.url_parameters(privacy=privacy, *args, **kwargs))

        if self.from_name is not None:
            # from_name specified; pass it back on the url
            params['name'] = self.from_name

        if self.cc:
            # Handle our Carbon Copy Addresses
            params['cc'] = ','.join(
                ['{}{}'.format(
                    '' if not e not in self.names
                    else '{}:'.format(self.names[e]), e) for e in self.cc])

        if self.bcc:
            # Handle our Blind Carbon Copy Addresses
            params['bcc'] = ','.join(self.bcc)

        # a simple boolean check as to whether we display our target emails
        # or not
        has_targets = \
            not (len(self.targets) == 1
                 and self.targets[0][1] == self.from_addr)

        return '{schema}://{user}@{host}/{apikey}/{targets}/?{params}'.format(
            schema=self.secure_protocol,
            host=self.host,
            user=NotifySparkPost.quote(self.user, safe=''),
            apikey=self.pprint(self.apikey, privacy, safe=''),
            targets='' if not has_targets else '/'.join(
                [NotifySparkPost.quote('{}{}'.format(
                    '' if not e[0] else '{}:'.format(e[0]), e[1]),
                    safe='') for e in self.targets]),
            params=NotifySparkPost.urlencode(params))

    def __len__(self):
        """
        Returns the number of targets associated with this notification
        """
        #
        # Factor batch into calculation
        #
        batch_size = 1 if not self.batch else self.default_batch_size
        targets = len(self.targets)
        if batch_size > 1:
            targets = int(targets / batch_size) + \
                (1 if targets % batch_size else 0)

        return targets if targets > 0 else 1

    @staticmethod
    def parse_url(url):
        """
        Parses the URL and returns enough arguments that can allow
        us to re-instantiate this object.

        """
        results = NotifyBase.parse_url(url, verify_host=False)
        if not results:
            # We're done early as we couldn't load the results
            return results

        # Get our entries; split_path() looks after unquoting content for us
        # by default
        results['targets'] = NotifySparkPost.split_path(results['fullpath'])

        # Our very first entry is reserved for our api key
        try:
            results['apikey'] = results['targets'].pop(0)

        except IndexError:
            # We're done - no API Key found
            results['apikey'] = None

        if 'name' in results['qsd'] and len(results['qsd']['name']):
            # Extract from name to associate with from address
            results['from_name'] = \
                NotifySparkPost.unquote(results['qsd']['name'])

        if 'region' in results['qsd'] and len(results['qsd']['region']):
            # Extract region
            results['region_name'] = \
                NotifySparkPost.unquote(results['qsd']['region'])

        # Handle 'to' email address
        if 'to' in results['qsd'] and len(results['qsd']['to']):
            results['targets'].append(results['qsd']['to'])

        # Handle Carbon Copy Addresses
        if 'cc' in results['qsd'] and len(results['qsd']['cc']):
            results['cc'] = results['qsd']['cc']

        # Handle Blind Carbon Copy Addresses
        if 'bcc' in results['qsd'] and len(results['qsd']['bcc']):
            results['bcc'] = results['qsd']['bcc']

        # Add our Meta Headers that the user can provide with their outbound
        # emails
        results['headers'] = {NotifyBase.unquote(x): NotifyBase.unquote(y)
                              for x, y in results['qsd+'].items()}

        # Add our template tokens (if defined)
        results['tokens'] = {NotifyBase.unquote(x): NotifyBase.unquote(y)
                             for x, y in results['qsd:'].items()}

        # Get Batch Mode Flag
        results['batch'] = \
            parse_bool(results['qsd'].get(
                'batch', NotifySparkPost.template_args['batch']['default']))

        return results
