#!/usr/bin/env python
import os
import json
import hashlib
import sys
import argparse
import shutil
import subprocess
import re

from typing import Any, Dict, List
# stubs
user_profile_stub = Dict[str, Any]
added_users_stub = Dict[str, int]


# Transported from https://github.com/zulip/zulip/blob/master/zerver/lib/export.py
def rm_tree(path: str) -> None:
    if os.path.exists(path):
        shutil.rmtree(path)

def users2zerver_userprofile(slack_dir: str, realm_id: int, timestamp: Any,
                             domain_name: str) -> (List[user_profile_stub], added_users_stub):
    """
    Returns:
    1. zerver_userprofile, which is a list of user profile
    2. added_users, which is a dictionary to map from slack user id to zulip
       user id
    """
    print('######### IMPORTING USERS STARTED #########\n')
    users = json.load(open(slack_dir + '/users.json'))
    zerver_userprofile = []
    added_users = {}
    user_id_count = 1
    for user in users:
        slack_user_id = user['id']
        profile = user['profile']
        DESKTOP_NOTIFICATION = True

        # email
        if 'email' not in profile:
            email = (hashlib.blake2b(user['real_name'].encode()).hexdigest() +
                     "@%s" % (domain_name))
        else:
            email = profile['email']

        # avatar
        # ref: https://chat.zulip.org/help/change-your-avatar
        avatar_source = 'U'
        if 'gravatar.com' in profile['image_32']:
            # use the avatar from gravatar
            avatar_source = 'G'

        # userprofile's quota is hardcoded as per
        # https://github.com/zulip/zulip/blob/e1498988d9094961e6f9988fb308b3e7310a8e74/zerver/migrations/0059_userprofile_quota.py#L18
        userprofile = dict(
            enable_desktop_notifications=DESKTOP_NOTIFICATION,
            is_staff=user.get('is_admin', False),
            avatar_source=avatar_source,
            is_bot=user.get('is_bot', False),
            avatar_version=1,
            autoscroll_forever=False,
            default_desktop_notifications=True,
            timezone=user.get("tz", ""),
            default_sending_stream=None,
            enable_offline_email_notifications=True,
            user_permissions=[],  # This is Zulip-specific
            is_mirror_dummy=False,
            pointer=-1,
            default_events_register_stream=None,
            is_realm_admin=user.get('is_owner', False),
            invites_granted=0,
            enter_sends=True,
            bot_type=1 if user.get('is_bot', False) else None,
            enable_stream_sounds=False,
            is_api_super_user=False,
            rate_limits="",
            last_login=timestamp,
            tos_version=None,
            default_all_public_streams=False,
            full_name=user.get('real_name', user['name']),
            twenty_four_hour_time=False,
            groups=[],  # This is Zulip-specific
            muted_topics=[],
            enable_online_push_notifications=False,
            alert_words="[]",
            # bot_owner=None,  # This is Zulip-specific
            short_name=user['name'],
            enable_offline_push_notifications=True,
            left_side_userlist=False,
            enable_stream_desktop_notifications=False,
            enable_digest_emails=True,
            last_pointer_updater="",
            email=email,
            date_joined=timestamp,
            last_reminder=timestamp,
            is_superuser=False,
            tutorial_status="T",
            default_language="en",
            enable_sounds=True,
            pm_content_in_desktop_notifications=True,
            is_active=user['deleted'],
            onboarding_steps="[]",
            emojiset="google",
            emoji_alt_code=False,
            realm=realm_id,
            quota=1073741824,
            invites_used=0,
            id=user_id_count)

        # TODO map the avatar
        # zerver auto-infer the url from Gravatar instead of from a specified
        # url; zerver.lib.avatar needs to be patched
        # profile['image_32'], Slack has 24, 32, 48, 72, 192, 512 size range

        zerver_userprofile.append(userprofile)
        added_users[slack_user_id] = user_id_count
        user_id_count += 1
        print(u"{} -> {}\nCreated\n".format(user['name'], userprofile['email']))
    print('######### IMPORTING USERS FINISHED #########\n')
    return zerver_userprofile, added_users

def channels2zerver_stream(slack_dir, realm_id, added_users):
    # type: (Dict[str, Dict[str, str]]) -> None
    print('######### IMPORTING CHANNELS STARTED #########\n')
    channels = json.load(open(slack_dir + '/channels.json'))
    added_channels = {}
    zerver_stream = []
    stream_id_count = 1
    zerver_subscription = []
    zerver_recipient = []
    subscription_id_count = 1

    for channel in channels:
        # slack_channel_id = channel['id']

        # map Slack's topic and purpose content into Zulip's stream description.
        # WARN This mapping is lossy since the topic.creator, topic.last_set,
        # purpose.creator, purpose.last_set fields are not preserved.
        description = "topic: {}\npurpose: {}".format(channel["topic"]["value"],
                                                      channel["purpose"]["value"])

        # construct the stream object and append it to zerver_stream
        stream = dict(
            realm=realm_id,
            name=channel["name"],
            deactivated=channel["is_archived"],
            description=description,
            invite_only=not channel["is_general"],
            date_created=channel["created"],
            id=stream_id_count)
        zerver_stream.append(stream)
        added_channels[stream['name']] = stream_id_count

        # construct the recipient object and append it zerver_recipient
        recipient = dict(
            type_id=stream_id_count,
            id=stream_id_count,
            type=2)
        zerver_recipient.append(recipient)
        # TOODO add recipients for private message and huddles

        # construct the subscription object and append it to zerver_subscription
        for member in channel['members']:
            sub = dict(
                recipient=stream_id_count,
                notifications=False,
                color="#c2c2c2",
                desktop_notifications=True,
                pin_to_top=False,
                in_home_view=True,
                active=True,
                user_profile=added_users[member],
                id=subscription_id_count)
            # proof :  https://github.com/zulip/zulip/blob/master/zerver/views/messages.py#L240 &
            # https://github.com/zulip/zulip/blob/master/zerver/views/messages.py#L324
            zerver_subscription.append(sub)
            subscription_id_count += 1
            # TOODO add zerver_subscription which correspond to
            # private messages and huddles type recipient
            # For private messages/huddle:
            # sub['recipient']=recipient['id'] where recipient['type_id']=added_users[member]

            # recipient
            # type_id's
            # 1: private message
            # 2: stream
            # 3: huddle
            # TOODO currently the goal is to map Slack's standard export
            # This defaults to 2
            # TOODO do private message subscriptions between each users have to
            # be generated from scratch?

        stream_id_count += 1
        print(u"{} -> created\n".format(channel['name']))

        # TODO map Slack's pins to Zulip's stars
        # There is the security model that Slack's pins are known to the team owner
        # as evident from where it is stored at (channels)
        # "pins": [
        #         {
        #             "id": "1444755381.000003",
        #             "type": "C",
        #             "user": "U061A5N1G",
        #             "owner": "U061A5N1G",
        #             "created": "1444755463"
        #         }
        #         ],
    print('######### IMPORTING STREAMS FINISHED #########\n')
    return zerver_stream, added_channels, zerver_subscription, zerver_recipient

def channelmessage2zerver_message(slack_dir, channel, added_users, added_channels):
    json_names = os.listdir(slack_dir + '/' + channel)
    users = json.load(open(slack_dir + '/users.json'))
    zerver_message = []
    msg_id_count = 1

    # Sanitize the message text
    def sanitize_text(text):
        tokens = text.split(' ')
        text = ' '.join([sanitize_token(t) for t in tokens])
        return text

    def sanitize_token(token):
        if (re.compile(r"<@.*|.*>").match(token)):
            token = token.replace('<@', ' ')
            token = token.replace('>', ' ')
            token = token.replace('|', ' ')
            length = len(token.split(' '))
            if length > 1:
                try:
                    short_name = token.split(' ')[2]
                except IndexError:
                    short_name = ''
                token = token.split(' ')[1]
            for user in users:
                if (user['id'] == token and user['name'] == short_name and length == 4) or \
                   (user['id'] == token and length == 3):
                    token = user.get('real_name', user['name'])
                    token = "@**" + token + "** "
        return token

    for json_name in json_names:
        msgs = json.load(open(slack_dir + '/%s/%s' % (channel, json_name)))
        for msg in msgs:
            text = msg['text']
            if "has joined the channel" in text:
                continue
            try:
                user = msg.get('user', msg['file']['user'])
            except KeyError:
                # black magic, explain this later TOODOO
                user = msg['user']
            zulip_message = dict(
                sending_client=1,
                rendered_content_version=1,  # This is Zulip-specific
                has_image=msg.get('has_image', False),
                subject=channel,  # This is Zulip-specific
                pub_date=msg['ts'],
                id=msg_id_count,
                has_attachment=False,  # attachment will be posted in the subsequent message; this is how Slack does it, i.e. less like email
                edit_history=None,
                sender=added_users[user],  # map slack id to zulip id
                content=sanitize_text(text),
                rendered_content=text,  # slack doesn't cache this
                recipient=added_channels[channel],
                last_edit_time=None,
                has_link=msg.get('has_link', False))
            zerver_message.append(zulip_message)
    return zerver_message

def main(slack_zip_file: str) -> None:
    slack_dir = slack_zip_file.replace('.zip', '')
    subprocess.check_call(['unzip', slack_zip_file])
    # with zipfile.ZipFile(slack_zip_file, 'r') as zip_ref:
    #     zip_ref.extractall(slack_dir)

    from datetime import datetime
    # TODO fetch realm config from zulip config
    DOMAIN_NAME = "zulipchat.com"
    REALM_ID = 1  # TODO how to find this
    REALM_NAME = "FleshEatingBatswithFangs"
    NOW = datetime.utcnow().timestamp()

    script_path = os.path.dirname(os.path.abspath(__file__)) + '/'
    zerver_realm_skeleton = json.load(open(script_path + 'zerver_realm_skeleton.json'))
    zerver_realm_skeleton[0]['id'] = REALM_ID
    zerver_realm_skeleton[0]['string_id'] = 'zulip'  # subdomain / short_name of realm
    zerver_realm_skeleton[0]['name'] = REALM_NAME
    zerver_realm_skeleton[0]['date_created'] = NOW

    # Make sure the directory output is clean
    output_dir = 'zulip_data'
    rm_tree(output_dir)
    os.makedirs(output_dir)

    realm = dict(zerver_defaultstream=[],  # TODO
                 zerver_client=[{"name": "populate_db", "id": 1},
                                {"name": "website", "id": 2},
                                {"name": "API", "id": 3}],
                 zerver_userpresence=[],  # TODO
                 zerver_userprofile_mirrordummy=[],
                 zerver_realmdomain=[{"realm": REALM_ID,
                                      "allow_subdomains": False,
                                      "domain": DOMAIN_NAME,
                                      "id": REALM_ID}],
                 zerver_useractivity=[],
                 zerver_realm=zerver_realm_skeleton,
                 zerver_huddle=[],
                 zerver_userprofile_crossrealm=[],
                 zerver_useractivityinterval=[],
                 zerver_realmfilter=[],
                 zerver_realmemoji=[])

    zerver_userprofile, added_users = users2zerver_userprofile(slack_dir,
                                                               REALM_ID,
                                                               int(NOW),
                                                               DOMAIN_NAME)
    realm['zerver_userprofile'] = zerver_userprofile

    zerver_stream, added_channels, zerver_subscription, zerver_recipient = channels2zerver_stream(slack_dir, REALM_ID, added_users)
    realm['zerver_stream'] = zerver_stream
    realm['zerver_subscription'] = zerver_subscription
    realm['zerver_recipient'] = zerver_recipient
    # IO
    realm_file = output_dir + '/realm.json'
    json.dump(realm, open(realm_file, 'w'))

    # now for message.json
    message_json = {}
    zerver_message = []
    # TODO map zerver_usermessage
    for channel in added_channels.keys():
        zerver_message.append(channelmessage2zerver_message(slack_dir, channel,
                              added_users, added_channels))
    message_json['zerver_message'] = zerver_message
    # IO
    message_file = output_dir + '/message.json'
    json.dump(message_json, open(message_file, 'w'))
    print('ls', os.listdir())
    print('pwd', os.getcwd())

    # TODO
    # attachments

    # remove slack dir
    rm_tree(slack_dir)

    # compress the folder
    subprocess.check_call(['zip', '-jpr', output_dir + '.zip', realm_file, message_file])

    # remove zulip dir
    rm_tree(output_dir)

    sys.exit(0)

if __name__ == '__main__':
    # from django.conf import settings
    # settings_module = "settings.py"
    # os.environ['DJANGO_SETTINGS_MODULE'] = settings_module
    description = ("script to convert Slack export data into Zulip export data")
    parser = argparse.ArgumentParser(description=description)
    slack_zip_file = sys.argv[1]
    main(slack_zip_file)