#!/bin/python
# Usage: python export.py <path_to_database> <path_for_new_folder>
# Output: folder in given directory

import argparse
import datetime
import json
import logging
import os
import sqlite3
import time

from six import iteritems


# Used in conjunction with sqlite3 to generate JSON-like format
def dict_factory(cursor, row):
    d = {}
    for index, column in enumerate(cursor.description):
        d[column[0]] = row[index]
    return d


# Turns unicode into text
def byteify(inp):
    if isinstance(inp, dict):
        return {byteify(key): byteify(value) for key, value in iteritems(inp)}
    if isinstance(inp, list):
        return [byteify(element) for element in inp]
    if "unicode" in vars(globals()["__builtins__"]) and isinstance(inp, unicode):
        return inp.encode("utf-8")
    return inp


def get_channel_name(channel_id):
    return ENV["id_channel"].get(channel_id, "None")


def get_date(ts):
    return datetime.datetime.fromtimestamp(int(ts)).strftime("%Y-%m-%d")


# Uncomment time in the future if running daily (Used to export last days of messages)
# time = time.time() - 86400 # One full day in seconds

parser = argparse.ArgumentParser()
parser.add_argument(
    "-d",
    "--database-path",
    default="slack.sqlite",
    help=("path to the SQLite database. (default = ./slack.sqlite)"),
)
parser.add_argument(
    "-a",
    "--archive_path",
    default="export",
    help=("path to export to (default ./export)"),
)
parser.add_argument(
    "-l",
    "--log-level",
    default="debug",
    help=("CRITICAL, ERROR, WARNING, INFO or DEBUG (default = DEBUG)"),
)
args = parser.parse_args()

database_path = args.database_path
archive_path = args.archive_path

log_level = args.log_level.upper()
assert log_level in ["CRITICAL", "ERROR", "WARNING", "INFO", "DEBUG"]
logging.basicConfig(level=getattr(logging, log_level))
logger = logging.getLogger(__name__)

time = 0.0
if not os.path.isdir(archive_path):
    os.makedirs(archive_path)
    time = 0.0  # Full export instead of day export

# Uncomment if you need to export entire archive or make this choice
# getAll = raw_input("Do you want to export all messages instead of last day?(y/N) ").lower()
# if (getAll=='y'):
#    time = 0.0


# Establish connection to SQL database
connection = sqlite3.connect(database_path)
connection.row_factory = dict_factory
cursor = connection.cursor()

# Get channel and user data
cursor.execute("SELECT * FROM channels")
channels = byteify(cursor.fetchall())
cursor.execute("SELECT * FROM users")
users = byteify(cursor.fetchall())
for u in users:
    u["profile"] = {}
    u["profile"]["image_72"] = u.pop("avatar")

# Save channel and user data files to archive folder
channel_file = os.path.join(archive_path, "channels.json")
with open(channel_file, "w") as outfile:
    json.dump(channels, outfile)
    outfile.close()
user_file = os.path.join(archive_path, "users.json")
with open(user_file, "w") as outfile:
    json.dump(users, outfile)
    outfile.close()


# Define the names associated with each channel id
ENV = {
    "channel_id": {},
    "id_channel": {},
}

ENV["channel_id"] = dict([(m["name"], m["id"]) for m in channels])
ENV["id_channel"] = dict([(m["id"], m["name"]) for m in channels])

# Get all messages after given time (in seconds since the Epoch)
command = (
    "SELECT * FROM messages WHERE timestamp > %s ORDER BY channel, timestamp"
) % time
cursor.execute(command)
results = byteify(cursor.fetchall())

# Clean and store message results in Slack-ish format
channel_msgs = dict([(c["name"], {}) for c in channels])
for message in results:
    message["text"] = message["message"]
    message["ts"] = message["timestamp"]
    message["type"] = "message"
    message.pop("message")
    message.pop("timestamp")

    channel_name = get_channel_name(message["channel"])
    if channel_name == "None":
        continue

    # timestamp format is #########.######
    day = get_date(message["ts"].split(".")[0])
    if channel_msgs[channel_name].get(day, None):
        channel_msgs[channel_name][day].append(message)
    else:
        channel_msgs[channel_name][day] = [message]

# Go to channel folder and title message collection as <date>.json
update_count = 0
for channel_name in channel_msgs.keys():
    # Checks for any messages from today
    if not channel_msgs[channel_name]:
        continue
    else:
        update_count += 1
        logger.info("%s has been updated" % channel_name)

    directory = os.path.join(archive_path, channel_name)
    if "None" in directory:
        logger.warning("Channel not found: %s" % channel_name)
        continue

    if not os.path.isdir(directory):
        os.makedirs(directory)

    for day in channel_msgs[channel_name].keys():
        file = os.path.join(directory, "%s.json") % day
        with open(file, "w") as outfile:
            json.dump(channel_msgs[channel_name][day], outfile)
            outfile.close()
logger.info("Updated %s channels" % update_count)

connection.close()