#!/usr/bin/python
# -*- coding: utf-8 -*-
import os
import dropbox
import docker
from dropbox.files import WriteMode
from dropbox.exceptions import ApiError, AuthError
from docker.errors import NotFound, APIError
from io import BytesIO
import time

BACKUP_AGE = 30
DOCKER_SOCK = 'unix://var/run/docker.sock'
POSTGRES_CONTAINER = 'postgres'
POSTGRES_USER = 'postgres'
ODOO_IMAGE = 'odoo/robert:8.0'

'''
'''
def get_dropbox_connection():
    token_file = open('token', 'r')
    token_str = token_file.read()
    token_file.close()

    dbx = dropbox.Dropbox(token_str)

    try:
        dbx.users_get_current_account()
        return dbx
    except AuthError:
        return None

'''
'''
def delete_dropbox_old_folder(dbx=None):
    if dbx == None:
        return

'''
'''
def create_folder_path():
    return '/' + time.strftime('%Y_%m_%d')

'''
'''
def create_dropbox_folder(folder_path, dbx=None):
    if dbx == None:
        return False

    try:
        result = dbx.files_search('', folder_path)
        
        if len(result.matches) > 0:
            return False

        dbx.files_create_folder(folder_path)
        return True
    except ApiError:
        return False

'''
'''
def get_docker_client():
    return docker.DockerClient(base_url=DOCKER_SOCK)

'''
'''
def get_pg_container(docker_client):
    try:
        pg_container = docker_client.containers.get(POSTGRES_CONTAINER)
        return pg_container
    except (NotFound, APIError):
        return None

'''
'''
def list_postgres_databases(docker_client):
    pg_container = get_pg_container(docker_client)

    if pg_container is None or pg_container.status == 'exited':
        return []
    
    command = "psql -U %s -t -c 'SELECT datname FROM pg_database'" % POSTGRES_USER
    result = pg_container.exec_run(command)

    if result.exit_code == -1:
        return []

    output = result.output.split('\n')
    output = map(lambda x: x.strip(), output)
    output = filter(lambda x: x != '', output)

    BLACK_LIST = ['postgres', 'template1', 'template0']
    output = filter(lambda x: x not in BLACK_LIST, output)

    return output

'''
'''
def filter_databases_by_active_containers(databases, docker_client):
    try:
        containers = docker_client.containers.list(filters={'status': 'running', 'ancestor': ODOO_IMAGE})
        containers_name = map(lambda x: x.name, containers)

        return filter(lambda x: x in containers_name, databases)
    except APIError:
        return []

'''
'''
def create_postgres_backup(database, docker_client):
    pg_container = get_pg_container(docker_client)

    if pg_container is None or pg_container.status == 'exited':
        return (False, None)

    tmp_file = '%s_%s.tar' % (database, time.strftime('%Y-%m-%d_%H:%M:%S'))
    command = 'pg_dump -U %s -d %s -F tar -C -b -c -f %s' % (POSTGRES_USER, database, tmp_file)
    
    result = pg_container.exec_run(command)

    if result.exit_code == -1:
        (False, tmp_file)
    
    return (True, tmp_file)

'''
'''
def upload_to_dropbox(backup_file_name, backup_path, docket_client, dbx):
    pg_container = get_pg_container(docket_client)

    if pg_container is None or pg_container.status == 'exited':
        return False

    try:
        (backup_file, _) = pg_container.get_archive('/%s' % backup_file_name)
        raw_data = BytesIO()

        for chunk in backup_file:
            raw_data.write(chunk)

        raw_data.seek(0)

        remote_path = ('%s/%s') % (backup_path, backup_file_name)
        dbx.files_upload(raw_data.read(), remote_path, mode=WriteMode('overwrite'))
        raw_data.close()

        return True
    except (APIError, ApiError):
        return False

'''
'''
def delete_backup_file(backup_name, docker_client):
    pg_container = get_pg_container(docker_client)

    if pg_container is None or pg_container.status == 'exited':
        return False
    
    command = 'rm %s' % backup_name
    result = pg_container.exec_run(command)

    if result.exit_code == -1:
        return False

    print(result.output)
    return True
    

'''
'''
def run_backup():
    # 1. get connection
    dbx = get_dropbox_connection()

    # 2. create folder name
    folder_path = create_folder_path()

    # 3. create dropbox folder
    create_dropbox_folder(folder_path, dbx)

    # 4. get docker client
    docker_client = get_docker_client()

    # 5. list database
    databases = list_postgres_databases(docker_client)

    # 6. filter databases by active containers
    databases = filter_databases_by_active_containers(databases, docker_client)

    # 7. backup databases
    for db in databases:
        (backup_ok, backup_name) = create_postgres_backup(db, docker_client)

        if not backup_ok:
            if backup_name:
                delete_backup_file(backup_name, docker_client)

            continue
        
        upload_to_dropbox(backup_name, folder_path, docker_client, dbx)
        delete_backup_file(backup_name, docker_client)

        time.sleep(1)

    docker_client.close()

run_backup()