#! /usr/bin/env python
# -*- coding: utf-8 -

import binascii
import sys
import string
from threading import Lock

import simplejson as json

from couchdb import Server, ResourceNotFound


server = Server()
lock = Lock()

BASE62_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
BASE62_VALUES = ''.join([chr(i) for i in range(62)])

D_BASE62_PRIMITIVES = string.maketrans(BASE62_VALUES, BASE62_CHARS)

def b62encode(value):
    """ encode int/long to base62 stsring.
    
    >>> b62encode(1123458)
    '4iGI'
    """
    number = value
    result = ''
    while number != 0:
        result = D_BASE62_PRIMITIVES[number % 62] + result
        number /= 62
    return result


def requests():
    line = sys.stdin.readline()
    while line:
        yield json.loads(line)
        line = sys.stdin.readline()
        
def respond(code=200, data={}, headers={}):
    sys.stdout.write("%s\n" % json.dumps({"code": code, "json": data, "headers": headers}))
    sys.stdout.flush()

def get_id(req):
    global lock, server
    
    dbname = req['info']['db_name']
    db = server[dbname]
    
    stem = 0
    with lock:
        try:
            doc = db['shortcode']
        except ResourceNotFound:
            doc = {}
        db['shortcode'] = doc
        stem, revid = doc['_rev'].split('-')
        stem = int(stem) + 10000
        return { "code": b62encode(stem), "code_num": stem}
        
def main():
    for req in requests():
        respond(data=get_id(req))
        
if __name__ == "__main__":
    #print get_id({ "info": { "db_name": "testing" }})
    main()