import basura
import simplejson, uuid
from simplejson import dumps as tojson, loads as fromjson

def request(environ, response):
  path = environ['PATH_INFO'].split('/',2)
  
  # /dbname or /dbname/
  if len(path) == 2 or not path[2]:
    # create a database
    basura.dbopen(path[1], 'n')
    response('201 Created')
    return tojson({"ok":True})
    
  # if the database doesn't exist, fail the request
  db = basura.dbexists(path[1])
  if db == False:
    response('404 Not Found')
    return tojson({"error":{"id":"not_found","reason":"missing"}})

  # parse the input stream
  data = environ['wsgi.input'].read(int(environ['CONTENT_LENGTH']))
  doc = fromjson(data.decode('utf-8'))
  doc["_id"] = path[2]

  # check for conflict
  if conflict(db, doc):
    response('409 Conflict')
    return tojson({"error":{"id":"conflict","reason":"conflict"}})

  # determine status
  doc["_rev"] = str(uuid.uuid1())
  stat = basura.doccheck(db, path[2], environ, '201 Created')
  etag, lmod = basura.docstat(doc)

  # update and reply
  response(stat, [('Etag', '"%s"' % etag), ('Last-Modified', lmod)]) 
  if stat == '201 Created':
    db[path[2]] = doc
    return tojson({"ok":True, "_id":doc["_id"], "_rev":doc["_rev"]})
  return ''

def conflict(db, doc):
  if not db.has_key(doc['_id']): return False # what if doc.has_key('_rev')?
  if db[doc['_id']]['_rev'] == doc.get("_rev",''): return False
  return True