from flask import Flask
from flask import abort, redirect, url_for, request, jsonify
import sys, os
sys.path.append("./lib")
from Pb import *

class InvalidUsage(Exception):
    status_code = 400

    def __init__(self, message, status_code=None, payload=None):
        Exception.__init__(self)
        self.message = message
        if status_code is not None:
            self.status_code = status_code
        self.payload = payload

    def to_dict(self):
        rv = dict(self.payload or ())
        rv['message'] = self.message
        return rv

class Server(object):
  def __init__(self):
    self.app = Flask(__name__)
    @self.app.route('/<pb_classname>', methods=['POST'])
    def pb(pb_classname):
      return self._response_post(pb_classname, request.form.to_dict())

    @self.app.errorhandler(InvalidUsage)
    def handle_invalid_usage(error):
        response = jsonify(error.to_dict())
        response.status_code = error.status_code
        return response

    self._classname_aliases = {
      'generate' : 'PbGenerate', 
      'imgrid' : 'PbGrid',
      'imbreak' : 'PbBreak',
      'impattern' : 'PbPattern',
      'imgradient' : 'PbGradient',
      'landscape' : 'PbLandscape',
    }

  def _find_class_by_name(self, pb_classname):
    pb_classname = self._classname_aliases.get(pb_classname, None) or pb_classname
    try:
      return filter(lambda c: c.__name__ == pb_classname, Pb.__subclasses__())[0]
    except IndexError:
      raise InvalidUsage('No such api', status_code=410)

  def _response_post(self, pb_classname, request_form):
    pb_class = self._find_class_by_name(pb_classname)
    classnames = map(lambda c: c.__name__, Pb.__subclasses__())
    try:
      pb = pb_class(**request_form)
      pb.create();
      pb.file_s3move()
      pb.db_send();
      return jsonify(pb.file_dict()); 

    #FIXME handle BadParamsError and PbError separately
    except Exception as e:
        sys.stderr.write("%s failure" % pb_class.__name__)
        sys.stderr.write("params:\n")
        sys.stderr.write(str(e))
        for i in request_form.keys():
            sys.stderr.write("{}:{}\n".format(i, request_form[i]))
        raise;
        return jsonify({ 'error' : 'Request could not be processed' })

  def run(self):
    self.app.run()