# -*- coding: utf-8 -*-
"""
    simplenote.py
    ~~~~~~~~~~~~~~

    Python library for accessing the Simplenote API

    :copyright: (c) 2011 by Daniel Schauenberg
    :license: MIT, see LICENSE for more details.
"""

import urllib
import urllib2
from urllib2 import HTTPError
import base64
try:
    import json
except ImportError:
    try:
        import simplejson as json
    except ImportError:
        # For Google AppEngine
        from django.utils import simplejson as json

AUTH_URL = 'https://simple-note.appspot.com/api/login'
DATA_URL = 'https://simple-note.appspot.com/api2/data'
INDX_URL = 'https://simple-note.appspot.com/api2/index?'
NOTE_FETCH_LENGTH = 20

class Simplenote(object):
    """ Class for interacting with the simplenote web service """

    def __init__(self, username, password):
        """ object constructor """
        self.username = urllib2.quote(username)
        self.password = urllib2.quote(password)
        self.token = None

    def authenticate(self, user, password):
        """ Method to get simplenote auth token

        Arguments:
            - user (string):     simplenote email address
            - password (string): simplenote password

        Returns:
            Simplenote API token as string

        """
        auth_params = "email=%s&password=%s" % (user, password)
        values = base64.encodestring(auth_params)
        request = Request(AUTH_URL, values)
        try:
            res = urllib2.urlopen(request).read()
            token = urllib2.quote(res)
        except IOError: # no connection exception
            token = None
        return token

    def get_token(self):
        """ Method to retrieve an auth token.

        The cached global token is looked up and returned if it exists. If it
        is `None` a new one is requested and returned.

        Returns:
            Simplenote API token as string

        """
        if self.token == None:
            self.token = self.authenticate(self.username, self.password)
        return self.token


    def get_note(self, noteid):
        """ method to get a specific note

        Arguments:
            - noteid (string): ID of the note to get

        Returns:
            A tuple `(note, status)`

            - note (dict): note object
            - status (int): 0 on sucesss and -1 otherwise

        """
        # request note
        params = '/%s?auth=%s&email=%s' % (str(noteid), self.get_token(),
                                           self.username)
        request = Request(DATA_URL+params)
        try:
            response = urllib2.urlopen(request)
        except HTTPError, e:
            return e, -1
        except IOError, e:
            return e, -1
        note = json.loads(response.read())
        #use UTF-8 encoding
        if isinstance(note["content"], str):
            note["content"] = note["content"].encode('utf-8')

        if note.has_key("tags"):
            note["tags"] = [t.encode('utf-8') if isinstance(t,str) else t for t in note["tags"]]

        return note, 0

    def update_note(self, note):
        """ function to update a specific note object, if the note object does not
        have a "key" field, a new note is created

        Arguments
            - note (dict): note object to update

        Returns:
            A tuple `(note, status)`

            - note (dict): note object
            - status (int): 0 on sucesss and -1 otherwise

        """

        # use UTF-8 encoding
        # cpbotha: in both cases check if it's not unicode already
        # otherwise you get "TypeError: decoding Unicode is not supported"
        if isinstance(note["content"], str):
            note["content"] = unicode(note["content"], 'utf-8')

        if note.has_key("tags"):
            # if a tag is a string, unicode it, otherwise pass it through
            # unchanged (it's unicode already)
            # using the ternary operator, because I like it: a if test else b
            note["tags"] = [unicode(t, 'utf-8') if isinstance(t, str) else t for t in note["tags"]]

        # determine whether to create a new note or updated an existing one
        if note.has_key("key"):
            url = '%s/%s?auth=%s&email=%s' % (DATA_URL, note["key"],
                                              self.get_token(), self.username)
        else:
            url = '%s?auth=%s&email=%s' % (DATA_URL, self.get_token(), self.username)
        request = Request(url, urllib.quote(json.dumps(note)))
        response = ""
        try:
            response = urllib2.urlopen(request).read()
        except IOError, e:
            return e, -1
        return json.loads(response), 0

    def add_note(self, note):
        """wrapper function to add a note

        The function can be passed the note as a dict with the `content`
        property set, which is then directly send to the web service for
        creation. Alternatively, only the body as string can also be passed. In
        this case the parameter is used as `content` for the new note.

        Arguments:
            - note (dict or string): the note to add

        Returns:
            A tuple `(note, status)`

            - note (dict): the newly created note
            - status (int): 0 on sucesss and -1 otherwise

        """
        if type(note) == str:
            return self.update_note({"content": note})
        elif (type(note) == dict) and note.has_key("content"):
            return self.update_note(note)
        else:
            return "No string or valid note.", -1

    def get_note_list(self, qty=float("inf")):
        """ function to get the note list

        The function can be passed an optional argument to limit the
        size of the list returned. If omitted a list of all notes is
        returned.

        Arguments:
            - quantity (integer number): of notes to list

        Returns:
            An array of note objects with all properties set except
            `content`.

        """
        # initialize data
        status = 0
        ret = []
        response = {}
        notes = { "data" : [] }

        # get the note index
        if qty < NOTE_FETCH_LENGTH:
            params = 'auth=%s&email=%s&length=%s' % (self.get_token(), self.username,
                                                 qty)
        else:
            params = 'auth=%s&email=%s&length=%s' % (self.get_token(), self.username,
                                                 NOTE_FETCH_LENGTH)
        # perform initial HTTP request
        try:
            request = Request(INDX_URL+params)
            response = json.loads(urllib2.urlopen(request).read())
            notes["data"].extend(response["data"])
        except IOError:
            status = -1

        # get additional notes if bookmark was set in response
        while response.has_key("mark") and len(notes["data"]) < qty:
            if (qty - len(notes["data"])) < NOTE_FETCH_LENGTH:
                vals = (self.get_token(), self.username, response["mark"], qty - len(notes["data"]))
            else:
                vals = (self.get_token(), self.username, response["mark"], NOTE_FETCH_LENGTH)
            params = 'auth=%s&email=%s&mark=%s&length=%s' % vals

            # perform the actual HTTP request
            try:
                request = Request(INDX_URL+params)
                response = json.loads(urllib2.urlopen(request).read())
                notes["data"].extend(response["data"])
            except IOError:
                status = -1

        # parse data fields in response
        ret = notes["data"]

        return ret, status

    def trash_note(self, note_id):
        """ method to move a note to the trash

        Arguments:
            - note_id (string): key of the note to trash

        Returns:
            A tuple `(note, status)`

            - note (dict): the newly created note or an error message
            - status (int): 0 on sucesss and -1 otherwise

        """
        # get note
        note, status = self.get_note(note_id)
        if (status == -1):
            return note, status
        # set deleted property
        note["deleted"] = 1
        # update note
        return self.update_note(note)

    def delete_note(self, note_id):
        """ method to permanently delete a note

        Arguments:
            - note_id (string): key of the note to trash

        Returns:
            A tuple `(note, status)`

            - note (dict): an empty dict or an error message
            - status (int): 0 on sucesss and -1 otherwise

        """
        # notes have to be trashed before deletion
        note, status = self.trash_note(note_id)
        if (status == -1):
            return note, status

        params = '/%s?auth=%s&email=%s' % (str(note_id), self.get_token(),
                                           self.username)
        request = Request(url=DATA_URL+params, method='DELETE')
        try:
            urllib2.urlopen(request)
        except IOError, e:
            return e, -1
        return {}, 0


class Request(urllib2.Request):
    """ monkey patched version of urllib2's Request to support HTTP DELETE
        Taken from http://python-requests.org, thanks @kennethreitz
    """

    def __init__(self, url, data=None, headers={}, origin_req_host=None,
                unverifiable=False, method=None):
        urllib2.Request.__init__(self, url, data, headers, origin_req_host, unverifiable)
        self.method = method

    def get_method(self):
        if self.method:
            return self.method

        return urllib2.Request.get_method(self)


