"""
This file is part of the web2py Web Framework
Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu>
License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html)
"""
import datetime
from storage import Storage
from html import TAG
from html import xmlescape
from languages import lazyT
import contrib.rss2 as rss2

try:
    import json as json_parser                      # try stdlib (Python 2.6)
except ImportError:
    try:
        import simplejson as json_parser            # try external module
    except:
        import contrib.simplejson as json_parser    # fallback to pure-Python module

def custom_json(o):
    if hasattr(o,'custom_json') and callable(o.custom_json):
        return o.custom_json()
    if isinstance(o, (datetime.date,
                      datetime.datetime,
                      datetime.time)):
        return o.isoformat()[:19].replace('T',' ')
    elif isinstance(o, (int, long)):
        return int(o)
    elif isinstance(o, lazyT):
        return str(o)
    elif hasattr(o,'as_list') and callable(o.as_list):
        return o.as_list()
    elif hasattr(o,'as_dict') and callable(o.as_dict):
        return o.as_dict()
    else:
        raise TypeError(repr(o) + " is not JSON serializable")


def xml_rec(value, key, quote=True):
    if hasattr(value,'custom_xml') and callable(value.custom_xml):
        return value.custom_xml()
    elif isinstance(value, (dict, Storage)):
        return TAG[key](*[TAG[k](xml_rec(v, '',quote)) \
                              for k, v in value.items()])
    elif isinstance(value, list):
        return TAG[key](*[TAG.item(xml_rec(item, '',quote)) for item in value])
    elif hasattr(value,'as_list') and callable(value.as_list):
        return str(xml_rec(value.as_list(),'',quote))
    elif hasattr(value,'as_dict') and callable(value.as_dict):
        return str(xml_rec(value.as_dict(),'',quote))
    else:
        return xmlescape(value,quote)


def xml(value, encoding='UTF-8', key='document', quote=True):
    return ('<?xml version="1.0" encoding="%s"?>' % encoding) + str(xml_rec(value,key,quote))


def json(value,default=custom_json):
    return json_parser.dumps(value,default=default)


def csv(value):
    return ''

def ics(events, title=None, link=None, timeshift=0):
    import datetime
    title = title or '(unkown)'
    if link and not callable(link):
        link = lambda item: link +'/%s' % link['id']
    s = 'BEGIN:VCALENDAR'
    s += '\nVERSION:2.0'
    s += '\nX-WR-CALNAME:%s' % title
    s += '\nSUMMARY:%s' % title
    s += '\nPRODID:Generated by web2py'
    s += '\nCALSCALE:GREGORIAN'
    s += '\nMETHOD:PUBLISH'
    for item in events:
        s += '\nBEGIN:VEVENT'
        s += '\nUID:%s' % item['id']
        if link:
            s += '\nURL:%s' % link(item)
        shift = datetime.timedelta(seconds=3600*timeshift)
        start = item['start_datetime']+shift
        stop = item['stop_datetime']+shift
        s += '\nDTSTART:%s' % start.strftime('%Y%m%dT%H%M%S')
        s += '\nDTEND:%s' % stop.strftime('%Y%m%dT%H%M%S')
        s += '\nSUMMARY:%s' % item['title']
        s += '\nEND:VEVENT'
    s += '\nEND:VCALENDAR'
    return s

def rss(feed):
    if not 'entries' in feed and 'items' in feed:
        feed['entries'] = feed['items']
    now=datetime.datetime.now()
    rss = rss2.RSS2(title = feed.get('title','(notitle)'),
                    link = feed.get('link',None),
                    description = feed.get('description',''),
                    lastBuildDate = feed.get('created_on', now),
                    items = [rss2.RSSItem(
                title=entry.get('title','(notitle)'),
                link=entry('link',None),
                description=entry.get('description',''),
                pubDate=entry.get('created_on', now)
                ) for entry in feed.get('entries',[])])
    return rss2.dumps(rss)