#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vim: ai ts=4 sts=4 et sw=4

"""
    Main script including controller, rooting, dependency management, and
    server run.
"""

import os
import sys
import thread
import urlparse
from datetime import datetime, timedelta

# add project dir and libs dir to the PYTHON PATH to ensure they are
# importable
from utils import settings, SettingsValidationError

import bottle
from bottle import (Bottle, run, static_file, view, request)

import clize

from paste import Paste
from utils import drop_privileges, dmerge


app = Bottle()
GLOBAL_CONTEXT = {
    'settings': settings,
    'pastes_count': Paste.get_pastes_count(),
    'refresh_counter': datetime.now()
}


@app.route('/')
@view('home')
def index():
    return GLOBAL_CONTEXT


@app.route('/faq/')
@view('faq')
def faq():
    return GLOBAL_CONTEXT


@app.route('/paste/create', method='POST')
def create_paste():
    try:
        body = urlparse.parse_qs(request.body.read(int(settings.MAX_SIZE * 1.1)))
    except ValueError:
        return {'status': 'error',
                'message': u"Wrong data payload."}

    try:
        content = unicode(''.join(body['content']), 'utf8')
    except (UnicodeDecodeError, KeyError):
        return {'status': 'error',
                'message': u"Encoding error: the paste couldn't be saved."}

    if '{"iv":' not in content:  # reject silently non encrypted content
        return {'status': 'error',
                'message': u"Wrong data payload."}

    if content:
        # check size of the paste. if more than settings return error
        # without saving paste.  prevent from unusual use of the
        # system.  need to be improved
        if len(content) < settings.MAX_SIZE:
            expiration = body.get('expiration', [u'burn_after_reading'])[0]
            paste = Paste(expiration=expiration, content=content,
                          uuid_length=settings.PASTE_ID_LENGTH)
            paste.save()

            # display counter
            if settings.DISPLAY_COUNTER:

                #increment paste counter
                paste.increment_counter()

                # if refresh time elapsed pick up new counter value
                now = datetime.now()
                timeout = (GLOBAL_CONTEXT['refresh_counter']
                           + timedelta(seconds=settings.REFRESH_COUNTER))
                if timeout < now:
                    GLOBAL_CONTEXT['pastes_count'] = Paste.get_pastes_count()
                    GLOBAL_CONTEXT['refresh_counter'] = now

            return {'status': 'ok',
                    'paste': paste.uuid}

    return {'status': 'error',
            'message': u"Serveur error: the paste couldn't be saved. "
                       u"Please try later."}


@app.route('/paste/:paste_id')
@view('paste')
def display_paste(paste_id):

    now = datetime.now()
    keep_alive = False
    try:
        paste = Paste.load(paste_id)
        # Delete the paste if it expired:
        if 'burn_after_reading' in str(paste.expiration):
            # burn_after_reading contains the paste creation date
            # if this read appends 10 seconds after the creation date
            # we don't delete the paste because it means it's the redirection
            # to the paste that happens during the paste creation
            try:
                keep_alive = paste.expiration.split('#')[1]
                keep_alive = datetime.strptime(keep_alive,
                                               '%Y-%m-%d %H:%M:%S.%f')
                keep_alive = now < keep_alive + timedelta(seconds=10)
            except IndexError:
                keep_alive = False
            if not keep_alive:
                paste.delete()

        elif paste.expiration < now:
            paste.delete()
            raise ValueError()

    except (TypeError, ValueError):
        return error404(ValueError)

    context = {'paste': paste, 'keep_alive': keep_alive}
    return dmerge(context, GLOBAL_CONTEXT)


@app.error(404)
@view('404')
def error404(code):
    return GLOBAL_CONTEXT


@app.route('/static/<filename:path>')
def server_static(filename):
    return static_file(filename, root=settings.STATIC_FILES_ROOT)


def get_app(debug=None, settings_file='',
            compressed_static=None, settings=settings):
    """
        Return a tuple (settings, app) configured using passed
        parameters and/or a setting file.
    """

    settings_file = settings_file or os.environ.get('ZEROBIN_SETTINGS_FILE')

    if settings_file:
        settings.update_with_file(os.path.realpath(settings_file))

    if settings.PASTE_ID_LENGTH < 4:
        raise SettingsValidationError('PASTE_ID_LENGTH cannot be lower than 4')

    if compressed_static is not None:
        settings.COMPRESSED_STATIC_FILES = compressed_static

    if debug is not None:
        settings.DEBUG = debug

    # make sure the templates can be loaded
    for d in reversed(settings.TEMPLATE_DIRS):
        bottle.TEMPLATE_PATH.insert(0, d)

    if settings.DEBUG:
        bottle.debug(True)

    return settings, app


@clize.clize(coerce={'debug': bool, 'compressed_static': bool})
def runserver(host='', port='', debug=None, user='', group='',
              settings_file='', compressed_static=None,
              version=False, paste_id_length=None, server="cherrypy"):

    if version:
        print '0bin V%s' % settings.VERSION
        sys.exit(0)

    settings.HOST = host or settings.HOST
    settings.PORT = port or settings.PORT
    settings.USER = user or settings.USER
    settings.GROUP = group or settings.GROUP
    settings.PASTE_ID_LENGTH = paste_id_length or settings.PASTE_ID_LENGTH

    try:
        _, app = get_app(debug, settings_file, compressed_static, settings=settings)
    except SettingsValidationError as err:
        print >>sys.stderr, 'Configuration error: %s' % err.message
        sys.exit(1)

    thread.start_new_thread(drop_privileges, (settings.USER, settings.GROUP))

    if settings.DEBUG:
        run(app, host=settings.HOST, port=settings.PORT, reloader=True,
            server="cherrypy")
    else:
        run(app, host=settings.HOST, port=settings.PORT, server="cherrypy")


def main():
    clize.run(runserver)