"""Persistent, JSON-serialized sessions.

"""
import os
import sys
import json
import glob
import errno
import codecs
import shutil
import subprocess

from requests.compat import urlparse
from requests import Session as RSession
from requests.cookies import RequestsCookieJar, create_cookie
from requests.auth import HTTPBasicAuth, HTTPDigestAuth

from.import __version__
from.config import CONFIG_DIR
from.output import PygmentsProcessor


SESSIONS_DIR = os.path.join(CONFIG_DIR, 'sessions')


def get_response(name, request_kwargs):
    host = Host(request_kwargs['headers'].get('Host', None)
    or urlparse(request_kwargs['url']).netloc.split('@')[-1])

    session = Session(host, name)
    session.load()

    # Update session headers with the request headers.
    session['headers'].update(request_kwargs.get('headers', {}))
    # Use the merged headers for the request
    request_kwargs['headers'] = session['headers']

    auth = request_kwargs.get('auth', None)
    if auth:
        session.auth = auth
    elif session.auth:
        request_kwargs['auth'] = session.auth

    rsession = RSession(cookies=session.cookies)
    try:
        response = rsession.request(**request_kwargs)
    except Exception:
        raise
    else:
        session.cookies = rsession.cookies
        session.save()
        return response


class Host(object):
    def __init__(self, name):
        self.name = name

    def __iter__(self):
        for fn in sorted(glob.glob1(self.path, '*.json')):
            yield os.path.splitext(fn)[0], os.path.join(self.path, fn)

    def delete(self):
        shutil.rmtree(self.path)

    @property
    def path(self):
        # Name will include ':' if a port is specified, which is invalid
        # on windows. DNS does not allow '_' in a domain, or for it to end
        # in a number (I think?)
        path = os.path.join(SESSIONS_DIR, self.name.replace(':', '_'))
        try:
            os.makedirs(path, mode=0o700)
        except OSError as e:
            if e.errno != errno.EEXIST:
                raise
        return path

    @classmethod
    def all(cls):
        for name in sorted(glob.glob1(SESSIONS_DIR, '*')):
            if os.path.isdir(os.path.join(SESSIONS_DIR, name)):
                yield Host(name)


class Session(dict):
    def __init__(self, host, name, *args, **kwargs):
        super(Session, self).__init__(*args, **kwargs)
        self.host = host
        self.name = name
        self['headers'] = {}
        self['cookies'] = {}

    @property
    def path(self):
        return os.path.join(self.host.path, self.name + '.json')

    def load(self):
        try:
            with open(self.path, 'rt') as f:
                try:
                    data = json.load(f)
                except ValueError as e:
                    raise ValueError('Invalid session: %s [%s]' %
                                     (e.message, self.path))
                self.update(data)
        except IOError as e:
            if e.errno != errno.ENOENT:
                raise

    def save(self):
        self['__version__'] = __version__
        with open(self.path, 'w') as f:
            json.dump(self, f, indent=4, sort_keys=True, ensure_ascii=True)
            f.write('\n')

    def delete(self):
        try:
            os.unlink(self.path)
        except OSError as e:
            if e.errno != errno.ENOENT:
                raise

    @property
    def cookies(self):
        jar = RequestsCookieJar()
        for name, cookie_dict in self['cookies'].items():
            jar.set_cookie(create_cookie(
                name, cookie_dict.pop('value'), **cookie_dict))
        jar.clear_expired_cookies()
        return jar

    @cookies.setter
    def cookies(self, jar):
        excluded = [
            '_rest', 'name', 'port_specified',
            'domain_specified', 'domain_initial_dot',
            'path_specified', 'comment', 'comment_url'
        ]
        self['cookies'] = {}
        for host in jar._cookies.values():
            for path in host.values():
                for name, cookie in path.items():
                    cookie_dict = {}
                    for k, v in cookie.__dict__.items():
                        if k not in excluded:
                            cookie_dict[k] = v
                    self['cookies'][name] = cookie_dict

    @property
    def auth(self):
        auth = self.get('auth', None)
        if not auth:
            return None
        Auth = {'basic': HTTPBasicAuth,
                'digest': HTTPDigestAuth}[auth['type']]
        return Auth(auth['username'], auth['password'])

    @auth.setter
    def auth(self, cred):
        self['auth'] = {
            'type': {HTTPBasicAuth: 'basic',
                     HTTPDigestAuth: 'digest'}[type(cred)],
            'username': cred.username,
            'password': cred.password,
            }


def list_command(args):
    if args.host:
        for name, path in Host(args.host):
            print(name + ' [' + path + ']')
    else:
        for host in Host.all():
            print(host.name)
            for name, path in host:
                print(' ' + name + ' [' + path + ']')


def show_command(args):
    path = Session(Host(args.host), args.name).path
    if not os.path.exists(path):
        sys.stderr.write('Session "%s" does not exist [%s].\n'
        % (args.name, path))
        sys.exit(1)

    with codecs.open(path, encoding='utf8') as f:
        print(path + ':\n')
        proc = PygmentsProcessor()
        print(proc.process_body(f.read(), 'application/json', 'json'))
        print('')


def delete_command(args):
    host = Host(args.host)
    if not args.name:
        host.delete()
    else:
        Session(host, args.name).delete()


def edit_command(args):
    editor = os.environ.get('EDITOR', None)
    if not editor:
        sys.stderr.write(
            'You need to configure the environment variable EDITOR.\n')
        sys.exit(1)
    command = editor.split()
    command.append(Session(Host(args.host), args.name).path)
    subprocess.call(command)


def add_commands(subparsers):
    # List
    list_ = subparsers.add_parser('session-list', help='list sessions')
    list_.set_defaults(command=list_command)
    list_.add_argument('host', nargs='?')

    # Show
    show = subparsers.add_parser('session-show', help='list or show sessions')
    show.set_defaults(command=show_command)
    show.add_argument('host')
    show.add_argument('name')

    # Edit
    edit = subparsers.add_parser(
        'session-edit', help='edit a session in $EDITOR')
    edit.set_defaults(command=edit_command)
    edit.add_argument('host')
    edit.add_argument('name')

    # Delete
    delete = subparsers.add_parser('session-delete', help='delete a session')
    delete.set_defaults(command=delete_command)
    delete.add_argument('host')
    delete.add_argument('name', nargs='?',
        help='The name of the session to be deleted.'
             ' If not specified, all host sessions are deleted.')