#!/usr/bin/env python
# index.py for a rudimentary key/value server by David Blume
import os
import sys
import time
import datetime
import cgi, cgitb
import filelock
import tempfile
import yaml  # You may need to "pip install pyyaml"
import texttime

cgitb.enable(display=0, logdir="/tmp")
store_name = 'store.txt'


def read_file(full_pathname):
    """ The file must be a YAML file containing a dict. """
    store = dict()
    if os.path.isfile(full_pathname):
        try:
            with filelock.FileLock(full_pathname):
                with open(full_pathname, 'r') as f:
                    store = yaml.load(f)
        except filelock.FileLockException as e:
            raise
    return store


def write_file(full_pathname, data):
    """ See http://david.dlma.com/blog/dads-project-in-the-garage """
    try:
        with filelock.FileLock(full_pathname):
            with tempfile.NamedTemporaryFile(mode='w',
                    dir=os.path.dirname(full_pathname),
                    delete=False) as f:
                yaml.dump(data, f)
                # exiting this "with" flushes, but does not sync
                f.flush()
                os.fdatasync(f.fileno())  # Faster, Unix only
                tempname = f.name
            os.rename(tempname, full_pathname)  # Atomic on Unix, not Windows
    except filelock.FileLockException as e:
        raise


def map_ip_to_location(ip):
    if ip == '67.188.28.83':
        return 'home'.ljust(13)
    elif ip in ('50.224.7.233', '50.224.7.248'):
        return 'work'.ljust(13)
    return ip


if __name__ == '__main__':
    localdir = os.path.abspath(os.path.dirname(sys.argv[0]))
    args = cgi.FieldStorage()
    key = None
    extra = None
    auth = None
    get_key = False
    auth_in_get = False
    doing_post = False

    # Find the parameters that are GET parameters
    # Could also check os.environ['REQUEST_METHOD'] == 'POST',
    # but that doesn't say which way individual params were sent.
    if os.environ['QUERY_STRING']:
        qs = os.environ['QUERY_STRING'].split('&')
        for pair in qs:
            k, v = pair.split('=')
            if k == 'k':
                get_key = True
            if k == 'auth':
                auth_in_get = True

    # Could be either GET or POST. Need to check QUERY_STRING above.
    if "k" in args:
        key = args["k"].value

    if os.environ['REQUEST_METHOD'] == 'POST':
        doing_post = True
        if not auth_in_get and "auth" in args:
            auth = args["auth"].value

    if "extra" in args:
        extra = args["extra"].value

    store = read_file(os.path.join(localdir, store_name))
    if get_key:
        keys = key.split(',')
        if len(keys) > 1:
            devices = set()
            for k in store:
                d = store[k]
                if k in keys:
                    devices.add((d['time'], key, d['value']))
            if devices:  # not empty
                print "Content-type: text/plain; charset=utf-8\n"
                sys.stdout.write(sorted(devices, reverse=True)[0][2])
            else:
                print 'Status: 404 Not Found\n'
        elif key in store:
            print "Content-type: text/plain; charset=utf-8\n"
            sys.stdout.write(store[key]['value'])
            if extra is not None:
                sys.stdout.write('\n%s' % (store[key]['time'],))
        else:
            print 'Status: 404 Not Found\n'
    else:
        wrote_response = False
        with open('auth.txt', 'r') as f:
            authorization = f.read().strip()
        if doing_post and auth == authorization:
            for new_key in args:
                if new_key not in ('auth', 'extra') and \
                    len(new_key) < 80 and len(args[new_key].value) < 140:
                    if new_key in store and 'created' in store[new_key]:
                        created_time = store[new_key]['created']
                    else:
                        created_time = int(time.time())
                    store[new_key] = {'value': args[new_key].value,
                                      'time': int(time.time()),
                                      'created': created_time,
                                      'origin': os.environ['REMOTE_ADDR']}
                    write_file(os.path.join(localdir, store_name), store)
                    wrote_response = True
                    print "Content-type: text/plain; charset=utf-8\n"
                    print "OK"
                    break
        elif not os.environ['QUERY_STRING'] and not doing_post:
            # just the home page, then
            print "Content-type: text/plain; charset=UTF-8\n"
            wrote_response = True
            print "key          \tvalue         \tcreated \tupdated \torigin      \tNotes"
            print "------------ \t------------- \t----------\t----------\t-------------\t---------------------"
            devices = { '1G': '(Au)',
                        '5S': '(Br)',
                        'YW': '(FW)',
                        'YY': '(Da)',
                        '2N': '(Li)',
                        '1R': '(Ty)',
                        'YU': '(Lf)',
                        'YP': '(C4)',
                      }
            for key in sorted(store, key=lambda k: store[k]['time'], reverse=True):
                if key[:2] in devices:
                    device = devices[key[:2]] + ' '
                else:
                    device = ''
                d = store[key]
                td = texttime.stringify(datetime.timedelta(seconds=time.time()-d['time']))
                if 'created' in d:
                    created = time.strftime('%Y-%m-%d', time.localtime(d['created']))
                else:
                    created = "          "
                if 'origin' in d:
                    origin = map_ip_to_location(d['origin'])
                else:
                    origin = "               "
                print '\t'.join((key.ljust(12), d['value'].ljust(13), created, str(d['time']), origin, "%supdated %s ago" % (device, td)))
            print
            print 'Tip:'
            print 'sync_ip () { export ENV_VAR=$(curl -s "%s?k=2FN50L002036,2FN44N010911"); }' % os.environ['SCRIPT_URI']
            print 'curl --data "`hostname -s`=`hostname -i`&auth=$AUTH" "%s"' % os.environ['SCRIPT_URI']

        if not wrote_response:
            print 'Status: 400 Bad Request\n'