# This Python file uses the following encoding: utf-8
import logging
import unicodecsv as csv
import re
import urllib2
import json
from itertools import count
from dateutil.parser import parse

import ckan.plugins.toolkit as toolkit
import ckan.model as model
from ckan.lib.navl.dictization_functions import Missing

from pylons import config

import pdb

_ = toolkit._

log = logging.getLogger(__name__)


def _extract_value(data, field):
    key = None
    for k in data.keys():
        if data[k] == field:
            key = k
            break
    if key is None:
        return None
    return data[(key[0], key[1], 'value')]


def validate_extra_groups(data, requireAtLeastOne, errors):
    value = _extract_value(data, 'groups')
    error_message_no_group = 'at least one group needed'
    if value != None:
        # 'value != None' means the extra key 'groups' was found,
        # so the dataset came from manual editing via the web-frontend.
        if not value:
            if requireAtLeastOne:
                errors['groups'] = error_message_no_group
            data[('groups', 0, 'id')] = ''
            return

        groups = [g.strip() for g in value.split(',') if value.strip()]
        for k in data.keys():
            if len(k) == 3 and k[0] == 'groups':
                data[k] = ''
                # del data[k]
        if len(groups) == 0:
            if requireAtLeastOne:
                errors['groups'] = error_message_no_group
            return

        for num, group in zip(range(len(groups)), groups):
            data[('groups', num, 'id')] = group
    else:  # no extra-field 'groups'
        # dataset might come from a harvest process
        if not data.get(('groups', 0, 'id'), False) and \
           not data.get(('groups', 0, 'name'), False):
            errors['groups'] = error_message_no_group


def validate_extras(key, data, errors, context):
    extra_errors = {}
    
    isStaNord = ('id',) in data and data[('id',)][:7] == 'StaNord'
    is_optional_temporal_start = toolkit.asbool(
        config.get('ckanext.odsh.is_optional_temporal_start', False)
    ) or isStaNord

    require_at_least_one_category = toolkit.asbool(
        config.get('ckanext.odsh.require_at_least_one_category', False)
    )
    validate_extra_groups(
        data=data, 
        requireAtLeastOne=require_at_least_one_category, 
        errors=extra_errors
    )
    
    is_date_start_before_date_end(data, extra_errors)
    
    validate_extra_date_new(
        key=key,
        field='issued',
        data=data,
        optional=isStaNord,
        errors=extra_errors
    )
    validate_extra_date_new(
        key=key,
        field='temporal_start',
        data=data,
        optional=is_optional_temporal_start, 
        errors=extra_errors
    )
    validate_extra_date_new(
        key=key,
        field='temporal_end',
        data=data,
        optional=True,
        errors=extra_errors
    )

    if len(extra_errors.values()):
        raise toolkit.Invalid(extra_errors)

def is_date_start_before_date_end(data, extra_errors):
    start_date = _extract_value(data, 'temporal_start')
    end_date = _extract_value(data, 'temporal_end')
    if start_date and end_date:
        if start_date > end_date:
            extra_errors['temporal_start'] = extra_errors['temporal_end'] = 'Please enter a valid period of time.'

def _set_value(data, field, value):
    key = None
    for k in data.keys():
        if data[k] == field:
            key = k
            break
    if key is None:
        return None
    data[(key[0], key[1], 'value')] = value


def validate_extra_date_new(key, field, data, optional, errors):
    value = _extract_value(data, field)

    if not value:
        if not optional:
            errors[field] = 'empty'
        return
    else:
        if re.match(r'\d\d\d\d-\d\d-\d\d', value):
            try:
                dt = parse(value)
                _set_value(data, field, dt.isoformat())
                return
            except ValueError:
                pass
        errors[field] = 'not a valid date'


def validate_licenseAttributionByText(key, data, errors, context):
    register = model.Package.get_license_register()
    isByLicense = False
    for k in data:
        if len(k) > 0 and k[0] == 'license_id' and data[k] and not isinstance(data[k], Missing) and \
                'Namensnennung' in register[data[k]].title:
            isByLicense = True
            break
    hasAttribution = False
    for k in data:
        if data[k] == 'licenseAttributionByText':
            if isinstance(data[(k[0], k[1], 'value')], Missing) or (k[0], k[1], 'value') not in data:
                del data[(k[0], k[1], 'value')]
                del data[(k[0], k[1], 'key')]
                break
            else:
                value = data[(k[0], k[1], 'value')]
                hasAttribution = value != ''
                break
    if not hasAttribution:
        current_indexes = [k[1] for k in data.keys()
                           if len(k) > 1 and k[0] == 'extras']

        new_index = max(current_indexes) + 1 if current_indexes else 0
        data[('extras', new_index, 'key')] = 'licenseAttributionByText'
        data[('extras', new_index, 'value')] = ''

    if isByLicense and not hasAttribution:
        raise toolkit.Invalid(
            'licenseAttributionByText: empty not allowed')

    if not isByLicense and hasAttribution:
        raise toolkit.Invalid(
            'licenseAttributionByText: text not allowed for this license')


def known_spatial_uri(key, data, errors, context):
    if data.get(('__extras',)) and 'spatial_uri_temp' in data.get(('__extras',)):
        _copy_spatial_uri_temp_to_extras(data)
    value = _extract_value(data, 'spatial_uri')
    require_spatial_uri = toolkit.asbool(
        config.get('ckanext.odsh.require_spatial_uri', False)
    )
    error_message_spatial_uri_empty = 'spatial_uri: empty not allowed'

    if not value:
        poly = None

        # some harvesters might import a polygon directly...
        # pdb.set_trace()
        poly = _extract_value(data, 'spatial')

        has_old_uri = False
        pkg = context.get('package', None)
        if pkg:
            old_uri = pkg.extras.get('spatial_uri', None)
            has_old_uri = old_uri != None and len(old_uri) > 0
            if not poly:
                poly = pkg.extras.get('spatial', None)
        if (not poly) and require_spatial_uri:
            raise toolkit.Invalid(error_message_spatial_uri_empty)
        if has_old_uri and require_spatial_uri:
            raise toolkit.Invalid(error_message_spatial_uri_empty)
        else:
            if poly:
                new_index = next_extra_index(data)
                data[('extras', new_index+1, 'key')] = 'spatial'
                data[('extras', new_index+1, 'value')] = poly
            return

    mapping_file = config.get('ckanext.odsh.spatial.mapping')
    try:
        mapping_file = urllib2.urlopen(mapping_file)
    except Exception:
        raise Exception("Could not load spatial mapping file!")

    not_found = True
    spatial_text = str()
    spatial = str()
    cr = csv.reader(mapping_file, delimiter="\t", encoding='utf-8')
    for row in cr:
        if row[0] == value:
            not_found = False
            spatial_text = row[1]
            loaded = json.loads(row[2])
            spatial = json.dumps(loaded['geometry'])
            break
    if not_found:
        raise toolkit.Invalid(
            'spatial_uri: uri unknown')

    new_index = next_extra_index(data)

    data[('extras', new_index, 'key')] = 'spatial_text'
    data[('extras', new_index, 'value')] = spatial_text
    data[('extras', new_index+1, 'key')] = 'spatial'
    data[('extras', new_index+1, 'value')] = spatial


def _copy_spatial_uri_temp_to_extras(data):
    '''
    copy the field spatial_uri_temp originating 
    from the user interface to extras
    '''
    spatial_uri = data.get(('__extras',)).get('spatial_uri_temp')
    is_spatial_uri_in_extras = _extract_value(data, 'spatial_uri') is not None
    if not is_spatial_uri_in_extras:
        next_index = next_extra_index(data)
        data[('extras', next_index, 'key')] = 'spatial_uri'
        data[('extras', next_index, 'value')] = spatial_uri
    else:
        _set_value(data, 'spatial_uri', spatial_uri)
    

def next_extra_index(data):
    current_indexes = [k[1] for k in data.keys()
                       if len(k) > 1 and k[0] == 'extras']

    return max(current_indexes) + 1 if current_indexes else 0


def tag_name_validator(value, context):
    tagname_match = re.compile('[\w \-.\:\(\)\´\`]*$', re.UNICODE)
    if not tagname_match.match(value):
        raise toolkit.Invalid(_('Tag "%s" must be alphanumeric '
                                'characters or symbols: -_.:()') % (value))
    return value


def tag_string_convert(key, data, errors, context):
    '''Takes a list of tags that is a comma-separated string (in data[key])
    and parses tag names. These are added to the data dict, enumerated. They
    are also validated.'''
    if isinstance(data[key], basestring):
        tags = [tag.strip()
                for tag in data[key].split(',')
                if tag.strip()]
    else:
        tags = data[key]

    current_index = max([int(k[1]) for k in data.keys()
                         if len(k) == 3 and k[0] == 'tags'] + [-1])

    for num, tag in zip(count(current_index+1), tags):
        data[('tags', num, 'name')] = tag

    for tag in tags:
        toolkit.get_validator('tag_length_validator')(tag, context)
        tag_name_validator(tag, context)


def _convert_subjectID_to_subjectText(subject_id, flattened_data):

    if not subject_id:
        return flattened_data

    default_subject_mapping_file_path = '/usr/lib/ckan/default/src/ckanext-odsh/subject_mapping.json'
    subject_mapping_file_path = config.get(
        'ckanext.odsh.subject_mapping_file_path', default_subject_mapping_file_path)
    
    try:
        with open(subject_mapping_file_path) as mapping_json:
             subject_mapping = json.loads(mapping_json.read())
    except IOError as err:
        log.error(
            'Could not load subject mapping file from {}'
            .format(subject_mapping_file_path)
        )
        raise
    except ValueError as err:
        log.error(
            'Could not convert subject mapping file from json. \nSubject mapping file: {}'
            .format(subject_mapping_file_path)
        )
        raise
    
    try: 
        subject_text = subject_mapping[subject_id]
    except:
        raise toolkit.Invalid(_('Subject must be a known URI.'))
        log.warning(
            'Subject_id "{}" not found in subject mapping dictionary.\nSubject mapping file: {}'
            .format(subject_id, subject_mapping_file_path)
        )
        

    new_index = next_extra_index(flattened_data)
    flattened_data[('extras', new_index, 'key')] = 'subject_text'
    flattened_data[('extras', new_index, 'value')] = subject_text
    return flattened_data


def validate_subject(key, flattened_data, errors, context):
    subject_id = flattened_data[key]
    require_subject = toolkit.asbool(
        config.get('ckanext.odsh.require_subject', True)
    )
    if not require_subject:
        flattened_data = _convert_subjectID_to_subjectText(subject_id, flattened_data)
        return
    if not subject_id:
        raise toolkit.Invalid(_('Subject must not be empty.'))
    flattened_data = _convert_subjectID_to_subjectText(subject_id, flattened_data)


def get_validators():
    return {
        'known_spatial_uri': known_spatial_uri,
        'odsh_tag_name_validator': tag_name_validator,
        'odsh_validate_extras': validate_extras,
        'validate_licenseAttributionByText': validate_licenseAttributionByText,
        'tpsh_validate_subject': validate_subject,
    }