# Copyright 2012 OpenStack Foundation
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

import base64
import logging
import os
import textwrap
import uuid

from oslo_serialization import jsonutils
from oslo_utils import encodeutils
from oslo_utils import importutils
import prettytable
from urllib import error
from urllib import parse
from urllib import request
import yaml

from searchlightclient import exc
from searchlightclient.i18n import _


LOG = logging.getLogger(__name__)


supported_formats = {
    "json": lambda x: jsonutils.dumps(x, indent=2),
    "yaml": yaml.safe_dump
}


def env(*args, **kwargs):
    """Returns the first environment variable set.

    If all are empty, defaults to '' or keyword arg `default`.
    """
    for arg in args:
        value = os.environ.get(arg)
        if value:
            return value
    return kwargs.get('default', '')


def link_formatter(links):
    def format_link(l):
        if 'rel' in l:
            return "%s (%s)" % (l.get('href', ''), l.get('rel', ''))
        else:
            return "%s" % (l.get('href', ''))
    return '\n'.join(format_link(l) for l in links or [])


def resource_nested_identifier(rsrc):
    nested_link = [l for l in rsrc.links or []
                   if l.get('rel') == 'nested']
    if nested_link:
        nested_href = nested_link[0].get('href')
        nested_identifier = nested_href.split("/")[-2:]
        return "/".join(nested_identifier)


def json_formatter(js):
    return jsonutils.dumps(js, indent=2, ensure_ascii=False,
                           separators=(', ', ': '))


def yaml_formatter(js):
    return yaml.safe_dump(js, default_flow_style=False)


def text_wrap_formatter(d):
    return '\n'.join(textwrap.wrap(d or '', 55))


def newline_list_formatter(r):
    return '\n'.join(r or [])


def print_dict(d, formatters=None):
    formatters = formatters or {}
    pt = prettytable.PrettyTable(['Property', 'Value'],
                                 caching=False, print_empty=False)
    pt.align = 'l'

    for field in d:
        if field in formatters:
            pt.add_row([field, formatters[field](d[field])])
        else:
            pt.add_row([field, d[field]])
    print(pt.get_string(sortby='Property'))


def event_log_formatter(events):
    """Return the events in log format."""
    event_log = []
    log_format = _("%(event_date)s  %(event_time)s  %(event_id)s "
                   "[%(rsrc_name)s]: %(rsrc_status)s  %(rsrc_status_reason)s")
    for event in events:
        event_time = getattr(event, 'event_time', '')
        time_date = event_time.split('T')
        try:
            event_date = time_date[0]
            event_time = time_date[1]
        except IndexError:
            event_time = event_date = ''

        log = log_format % {
            'event_date': event_date, 'event_time': event_time,
            'event_id': getattr(event, 'id', ''),
            'rsrc_name': getattr(event, 'resource_name', ''),
            'rsrc_status': getattr(event, 'resource_status', ''),
            'rsrc_status_reason': getattr(event, 'resource_status_reason', '')
        }
        event_log.append(log)

    return "\n".join(event_log)


def print_update_list(lst, fields, formatters=None):
    """Print the stack-update --dry-run output as a table.

    This function is necessary to print the stack-update --dry-run
    output, which contains additional information about the update.
    """
    formatters = formatters or {}
    pt = prettytable.PrettyTable(fields, caching=False, print_empty=False)
    pt.align = 'l'

    for change in lst:
        row = []
        for field in fields:
            if field in formatters:
                row.append(formatters[field](change.get(field, None)))
            else:
                row.append(change.get(field, None))

        pt.add_row(row)

    print(encodeutils.safe_encode(pt.get_string()).decode())


def find_resource(manager, name_or_id):
    """Helper for the _find_* methods."""
    # first try to get entity as integer id
    try:
        if isinstance(name_or_id, int) or name_or_id.isdigit():
            return manager.get(int(name_or_id))
    except exc.NotFound:
        pass

    # now try to get entity as uuid
    try:
        uuid.UUID(str(name_or_id))
        return manager.get(name_or_id)
    except (ValueError, exc.NotFound):
        pass

    # finally try to find entity by name
    try:
        return manager.find(name=name_or_id)
    except exc.NotFound:
        msg = _("No %(name)s with a name or ID of "
                "'%(name_or_id)s' exists.") % \
            {
                'name': manager.resource_class.__name__.lower(),
                'name_or_id': name_or_id}
        raise exc.CommandError(msg)


def import_versioned_module(version, submodule=None):
    module = 'searchlightclient.v%s' % version
    if submodule:
        module = '.'.join((module, submodule))
    return importutils.import_module(module)


def format_parameters(params, parse_semicolon=True):
    '''Reformat parameters into dict of format expected by the API.'''

    if not params:
        return {}

    if parse_semicolon:
        # expect multiple invocations of --parameters but fall back
        # to ; delimited if only one --parameters is specified
        if len(params) == 1:
            params = params[0].split(';')

    parameters = {}
    for p in params:
        try:
            (n, v) = p.split(('='), 1)
        except ValueError:
            msg = _('Malformed parameter(%s). Use the key=value format.') % p
            raise exc.CommandError(msg)

        if n not in parameters:
            parameters[n] = v
        else:
            if not isinstance(parameters[n], list):
                parameters[n] = [parameters[n]]
            parameters[n].append(v)

    return parameters


def format_all_parameters(params, param_files,
                          template_file=None, template_url=None):
    parameters = {}
    parameters.update(format_parameters(params))
    parameters.update(format_parameter_file(
        param_files,
        template_file,
        template_url))
    return parameters


def format_parameter_file(param_files, template_file=None,
                          template_url=None):
    '''Reformat file parameters into dict of format expected by the API.'''
    if not param_files:
        return {}
    params = format_parameters(param_files, False)

    template_base_url = None
    if template_file or template_url:
        template_base_url = base_url_for_url(get_template_url(
            template_file, template_url))

    param_file = {}
    for key, value in iter(params.items()):
        param_file[key] = resolve_param_get_file(value,
                                                 template_base_url)
    return param_file


def resolve_param_get_file(file, base_url):
    if base_url and not base_url.endswith('/'):
        base_url = base_url + '/'
    str_url = parse.urljoin(base_url, file)
    return read_url_content(str_url)


def format_output(output, format='yaml'):
    """Format the supplied dict as specified."""
    output_format = format.lower()
    try:
        return supported_formats[output_format](output)
    except KeyError:
        raise exc.HTTPUnsupported(_("The format(%s) is unsupported.")
                                  % output_format)


def parse_query_url(url):
    base_url, query_params = url.split('?')
    return base_url, parse.parse_qs(query_params)


def get_template_url(template_file=None, template_url=None):
    if template_file:
        template_url = normalise_file_path_to_url(template_file)
    return template_url


def read_url_content(url):
    try:
        content = request.urlopen(url).read()
    except error.URLError:
        raise exc.CommandError(_('Could not fetch contents for %s') % url)

    if content:
        try:
            content.decode('utf-8')
        except ValueError:
            content = base64.encodestring(content)
    return content


def base_url_for_url(url):
    parsed = parse.urlparse(url)
    parsed_dir = os.path.dirname(parsed.path)
    return parse.urljoin(url, parsed_dir)


def normalise_file_path_to_url(path):
    if parse.urlparse(path).scheme:
        return path
    path = os.path.abspath(path)
    return parse.urljoin('file:', request.pathname2url(path))


def get_response_body(resp):
    body = resp.content
    if 'application/json' in resp.headers.get('content-type', ''):
        try:
            body = resp.json()
        except ValueError:
            LOG.error('Could not decode response body as JSON')
    else:
        body = None
    return body
