# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2014 IBM Corporation
# Copyright 2015 Lenovo
#
# 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.
# concept here that mapping from the resource tree and arguments go to
# specific python class signatures.  The intent is to require
# plugin authors to come here if they *really* think they need new 'commands'
# and hopefully curtail deviation by each plugin author

# have to specify a standard place for cfg selection of *which* plugin
# as well a standard to map api requests to python funcitons
# e.g. <nodeelement>/power/state maps to some plugin
# HardwareManager.get_power/set_power selected by hardwaremanagement.method
# plugins can advertise a set of names if there is a desire for readable things
# exceptions to handle os images
# endpoints point to a class... usually, the class should have:
# -create
# -retrieve
# -update
# -delete
# functions.  Console is special and just get's passed through
# see API.txt

import confluentd.alerts as alerts
import confluentd.config.attributes as attrscheme
import confluentd.interface.console as console
import confluentd.exceptions as exc
import confluentd.messages as msg
import confluentd.noderange as noderange
try:
    import confluentd.shellmodule as shellmodule
except ImportError:
    pass
import itertools
import os
import sys

pluginmap = {}


def seek_element(currplace, currkey):
    try:
        return currplace[currkey]
    except TypeError:
        if isinstance(currplace, PluginCollection):
            # we hit a plugin curated collection, all children
            # are up to the plugin to comprehend
            return currplace
        raise


def nested_lookup(nestdict, key):
    try:
        return reduce(seek_element, key, nestdict)
    except TypeError:
        raise exc.NotFoundException("Invalid element requested")


def load_plugins():
    # To know our plugins directory, we get the parent path of 'bin'
    path = os.path.dirname(os.path.realpath(__file__))
    plugintop = os.path.realpath(os.path.join(path, 'plugins'))
    plugins = set()
    for plugindir in os.listdir(plugintop):
        plugindir = os.path.join(plugintop, plugindir)
        if not os.path.isdir(plugindir):
            continue
        sys.path.append(plugindir)
        # two passes, to avoid adding both py and pyc files
        for plugin in os.listdir(plugindir):
            if plugin.startswith('.'):
                continue
            (plugin, plugtype) = os.path.splitext(plugin)
            if plugtype == '.sh':
                pluginmap[plugin] = shellmodule.Plugin(
                    os.path.join(plugindir, plugin + '.sh'))
            elif "__init__" not in plugin:
                plugins.add(plugin)
        for plugin in plugins:
            tmpmod = __import__(plugin)
            if 'plugin_names' in tmpmod.__dict__:
                for name in tmpmod.plugin_names:
                    pluginmap[name] = tmpmod
            else:
                pluginmap[plugin] = tmpmod


rootcollections = ['noderange/', 'nodes/', 'nodegroups/', 'users/', 'events/']


class PluginRoute(object):
    def __init__(self, routedict):
        self.routeinfo = routedict


class PluginCollection(object):
    def __init__(self, routedict):
        self.routeinfo = routedict

# _ prefix indicates internal use (e.g. special console scheme) and should not
# be enumerated in any collection
noderesources = {
    'attributes': {
        'all': PluginRoute({'handler': 'attributes'}),
        'current': PluginRoute({'handler': 'attributes'}),
    },
    'boot': {
        'nextdevice': PluginRoute({
            'pluginattrs': ['hardwaremanagement.method'],
            'default': 'ipmi',
        }),
    },
    'configuration': {
        'management_controller': {
            'alerts': {
                'destinations': PluginCollection({
                    'pluginattrs': ['hardwaremanagement.method'],
                    'default': 'ipmi',
                }),
            },
            'users': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'net_interfaces': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'reset': PluginRoute({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'identifier': PluginRoute({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
        }
    },
    '_console': {
        'session': PluginRoute({
            'pluginattrs': ['console.method'],
        }),
    },
    'console': {
        # this is a dummy value, http or socket must handle special
        'session': PluginRoute({}),
    },
    'events': {
        'hardware': {
            'log': PluginRoute({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'decode': PluginRoute({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
        },
    },
    'health': {
        'hardware': PluginRoute({
            'pluginattrs': ['hardwaremanagement.method'],
            'default': 'ipmi',
        }),
    },
    'identify': PluginRoute({
        'pluginattrs': ['hardwaremanagement.method'],
        'default': 'ipmi',
    }),
    'inventory': {
        'hardware': {
            'all': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
        },
        'firmware': {
            'all': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
        },
    },
    'power': {
        'state': PluginRoute({
            'pluginattrs': ['hardwaremanagement.method'],
            'default': 'ipmi',
        }),
    },
    'sensors': {
        'hardware': {
            'all': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'temperature': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'power': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
            'fans': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            }),
        },
        'led': {
            'all': PluginCollection({
                'pluginattrs': ['hardwaremanagement.method'],
                'default': 'ipmi',
            })
        },
    },
}

nodegroupresources = {
    'attributes': {
        'all': PluginRoute({'handler': 'attributes'}),
        'current': PluginRoute({'handler': 'attributes'}),
    },
}


def create_user(inputdata, configmanager):
    try:
        username = inputdata['name']
        del inputdata['name']
    except (KeyError, ValueError):
        raise exc.InvalidArgumentException()
    configmanager.create_user(username, attributemap=inputdata)


def update_user(name, attribmap, configmanager):
    try:
        configmanager.set_user(name, attribmap)
    except ValueError:
        raise exc.InvalidArgumentException()


def show_user(name, configmanager):
    userobj = configmanager.get_user(name)
    rv = {}
    for attr in attrscheme.user.iterkeys():
        rv[attr] = None
        if attr == 'password':
            if 'cryptpass' in userobj:
                rv['password'] = {'cryptvalue': True}
            yield msg.CryptedAttributes(kv={'password': rv['password']},
                                        desc=attrscheme.user[attr][
                                            'description'])
        else:
            if attr in userobj:
                rv[attr] = userobj[attr]
            yield msg.Attributes(kv={attr: rv[attr]},
                                 desc=attrscheme.user[attr]['description'])


def stripnode(iterablersp, node):
    for i in iterablersp:
        if i is None:
            raise exc.NotImplementedException("Not Implemented")
        i.strip_node(node)
        yield i


def iterate_collections(iterable, forcecollection=True):
    for coll in iterable:
        if forcecollection and coll[-1] != '/':
            coll += '/'
        yield msg.ChildCollection(coll, candelete=True)


def iterate_resources(fancydict):
    for resource in fancydict.iterkeys():
        if resource.startswith("_"):
            continue
        if not isinstance(fancydict[resource], PluginRoute):  # a resource
            resource += '/'
        yield msg.ChildCollection(resource)


def delete_user(user, configmanager):
    configmanager.del_user(user)
    yield msg.DeletedResource(user)


def delete_nodegroup_collection(collectionpath, configmanager):
    if len(collectionpath) == 2:  # just the nodegroup
        group = collectionpath[-1]
        configmanager.del_groups([group])
        yield msg.DeletedResource(group)
    else:
        raise Exception("Not implemented")


def delete_node_collection(collectionpath, configmanager):
    if len(collectionpath) == 2:  # just node
        node = collectionpath[-1]
        configmanager.del_nodes([node])
        yield msg.DeletedResource(node)
    else:
        raise Exception("Not implemented")


def enumerate_nodegroup_collection(collectionpath, configmanager):
    nodegroup = collectionpath[1]
    if not configmanager.is_nodegroup(nodegroup):
        raise exc.NotFoundException("Invalid element requested")
    del collectionpath[0:2]
    collection = nested_lookup(nodegroupresources, collectionpath)
    return iterate_resources(collection)


def enumerate_node_collection(collectionpath, configmanager):
    if collectionpath == ['nodes']:  # it is just '/node/', need to list nodes
        allnodes = list(configmanager.list_nodes())
        try:
            allnodes.sort(key=noderange.humanify_nodename)
        except TypeError:
            allnodes.sort()
        return iterate_collections(allnodes)
    nodeorrange = collectionpath[1]
    if collectionpath[0] == 'nodes' and not configmanager.is_node(nodeorrange):
        raise exc.NotFoundException("Invalid element requested")
    collection = nested_lookup(noderesources, collectionpath[2:])
    if len(collectionpath) == 2 and collectionpath[0] == 'noderange':
        collection['nodes'] = {}
    if not isinstance(collection, dict):
        raise exc.NotFoundException("Invalid element requested")
    return iterate_resources(collection)


def create_group(inputdata, configmanager):
    try:
        groupname = inputdata['name']
        del inputdata['name']
        attribmap = {groupname: inputdata}
    except KeyError:
        raise exc.InvalidArgumentException()
    try:
        configmanager.add_group_attributes(attribmap)
    except ValueError as e:
        raise exc.InvalidArgumentException(str(e))


def create_node(inputdata, configmanager):
    try:
        nodename = inputdata['name']
        del inputdata['name']
        attribmap = {nodename: inputdata}
    except KeyError:
        raise exc.InvalidArgumentException('name not specified')
    try:
        configmanager.add_node_attributes(attribmap)
    except ValueError as e:
        raise exc.InvalidArgumentException(str(e))


def enumerate_collections(collections):
    for collection in collections:
        yield msg.ChildCollection(collection)


def handle_nodegroup_request(configmanager, inputdata,
                             pathcomponents, operation):
    iscollection = False
    routespec = None
    if len(pathcomponents) < 2:
        if operation == "create":
            inputdata = msg.InputAttributes(pathcomponents, inputdata)
            create_group(inputdata.attribs, configmanager)
        allgroups = list(configmanager.get_groups())
        try:
            allgroups.sort(key=noderange.humanify_nodename)
        except TypeError:
            allgroups.sort()
        return iterate_collections(allgroups)
    elif len(pathcomponents) == 2:
        iscollection = True
    else:
        try:
            routespec = nested_lookup(nodegroupresources, pathcomponents[2:])
            if isinstance(routespec, dict):
                iscollection = True
            elif isinstance(routespec, PluginCollection):
                iscollection = False  # it is a collection, but plugin defined
        except KeyError:
            raise exc.NotFoundException("Invalid element requested")
    if iscollection:
        if operation == "delete":
            return delete_nodegroup_collection(pathcomponents,
                                               configmanager)
        elif operation == "retrieve":
            return enumerate_nodegroup_collection(pathcomponents,
                                                  configmanager)
        else:
            raise Exception("TODO")
    plugroute = routespec.routeinfo
    inputdata = msg.get_input_message(
        pathcomponents[2:], operation, inputdata)
    if 'handler' in plugroute:  # fixed handler definition
        hfunc = getattr(pluginmap[plugroute['handler']], operation)
        return hfunc(
            nodes=None, element=pathcomponents,
            configmanager=configmanager,
            inputdata=inputdata)
    raise Exception("unknown case encountered")


def handle_node_request(configmanager, inputdata, operation,
                        pathcomponents, autostrip=True):
    iscollection = False
    routespec = None
    if pathcomponents[0] == 'noderange':
        if len(pathcomponents) > 3 and pathcomponents[2] == 'nodes':
            # transform into a normal looking node request
            # this does mean we don't see if it is a valid
            # child, but that's not a goal for the noderange
            # facility anyway
            isnoderange = False
            pathcomponents = pathcomponents[2:]
        else:
            isnoderange = True
    else:
        isnoderange = False
    try:
        nodeorrange = pathcomponents[1]
        if not isnoderange and not configmanager.is_node(nodeorrange):
            raise exc.NotFoundException("Invalid Node")
        if isnoderange:
            try:
                nodes = noderange.NodeRange(nodeorrange, configmanager).nodes
            except Exception as e:
                raise exc.NotFoundException("Invalid Noderange: " + str(e))
        else:
            nodes = (nodeorrange,)
    except IndexError:  # doesn't actually have a long enough path
        # this is enumerating a list of nodes or just empty noderange
        if isnoderange and operation == "retrieve":
            return iterate_collections([])
        elif isnoderange or operation == "delete":
            raise exc.InvalidArgumentException()
        if operation == "create":
            inputdata = msg.InputAttributes(pathcomponents, inputdata)
            create_node(inputdata.attribs, configmanager)
        allnodes = list(configmanager.list_nodes())
        try:
            allnodes.sort(key=noderange.humanify_nodename)
        except TypeError:
            allnodes.sort()
        return iterate_collections(allnodes)
    if (isnoderange and len(pathcomponents) == 3 and
            pathcomponents[2] == 'nodes'):
        # this means that it's a list of relevant nodes
        nodes = list(nodes)
        try:
            nodes.sort(key=noderange.humanify_nodename)
        except TypeError:
            nodes.sort()
        return iterate_collections(nodes)
    if len(pathcomponents) == 2:
        iscollection = True
    else:
        try:
            routespec = nested_lookup(noderesources, pathcomponents[2:])
        except KeyError:
            raise exc.NotFoundException("Invalid element requested")
        if isinstance(routespec, dict):
            iscollection = True
        elif isinstance(routespec, PluginCollection):
            iscollection = False  # it is a collection, but plugin defined
    if iscollection:
        if operation == "delete":
            return delete_node_collection(pathcomponents, configmanager)
        elif operation == "retrieve":
            return enumerate_node_collection(pathcomponents, configmanager)
        else:
            raise Exception("TODO here")
    del pathcomponents[0:2]
    passvalues = []
    plugroute = routespec.routeinfo
    inputdata = msg.get_input_message(
        pathcomponents, operation, inputdata, nodes, isnoderange)
    if 'handler' in plugroute:  # fixed handler definition, easy enough
        hfunc = getattr(pluginmap[plugroute['handler']], operation)
        passvalue = hfunc(
            nodes=nodes, element=pathcomponents,
            configmanager=configmanager,
            inputdata=inputdata)
        if isnoderange:
            return passvalue
        else:
            return stripnode(passvalue, nodes[0])
    elif 'pluginattrs' in plugroute:
        nodeattr = configmanager.get_node_attributes(
            nodes, plugroute['pluginattrs'])
        plugpath = None
        if 'default' in plugroute:
            plugpath = plugroute['default']
        nodesbyhandler = {}
        for node in nodes:
            for attrname in plugroute['pluginattrs']:
                if attrname in nodeattr[node]:
                    plugpath = nodeattr[node][attrname]['value']
            if plugpath is not None:
                hfunc = getattr(pluginmap[plugpath], operation)
                if hfunc in nodesbyhandler:
                    nodesbyhandler[hfunc].append(node)
                else:
                    nodesbyhandler[hfunc] = [node]
        for hfunc in nodesbyhandler:
            passvalues.append(hfunc(
                nodes=nodesbyhandler[hfunc], element=pathcomponents,
                configmanager=configmanager,
                inputdata=inputdata))
        if isnoderange or not autostrip:
            return itertools.chain(*passvalues)
        elif isinstance(passvalues[0], console.Console):
            return passvalues[0]
        else:
            return stripnode(passvalues[0], nodes[0])


def handle_path(path, operation, configmanager, inputdata=None, autostrip=True):
    """Given a full path request, return an object.

    The plugins should generally return some sort of iterator.
    An exception is made for console/session, which should return
    a class with connect(), read(), write(bytes), and close()
    """
    pathcomponents = path.split('/')
    del pathcomponents[0]  # discard the value from leading /
    if pathcomponents[-1] == '':
        del pathcomponents[-1]
    if not pathcomponents:  # root collection list
        return enumerate_collections(rootcollections)
    elif pathcomponents[0] == 'noderange':
        return handle_node_request(configmanager, inputdata, operation,
                                   pathcomponents, autostrip)
    elif pathcomponents[0] == 'nodegroups':
        return handle_nodegroup_request(configmanager, inputdata,
                                        pathcomponents,
                                        operation)
    elif pathcomponents[0] == 'nodes':
        # single node request of some sort
        return handle_node_request(configmanager, inputdata,
                                   operation, pathcomponents, autostrip)
    elif pathcomponents[0] == 'users':
        # TODO: when non-administrator accounts exist,
        # they must only be allowed to see their own user
        try:
            user = pathcomponents[1]
        except IndexError:  # it's just users/
            if operation == 'create':
                inputdata = msg.get_input_message(
                    pathcomponents, operation, inputdata)
                create_user(inputdata.attribs, configmanager)
            return iterate_collections(configmanager.list_users(),
                                       forcecollection=False)
        if user not in configmanager.list_users():
            raise exc.NotFoundException("Invalid user %s" % user)
        if operation == 'retrieve':
            return show_user(user, configmanager)
        elif operation == 'delete':
            return delete_user(user, configmanager)
        elif operation == 'update':
            inputdata = msg.get_input_message(
                pathcomponents, operation, inputdata)
            update_user(user, inputdata.attribs, configmanager)
            return show_user(user, configmanager)
    elif pathcomponents[0] == 'events':
        try:
            element = pathcomponents[1]
        except IndexError:
            if operation != 'retrieve':
                raise exc.InvalidArgumentException('Target is read-only')
            return (msg.ChildCollection('decode'),)
        if element != 'decode':
            raise exc.NotFoundException()
        if operation == 'update':
            return alerts.decode_alert(inputdata, configmanager)
    else:
        raise exc.NotFoundException()