#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2015, Maciej Delmanowski <drybjed@gmail.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

ANSIBLE_METADATA = {'status': ['preview'],
                    'supported_by': 'community',
                    'version': '1.0'}

DOCUMENTATION = '''
---
module: virt_pool
author: "Maciej Delmanowski (@drybjed)"
version_added: "2.0"
short_description: Manage libvirt storage pools
description:
    - Manage I(libvirt) storage pools.
options:
    name:
        required: false
        aliases: [ "pool" ]
        description:
            - name of the storage pool being managed. Note that pool must be previously
              defined with xml.
    state:
        required: false
        choices: [ "active", "inactive", "present", "absent", "undefined", "deleted" ]
        description:
            - specify which state you want a storage pool to be in.
              If 'active', pool will be started.
              If 'present', ensure that pool is present but do not change its
              state; if it's missing, you need to specify xml argument.
              If 'inactive', pool will be stopped.
              If 'undefined' or 'absent', pool will be removed from I(libvirt) configuration.
              If 'deleted', pool contents will be deleted and then pool undefined.
    command:
        required: false
        choices: [ "define", "build", "create", "start", "stop", "destroy",
                   "delete", "undefine", "get_xml", "list_pools", "facts",
                   "info", "status" ]
        description:
            - in addition to state management, various non-idempotent commands are available.
              See examples.
    autostart:
        required: false
        choices: ["yes", "no"]
        description:
            - Specify if a given storage pool should be started automatically on system boot.
    uri:
        required: false
        default: "qemu:///system"
        description:
            - I(libvirt) connection uri.
    xml:
        required: false
        description:
            - XML document used with the define command.
    mode:
        required: false
        choices: [ 'new', 'repair', 'resize', 'no_overwrite', 'overwrite', 'normal', 'zeroed' ]
        description:
            - Pass additional parameters to 'build' or 'delete' commands.
requirements:
    - "python >= 2.6"
    - "python-libvirt"
    - "python-lxml"
'''

EXAMPLES = '''
# Define a new storage pool
- virt_pool:
    command: define
    name: vms
    xml: '{{ lookup("template", "pool/dir.xml.j2") }}'

# Build a storage pool if it does not exist
- virt_pool:
    command: build
    name: vms

# Start a storage pool
- virt_pool:
    command: create
    name: vms

# List available pools
- virt_pool:
    command: list_pools

# Get XML data of a specified pool
- virt_pool:
    command: get_xml
    name: vms

# Stop a storage pool
- virt_pool:
    command: destroy
    name: vms

# Delete a storage pool (destroys contents)
- virt_pool:
    command: delete
    name: vms

# Undefine a storage pool
- virt_pool:
    command: undefine
    name: vms

# Gather facts about storage pools
# Facts will be available as 'ansible_libvirt_pools'
- virt_pool:
    command: facts

# Gather information about pools managed by 'libvirt' remotely using uri
- virt_pool:
    command: info
    uri: '{{ item }}'
  with_items: '{{ libvirt_uris }}'
  register: storage_pools

# Ensure that a pool is active (needs to be defined and built first)
- virt_pool:
    state: active
    name: vms

# Ensure that a pool is inactive
- virt_pool:
    state: inactive
    name: vms

# Ensure that a given pool will be started at boot
- virt_pool:
    autostart: yes
    name: vms

# Disable autostart for a given pool
- virt_pool:
    autostart: no
    name: vms
'''

VIRT_FAILED = 1
VIRT_SUCCESS = 0
VIRT_UNAVAILABLE=2

try:
    import libvirt
except ImportError:
    HAS_VIRT = False
else:
    HAS_VIRT = True

try:
    from lxml import etree
except ImportError:
    HAS_XML = False
else:
    HAS_XML = True

from ansible.module_utils.basic import AnsibleModule


ALL_COMMANDS = []
ENTRY_COMMANDS = ['create', 'status', 'start', 'stop', 'build', 'delete',
                  'undefine', 'destroy', 'get_xml', 'define', 'refresh']
HOST_COMMANDS = [ 'list_pools', 'facts', 'info' ]
ALL_COMMANDS.extend(ENTRY_COMMANDS)
ALL_COMMANDS.extend(HOST_COMMANDS)

ENTRY_STATE_ACTIVE_MAP = {
    0 : "inactive",
    1 : "active"
}

ENTRY_STATE_AUTOSTART_MAP = {
    0 : "no",
    1 : "yes"
}

ENTRY_STATE_PERSISTENT_MAP = {
    0 : "no",
    1 : "yes"
}

ENTRY_STATE_INFO_MAP = {
    0 : "inactive",
    1 : "building",
    2 : "running",
    3 : "degraded",
    4 : "inaccessible"
}

ENTRY_BUILD_FLAGS_MAP = {
    "new" : 0,
    "repair" : 1,
    "resize" : 2,
    "no_overwrite"  : 4,
    "overwrite" : 8
}

ENTRY_DELETE_FLAGS_MAP = {
    "normal" : 0,
    "zeroed" : 1
}

ALL_MODES = []
ALL_MODES.extend(ENTRY_BUILD_FLAGS_MAP.keys())
ALL_MODES.extend(ENTRY_DELETE_FLAGS_MAP.keys())


class EntryNotFound(Exception):
    pass


class LibvirtConnection(object):

    def __init__(self, uri, module):

        self.module = module

        conn = libvirt.open(uri)

        if not conn:
            raise Exception("hypervisor connection failure")

        self.conn = conn

    def find_entry(self, entryid):
        # entryid = -1 returns a list of everything

        results = []

        # Get active entries
        for name in self.conn.listStoragePools():
            entry = self.conn.storagePoolLookupByName(name)
            results.append(entry)

        # Get inactive entries
        for name in self.conn.listDefinedStoragePools():
            entry = self.conn.storagePoolLookupByName(name)
            results.append(entry)

        if entryid == -1:
            return results

        for entry in results:
            if entry.name() == entryid:
                return entry

        raise EntryNotFound("storage pool %s not found" % entryid)

    def create(self, entryid):
        if not self.module.check_mode:
            return self.find_entry(entryid).create()
        else:
            try:
                state = self.find_entry(entryid).isActive()
            except:
                return self.module.exit_json(changed=True)
            if not state:
                return self.module.exit_json(changed=True)

    def destroy(self, entryid):
        if not self.module.check_mode:
            return self.find_entry(entryid).destroy()
        else:
            if self.find_entry(entryid).isActive():
                return self.module.exit_json(changed=True)

    def undefine(self, entryid):
        if not self.module.check_mode:
            return self.find_entry(entryid).undefine()
        else:
            if not self.find_entry(entryid):
                return self.module.exit_json(changed=True)

    def get_status2(self, entry):
        state = entry.isActive()
        return ENTRY_STATE_ACTIVE_MAP.get(state,"unknown")

    def get_status(self, entryid):
        if not self.module.check_mode:
            state = self.find_entry(entryid).isActive()
            return ENTRY_STATE_ACTIVE_MAP.get(state,"unknown")
        else:
            try:
                state = self.find_entry(entryid).isActive()
                return ENTRY_STATE_ACTIVE_MAP.get(state,"unknown")
            except:
                return ENTRY_STATE_ACTIVE_MAP.get("inactive","unknown")

    def get_uuid(self, entryid):
        return self.find_entry(entryid).UUIDString()

    def get_xml(self, entryid):
        return self.find_entry(entryid).XMLDesc(0)

    def get_info(self, entryid):
        return self.find_entry(entryid).info()

    def get_volume_count(self, entryid):
        return self.find_entry(entryid).numOfVolumes()

    def get_volume_names(self, entryid):
        return self.find_entry(entryid).listVolumes()

    def get_devices(self, entryid):
        xml = etree.fromstring(self.find_entry(entryid).XMLDesc(0))
        if xml.xpath('/pool/source/device'):
            result = []
            for device in xml.xpath('/pool/source/device'):
                result.append(device.get('path'))
        try:
            return result
        except:
            raise ValueError('No devices specified')

    def get_format(self, entryid):
        xml = etree.fromstring(self.find_entry(entryid).XMLDesc(0))
        try:
            result = xml.xpath('/pool/source/format')[0].get('type')
        except:
            raise ValueError('Format not specified')
        return result

    def get_host(self, entryid):
        xml = etree.fromstring(self.find_entry(entryid).XMLDesc(0))
        try:
            result = xml.xpath('/pool/source/host')[0].get('name')
        except:
            raise ValueError('Host not specified')
        return result

    def get_source_path(self, entryid):
        xml = etree.fromstring(self.find_entry(entryid).XMLDesc(0))
        try:
            result = xml.xpath('/pool/source/dir')[0].get('path')
        except:
            raise ValueError('Source path not specified')
        return result

    def get_path(self, entryid):
        xml = etree.fromstring(self.find_entry(entryid).XMLDesc(0))
        return xml.xpath('/pool/target/path')[0].text

    def get_type(self, entryid):
        xml = etree.fromstring(self.find_entry(entryid).XMLDesc(0))
        return xml.get('type')

    def build(self, entryid, flags):
        if not self.module.check_mode:
            return self.find_entry(entryid).build(flags)
        else:
            try:
                state = self.find_entry(entryid)
            except:
                return self.module.exit_json(changed=True)
            if not state:
                return self.module.exit_json(changed=True)

    def delete(self, entryid, flags):
        if not self.module.check_mode:
            return self.find_entry(entryid).delete(flags)
        else:
            try:
                state = self.find_entry(entryid)
            except:
                return self.module.exit_json(changed=True)
            if state:
                return self.module.exit_json(changed=True)

    def get_autostart(self, entryid):
        state = self.find_entry(entryid).autostart()
        return ENTRY_STATE_AUTOSTART_MAP.get(state,"unknown")

    def get_autostart2(self, entryid):
        if not self.module.check_mode:
            return self.find_entry(entryid).autostart()
        else:
            try:
                return self.find_entry(entryid).autostart()
            except:
                return self.module.exit_json(changed=True)

    def set_autostart(self, entryid, val):
        if not self.module.check_mode:
            return self.find_entry(entryid).setAutostart(val)
        else:
            try:
                state = self.find_entry(entryid).autostart()
            except:
                return self.module.exit_json(changed=True)
            if bool(state) != val:
                return self.module.exit_json(changed=True)

    def refresh(self, entryid):
        return self.find_entry(entryid).refresh()

    def get_persistent(self, entryid):
        state = self.find_entry(entryid).isPersistent()
        return ENTRY_STATE_PERSISTENT_MAP.get(state,"unknown")

    def define_from_xml(self, entryid, xml):
        if not self.module.check_mode:
            return self.conn.storagePoolDefineXML(xml)
        else:
            try:
                self.find_entry(entryid)
            except:
                return self.module.exit_json(changed=True)


class VirtStoragePool(object):

    def __init__(self, uri, module):
        self.module = module
        self.uri = uri
        self.conn = LibvirtConnection(self.uri, self.module)

    def get_pool(self, entryid):
        return self.conn.find_entry(entryid)

    def list_pools(self, state=None):
        results = []
        for entry in self.conn.find_entry(-1):
            if state:
                if state == self.conn.get_status2(entry):
                    results.append(entry.name())
            else:
                results.append(entry.name())
        return results

    def state(self):
        results = []
        for entry in self.list_pools():
            state_blurb = self.conn.get_status(entry)
            results.append("%s %s" % (entry,state_blurb))
        return results

    def autostart(self, entryid):
        return self.conn.set_autostart(entryid, True)

    def get_autostart(self, entryid):
        return self.conn.get_autostart2(entryid)

    def set_autostart(self, entryid, state):
        return self.conn.set_autostart(entryid, state)

    def create(self, entryid):
        return self.conn.create(entryid)

    def start(self, entryid):
        return self.conn.create(entryid)

    def stop(self, entryid):
        return self.conn.destroy(entryid)

    def destroy(self, entryid):
        return self.conn.destroy(entryid)

    def undefine(self, entryid):
        return self.conn.undefine(entryid)

    def status(self, entryid):
        return self.conn.get_status(entryid)

    def get_xml(self, entryid):
        return self.conn.get_xml(entryid)

    def define(self, entryid, xml):
        return self.conn.define_from_xml(entryid, xml)

    def build(self, entryid, flags):
        return self.conn.build(entryid, ENTRY_BUILD_FLAGS_MAP.get(flags,0))

    def delete(self, entryid, flags):
        return self.conn.delete(entryid, ENTRY_DELETE_FLAGS_MAP.get(flags,0))

    def refresh(self, entryid):
        return self.conn.refresh(entryid)

    def info(self):
        return self.facts(facts_mode='info')

    def facts(self, facts_mode='facts'):
        results = dict()
        for entry in self.list_pools():
            results[entry] = dict()
            if self.conn.find_entry(entry):
                data = self.conn.get_info(entry)
                # libvirt returns maxMem, memory, and cpuTime as long()'s, which
                # xmlrpclib tries to convert to regular int's during serialization.
                # This throws exceptions, so convert them to strings here and
                # assume the other end of the xmlrpc connection can figure things
                # out or doesn't care.
                results[entry] = {
                    "status"    : ENTRY_STATE_INFO_MAP.get(data[0],"unknown"),
                    "size_total"  : str(data[1]),
                    "size_used"  : str(data[2]),
                    "size_available"  : str(data[3]),
                }
                results[entry]["autostart"] = self.conn.get_autostart(entry)
                results[entry]["persistent"] = self.conn.get_persistent(entry)
                results[entry]["state"] = self.conn.get_status(entry)
                results[entry]["path"] = self.conn.get_path(entry)
                results[entry]["type"] = self.conn.get_type(entry)
                results[entry]["uuid"] = self.conn.get_uuid(entry)
                if self.conn.find_entry(entry).isActive():
                    results[entry]["volume_count"] = self.conn.get_volume_count(entry)
                    results[entry]["volumes"] = list()
                    for volume in self.conn.get_volume_names(entry):
                        results[entry]["volumes"].append(volume)
                else:
                    results[entry]["volume_count"] = -1

                try:
                    results[entry]["host"] = self.conn.get_host(entry)
                except ValueError:
                    pass

                try:
                    results[entry]["source_path"] = self.conn.get_source_path(entry)
                except ValueError:
                    pass

                try:
                    results[entry]["format"] = self.conn.get_format(entry)
                except ValueError:
                    pass

                try:
                    devices = self.conn.get_devices(entry)
                    results[entry]["devices"] = devices
                except ValueError:
                    pass

            else:
                results[entry]["state"] = self.conn.get_status(entry)

        facts = dict()
        if facts_mode == 'facts':
            facts["ansible_facts"] = dict()
            facts["ansible_facts"]["ansible_libvirt_pools"] = results
        elif facts_mode == 'info':
            facts['pools'] = results
        return facts


def core(module):

    state     = module.params.get('state', None)
    name      = module.params.get('name', None)
    command   = module.params.get('command', None)
    uri       = module.params.get('uri', None)
    xml       = module.params.get('xml', None)
    autostart = module.params.get('autostart', None)
    mode      = module.params.get('mode', None)

    v = VirtStoragePool(uri, module)
    res = {}

    if state and command == 'list_pools':
        res = v.list_pools(state=state)
        if not isinstance(res, dict):
            res = { command: res }
        return VIRT_SUCCESS, res

    if state:
        if not name:
            module.fail_json(msg = "state change requires a specified name")

        res['changed'] = False
        if state in [ 'active' ]:
            if v.status(name) is not 'active':
                res['changed'] = True
                res['msg'] = v.start(name)
        elif state in [ 'present' ]:
            try:
                v.get_pool(name)
            except EntryNotFound:
                if not xml:
                    module.fail_json(msg = "storage pool '" + name + "' not present, but xml not specified")
                v.define(name, xml)
                res = {'changed': True, 'created': name}
        elif state in [ 'inactive' ]:
            entries = v.list_pools()
            if name in entries:
                if v.status(name) is not 'inactive':
                    res['changed'] = True
                    res['msg'] = v.destroy(name)
        elif state in [ 'undefined', 'absent' ]:
            entries = v.list_pools()
            if name in entries:
                if v.status(name) is not 'inactive':
                    v.destroy(name)
                res['changed'] = True
                res['msg'] = v.undefine(name)
        elif state in [ 'deleted' ]:
            entries = v.list_pools()
            if name in entries:
                if v.status(name) is not 'inactive':
                    v.destroy(name)
                v.delete(name, mode)
                res['changed'] = True
                res['msg'] = v.undefine(name)
        else:
            module.fail_json(msg="unexpected state")

        return VIRT_SUCCESS, res

    if command:
        if command in ENTRY_COMMANDS:
            if not name:
                module.fail_json(msg = "%s requires 1 argument: name" % command)
            if command == 'define':
                if not xml:
                    module.fail_json(msg = "define requires xml argument")
                try:
                    v.get_pool(name)
                except EntryNotFound:
                    v.define(name, xml)
                    res = {'changed': True, 'created': name}
                return VIRT_SUCCESS, res
            elif command == 'build':
                res = v.build(name, mode)
                if not isinstance(res, dict):
                    res = { 'changed': True, command: res }
                return VIRT_SUCCESS, res
            elif command == 'delete':
                res = v.delete(name, mode)
                if not isinstance(res, dict):
                    res = { 'changed': True, command: res }
                return VIRT_SUCCESS, res
            res = getattr(v, command)(name)
            if not isinstance(res, dict):
                res = { command: res }
            return VIRT_SUCCESS, res

        elif hasattr(v, command):
            res = getattr(v, command)()
            if not isinstance(res, dict):
                res = { command: res }
            return VIRT_SUCCESS, res

        else:
            module.fail_json(msg="Command %s not recognized" % command)

    if autostart is not None:
        if not name:
            module.fail_json(msg = "state change requires a specified name")

        res['changed'] = False
        if autostart:
            if not v.get_autostart(name):
                res['changed'] = True
                res['msg'] = v.set_autostart(name, True)
        else:
            if v.get_autostart(name):
                res['changed'] = True
                res['msg'] = v.set_autostart(name, False)

        return VIRT_SUCCESS, res

    module.fail_json(msg="expected state or command parameter to be specified")


def main():

    module = AnsibleModule (
        argument_spec = dict(
            name = dict(aliases=['pool']),
            state = dict(choices=['active', 'inactive', 'present', 'absent', 'undefined', 'deleted']),
            command = dict(choices=ALL_COMMANDS),
            uri = dict(default='qemu:///system'),
            xml = dict(),
            autostart = dict(type='bool'),
            mode = dict(choices=ALL_MODES),
        ),
        supports_check_mode = True
    )

    if not HAS_VIRT:
        module.fail_json(
            msg='The `libvirt` module is not importable. Check the requirements.'
        )

    if not HAS_XML:
        module.fail_json(
            msg='The `lxml` module is not importable. Check the requirements.'
        )

    rc = VIRT_SUCCESS
    try:
        rc, result = core(module)
    except Exception as e:
        module.fail_json(msg=str(e))

    if rc != 0: # something went wrong emit the msg
        module.fail_json(rc=rc, msg=result)
    else:
        module.exit_json(**result)


if __name__ == '__main__':
    main()