# :coding: utf-8
# :copyright: Copyright (c) 2016 ftrack

from __future__ import absolute_import

import logging
import json
import sys
import os

import ftrack_api
import ftrack_api.structure.standard as _standard
from ftrack_api.logging import LazyLogMessage as L


scenario_name = 'ftrack.centralized-storage'


class ConfigureCentralizedStorageScenario(object):
    '''Configure a centralized storage scenario.'''

    def __init__(self):
        '''Instansiate centralized storage scenario.'''
        self.logger = logging.getLogger(
            __name__ + '.' + self.__class__.__name__
        )

    @property
    def storage_scenario(self):
        '''Return storage scenario setting.'''
        return self.session.query(
            'select value from Setting '
            'where name is "storage_scenario" and group is "STORAGE"'
        ).one()

    @property
    def existing_centralized_storage_configuration(self):
        '''Return existing centralized storage configuration.'''
        storage_scenario = self.storage_scenario

        try:
            configuration = json.loads(storage_scenario['value'])
        except (ValueError, TypeError):
            return None

        if not isinstance(configuration, dict):
            return None

        if configuration.get('scenario') != scenario_name:
            return None

        return configuration.get('data', {})

    def _get_confirmation_text(self, configuration):
        '''Return confirmation text from *configuration*.'''
        configure_location = configuration.get('configure_location')
        select_location = configuration.get('select_location')
        select_mount_point = configuration.get('select_mount_point')

        if configure_location:
            location_text = unicode(
                'A new location will be created:\n\n'
                '* Label: {location_label}\n'
                '* Name: {location_name}\n'
                '* Description: {location_description}\n'
            ).format(**configure_location)
        else:
            location = self.session.get(
                'Location', select_location['location_id']
            )
            location_text = (
                u'You have choosen to use an existing location: {0}'.format(
                    location['label']
                )
            )

        mount_points_text = unicode(
            '* Linux: {linux}\n'
            '* OS X: {osx}\n'
            '* Windows: {windows}\n\n'
        ).format(
            linux=select_mount_point.get('linux_mount_point') or '*Not set*',
            osx=select_mount_point.get('osx_mount_point') or '*Not set*',
            windows=select_mount_point.get('windows_mount_point') or '*Not set*'
        )

        mount_points_not_set = []

        if not select_mount_point.get('linux_mount_point'):
            mount_points_not_set.append('Linux')

        if not select_mount_point.get('osx_mount_point'):
            mount_points_not_set.append('OS X')

        if not select_mount_point.get('windows_mount_point'):
            mount_points_not_set.append('Windows')

        if mount_points_not_set:
            mount_points_text += unicode(
                'Please be aware that this location will not be working on '
                '{missing} because the mount points are not set up.'
            ).format(
                missing=' and '.join(mount_points_not_set)
            )

        text = unicode(
            '#Confirm storage setup#\n\n'
            'Almost there! Please take a moment to verify the settings you '
            'are about to save. You can always come back later and update the '
            'configuration.\n'
            '##Location##\n\n'
            '{location}\n'
            '##Mount points##\n\n'
            '{mount_points}'
        ).format(
            location=location_text,
            mount_points=mount_points_text
        )

        return text

    def configure_scenario(self, event):
        '''Configure scenario based on *event* and return form items.'''
        steps = (
            'select_scenario',
            'select_location',
            'configure_location',
            'select_structure',
            'select_mount_point',
            'confirm_summary',
            'save_configuration'
        )

        warning_message = ''
        values = event['data'].get('values', {})

        # Calculate previous step and the next.
        previous_step = values.get('step', 'select_scenario')
        next_step = steps[steps.index(previous_step) + 1]
        state = 'configuring'

        self.logger.info(L(
            u'Configuring scenario, previous step: {0}, next step: {1}. '
            u'Values {2!r}.',
            previous_step, next_step, values
        ))

        if 'configuration' in values:
            configuration = values.pop('configuration')
        else:
            configuration = {}

        if values:
            # Update configuration with values from the previous step.
            configuration[previous_step] = values

        if previous_step == 'select_location':
            values = configuration['select_location']
            if values.get('location_id') != 'create_new_location':
                location_exists = self.session.query(
                    'Location where id is "{0}"'.format(
                        values.get('location_id')
                    )
                ).first()
                if not location_exists:
                    next_step = 'select_location'
                    warning_message = (
                        '**The selected location does not exist. Please choose '
                        'one from the dropdown or create a new one.**'
                    )

        if next_step == 'select_location':
            try:
                location_id = (
                    self.existing_centralized_storage_configuration['location_id']
                )
            except (KeyError, TypeError):
                location_id = None

            options = [{
                'label': 'Create new location',
                'value': 'create_new_location'
            }]
            for location in self.session.query(
                'select name, label, description from Location'
            ):
                if location['name'] not in (
                    'ftrack.origin', 'ftrack.unmanaged', 'ftrack.connect',
                    'ftrack.server', 'ftrack.review'
                ):
                    options.append({
                        'label': u'{label} ({name})'.format(
                            label=location['label'], name=location['name']
                        ),
                        'description': location['description'],
                        'value': location['id']
                    })

            warning = ''
            if location_id is not None:
                # If there is already a location configured we must make the
                # user aware that changing the location may be problematic.
                warning = (
                    '\n\n**Be careful if you switch to another location '
                    'for an existing storage scenario. Components that have '
                    'already been published to the previous location will be '
                    'made unavailable for common use.**'
                )
                default_value = location_id
            elif location_id is None and len(options) == 1:
                # No location configured and no existing locations to use.
                default_value = 'create_new_location'
            else:
                # There are existing locations to choose from but non of them
                # are currently active in the centralized storage scenario.
                default_value = None

            items = [{
                'type': 'label',
                'value': (
                    '#Select location#\n'
                    'Choose an already existing location or create a new one '
                    'to represent your centralized storage. {0}'.format(
                        warning
                    )
                )
            }, {
                'type': 'enumerator',
                'label': 'Location',
                'name': 'location_id',
                'value': default_value,
                'data': options
            }]

        default_location_name = 'studio.central-storage-location'
        default_location_label = 'Studio location'
        default_location_description = (
            'The studio central location where all components are '
            'stored.'
        )

        if previous_step == 'configure_location':
            configure_location = configuration.get(
                'configure_location'
            )

            if configure_location:
                try:
                    existing_location = self.session.query(
                        u'Location where name is "{0}"'.format(
                            configure_location.get('location_name')
                        )
                    ).first()
                except UnicodeEncodeError:                
                    next_step = 'configure_location'
                    warning_message += (
                        '**The location name contains non-ascii characters. '
                        'Please change the name and try again.**'
                    )
                    values = configuration['select_location']
                else:
                    if existing_location:
                        next_step = 'configure_location'
                        warning_message += (
                            u'**There is already a location named {0}. '
                            u'Please change the name and try again.**'.format(
                                configure_location.get('location_name')
                            )
                        )
                        values = configuration['select_location']

                if (
                    not configure_location.get('location_name') or
                    not configure_location.get('location_label') or
                    not configure_location.get('location_description')
                ):
                    next_step = 'configure_location'
                    warning_message += (
                        '**Location name, label and description cannot '
                        'be empty.**'
                    )
                    values = configuration['select_location']

            if next_step == 'configure_location':
                # Populate form with previous configuration.
                default_location_label = configure_location['location_label']
                default_location_name = configure_location['location_name']
                default_location_description = (
                    configure_location['location_description']
                )

        if next_step == 'configure_location':

            if values.get('location_id') == 'create_new_location':
                # Add options to create a new location.
                items = [{
                    'type': 'label',
                    'value': (
                        '#Create location#\n'
                        'Here you will create a new location to be used '
                        'with your new Storage scenario. For your '
                        'convenience we have already filled in some default '
                        'values. If this is the first time you are configuring '
                        'a storage scenario in ftrack we recommend that you '
                        'stick with these settings.'
                    )
                }, {
                    'label': 'Label',
                    'name': 'location_label',
                    'value': default_location_label,
                    'type': 'text'
                }, {
                    'label': 'Name',
                    'name': 'location_name',
                    'value': default_location_name,
                    'type': 'text'
                }, {
                    'label': 'Description',
                    'name': 'location_description',
                    'value': default_location_description,
                    'type': 'text'
                }]

            else:
                # The user selected an existing location. Move on to next
                # step.
                next_step = 'select_mount_point'

        if next_step == 'select_structure':
            # There is only one structure to choose from, go to next step.
            next_step = 'select_mount_point'
            # items = [
            #     {
            #         'type': 'label',
            #         'value': (
            #             '#Select structure#\n'
            #             'Select which structure to use with your location. '
            #             'The structure is used to generate the filesystem '
            #             'path for components that are added to this location.'
            #         )
            #     },
            #     {
            #         'type': 'enumerator',
            #         'label': 'Structure',
            #         'name': 'structure_id',
            #         'value': 'standard',
            #         'data': [{
            #             'label': 'Standard',
            #             'value': 'standard',
            #             'description': (
            #                 'The Standard structure uses the names in your '
            #                 'project structure to determine the path.'
            #             )
            #         }]
            #     }
            # ]

        if next_step == 'select_mount_point':
            try:
                mount_points = (
                    self.existing_centralized_storage_configuration['accessor']['mount_points']
                )
            except (KeyError, TypeError):
                mount_points = dict()

            items = [
                {
                    'value': (
                        '#Mount points#\n'
                        'Set mount points for your centralized storage '
                        'location. For the location to work as expected each '
                        'platform that you intend to use must have the '
                        'corresponding mount point set and the storage must '
                        'be accessible. If not set correctly files will not be '
                        'saved or read.'
                    ),
                    'type': 'label'
                }, {
                    'type': 'text',
                    'label': 'Linux',
                    'name': 'linux_mount_point',
                    'empty_text': 'E.g. /usr/mnt/MyStorage ...',
                    'value': mount_points.get('linux', '')
                }, {
                    'type': 'text',
                    'label': 'OS X',
                    'name': 'osx_mount_point',
                    'empty_text': 'E.g. /Volumes/MyStorage ...',
                    'value': mount_points.get('osx', '')
                }, {
                    'type': 'text',
                    'label': 'Windows',
                    'name': 'windows_mount_point',
                    'empty_text': 'E.g. \\\\MyStorage ...',
                    'value': mount_points.get('windows', '')
                }
            ]

        if next_step == 'confirm_summary':
            items = [{
                'type': 'label',
                'value': self._get_confirmation_text(configuration)
            }]
            state = 'confirm'

        if next_step == 'save_configuration':
            mount_points = configuration['select_mount_point']
            select_location = configuration['select_location']

            if select_location['location_id'] == 'create_new_location':
                configure_location = configuration['configure_location']
                location = self.session.create(
                    'Location',
                    {
                        'name': configure_location['location_name'],
                        'label': configure_location['location_label'],
                        'description': (
                            configure_location['location_description']
                        )
                    }
                )

            else:
                location = self.session.query(
                    'Location where id is "{0}"'.format(
                        select_location['location_id']
                    )
                ).one()

            setting_value = json.dumps({
                'scenario': scenario_name,
                'data': {
                    'location_id': location['id'],
                    'location_name': location['name'],
                    'accessor': {
                        'mount_points': {
                            'linux': mount_points['linux_mount_point'],
                            'osx': mount_points['osx_mount_point'],
                            'windows': mount_points['windows_mount_point']
                        }
                    }
                }
            })

            self.storage_scenario['value'] = setting_value
            self.session.commit()

            # Broadcast an event that storage scenario has been configured.
            event = ftrack_api.event.base.Event(
                topic='ftrack.storage-scenario.configure-done'
            )
            self.session.event_hub.publish(event)

            items = [{
                'type': 'label',
                'value': (
                    '#Done!#\n'
                    'Your storage scenario is now configured and ready '
                    'to use. **Note that you may have to restart Connect and '
                    'other applications to start using it.**'
                )
            }]
            state = 'done'

        if warning_message:
            items.insert(0, {
                'type': 'label',
                'value': warning_message
            })

        items.append({
            'type': 'hidden',
            'value': configuration,
            'name': 'configuration'
        })
        items.append({
            'type': 'hidden',
            'value': next_step,
            'name': 'step'
        })

        return {
            'items': items,
            'state': state
        }

    def discover_centralized_scenario(self, event):
        '''Return action discover dictionary for *event*.'''
        return {
            'id': scenario_name,
            'name': 'Centralized storage scenario',
            'description': (
                '(Recommended) centralized storage scenario where all files '
                'are kept on a storage that is mounted and available to '
                'everyone in the studio.'
            )
        }

    def register(self, session):
        '''Subscribe to events on *session*.'''
        self.session = session

        #: TODO: Move these to a separate function.
        session.event_hub.subscribe(
            unicode(
                'topic=ftrack.storage-scenario.discover '
                'and source.user.username="{0}"'
            ).format(
                session.api_user
            ),
            self.discover_centralized_scenario
        )
        session.event_hub.subscribe(
            unicode(
                'topic=ftrack.storage-scenario.configure '
                'and data.scenario_id="{0}" '
                'and source.user.username="{1}"'
            ).format(
                scenario_name,
                session.api_user
            ),
            self.configure_scenario
        )


class ActivateCentralizedStorageScenario(object):
    '''Activate a centralized storage scenario.'''

    def __init__(self):
        '''Instansiate centralized storage scenario.'''
        self.logger = logging.getLogger(
            __name__ + '.' + self.__class__.__name__
        )

    def activate(self, event):
        '''Activate scenario in *event*.'''
        storage_scenario = event['data']['storage_scenario']

        try:
            location_data = storage_scenario['data']
            location_name = location_data['location_name']
            location_id = location_data['location_id']
            mount_points = location_data['accessor']['mount_points']

        except KeyError:
            error_message = (
                'Unable to read storage scenario data.'
            )
            self.logger.error(L(error_message))
            raise ftrack_api.exception.LocationError(
                'Unable to configure location based on scenario.'
            )

        else:
            location = self.session.create(
                'Location',
                data=dict(
                    name=location_name,
                    id=location_id
                ),
                reconstructing=True
            )

            if sys.platform == 'darwin':
                prefix = mount_points['osx']
            elif sys.platform == 'linux2':
                prefix = mount_points['linux']
            elif sys.platform == 'win32':
                prefix = mount_points['windows']
            else:
                raise ftrack_api.exception.LocationError(
                    (
                        'Unable to find accessor prefix for platform {0}.'
                    ).format(sys.platform)
                )

            location.accessor = ftrack_api.accessor.disk.DiskAccessor(
                prefix=prefix
            )
            location.structure = _standard.StandardStructure()
            location.priority = 1
            self.logger.info(L(
                u'Storage scenario activated. Configured {0!r} from '
                u'{1!r}',
                location, storage_scenario
            ))

    def _verify_startup(self, event):
        '''Verify the storage scenario configuration.'''
        storage_scenario = event['data']['storage_scenario']
        location_data = storage_scenario['data']
        mount_points = location_data['accessor']['mount_points']

        prefix = None
        if sys.platform == 'darwin':
            prefix = mount_points['osx']
        elif sys.platform == 'linux2':
            prefix = mount_points['linux']
        elif sys.platform == 'win32':
            prefix = mount_points['windows']

        if not prefix:
            return (
                u'The storage scenario has not been configured for your '
                u'operating system. ftrack may not be able to '
                u'store and track files correctly.'
            )

        if not os.path.isdir(prefix):
            return (
                unicode(
                    'The path {0} does not exist. ftrack may not be able to '
                    'store and track files correctly. \n\nIf the storage is '
                    'newly setup you may want to create necessary folder '
                    'structures. If the storage is a network drive you should '
                    'make sure that it is mounted correctly.'
                ).format(prefix)
            )

    def register(self, session):
        '''Subscribe to events on *session*.'''
        self.session = session

        session.event_hub.subscribe(
            (
                'topic=ftrack.storage-scenario.activate '
                'and data.storage_scenario.scenario="{0}"'.format(
                    scenario_name
                )
            ),
            self.activate
        )

        # Listen to verify startup event from ftrack connect to allow responding
        # with a message if something is not working correctly with this
        # scenario that the user should be notified about.
        self.session.event_hub.subscribe(
            (
                'topic=ftrack.connect.verify-startup '
                'and data.storage_scenario.scenario="{0}"'.format(
                    scenario_name
                )
            ),
            self._verify_startup
        )

def register(session):
    '''Register storage scenario.'''
    scenario = ActivateCentralizedStorageScenario()
    scenario.register(session)


def register_configuration(session):
    '''Register storage scenario.'''
    scenario = ConfigureCentralizedStorageScenario()
    scenario.register(session)
