# -*- coding: utf-8 -*-
#
# Copyright (C) 2006-2009 Edgewall Software
# Copyright (C) 2006 Alec Thomas
# Copyright (C) 2007 Eli Carter
# Copyright (C) 2007 Christian Boos <cboos@neuf.fr>
# All rights reserved.
#
# This software is licensed as described in the file COPYING, which
# you should have received as part of this distribution. The terms
# are also available at http://trac.edgewall.org/wiki/TracLicense.
#
# This software consists of voluntary contributions made by many
# individuals. For the exact contribution history, see the revision
# history and logs, available at http://trac.edgewall.org/log/.
#
# Author: Eli Carter

import pkg_resources

from genshi.builder import tag

from trac.core import *
from trac.perm import PermissionSystem
from trac.env import IEnvironmentSetupParticipant
from trac.config import Configuration
from trac.ticket.api import ITicketActionController, TicketSystem
from trac.util.compat import set
from trac.util.translation import _

# -- Utilities for the ConfigurableTicketWorkflow

def parse_workflow_config(rawactions):
    """Given a list of options from [ticket-workflow]"""
    actions = {}
    for option, value in rawactions:
        parts = option.split('.')
        action = parts[0]
        if action not in actions:
            actions[action] = {}
        if len(parts) == 1:
            # Base name, of the syntax: old,states,here -> newstate
            try:
                oldstates, newstate = [x.strip() for x in value.split('->')]
            except ValueError:
                raise Exception('Bad option "%s"' % (option, )) # 500, no _
            actions[action]['newstate'] = newstate
            actions[action]['oldstates'] = oldstates
        else:
            action, attribute = option.split('.')
            actions[action][attribute] = value
    # Fill in the defaults for every action, and normalize them to the desired
    # types
    for action, attributes in actions.items():
        # Default the 'name' attribute to the name used in the ini file
        if 'name' not in attributes:
            attributes['name'] = action
        # If not specified, an action is not the default.
        if 'default' not in attributes:
            attributes['default'] = 0
        else:
            attributes['default'] = int(attributes['default'])
        # If operations are not specified, that means no operations
        if 'operations' not in attributes:
            attributes['operations'] = []
        else:
            attributes['operations'] = [a.strip() for a in
                                        attributes['operations'].split(',')]
        # If no permissions are specified, then no permissions are needed
        if 'permissions' not in attributes:
            attributes['permissions'] = []
        else:
            attributes['permissions'] = [a.strip() for a in
                                         attributes['permissions'].split(',')]
        # Normalize the oldstates
        attributes['oldstates'] = [x.strip() for x in
                                   attributes['oldstates'].split(',')]
    return actions

def get_workflow_config(config):
    """Usually passed self.config, this will return the parsed ticket-workflow
    section.
    """
    raw_actions = list(config.options('ticket-workflow'))
    actions = parse_workflow_config(raw_actions)
    return actions

def load_workflow_config_snippet(config, filename):
    """Loads the ticket-workflow section from the given file (expected to be in
    the 'workflows' tree) into the provided config.
    """
    filename = pkg_resources.resource_filename('trac.ticket',
                    'workflows/%s' % filename)
    new_config = Configuration(filename)
    for name, value in new_config.options('ticket-workflow'):
        config.set('ticket-workflow', name, value)


class ConfigurableTicketWorkflow(Component):
    """Ticket action controller which provides actions according to a
    workflow defined in the TracIni configuration file, inside the
    [ticket-workflow] section.
    """
    
    def __init__(self, *args, **kwargs):
        Component.__init__(self, *args, **kwargs)
        self.actions = get_workflow_config(self.config)
        if not '_reset' in self.actions:
            # Special action that gets enabled if the current status no longer
            # exists, as no other action can then change its state. (#5307)
            self.actions['_reset'] = {
                'default': 0,
                'name': 'reset',
                'newstate': 'new',
                'oldstates': [],  # Will not be invoked unless needed
                'operations': ['reset_workflow'],
                'permissions': []}
        self.log.debug('Workflow actions at initialization: %s\n' %
                       str(self.actions))

    implements(ITicketActionController, IEnvironmentSetupParticipant)

    # IEnvironmentSetupParticipant methods

    def environment_created(self):
        """When an environment is created, we provide the basic-workflow,
        unless a ticket-workflow section already exists.
        """
        if not 'ticket-workflow' in self.config.sections():
            load_workflow_config_snippet(self.config, 'basic-workflow.ini')
            self.config.save()
            self.actions = get_workflow_config(self.config)

    def environment_needs_upgrade(self, db):
        """The environment needs an upgrade if there is no [ticket-workflow]
        section in the config.
        """
        return not list(self.config.options('ticket-workflow'))

    def upgrade_environment(self, db):
        """Insert a [ticket-workflow] section using the original-workflow"""
        load_workflow_config_snippet(self.config, 'original-workflow.ini')
        self.config.save()
        self.actions = get_workflow_config(self.config)
        info_message = """

==== Upgrade Notice ====

The ticket Workflow is now configurable.

Your environment has been upgraded, but configured to use the original
workflow. It is recommended that you look at changing this configuration to use
basic-workflow. 

Read TracWorkflow for more information (don't forget to 'wiki upgrade' as well)

"""
        self.log.info(info_message.replace('\n', ' ').replace('==', ''))
        print info_message

    # ITicketActionController methods

    def get_ticket_actions(self, req, ticket):
        """Returns a list of (weight, action) tuples that are valid for this
        request and this ticket."""
        # Get the list of actions that can be performed

        # Determine the current status of this ticket.  If this ticket is in
        # the process of being modified, we need to base our information on the
        # pre-modified state so that we don't try to do two (or more!) steps at
        # once and get really confused.
        status = ticket._old.get('status', ticket['status']) or 'new'

        allowed_actions = []
        for action_name, action_info in self.actions.items():
            oldstates = action_info['oldstates']
            if oldstates == ['*'] or status in oldstates:
                # This action is valid in this state.  Check permissions.
                allowed = 0
                required_perms = action_info['permissions']
                if required_perms:
                    for permission in required_perms:
                        if permission in req.perm(ticket.resource):
                            allowed = 1
                            break
                else:
                    allowed = 1
                if allowed:
                    allowed_actions.append((action_info['default'],
                                            action_name))
        if not (status in ['new', 'closed'] or \
                    status in TicketSystem(self.env).get_all_status()) \
                and 'TICKET_ADMIN' in req.perm(ticket.resource):
            # State no longer exists - add a 'reset' action if admin.
            allowed_actions.append((0, '_reset'))
        return allowed_actions

    def get_all_status(self):
        """Return a list of all states described by the configuration.

        """
        all_status = set()
        for action_name, action_info in self.actions.items():
            all_status.update(action_info['oldstates'])
            all_status.add(action_info['newstate'])
        all_status.discard('*')
        return all_status
        
    def render_ticket_action_control(self, req, ticket, action):
        from trac.ticket import model

        self.log.debug('render_ticket_action_control: action "%s"' % action)

        this_action = self.actions[action]
        status = this_action['newstate']        
        operations = this_action['operations']
        current_owner = ticket._old.get('owner', ticket['owner'] or '(none)')

        control = [] # default to nothing
        hints = []
        if 'reset_workflow' in operations:
            control.append(tag("from invalid state "))
            hints.append(_("Current state no longer exists"))
        if 'del_owner' in operations:
            hints.append(_("The ticket will be disowned"))
        if 'set_owner' in operations:
            id = 'action_%s_reassign_owner' % action
            selected_owner = req.args.get(id, req.authname)

            if this_action.has_key('set_owner'):
                owners = [x.strip() for x in
                          this_action['set_owner'].split(',')]
            elif self.config.getbool('ticket', 'restrict_owner'):
                perm = PermissionSystem(self.env)
                owners = perm.get_users_with_permission('TICKET_MODIFY')
                owners.sort()
            else:
                owners = None

            if owners == None:
                owner = req.args.get(id, req.authname)
                control.append(tag(['to ', tag.input(type='text', id=id,
                                                     name=id, value=owner)]))
                hints.append(_("The owner will change from %(current_owner)s",
                               current_owner=current_owner))
            elif len(owners) == 1:
                control.append(tag('to %s ' % owners[0]))
                if ticket['owner'] != owners[0]:
                    hints.append(_("The owner will change from "
                                   "%(current_owner)s to %(selected_owner)s",
                                   current_owner=current_owner,
                                   selected_owner=owners[0]))
            else:
                control.append(tag([_("to "), tag.select(
                    [tag.option(x, selected=(x == selected_owner or None))
                     for x in owners],
                    id=id, name=id)]))
                hints.append(_("The owner will change from %(current_owner)s",
                               current_owner=current_owner))
        if 'set_owner_to_self' in operations and \
                ticket._old.get('owner', ticket['owner']) != req.authname:
            hints.append(_("The owner will change from %(current_owner)s "
                           "to %(authname)s", current_owner=current_owner,
                           authname=req.authname))
        if 'set_resolution' in operations:
            if this_action.has_key('set_resolution'):
                resolutions = [x.strip() for x in
                               this_action['set_resolution'].split(',')]
            else:
                resolutions = [val.name for val in
                               model.Resolution.select(self.env)]
            if not resolutions:
                raise TracError(_("Your workflow attempts to set a resolution "
                                  "but none is defined (configuration issue, "
                                  "please contact your Trac admin)."))
            if len(resolutions) == 1:
                control.append(tag('as %s' % resolutions[0]))
                hints.append(_("The resolution will be set to %s") %
                             resolutions[0])
            else:
                id = 'action_%s_resolve_resolution' % action
                selected_option = req.args.get(id,
                        self.config.get('ticket', 'default_resolution'))
                control.append(tag(['as ', tag.select(
                    [tag.option(x, selected=(x == selected_option or None))
                     for x in resolutions],
                    id=id, name=id)]))
                hints.append(_("The resolution will be set"))
        if 'leave_status' in operations:
            control.append('as %s ' % ticket._old.get('status', 
                                                      ticket['status']))
        else:
            if status != '*':
                hints.append(_("Next status will be '%s'") % status)
        return (this_action['name'], tag(*control), '. '.join(hints))

    def get_ticket_changes(self, req, ticket, action):
        this_action = self.actions[action]

        # Enforce permissions
        if not self._has_perms_for_action(req, this_action, ticket.resource):
            # The user does not have any of the listed permissions, so we won't
            # do anything.
            return {}

        updated = {}
        # Status changes
        status = this_action['newstate']
        if status != '*':
            updated['status'] = status

        for operation in this_action['operations']:
            if operation == 'reset_workflow':
                updated['status'] = 'new'
            if operation == 'del_owner':
                updated['owner'] = ''
            elif operation == 'set_owner':
                newowner = req.args.get('action_%s_reassign_owner' % action,
                                    this_action.get('set_owner', '').strip())
                # If there was already an owner, we get a list, [new, old],
                # but if there wasn't we just get new.
                if type(newowner) == list:
                    newowner = newowner[0]
                updated['owner'] = newowner
            elif operation == 'set_owner_to_self':
                updated['owner'] = req.authname

            if operation == 'del_resolution':
                updated['resolution'] = ''
            elif operation == 'set_resolution':
                newresolution = req.args.get('action_%s_resolve_resolution' % \
                                             action,
                                this_action.get('set_resolution', '').strip())
                updated['resolution'] = newresolution

            # leave_status is just a no-op here, so we don't look for it.
        return updated

    def apply_action_side_effects(self, req, ticket, action):
        pass

    def _has_perms_for_action(self, req, action, resource):
        required_perms = action['permissions']
        if required_perms:
            for permission in required_perms:
                if permission in req.perm(resource):
                    break
            else:
                # The user does not have any of the listed permissions
                return False
        return True

    # Public methods (for other ITicketActionControllers that want to use
    #                 our config file and provide an operation for an action)
    
    def get_actions_by_operation(self, operation):
        """Return a list of all actions with a given operation
        (for use in the controller's get_all_status())
        """
        actions = [(info['default'], action) for action, info
                   in self.actions.items()
                   if operation in info['operations']]
        return actions

    def get_actions_by_operation_for_req(self, req, ticket, operation):
        """Return list of all actions with a given operation that are valid
        in the given state for the controller's get_ticket_actions().

        If state='*' (the default), all actions with the given operation are
        returned.
        """
        # Be sure to look at the original status.
        status = ticket._old.get('status', ticket['status'])
        actions = [(info['default'], action) for action, info
                   in self.actions.items()
                   if operation in info['operations'] and
                      ('*' in info['oldstates'] or
                       status in info['oldstates']) and
                      self._has_perms_for_action(req, info, ticket.resource)]
        return actions

