# -*- coding: utf-8 -*-
from copy import deepcopy

from SpiffWorkflow.task import TaskState
from .BpmnSpecMixin import BpmnSpecMixin
from ..exceptions import WorkflowDataException


class SubWorkflowTask(BpmnSpecMixin):
    """
    Task Spec for a bpmn node containing a subworkflow.
    """
    def __init__(self, wf_spec, name, subworkflow_spec, transaction=False, **kwargs):
        """
        Constructor.

        :param bpmn_wf_spec: the BpmnProcessSpec for the sub process.
        :param bpmn_wf_class: the BpmnWorkflow class to instantiate
        """
        super(SubWorkflowTask, self).__init__(wf_spec, name, **kwargs)
        self.spec = subworkflow_spec
        self.transaction = transaction

    @property
    def spec_type(self):
        return 'Subprocess'

    def _on_ready_before_hook(self, my_task):
        subworkflow = my_task.workflow.create_subprocess(my_task, self.spec, self.name)
        subworkflow.completed_event.connect(self._on_subworkflow_completed, my_task)
        subworkflow.data = deepcopy(my_task.workflow.data)

    def _on_ready_hook(self, my_task):

        super()._on_ready_hook(my_task)
        self.start_workflow(my_task)

    def _on_subworkflow_completed(self, subworkflow, my_task):

        if len(subworkflow.spec.data_outputs) == 0:
            # Copy all workflow data if no outputs are specified
            my_task.data = deepcopy(subworkflow.last_task.data)
        else:
            end = subworkflow.get_tasks_from_spec_name('End', workflow=subworkflow)
            # Otherwise only copy data with the specified names
            for var in subworkflow.spec.data_outputs:
                try:
                    var.copy(end[0], my_task, data_output=True)
                except WorkflowDataException as wde:
                    wde.add_note("A Data Output was not provided as promised.")
                    raise wde

        my_task._set_state(TaskState.READY)

    def _update_hook(self, my_task):
        wf = my_task.workflow._get_outermost_workflow(my_task)
        if my_task.id not in wf.subprocesses:
            return super()._update_hook(my_task)

    def _on_cancel(self, my_task):
        subworkflow = my_task.workflow.get_subprocess(my_task)
        if subworkflow is not None:
            subworkflow.cancel()

    def start_workflow(self, my_task):

        subworkflow = my_task.workflow.get_subprocess(my_task)
        start = subworkflow.get_tasks_from_spec_name('Start', workflow=subworkflow)

        if len(subworkflow.spec.data_inputs) == 0:
            # Copy all task data into start task if no inputs specified
            start[0].set_data(**my_task.data)
        else:
            # Otherwise copy only task data with the specified names
            for var in subworkflow.spec.data_inputs:
                try:
                    var.copy(my_task, start[0], data_input=True)
                except WorkflowDataException as wde:
                    wde.add_note("You are missing a required Data Input for a call activity.")
                    raise wde
        for child in subworkflow.task_tree.children:
            child.task_spec._update(child)

        my_task._set_state(TaskState.WAITING)

    def task_will_set_children_future(self, my_task):
        my_task.workflow.delete_subprocess(my_task)


class CallActivity(SubWorkflowTask):

    def __init__(self, wf_spec, name, subworkflow_spec, **kwargs):
        super(CallActivity, self).__init__(wf_spec, name, subworkflow_spec, False, **kwargs)

    @property
    def spec_type(self):
        return 'Call Activity'


class TransactionSubprocess(SubWorkflowTask):

    def __init__(self, wf_spec, name, subworkflow_spec, **kwargs):
        super(TransactionSubprocess, self).__init__(wf_spec, name, subworkflow_spec, True, **kwargs)

    @property
    def spec_type(self):
        return 'Transactional Subprocess'