from __future__ import unicode_literals

import logging

from kombu import Exchange, Queue
import sh

from django.db.models.signals import post_save
from django.utils.translation import ugettext_lazy as _

from acls import ModelPermission
from common import (
    MayanAppConfig, menu_facet, menu_multi_item, menu_object, menu_secondary,
    menu_tools
)
from common.utils import encapsulate
from documents.models import Document, DocumentType, DocumentVersion
from documents.search import document_search
from documents.signals import post_version_upload
from documents.widgets import document_link
from installation import PropertyNamespace
from mayan.celery import app
from navigation import SourceColumn
from rest_api.classes import APIEndPoint

from .handlers import initialize_new_ocr_settings, post_version_upload_ocr
from .links import (
    link_document_content, link_document_submit, link_document_submit_all,
    link_document_submit_multiple, link_document_type_ocr_settings,
    link_entry_delete, link_entry_delete_multiple, link_entry_list,
    link_entry_re_queue, link_entry_re_queue_multiple
)
from .models import DocumentVersionOCRError
from .permissions import permission_ocr_document, permission_ocr_content_view
from .settings import setting_pdftotext_path, setting_tesseract_path, setting_unpaper_path
from .tasks import task_do_ocr

logger = logging.getLogger(__name__)


def document_ocr_submit(self):
    task_do_ocr.apply_async(args=[self.latest_version.pk])


def document_version_ocr_submit(self):
    task_do_ocr.apply_async(args=[self.pk])


class OCRApp(MayanAppConfig):
    name = 'ocr'
    verbose_name = _('OCR')

    def ready(self):
        super(OCRApp, self).ready()

        APIEndPoint('ocr')

        Document.add_to_class('submit_for_ocr', document_ocr_submit)
        DocumentVersion.add_to_class('submit_for_ocr', document_version_ocr_submit)

        ModelPermission.register(
            model=Document, permissions=(
                permission_ocr_document, permission_ocr_content_view
            )
        )

        SourceColumn(source=DocumentVersionOCRError, label=_('Document'), attribute=encapsulate(lambda entry: document_link(entry.document_version.document)))
        SourceColumn(source=DocumentVersionOCRError, label=_('Added'), attribute='datetime_submitted')
        SourceColumn(source=DocumentVersionOCRError, label=_('Result'), attribute='result')

        app.conf.CELERY_QUEUES.append(
            Queue('ocr', Exchange('ocr'), routing_key='ocr'),
        )

        app.conf.CELERY_ROUTES.update(
            {
                'ocr.tasks.task_do_ocr': {
                    'queue': 'ocr'
                },
            }
        )

        document_search.add_model_field(field='versions__pages__ocr_content__content', label=_('Content'))

        menu_facet.bind_links(links=[link_document_content], sources=[Document])
        menu_multi_item.bind_links(links=[link_document_submit_multiple], sources=[Document])
        menu_multi_item.bind_links(links=[link_entry_re_queue_multiple, link_entry_delete_multiple], sources=[DocumentVersionOCRError])
        menu_object.bind_links(links=[link_document_submit], sources=[Document])
        menu_object.bind_links(links=[link_entry_re_queue, link_entry_delete], sources=[DocumentVersionOCRError])
        menu_object.bind_links(links=[link_document_type_ocr_settings], sources=[DocumentType])
        menu_secondary.bind_links(links=[link_entry_list], sources=['ocr:entry_list', 'ocr:entry_delete_multiple', 'ocr:entry_re_queue_multiple', DocumentVersionOCRError])
        menu_tools.bind_links(links=[link_document_submit_all, link_entry_list])

        post_save.connect(initialize_new_ocr_settings, dispatch_uid='initialize_new_ocr_settings', sender=DocumentType)
        post_version_upload.connect(post_version_upload_ocr, dispatch_uid='post_version_upload_ocr', sender=DocumentVersion)

        namespace = PropertyNamespace('ocr', _('OCR'))

        try:
            pdftotext = sh.Command(setting_pdftotext_path.value)
        except sh.CommandNotFound:
            namespace.add_property('pdftotext', _('pdftotext version'), _('not found'), report=True)
        except Exception:
            namespace.add_property('pdftotext', _('pdftotext version'), _('error getting version'), report=True)
        else:
            namespace.add_property('pdftotext', _('pdftotext version'), pdftotext('-v').stderr, report=True)

        try:
            tesseract = sh.Command(setting_tesseract_path.value)
        except sh.CommandNotFound:
            namespace.add_property('tesseract', _('tesseract version'), _('not found'), report=True)
        except Exception:
            namespace.add_property('tesseract', _('tesseract version'), _('error getting version'), report=True)
        else:
            namespace.add_property('tesseract', _('tesseract version'), tesseract('-v').stderr, report=True)

        try:
            unpaper = sh.Command(setting_unpaper_path.value)
        except sh.CommandNotFound:
            namespace.add_property('unpaper', _('unpaper version'), _('not found'), report=True)
        except Exception:
            namespace.add_property('unpaper', _('unpaper version'), _('error getting version'), report=True)
        else:
            namespace.add_property('unpaper', _('unpaper version'), unpaper('-V').stdout, report=True)