import os
import shutil

from django.http.response import StreamingHttpResponse
from django.urls import reverse
from django.conf import settings

from InvenTree.api_tester import InvenTreeAPITestCase

import report.models as report_models
from common.models import InvenTreeUserSetting
from stock.models import StockItem
from build.models import Build


class ReportTest(InvenTreeAPITestCase):

    fixtures = [
        'category',
        'part',
        'company',
        'location',
        'supplier_part',
        'stock',
        'stock_tests',
        'bom',
        'build',
    ]

    model = None
    list_url = None
    detail_url = None
    print_url = None

    def setUp(self):
        super().setUp()

    def copyReportTemplate(self, filename, description):
        """
        Copy the provided report template into the required media directory
        """

        src_dir = os.path.join(
            os.path.dirname(os.path.realpath(__file__)),
            'templates',
            'report'
        )

        template_dir = os.path.join(
            'report',
            'inventree',
            self.model.getSubdir(),
        )

        dst_dir = os.path.join(
            settings.MEDIA_ROOT,
            template_dir
        )

        if not os.path.exists(dst_dir):  # pragma: no cover
            os.makedirs(dst_dir, exist_ok=True)

        src_file = os.path.join(src_dir, filename)
        dst_file = os.path.join(dst_dir, filename)

        if not os.path.exists(dst_file):  # pragma: no cover
            shutil.copyfile(src_file, dst_file)

        # Convert to an "internal" filename
        db_filename = os.path.join(
            template_dir,
            filename
        )

        # Create a database entry for this report template!
        self.model.objects.create(
            name=os.path.splitext(filename)[0],
            description=description,
            template=db_filename,
            enabled=True
        )

    def test_list_endpoint(self):
        """
        Test that the LIST endpoint works for each report
        """

        if not self.list_url:
            return

        url = reverse(self.list_url)

        response = self.get(url)
        self.assertEqual(response.status_code, 200)

        reports = self.model.objects.all()

        n = len(reports)

        # API endpoint must return correct number of reports
        self.assertEqual(len(response.data), n)

        # Filter by "enabled" status
        response = self.get(url, {'enabled': True})
        self.assertEqual(len(response.data), n)

        response = self.get(url, {'enabled': False})
        self.assertEqual(len(response.data), 0)

        # Disable each report
        for report in reports:
            report.enabled = False
            report.save()

        # Filter by "enabled" status
        response = self.get(url, {'enabled': True})
        self.assertEqual(len(response.data), 0)

        response = self.get(url, {'enabled': False})
        self.assertEqual(len(response.data), n)


class TestReportTest(ReportTest):

    model = report_models.TestReport

    list_url = 'api-stockitem-testreport-list'
    detail_url = 'api-stockitem-testreport-detail'
    print_url = 'api-stockitem-testreport-print'

    def setUp(self):

        self.copyReportTemplate('inventree_test_report.html', 'stock item test report')

        return super().setUp()

    def test_print(self):
        """
        Printing tests for the TestReport
        """

        report = self.model.objects.first()

        url = reverse(self.print_url, kwargs={'pk': report.pk})

        # Try to print without providing a valid StockItem
        response = self.get(url, expected_code=400)

        # Try to print with an invalid StockItem
        response = self.get(url, {'item': 9999}, expected_code=400)

        # Now print with a valid StockItem
        item = StockItem.objects.first()

        response = self.get(url, {'item': item.pk})

        # Response should be a StreamingHttpResponse (PDF file)
        self.assertEqual(type(response), StreamingHttpResponse)

        headers = response.headers

        self.assertEqual(headers['Content-Type'], 'application/pdf')


class BuildReportTest(ReportTest):

    model = report_models.BuildReport

    list_url = 'api-build-report-list'
    detail_url = 'api-build-report-detail'
    print_url = 'api-build-report-print'

    def setUp(self):

        self.copyReportTemplate('inventree_build_order.html', 'build order template')

        return super().setUp()

    def test_print(self):
        """
        Printing tests for the BuildReport
        """

        report = self.model.objects.first()

        url = reverse(self.print_url, kwargs={'pk': report.pk})

        # Try to print without providing a valid BuildOrder
        response = self.get(url, expected_code=400)

        # Try to print with an invalid BuildOrder
        response = self.get(url, {'build': 9999}, expected_code=400)

        # Now print with a valid BuildOrder

        build = Build.objects.first()

        response = self.get(url, {'build': build.pk})

        self.assertEqual(type(response), StreamingHttpResponse)

        headers = response.headers

        self.assertEqual(headers['Content-Type'], 'application/pdf')
        self.assertEqual(headers['Content-Disposition'], 'attachment; filename="report.pdf"')

        # Now, set the download type to be "inline"
        inline = InvenTreeUserSetting.get_setting_object('REPORT_INLINE', self.user)
        inline.value = True
        inline.save()

        response = self.get(url, {'build': 1})
        headers = response.headers
        self.assertEqual(headers['Content-Type'], 'application/pdf')
        self.assertEqual(headers['Content-Disposition'], 'inline; filename="report.pdf"')


class BOMReportTest(ReportTest):

    model = report_models.BillOfMaterialsReport

    list_url = 'api-bom-report-list'
    detail_url = 'api-bom-report-detail'
    print_url = 'api-bom-report-print'


class PurchaseOrderReportTest(ReportTest):

    model = report_models.PurchaseOrderReport

    list_url = 'api-po-report-list'
    detail_url = 'api-po-report-detail'
    print_url = 'api-po-report-print'


class SalesOrderReportTest(ReportTest):

    model = report_models.SalesOrderReport

    list_url = 'api-so-report-list'
    detail_url = 'api-so-report-detail'
    print_url = 'api-so-report-print'