from io import BytesIO
from unittest.mock import patch

from django.test import override_settings
from openpyxl import load_workbook
from rest_framework import status
from rest_framework.test import APITestCase

from apps.reports.services.oauth import OAuth2ClientCredentials


class GenerateReportTests(APITestCase):
    @patch("apps.reports.services.data_sources.ReportDataSources.fetch_user_metrics")
    @patch("apps.reports.services.data_sources.ReportDataSources.fetch_users")
    def test_generate_user_report_is_public_and_returns_excel(
        self,
        mock_fetch_users,
        mock_fetch_user_metrics,
    ):
        mock_fetch_users.return_value = [
            {
                "id": 1,
                "full_name": "Alice Doe",
                "email": "alice@example.com",
                "status": "active",
            }
        ]
        mock_fetch_user_metrics.return_value = {
            1: {"ticket_count": 3},
        }

        response = self.client.post(
            "/api/reports/generate/",
            {
                "report_type": "user",
                "filters": {"status": "active"},
            },
            format="json",
        )

        self.assertEqual(response.status_code, status.HTTP_200_OK)
        self.assertEqual(
            response["Content-Type"],
            "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
        )
        self.assertEqual(
            response["Content-Disposition"],
            'attachment; filename="user-report.xlsx"',
        )

        workbook = load_workbook(BytesIO(response.content))
        worksheet = workbook.active
        self.assertEqual(worksheet["A1"].value, "User Report")
        self.assertEqual(
            [cell.value for cell in worksheet[2]],
            ["User ID", "Full Name", "Email", "Status", "Ticket Count"],
        )
        self.assertEqual(
            [cell.value for cell in worksheet[3]],
            [1, "Alice Doe", "alice@example.com", "active", 3],
        )
        mock_fetch_users.assert_called_once_with({"status": "active"})

    @patch("apps.reports.services.data_sources.ReportDataSources.fetch_ticket_metrics")
    @patch("apps.reports.services.data_sources.ReportDataSources.fetch_tickets")
    def test_generate_tickets_report_uses_static_columns(
        self,
        mock_fetch_tickets,
        mock_fetch_ticket_metrics,
    ):
        mock_fetch_tickets.return_value = [
            {
                "id": 11,
                "title": "Login issue",
                "status": "open",
                "priority": "high",
                "assignee": {"name": "Support Agent"},
                "created_at": "2026-05-20T10:00:00Z",
            }
        ]
        mock_fetch_ticket_metrics.return_value = {}

        response = self.client.post(
            "/api/reports/generate/",
            {"report_type": "tickets"},
            format="json",
        )

        self.assertEqual(response.status_code, status.HTTP_200_OK)
        self.assertEqual(
            response["Content-Disposition"],
            'attachment; filename="tickets-report.xlsx"',
        )

        workbook = load_workbook(BytesIO(response.content))
        worksheet = workbook.active
        self.assertEqual(worksheet["A1"].value, "Tickets Report")
        self.assertEqual(
            [cell.value for cell in worksheet[2]],
            ["Ticket ID", "Title", "Status", "Priority", "Assignee", "Created At"],
        )
        self.assertEqual(
            [cell.value for cell in worksheet[3]],
            [
                11,
                "Login issue",
                "open",
                "high",
                "Support Agent",
                "2026-05-20T10:00:00Z",
            ],
        )

    def test_unknown_report_type_returns_validation_error(self):
        response = self.client.post(
            "/api/reports/generate/",
            {"report_type": "unknown"},
            format="json",
        )

        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)


class OAuth2ClientCredentialsTests(APITestCase):
    @override_settings(
        OAUTH2_PROVIDER_PRIVATE_URL="https://auth.internal",
        OAUTH2_CLIENT_ID="client-id",
        OAUTH2_CLIENT_SECRET="client-secret",
        OAUTH2_SCOPES="reports:read customers:read",
        SERVICE_REQUEST_TIMEOUT=10,
    )
    @patch("apps.reports.services.oauth.requests.post")
    def test_get_access_token_uses_client_credentials(self, mock_post):
        mock_post.return_value.json.return_value = {
            "access_token": "token-value",
            "expires_in": 3600,
        }
        mock_post.return_value.raise_for_status.return_value = None

        token = OAuth2ClientCredentials().get_access_token()

        self.assertEqual(token, "token-value")
        mock_post.assert_called_once_with(
            "https://auth.internal/oauth2/token",
            data={
                "grant_type": "client_credentials",
                "scope": "reports:read customers:read",
            },
            auth=("client-id", "client-secret"),
            timeout=10,
        )