"""
Contract test for GET /subscriptions endpoint.
This test MUST fail before implementation.
"""

import pytest
from django.test import TestCase
from django.urls import reverse
from rest_framework.test import APIClient
from rest_framework import status
import json


class SubscriptionsGetContractTest(TestCase):
    def setUp(self):
        self.client = APIClient()
        self.subscriptions_url = '/api/v1/subscriptions/'

        # Admin authentication header
        self.admin_auth = {'HTTP_AUTHORIZATION': 'Bearer admin_token'}

        # Tenant admin authentication header
        self.tenant_admin_auth = {'HTTP_AUTHORIZATION': 'Bearer tenant_admin_token'}

    def test_get_subscriptions_success_admin(self):
        """Test successful retrieval of subscriptions list by admin."""
        response = self.client.get(
            self.subscriptions_url,
            **self.admin_auth
        )

        # This should fail before implementation
        assert response.status_code == status.HTTP_200_OK

        data = response.json()
        assert 'subscriptions' in data
        assert isinstance(data['subscriptions'], list)

        # Check pagination structure
        assert 'pagination' in data
        pagination = data['pagination']
        assert 'page' in pagination
        assert 'limit' in pagination
        assert 'total' in pagination
        assert 'pages' in pagination

    def test_get_subscriptions_success_tenant_admin(self):
        """Test successful retrieval of subscriptions list by tenant admin."""
        response = self.client.get(
            self.subscriptions_url,
            **self.tenant_admin_auth
        )

        # This should fail before implementation
        assert response.status_code == status.HTTP_200_OK

        data = response.json()
        assert 'subscriptions' in data
        assert isinstance(data['subscriptions'], list)

        # Tenant admin should only see subscriptions from their tenant
        # This will be validated once implementation exists

    def test_get_subscriptions_unauthorized(self):
        """Test subscriptions list retrieval without authentication."""
        response = self.client.get(self.subscriptions_url)

        assert response.status_code == status.HTTP_401_UNAUTHORIZED

    def test_get_subscriptions_with_pagination(self):
        """Test subscriptions list retrieval with pagination parameters."""
        params = {
            'page': 2,
            'limit': 10
        }

        response = self.client.get(
            self.subscriptions_url,
            data=params,
            **self.admin_auth
        )

        assert response.status_code == status.HTTP_200_OK

        data = response.json()
        assert data['pagination']['page'] == 2
        assert data['pagination']['limit'] == 10

    def test_get_subscriptions_filter_by_status(self):
        """Test subscriptions list retrieval filtered by status."""
        params = {
            'status': 'ACTIVE'
        }

        response = self.client.get(
            self.subscriptions_url,
            data=params,
            **self.admin_auth
        )

        assert response.status_code == status.HTTP_200_OK

        data = response.json()
        # All returned subscriptions should have the specified status
        for subscription in data['subscriptions']:
            assert subscription['status'] == 'ACTIVE'

    def test_get_subscriptions_filter_by_plan(self):
        """Test subscriptions list retrieval filtered by plan."""
        params = {
            'plan': 'GROWTH'
        }

        response = self.client.get(
            self.subscriptions_url,
            data=params,
            **self.admin_auth
        )

        assert response.status_code == status.HTTP_200_OK

        data = response.json()
        # All returned subscriptions should have the specified plan
        for subscription in data['subscriptions']:
            assert subscription['plan'] == 'GROWTH'

    def test_get_subscriptions_filter_by_tenant(self):
        """Test subscriptions list retrieval filtered by tenant."""
        params = {
            'tenant_id': 'test-tenant-id'
        }

        response = self.client.get(
            self.subscriptions_url,
            data=params,
            **self.admin_auth
        )

        assert response.status_code == status.HTTP_200_OK

        data = response.json()
        # All returned subscriptions should belong to the specified tenant
        for subscription in data['subscriptions']:
            assert subscription['tenant_id'] == 'test-tenant-id'

    def test_get_subscriptions_tenant_isolation(self):
        """Test that tenant admin can only see subscriptions from their tenant."""
        # This test verifies tenant isolation for subscription data
        response = self.client.get(
            self.subscriptions_url,
            **self.tenant_admin_auth
        )

        if response.status_code == status.HTTP_200_OK:
            data = response.json()
            # For tenant users, all returned subscriptions should belong to their tenant
            # This will be validated once implementation exists
            pass

    def test_get_subscriptions_data_structure(self):
        """Test that subscription data structure matches the contract."""
        response = self.client.get(
            self.subscriptions_url,
            **self.admin_auth
        )

        if response.status_code == status.HTTP_200_OK and len(response.json()['subscriptions']) > 0:
            subscription = response.json()['subscriptions'][0]

            # Required fields according to contract
            required_fields = [
                'id', 'tenant_id', 'plan', 'status', 'pricing_model',
                'billing_cycle', 'current_period_start', 'current_period_end',
                'trial_end', 'created_at', 'updated_at'
            ]

            for field in required_fields:
                assert field in subscription

            # Field types and enums
            assert isinstance(subscription['id'], str)
            assert isinstance(subscription['tenant_id'], str)
            assert subscription['plan'] in ['STARTER', 'GROWTH', 'PRO', 'ENTERPRISE']
            assert subscription['status'] in ['TRIAL', 'ACTIVE', 'PAST_DUE', 'CANCELLED', 'EXPIRED']
            assert subscription['pricing_model'] in ['SUBSCRIPTION', 'PERPETUAL']
            assert subscription['billing_cycle'] in ['MONTHLY', 'QUARTERLY', 'YEARLY']

    def test_get_subscriptions_with_usage_data(self):
        """Test that subscription data includes usage information."""
        response = self.client.get(
            self.subscriptions_url,
            **self.admin_auth
        )

        if response.status_code == status.HTTP_200_OK and len(response.json()['subscriptions']) > 0:
            subscription = response.json()['subscriptions'][0]

            # Should include usage metrics
            assert 'usage' in subscription
            usage = subscription['usage']

            # Usage should include relevant metrics
            expected_usage_fields = ['users_count', 'storage_used', 'api_calls']
            for field in expected_usage_fields:
                assert field in usage

    def test_get_subscriptions_with_billing_info(self):
        """Test that subscription data includes billing information."""
        response = self.client.get(
            self.subscriptions_url,
            **self.admin_auth
        )

        if response.status_code == status.HTTP_200_OK and len(response.json()['subscriptions']) > 0:
            subscription = response.json()['subscriptions'][0]

            # Should include billing information
            assert 'billing' in subscription
            billing = subscription['billing']

            # Billing should include relevant fields
            expected_billing_fields = ['next_billing_date', 'amount', 'currency', 'payment_method']
            for field in expected_billing_fields:
                assert field in billing