"""Tests for dashboard.views."""
from unittest.mock import patch, MagicMock

from django.test import TestCase, RequestFactory
from django.core.cache import cache

from dashboard.views import index, collect_context


def _minimal_render_context(region_name="test", first_flavor_name="f1", vm_count=1):
    """Context with all keys the index.html template expects."""
    return {
        "region": {"name": region_name, "hosts_total": 1},
        "pcpu": {"total": 1, "usage": 0, "free": 1, "used_percentage": 0},
        "vcpu": {"total": 2, "allocated": 1, "free": 1, "allocated_percentage": 50, "overcommit_ratio": 1, "overcommit_max": 2},
        "pram": {"total": 1024**3, "usage": 0, "free": 1024**3, "used_percentage": 0},
        "vram": {"total": 1024**3, "allocated": 0, "free": 1024**3, "allocated_percentage": 0, "overcommit_ratio": 0, "overcommit_max": 1},
        "vm": {"count": vm_count, "active": vm_count, "stopped": 0, "avg_cpu": 1, "avg_ram": 0, "density": float(vm_count)},
        "flavors": {
            "first_common_flavor": {"name": first_flavor_name, "count": vm_count},
            "second_common_flavor": {"name": "—", "count": 0},
            "third_common_flavor": {"name": "—", "count": 0},
        },
        "audits": [],
    }


class IndexViewTest(TestCase):
    """Tests for the index view."""

    def setUp(self):
        self.factory = RequestFactory()

    @patch("dashboard.views.settings")
    def test_index_use_mock_data_returns_200_and_mock_context(self, mock_settings):
        mock_settings.USE_MOCK_DATA = True
        mock_settings.DASHBOARD_CACHE_TTL = 120
        request = self.factory.get("/")
        response = index(request)
        self.assertEqual(response.status_code, 200)
        # Mock context contains mock-region and flavors; render uses index.html
        content = response.content.decode()
        self.assertIn("mock-region", content)
        self.assertIn("m1.small", content)

    @patch("dashboard.views.collect_context")
    @patch("dashboard.views.get_mock_context")
    @patch("dashboard.views.settings")
    def test_index_with_real_path_uses_cache_and_collect_context(
        self, mock_settings, mock_get_mock_context, mock_collect_context
    ):
        mock_settings.USE_MOCK_DATA = False
        mock_settings.DASHBOARD_CACHE_TTL = 120
        mock_collect_context.return_value = _minimal_render_context(
            region_name="cached-region", first_flavor_name="f1"
        )
        cache.clear()
        request = self.factory.get("/")
        with patch.object(cache, "get", return_value=None):
            with patch.object(cache, "set") as mock_cache_set:
                response = index(request)
        self.assertEqual(response.status_code, 200)
        mock_collect_context.assert_called_once()
        mock_cache_set.assert_called_once()
        mock_get_mock_context.assert_not_called()
        content = response.content.decode()
        self.assertIn("cached-region", content)
        self.assertIn("f1", content)

    @patch("dashboard.views.collect_context")
    @patch("dashboard.views.settings")
    def test_index_with_cache_hit_does_not_call_collect_context(
        self, mock_settings, mock_collect_context
    ):
        mock_settings.USE_MOCK_DATA = False
        mock_settings.DASHBOARD_CACHE_TTL = 120
        cached = _minimal_render_context(region_name="from-cache", first_flavor_name="cached-flavor", vm_count=2)
        cache.clear()
        cache.set("dashboard_context", cached, timeout=120)
        request = self.factory.get("/")
        response = index(request)
        self.assertEqual(response.status_code, 200)
        mock_collect_context.assert_not_called()
        content = response.content.decode()
        self.assertIn("from-cache", content)


class CollectContextTest(TestCase):
    """Tests for collect_context with mocked dependencies."""

    def _make_mock_connection(self, region_name="test-region"):
        conn = MagicMock()
        conn._compute_region = region_name
        return conn

    @patch("dashboard.views._fetch_prometheus_metrics")
    @patch("dashboard.views.get_audits")
    @patch("dashboard.views.get_flavor_list")
    @patch("dashboard.views.get_connection")
    def test_collect_context_structure_and_calculation(
        self, mock_get_connection, mock_get_flavor_list, mock_get_audits, mock_fetch_metrics
    ):
        mock_get_connection.return_value = self._make_mock_connection("my-region")
        mock_get_flavor_list.return_value = {
            "first_common_flavor": {"name": "m1.small", "count": 5},
            "second_common_flavor": {"name": "—", "count": 0},
            "third_common_flavor": {"name": "—", "count": 0},
        }
        mock_get_audits.return_value = [
            {
                "migrations": [],
                "host_labels": ["h0", "h1"],
                "cpu_current": [30.0, 40.0],
                "cpu_projected": [35.0, 35.0],
            }
        ]
        mock_fetch_metrics.return_value = {
            "hosts_total": 2,
            "pcpu_total": 8,
            "pcpu_usage": 2.5,
            "vcpu_allocated": 16,
            "vcpu_overcommit_max": 2.0,
            "pram_total": 32 * 1024**3,
            "pram_usage": 8 * 1024**3,
            "vram_allocated": 24 * 1024**3,
            "vram_overcommit_max": 1.5,
            "vm_count": 4,
            "vm_active": 4,
        }

        context = collect_context()

        self.assertEqual(context["region"]["name"], "my-region")
        self.assertEqual(context["region"]["hosts_total"], 2)
        self.assertEqual(context["pcpu"]["total"], 8)
        self.assertEqual(context["pcpu"]["usage"], 2.5)
        self.assertEqual(context["vcpu"]["total"], 8 * 2.0)  # pcpu_total * vcpu_overcommit_max
        self.assertEqual(context["vcpu"]["allocated"], 16)
        self.assertEqual(context["vram"]["total"], 32 * 1024**3 * 1.5)
        self.assertEqual(context["flavors"]["first_common_flavor"]["name"], "m1.small")
        self.assertEqual(len(context["audits"]), 1)
        # Serialized for JS
        import json
        self.assertIsInstance(context["audits"][0]["migrations"], str)
        self.assertEqual(json.loads(context["audits"][0]["host_labels"]), ["h0", "h1"])