package alertapi

import (
	"context"
	"encoding/json"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"

	"github.com/itworx/pulse/internal/alert"
	"github.com/itworx/pulse/internal/audit"
	"github.com/itworx/pulse/internal/auth"
	"github.com/itworx/pulse/internal/metriccatalog"
)

type fakeStore struct {
	rule                                            alert.Rule
	getCalls, createCalls, updateCalls, toggleCalls int
}

func (f *fakeStore) Create(_ context.Context, _ string, document alert.Document, _ string) (alert.Rule, alert.Version, error) {
	f.createCalls++
	f.rule = alert.Rule{Document: document, Revision: 1, CurrentVersion: 1}
	return f.rule, alert.Version{RuleID: document.ID, VersionNumber: 1, Document: document}, nil
}
func (f *fakeStore) Get(_ context.Context, _ string) (alert.Rule, error) {
	f.getCalls++
	return f.rule, nil
}
func (f *fakeStore) List(_ context.Context, _ int) ([]alert.Rule, error) {
	return []alert.Rule{f.rule}, nil
}
func (f *fakeStore) Update(_ context.Context, id, _ string, _ int64, document alert.Document, _ string) (alert.Rule, error) {
	f.updateCalls++
	document.ID = id
	f.rule.Document = document
	f.rule.Revision++
	return f.rule, nil
}
func (f *fakeStore) Versions(_ context.Context, _ string, _ int) ([]alert.Version, error) {
	return []alert.Version{{Document: f.rule.Document, VersionNumber: 1}}, nil
}
func (f *fakeStore) SetEnabled(_ context.Context, _ string, _ int64, enabled bool) (alert.Rule, error) {
	f.toggleCalls++
	f.rule.Enabled = enabled
	f.rule.Document.Enabled = enabled
	f.rule.Revision++
	return f.rule, nil
}

func requestWithPrincipal(method, path string, body any, role auth.Role) *http.Request {
	data, _ := json.Marshal(body)
	request := httptest.NewRequest(method, path, strings.NewReader(string(data)))
	request.Header.Set("Content-Type", "application/json")
	return request.WithContext(auth.WithPrincipal(request.Context(), auth.Principal{Subject: "editor-1", Role: role}))
}

func TestViewerCannotCreateAlertRule(t *testing.T) {
	document, registry := validDocumentForHandler(t)
	store := &fakeStore{}
	handler := Handler{Repository: store, Registry: registry}
	response := httptest.NewRecorder()
	handler.ServeHTTP(response, requestWithPrincipal(http.MethodPost, "/api/v1/alert-rules", document, auth.RoleViewer))
	if response.Code != http.StatusForbidden || store.createCalls != 0 {
		t.Fatalf("status=%d creates=%d", response.Code, store.createCalls)
	}
}

func TestPreviewDoesNotWriteOrAudit(t *testing.T) {
	document, registry := validDocumentForHandler(t)
	store := &fakeStore{}
	auditStore := &audit.MemoryStore{}
	handler := Handler{Repository: store, Registry: registry, Audit: auditStore}
	response := httptest.NewRecorder()
	handler.ServeHTTP(response, requestWithPrincipal(http.MethodPost, "/api/v1/alert-rules/"+document.ID+"/test", map[string]any{"rule": document, "value": 90}, auth.RoleEditor))
	if response.Code != http.StatusOK {
		t.Fatalf("preview status=%d body=%s", response.Code, response.Body.String())
	}
	if store.createCalls != 0 || store.updateCalls != 0 || store.toggleCalls != 0 || len(auditStore.Events) != 0 {
		t.Fatalf("preview had side effects: store=%#v audit=%d", store, len(auditStore.Events))
	}
	var body map[string]any
	if err := json.Unmarshal(response.Body.Bytes(), &body); err != nil {
		t.Fatal(err)
	}
	if body["preview"] == nil {
		t.Fatal("preview result missing")
	}
}

func TestEnableIsAudited(t *testing.T) {
	document, registry := validDocumentForHandler(t)
	store := &fakeStore{rule: alert.Rule{Document: document, Revision: 1}}
	auditStore := &audit.MemoryStore{}
	handler := Handler{Repository: store, Registry: registry, Audit: auditStore}
	request := requestWithPrincipal(http.MethodPost, "/api/v1/alert-rules/"+document.ID+"/enable?revision=1", map[string]any{}, auth.RoleEditor)
	response := httptest.NewRecorder()
	handler.ServeHTTP(response, request)
	if response.Code != http.StatusOK || store.toggleCalls != 1 {
		t.Fatalf("status=%d toggles=%d", response.Code, store.toggleCalls)
	}
	if len(auditStore.Events) != 1 || auditStore.Events[0].Action != "alert_rule.enable" {
		t.Fatalf("audit=%#v", auditStore.Events)
	}
}

func validDocumentForHandler(t *testing.T) (alert.Document, metriccatalog.Registry) {
	t.Helper()
	registry, err := metriccatalog.DefaultRegistry()
	if err != nil {
		t.Fatal(err)
	}
	return alert.Document{
		SchemaVersion: 1, ID: alert.NewID(), Name: "CPU aandacht", Severity: alert.SeverityAttention,
		Scope:                     map[string]any{"entityType": "host"},
		Condition:                 alert.Condition{InputType: "metric", Metric: registry.Metrics()[0].SemanticName, Operator: ">", Threshold: float64(80)},
		EvaluationIntervalSeconds: 30, UnknownBehavior: alert.UnknownRetain,
		Message: alert.Message{TitleKey: "alerts.cpu.title", BodyKey: "alerts.cpu.body"},
	}, registry
}