package main

import (
	"errors"
	"net/http"
	"net/http/httptest"
	"strings"
	"testing"
	"time"

	"github.com/golang/mock/gomock"
	immetrics "github.com/tinode/chat/server/metrics"
	"github.com/tinode/chat/server/store"
	"github.com/tinode/chat/server/store/mock_store"
)

func TestServeHealthzOK(t *testing.T) {
	ctrl := gomock.NewController(t)
	mockStore := mock_store.NewMockPersistentStorageInterface(ctrl)
	oldStore := store.Store
	store.Store = mockStore
	t.Cleanup(func() { store.Store = oldStore })
	mockStore.EXPECT().HealthCheck(gomock.Any()).Return(nil)

	wrt := httptest.NewRecorder()
	serveHealthz(wrt, httptest.NewRequest(http.MethodGet, "/healthz", nil))

	if wrt.Code != http.StatusOK {
		t.Fatalf("unexpected status %d body=%s", wrt.Code, wrt.Body.String())
	}
	if body := wrt.Body.String(); !strings.Contains(body, `"status":"ok"`) || !strings.Contains(body, `"mysql":"ok"`) {
		t.Fatalf("unexpected body %s", body)
	}
}

func TestServeHealthzError(t *testing.T) {
	ctrl := gomock.NewController(t)
	mockStore := mock_store.NewMockPersistentStorageInterface(ctrl)
	oldStore := store.Store
	store.Store = mockStore
	t.Cleanup(func() { store.Store = oldStore })
	mockStore.EXPECT().HealthCheck(gomock.Any()).Return(errors.New("dial timeout"))

	wrt := httptest.NewRecorder()
	serveHealthz(wrt, httptest.NewRequest(http.MethodGet, "/healthz", nil))

	if wrt.Code != http.StatusServiceUnavailable {
		t.Fatalf("unexpected status %d body=%s", wrt.Code, wrt.Body.String())
	}
	if body := wrt.Body.String(); !strings.Contains(body, `"status":"error"`) || !strings.Contains(body, `"mysql":"dial timeout"`) {
		t.Fatalf("unexpected body %s", body)
	}
}

func TestServeMetricsIncludesWSConnections(t *testing.T) {
	wrt := httptest.NewRecorder()
	serveMetrics(wrt, httptest.NewRequest(http.MethodGet, "/metrics", nil))

	if wrt.Code != http.StatusOK {
		t.Fatalf("unexpected status %d body=%s", wrt.Code, wrt.Body.String())
	}
	body := wrt.Body.String()
	if !strings.Contains(body, "# TYPE ws_connections_active gauge") || !strings.Contains(body, "ws_connections_active ") {
		t.Fatalf("unexpected body %s", body)
	}
}

func TestMonitorHTTPRecordsRequestMetrics(t *testing.T) {
	handler := monitorHTTP(http.HandlerFunc(func(wrt http.ResponseWriter, req *http.Request) {
		wrt.WriteHeader(http.StatusCreated)
	}))

	handler.ServeHTTP(httptest.NewRecorder(), httptest.NewRequest(http.MethodPost, "/v1/im/users/1234567890123456789/profile", nil))
	wrt := httptest.NewRecorder()
	serveMetrics(wrt, httptest.NewRequest(http.MethodGet, "/metrics", nil))

	body := wrt.Body.String()
	if !strings.Contains(body, `http_requests_total{method="POST",path="/v1/im/users/{id}/profile",status="201"} 1`) {
		t.Fatalf("request counter was not exported: %s", body)
	}
	if !strings.Contains(body, `http_request_duration_seconds_bucket{method="POST",path="/v1/im/users/{id}/profile",status="201"`) {
		t.Fatalf("request duration was not exported: %s", body)
	}
}

func TestServeMetricsIncludesDBQueryDuration(t *testing.T) {
	immetrics.ObserveDB("mysql", "query", time.Now().Add(-time.Millisecond), nil)

	wrt := httptest.NewRecorder()
	serveMetrics(wrt, httptest.NewRequest(http.MethodGet, "/metrics", nil))

	body := wrt.Body.String()
	if !strings.Contains(body, `db_query_duration_seconds_bucket{driver="mysql",operation="query",status="ok"`) {
		t.Fatalf("db query duration was not exported: %s", body)
	}
}