// Copyright © 2023 OpenIM. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package prommetrics

import (
	"testing"

	"github.com/prometheus/client_golang/prometheus"
	"github.com/stretchr/testify/assert"

	config2 "github.com/openimsdk/open-im-server/v3/pkg/common/config"
)

func TestNewGrpcPromObj(t *testing.T) {
	// Create a custom metric to pass into the NewGrpcPromObj function.
	customMetric := prometheus.NewCounter(prometheus.CounterOpts{
		Name: "test_metric",
		Help: "This is a test metric.",
	})
	cusMetrics := []prometheus.Collector{customMetric}

	// Call NewGrpcPromObj with the custom metrics.
	reg, grpcMetrics, err := NewGrpcPromObj(cusMetrics)

	// Assert no error was returned.
	assert.NoError(t, err)

	// Assert the registry was correctly initialized.
	assert.NotNil(t, reg)

	// Assert the grpcMetrics was correctly initialized.
	assert.NotNil(t, grpcMetrics)

	// Assert that the custom metric is registered.
	mfs, err := reg.Gather()
	assert.NoError(t, err)
	assert.NotEmpty(t, mfs) // Ensure some metrics are present.
	found := false
	for _, mf := range mfs {
		if *mf.Name == "test_metric" {
			found = true
			break
		}
	}
	assert.True(t, found, "Custom metric not found in registry")
}

func TestGetGrpcCusMetrics(t *testing.T) {
	// Test various cases based on the switch statement in the GetGrpcCusMetrics function.
	testCases := []struct {
		name     string
		expected int // The expected number of metrics for each case.
	}{
		{config2.Config.RpcRegisterName.OpenImMessageGatewayName, 1},
	}

	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			metrics := GetGrpcCusMetrics(tc.name)
			assert.Len(t, metrics, tc.expected)
		})
	}
}