// Copyright The OpenTelemetry Authors
//
// 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 config

import (
	"errors"
	"testing"

	"github.com/stretchr/testify/assert"
)

func TestConfigValidate(t *testing.T) {
	var testCases = []struct {
		name     string // test case name (also file name containing config yaml)
		cfgFn    func() *Config
		expected error
	}{
		{
			name:     "valid",
			cfgFn:    generateConfig,
			expected: nil,
		},
		{
			name: "missing-exporters",
			cfgFn: func() *Config {
				cfg := generateConfig()
				cfg.Exporters = nil
				return cfg
			},
			expected: errMissingExporters,
		},
		{
			name: "missing-receivers",
			cfgFn: func() *Config {
				cfg := generateConfig()
				cfg.Receivers = nil
				return cfg
			},
			expected: errMissingReceivers,
		},
		{
			name: "invalid-extension-reference",
			cfgFn: func() *Config {
				cfg := generateConfig()
				cfg.Service.Extensions = append(cfg.Service.Extensions, "nop/2")
				return cfg
			},
			expected: errors.New(`service references extension "nop/2" which does not exist`),
		},
		{
			name: "invalid-receiver-reference",
			cfgFn: func() *Config {
				cfg := generateConfig()
				pipe := cfg.Service.Pipelines["traces"]
				pipe.Receivers = append(pipe.Receivers, "nop/2")
				return cfg
			},
			expected: errors.New(`pipeline "traces" references receiver "nop/2" which does not exist`),
		},
		{
			name: "invalid-processor-reference",
			cfgFn: func() *Config {
				cfg := generateConfig()
				pipe := cfg.Service.Pipelines["traces"]
				pipe.Processors = append(pipe.Processors, "nop/2")
				return cfg
			},
			expected: errors.New(`pipeline "traces" references processor "nop/2" which does not exist`),
		},
		{
			name: "invalid-exporter-reference",
			cfgFn: func() *Config {
				cfg := generateConfig()
				pipe := cfg.Service.Pipelines["traces"]
				pipe.Exporters = append(pipe.Exporters, "nop/2")
				return cfg
			},
			expected: errors.New(`pipeline "traces" references exporter "nop/2" which does not exist`),
		},
		{
			name: "missing-pipeline-receivers",
			cfgFn: func() *Config {
				cfg := generateConfig()
				pipe := cfg.Service.Pipelines["traces"]
				pipe.Receivers = nil
				return cfg
			},
			expected: errors.New(`pipeline "traces" must have at least one receiver`),
		},
		{
			name: "missing-pipeline-exporters",
			cfgFn: func() *Config {
				cfg := generateConfig()
				pipe := cfg.Service.Pipelines["traces"]
				pipe.Exporters = nil
				return cfg
			},
			expected: errors.New(`pipeline "traces" must have at least one exporter`),
		},
		{
			name: "missing-pipelines",
			cfgFn: func() *Config {
				cfg := generateConfig()
				cfg.Service.Pipelines = nil
				return cfg
			},
			expected: errMissingServicePipelines,
		},
	}

	for _, test := range testCases {
		t.Run(test.name, func(t *testing.T) {
			cfg := test.cfgFn()
			assert.Equal(t, test.expected, cfg.Validate())
		})
	}
}

func generateConfig() *Config {
	return &Config{
		Receivers: map[string]Receiver{
			"nop": &ReceiverSettings{TypeVal: "nop"},
		},
		Exporters: map[string]Exporter{
			"nop": &ExporterSettings{TypeVal: "nop"},
		},
		Processors: map[string]Processor{
			"nop": &ProcessorSettings{TypeVal: "nop"},
		},
		Extensions: map[string]Extension{
			"nop": &ExtensionSettings{TypeVal: "nop"},
		},
		Service: Service{
			Extensions: []string{"nop"},
			Pipelines: map[string]*Pipeline{
				"traces": {
					Name:       "traces",
					InputType:  TracesDataType,
					Receivers:  []string{"nop"},
					Processors: []string{"nop"},
					Exporters:  []string{"nop"},
				},
			},
		},
	}
}