// Copyright 2019, 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 signalfxexporter

import (
	"context"
	"fmt"
	"strings"
	"time"

	"go.opentelemetry.io/collector/component"
	otelconfig "go.opentelemetry.io/collector/config"
	"go.opentelemetry.io/collector/config/configmodels"
	"go.opentelemetry.io/collector/exporter/exporterhelper"

	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/signalfxexporter/translation"
	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/splunk"
)

const (
	// The value of "type" key in configuration.
	typeStr = "signalfx"

	defaultHTTPTimeout = time.Second * 5
)

// NewFactory creates a factory for SignalFx exporter.
func NewFactory() component.ExporterFactory {
	return exporterhelper.NewFactory(
		typeStr,
		createDefaultConfig,
		exporterhelper.WithMetrics(createMetricsExporter),
		exporterhelper.WithLogs(createLogsExporter))
}

func createDefaultConfig() configmodels.Exporter {
	return &Config{
		ExporterSettings: configmodels.ExporterSettings{
			TypeVal: configmodels.Type(typeStr),
			NameVal: typeStr,
		},
		TimeoutSettings: exporterhelper.TimeoutSettings{Timeout: defaultHTTPTimeout},
		RetrySettings:   exporterhelper.CreateDefaultRetrySettings(),
		QueueSettings:   exporterhelper.CreateDefaultQueueSettings(),
		AccessTokenPassthroughConfig: splunk.AccessTokenPassthroughConfig{
			AccessTokenPassthrough: true,
		},
		SendCompatibleMetrics: false,
		TranslationRules:      nil,
		DeltaTranslationTTL:   3600,
	}
}

func createMetricsExporter(
	_ context.Context,
	params component.ExporterCreateParams,
	config configmodels.Exporter,
) (component.MetricsExporter, error) {

	expCfg := config.(*Config)
	err := setTranslationRules(expCfg)
	if err != nil {
		return nil, err
	}

	exp, err := newSignalFxExporter(expCfg, params.Logger)
	if err != nil {
		return nil, err
	}

	me, err := exporterhelper.NewMetricsExporter(
		expCfg,
		exp.pushMetrics,
		// explicitly disable since we rely on http.Client timeout logic.
		exporterhelper.WithTimeout(exporterhelper.TimeoutSettings{Timeout: 0}),
		exporterhelper.WithRetry(expCfg.RetrySettings),
		exporterhelper.WithQueue(expCfg.QueueSettings))

	return &signalfMetadataExporter{
		MetricsExporter: me,
		pushMetadata:    exp.pushMetadata,
	}, err
}

func setTranslationRules(cfg *Config) error {
	if cfg.SendCompatibleMetrics && cfg.TranslationRules == nil {
		defaultRules, err := loadDefaultTranslationRules()
		if err != nil {
			return err
		}
		cfg.TranslationRules = defaultRules
	}
	if len(cfg.ExcludeMetrics) > 0 {
		cfg.TranslationRules = append(cfg.TranslationRules,
			translation.GetExcludeMetricsRule(cfg.ExcludeMetrics))
	}
	return nil
}

func loadDefaultTranslationRules() ([]translation.Rule, error) {
	config := Config{}

	v := otelconfig.NewViper()
	v.SetConfigType("yaml")
	v.ReadConfig(strings.NewReader(translation.DefaultTranslationRulesYaml))
	err := v.UnmarshalExact(&config)
	if err != nil {
		return nil, fmt.Errorf("failed to load default translation rules: %v", err)
	}

	return config.TranslationRules, nil
}

func createLogsExporter(
	_ context.Context,
	params component.ExporterCreateParams,
	cfg configmodels.Exporter,
) (component.LogsExporter, error) {
	expCfg := cfg.(*Config)

	exp, err := newEventExporter(expCfg, params.Logger)
	if err != nil {
		return nil, err
	}

	return exporterhelper.NewLogsExporter(
		expCfg,
		exp.pushLogs,
		// explicitly disable since we rely on http.Client timeout logic.
		exporterhelper.WithTimeout(exporterhelper.TimeoutSettings{Timeout: 0}),
		exporterhelper.WithRetry(expCfg.RetrySettings),
		exporterhelper.WithQueue(expCfg.QueueSettings))
}