/*
Copyright 2018 The KubeSphere 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 log

import (
	"github.com/jinzhu/gorm"
	"github.com/json-iterator/go"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/client-go/rest"
	es "kubesphere.io/kubesphere/pkg/simple/client/elasticsearch"
	fb "kubesphere.io/kubesphere/pkg/simple/client/fluentbit"
	"kubesphere.io/kubesphere/pkg/simple/client/mysql"
	"net/http"
	"strings"
	"time"

	_ "github.com/go-sql-driver/mysql"
)

var jsonIter = jsoniter.ConfigCompatibleWithStandardLibrary

func createCRDClientSet() (*rest.RESTClient, *runtime.Scheme, error) {
	config, err := fb.GetClientConfig("")
	if err != nil {
		//panic(err.Error())
		return nil, nil, err
	}

	// Create a new clientset which include our CRD schema
	return fb.NewFluentbitCRDClient(config)
}

func getParameterValue(parameters []fb.Parameter, name string) string {
	var value string

	value = ""
	for _, parameter := range parameters {
		if parameter.Name == name {
			value = parameter.Value
		}
	}

	return value
}

func getFilters(result *FluentbitFiltersResult, Filters []fb.Plugin) {
	for _, filter := range Filters {
		if strings.Compare(filter.Name, "fluentbit-filter-input-regex") == 0 {
			parameters := strings.Split(getParameterValue(filter.Parameters, "Regex"), " ")
			field := strings.TrimSuffix(strings.TrimPrefix(parameters[0], "kubernetes_"), "_name")
			expression := parameters[1]
			result.Filters = append(result.Filters, FluentbitFilter{"Regex", field, expression})
		}
		if strings.Compare(filter.Name, "fluentbit-filter-input-exclude") == 0 {
			parameters := strings.Split(getParameterValue(filter.Parameters, "Exclude"), " ")
			field := strings.TrimSuffix(strings.TrimPrefix(parameters[0], "kubernetes_"), "_name")
			expression := parameters[1]
			result.Filters = append(result.Filters, FluentbitFilter{"Exclude", field, expression})
		}
	}
}

func FluentbitFiltersQuery() *FluentbitFiltersResult {
	var result FluentbitFiltersResult

	crdcs, scheme, err := createCRDClientSet()
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	// Create a CRD client interface
	crdclient := fb.CrdClient(crdcs, scheme, "kubesphere-logging-system")

	item, err := crdclient.Get("fluent-bit")
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	getFilters(&result, item.Spec.Filter)

	result.Status = http.StatusOK

	return &result
}

func FluentbitFiltersUpdate(filters *[]FluentbitFilter) *FluentbitFiltersResult {
	var result FluentbitFiltersResult

	//Generate filter plugin config
	var filter []fb.Plugin

	var para_kubernetes []fb.Parameter
	para_kubernetes = append(para_kubernetes, fb.Parameter{Name: "Name", Value: "kubernetes"})
	para_kubernetes = append(para_kubernetes, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_kubernetes = append(para_kubernetes, fb.Parameter{Name: "Kube_URL", Value: "https://kubernetes.default.svc:443"})
	para_kubernetes = append(para_kubernetes, fb.Parameter{Name: "Kube_CA_File", Value: "/var/run/secrets/kubernetes.io/serviceaccount/ca.crt"})
	para_kubernetes = append(para_kubernetes, fb.Parameter{Name: "Kube_Token_File", Value: "/var/run/secrets/kubernetes.io/serviceaccount/token"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-kubernetes", Parameters: para_kubernetes})

	var para_lift []fb.Parameter
	para_lift = append(para_lift, fb.Parameter{Name: "Name", Value: "nest"})
	para_lift = append(para_lift, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_lift = append(para_lift, fb.Parameter{Name: "Operation", Value: "lift"})
	para_lift = append(para_lift, fb.Parameter{Name: "Nested_under", Value: "kubernetes"})
	para_lift = append(para_lift, fb.Parameter{Name: "Prefix_with", Value: "kubernetes_"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-lift", Parameters: para_lift})

	var para_remove_stream []fb.Parameter
	para_remove_stream = append(para_remove_stream, fb.Parameter{Name: "Name", Value: "modify"})
	para_remove_stream = append(para_remove_stream, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_remove_stream = append(para_remove_stream, fb.Parameter{Name: "Remove", Value: "stream"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-remove-stream", Parameters: para_remove_stream})

	var para_remove_labels []fb.Parameter
	para_remove_labels = append(para_remove_labels, fb.Parameter{Name: "Name", Value: "modify"})
	para_remove_labels = append(para_remove_labels, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_remove_labels = append(para_remove_labels, fb.Parameter{Name: "Remove", Value: "kubernetes_labels"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-remove-labels", Parameters: para_remove_labels})

	var para_remove_annotations []fb.Parameter
	para_remove_annotations = append(para_remove_annotations, fb.Parameter{Name: "Name", Value: "modify"})
	para_remove_annotations = append(para_remove_annotations, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_remove_annotations = append(para_remove_annotations, fb.Parameter{Name: "Remove", Value: "kubernetes_annotations"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-remove-annotations", Parameters: para_remove_annotations})

	var para_remove_pod_id []fb.Parameter
	para_remove_pod_id = append(para_remove_pod_id, fb.Parameter{Name: "Name", Value: "modify"})
	para_remove_pod_id = append(para_remove_pod_id, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_remove_pod_id = append(para_remove_pod_id, fb.Parameter{Name: "Remove", Value: "kubernetes_pod_id"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-remove-podid", Parameters: para_remove_pod_id})

	var para_remove_docker_id []fb.Parameter
	para_remove_docker_id = append(para_remove_docker_id, fb.Parameter{Name: "Name", Value: "modify"})
	para_remove_docker_id = append(para_remove_docker_id, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_remove_docker_id = append(para_remove_docker_id, fb.Parameter{Name: "Remove", Value: "kubernetes_docker_id"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-remove-dockerid", Parameters: para_remove_docker_id})

	if len(*filters) > 0 {
		for _, item := range *filters {
			if strings.Compare(item.Type, "Regex") == 0 {
				field := "kubernetes_" + strings.TrimSpace(item.Field) + "_name"
				expression := strings.TrimSpace(item.Expression)

				var para_regex []fb.Parameter
				para_regex = append(para_regex, fb.Parameter{Name: "Name", Value: "grep"})
				para_regex = append(para_regex, fb.Parameter{Name: "Match", Value: "kube.*"})
				para_regex = append(para_regex, fb.Parameter{Name: "Regex", Value: field + " " + expression})
				filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-regex", Parameters: para_regex})
			}

			if strings.Compare(item.Type, "Exclude") == 0 {
				field := "kubernetes_" + strings.TrimSpace(item.Field) + "_name"
				expression := strings.TrimSpace(item.Expression)

				var para_exclude []fb.Parameter
				para_exclude = append(para_exclude, fb.Parameter{Name: "Name", Value: "grep"})
				para_exclude = append(para_exclude, fb.Parameter{Name: "Match", Value: "kube.*"})
				para_exclude = append(para_exclude, fb.Parameter{Name: "Exclude", Value: field + " " + expression})
				filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-exclude", Parameters: para_exclude})
			}
		}
	}

	var para_nest []fb.Parameter
	para_nest = append(para_nest, fb.Parameter{Name: "Name", Value: "nest"})
	para_nest = append(para_nest, fb.Parameter{Name: "Match", Value: "kube.*"})
	para_nest = append(para_nest, fb.Parameter{Name: "Operation", Value: "nest"})
	para_nest = append(para_nest, fb.Parameter{Name: "Wildcard", Value: "kubernetes_*"})
	para_nest = append(para_nest, fb.Parameter{Name: "Nested_under", Value: "kubernetes"})
	para_nest = append(para_nest, fb.Parameter{Name: "Remove_prefix", Value: "kubernetes_"})
	filter = append(filter, fb.Plugin{Type: "fluentbit_filter", Name: "fluentbit-filter-input-nest", Parameters: para_nest})

	crdcs, scheme, err := createCRDClientSet()
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	// Create a CRD client interface
	crdclient := fb.CrdClient(crdcs, scheme, "kubesphere-logging-system")

	var item *fb.FluentBit
	var err_read error

	item, err_read = crdclient.Get("fluent-bit")
	if err_read != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	item.Spec.Filter = filter

	itemnew, err := crdclient.Update("fluent-bit", item)
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	getFilters(&result, itemnew.Spec.Filter)
	result.Status = http.StatusOK

	return &result
}

func FluentbitOutputsQuery() *FluentbitOutputsResult {
	var result FluentbitOutputsResult

	// Retrieve outputs from DB
	db := mysql.Client()

	var outputs []OutputDBBinding

	err := db.Find(&outputs).Error
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	var unmarshaledOutputs []fb.OutputPlugin

	for _, output := range outputs {
		var params []fb.Parameter

		err = jsonIter.UnmarshalFromString(output.Parameters, &params)
		if err != nil {
			result.Status = http.StatusInternalServerError
			return &result
		}

		unmarshaledOutputs = append(unmarshaledOutputs,
			fb.OutputPlugin{Plugin: fb.Plugin{Type: output.Type, Name: output.Name, Parameters: params},
				Id: output.Id, Enable: output.Enable, Updatetime: output.Updatetime})
	}

	result.Outputs = unmarshaledOutputs
	result.Status = http.StatusOK

	return &result
}

func FluentbitOutputInsert(output fb.OutputPlugin) *FluentbitOutputsResult {
	var result FluentbitOutputsResult

	params, err := jsoniter.MarshalToString(output.Parameters)
	if err != nil {
		result.Status = http.StatusBadRequest
		return &result
	}

	// 1. Update DB
	db := mysql.Client()

	marshaledOutput := OutputDBBinding{Type: output.Type, Name: output.Name,
		Parameters: params, Enable: output.Enable, Updatetime: time.Now()}
	err = db.Create(&marshaledOutput).Error
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	// 2. Keep CRD in inline with DB
	err = syncFluentbitCRDOutputWithDB(db)
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	// 3. If it's an configs output added, reset configs client configs
	configs := ParseEsOutputParams(output.Parameters)
	if configs != nil {
		configs.WriteESConfigs()
	}

	result.Status = http.StatusOK
	return &result
}

func FluentbitOutputUpdate(output fb.OutputPlugin, id string) *FluentbitOutputsResult {
	var result FluentbitOutputsResult

	// 1. Update DB
	db := mysql.Client()

	params, err := jsoniter.MarshalToString(output.Parameters)
	if err != nil {
		result.Status = http.StatusBadRequest
		return &result
	}

	var marshaledOutput OutputDBBinding
	err = db.Where("id = ?", id).First(&marshaledOutput).Error
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	marshaledOutput.Name = output.Name
	marshaledOutput.Type = output.Type
	marshaledOutput.Parameters = params
	marshaledOutput.Enable = output.Enable

	err = db.Save(&marshaledOutput).Error
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	// 2. Keep CRD in inline with DB
	err = syncFluentbitCRDOutputWithDB(db)
	if err != nil {
		result.Status = http.StatusBadRequest
		return &result
	}

	// 3. If it's an configs output updated, reset configs client configs
	configs := ParseEsOutputParams(output.Parameters)
	if configs != nil {
		configs.WriteESConfigs()
	}

	result.Status = http.StatusOK
	return &result
}

func FluentbitOutputDelete(id string) *FluentbitOutputsResult {
	var result FluentbitOutputsResult

	// 1. Remove the record from DB
	db := mysql.Client()

	err := db.Where("id = ?", id).Delete(&OutputDBBinding{}).Error
	if err != nil {
		result.Status = http.StatusInternalServerError
		return &result
	}

	// 2. Keep CRD in inline with DB
	err = syncFluentbitCRDOutputWithDB(db)
	if err != nil {
		result.Status = http.StatusBadRequest
		return &result
	}

	result.Status = http.StatusOK
	return &result
}

func syncFluentbitCRDOutputWithDB(db *gorm.DB) error {
	var outputs []OutputDBBinding

	err := db.Where("enable is true").Find(&outputs).Error
	if err != nil {
		return err
	}

	var unmarshaledOutputs []fb.Plugin

	for _, output := range outputs {
		var params []fb.Parameter

		err = jsonIter.UnmarshalFromString(output.Parameters, &params)
		if err != nil {
			return err
		}

		unmarshaledOutputs = append(unmarshaledOutputs, fb.Plugin{Type: output.Type, Name: output.Name, Parameters: params})
	}
	// Empty output is not allowed, must specify a null-type output
	if len(unmarshaledOutputs) == 0 {
		unmarshaledOutputs = []fb.Plugin{
			{
				Type: "fluentbit_output",
				Name: "fluentbit-output-null",
				Parameters: []fb.Parameter{
					{
						Name:  "Name",
						Value: "null",
					},
					{
						Name:  "Match",
						Value: "*",
					},
				},
			},
		}
	}

	crdcs, scheme, err := createCRDClientSet()
	if err != nil {
		return err
	}

	// Create a CRD client interface
	crdclient := fb.CrdClient(crdcs, scheme, "kubesphere-logging-system")

	fluentbit, err := crdclient.Get("fluent-bit")
	if err != nil {
		return err
	}

	fluentbit.Spec.Output = unmarshaledOutputs
	_, err = crdclient.Update("fluent-bit", fluentbit)
	if err != nil {
		return err
	}

	return nil
}

// Parse es host, port and index
func ParseEsOutputParams(params []fb.Parameter) *es.ESConfigs {

	var (
		isEsFound bool

		host           = "127.0.0.1"
		port           = "9200"
		index          = "logstash"
		logstashFormat string
		logstashPrefix string
	)

	for _, param := range params {
		switch param.Name {
		case "Name":
			if param.Value == "es" {
				isEsFound = true
			}
		case "Host":
			host = param.Value
		case "Port":
			port = param.Value
		case "Index":
			index = param.Value
		case "Logstash_Format":
			logstashFormat = strings.ToLower(param.Value)
		case "Logstash_Prefix":
			logstashPrefix = param.Value
		}
	}

	if !isEsFound {
		return nil
	}

	// If Logstash_Format is On/True, ignore Index
	if logstashFormat == "on" || logstashFormat == "true" {
		if logstashPrefix != "" {
			index = logstashPrefix
		} else {
			index = "logstash"
		}
	}

	return &es.ESConfigs{Host: host, Port: port, Index: index}
}