//go:generate ../../../tools/readme_config_includer/generator
package consul

import (
	_ "embed"
	"net/http"
	"strings"

	"github.com/hashicorp/consul/api"

	"github.com/influxdata/telegraf"
	"github.com/influxdata/telegraf/plugins/common/tls"
	"github.com/influxdata/telegraf/plugins/inputs"
)

//go:embed sample.conf
var sampleConfig string

type Consul struct {
	Address    string
	Scheme     string
	Token      string
	Username   string
	Password   string
	Datacentre string `toml:"datacentre" deprecated:"1.10.0;1.35.0;use 'datacenter' instead"`
	Datacenter string
	tls.ClientConfig
	TagDelimiter  string
	MetricVersion int
	Log           telegraf.Logger

	// client used to connect to Consul agnet
	client *api.Client
}

func (*Consul) SampleConfig() string {
	return sampleConfig
}

func (c *Consul) Init() error {
	if c.MetricVersion != 2 {
		c.Log.Warnf("Use of deprecated configuration: 'metric_version = 1'; please update to 'metric_version = 2'")
	}

	return nil
}

func (c *Consul) createAPIClient() (*api.Client, error) {
	config := api.DefaultConfig()

	if c.Address != "" {
		config.Address = c.Address
	}

	if c.Scheme != "" {
		config.Scheme = c.Scheme
	}

	if c.Datacentre != "" {
		config.Datacenter = c.Datacentre
	}

	if c.Datacenter != "" {
		config.Datacenter = c.Datacenter
	}

	if c.Token != "" {
		config.Token = c.Token
	}

	if c.Username != "" {
		config.HttpAuth = &api.HttpBasicAuth{
			Username: c.Username,
			Password: c.Password,
		}
	}

	tlsCfg, err := c.ClientConfig.TLSConfig()
	if err != nil {
		return nil, err
	}

	config.Transport = &http.Transport{
		TLSClientConfig: tlsCfg,
	}

	return api.NewClient(config)
}

func (c *Consul) GatherHealthCheck(acc telegraf.Accumulator, checks []*api.HealthCheck) {
	for _, check := range checks {
		record := make(map[string]interface{})
		tags := make(map[string]string)

		record["passing"] = 0
		record["critical"] = 0
		record["warning"] = 0
		record[check.Status] = 1

		if c.MetricVersion == 2 {
			tags["check_name"] = check.Name
			tags["service_id"] = check.ServiceID
			tags["status"] = check.Status
		} else {
			record["check_name"] = check.Name
			record["service_id"] = check.ServiceID
			record["status"] = check.Status
		}

		tags["node"] = check.Node
		tags["service_name"] = check.ServiceName
		tags["check_id"] = check.CheckID

		for _, checkTag := range check.ServiceTags {
			if c.TagDelimiter != "" {
				splittedTag := strings.SplitN(checkTag, c.TagDelimiter, 2)
				if len(splittedTag) == 1 && checkTag != "" {
					tags[checkTag] = checkTag
				} else if len(splittedTag) == 2 && splittedTag[1] != "" {
					tags[splittedTag[0]] = splittedTag[1]
				}
			} else if checkTag != "" {
				tags[checkTag] = checkTag
			}
		}

		acc.AddFields("consul_health_checks", record, tags)
	}
}

func (c *Consul) Gather(acc telegraf.Accumulator) error {
	if c.client == nil {
		newClient, err := c.createAPIClient()

		if err != nil {
			return err
		}

		c.client = newClient
	}

	checks, _, err := c.client.Health().State("any", nil)

	if err != nil {
		return err
	}

	c.GatherHealthCheck(acc, checks)

	return nil
}

func init() {
	inputs.Add("consul", func() telegraf.Input {
		return &Consul{}
	})
}