package main

import (
	"crypto/x509"
	"crypto/x509/pkix"
	"log"
	"net/url"
	"os"
	"regexp"

	"github.com/kelseyhightower/envconfig"
	"gopkg.in/yaml.v2"
)

type (
	CertPool struct{ *x509.CertPool }
	CertList struct{ *pkix.CertificateList }
	Targets  struct {
		targets []*url.URL
	}
	Config struct {
		URLs   *Targets `envconfig:"URLS" yaml:"urls" default:"http://localhost:9100/metrics"`
		Listen string   `envconfig:"LISTEN" yaml:"listen" default:"0.0.0.0:9443"`

		DisableTLS bool      `envconfig:"DISABLE_TLS" yaml:"disable_tls" default:"false"`
		ClientCA   *CertPool `envconfig:"CA_FILE" yaml:"ca_file"`
		CRL        *CertList `envconfig:"CRL_FILE" yaml:"crl_file"`
		Cert       string    `envconfig:"CERT_FILE" yaml:"cert_file"`
		Key        string    `envconfig:"KEY_FILE" yaml:"key_file"`
	}
)

var re = regexp.MustCompile("^(?P<name>[^#][^ {]+)(?:{(?P<labels>.*)})? (?P<value>-?[0-9]+(?:\\.[0-9]+)?)")

func main() {
	f, err := os.Open("test.yml")
	config := &Config{}
	if err == nil {
		err := yaml.NewDecoder(f).Decode(config)
		if err != nil {
			log.Fatalf("unable to parse yaml: %s", err)
		}
	} else {
		log.Printf("unable to open config file: %s", err)
		log.Printf("fallback to environment")
		err = envconfig.Process("", config)
		if err != nil {
			log.Fatalf("unable to parse environment: %s", err)
		}
	}
	if !config.DisableTLS && (config.CRL == nil || config.ClientCA == nil || config.Cert == "" || config.Key == "") {
		log.Fatalf("please specifiy all tls parameters or disable tls")
	}

	web := NewWeb(config)
	err = web.ListenAndServe()
	if err != nil {
		log.Fatalf("unable to listen: %s", err)
	}
}