package main

import (
	"bytes"
	"flag"
	"fmt"
	"gopkg.in/yaml.v3"
	"os"
	"time"

	"riedstra.dev/go/checkup"
)

type Config struct {
	RocketChatURL      string             `yaml:"RocketChatURL"`
	DiscordURL         string             `yaml:"DiscordURL"`
	DefaultCertPort    string             `yaml:"DefaultCertPort"`
	CertWindow         int                `yaml:"CertWindow"`
	CheckCerts         map[string]*string `yaml:"CheckCerts"`
	ExpectedStatusCode int                `yaml:"ExpectedStatusCode"`
	StatusChecks       map[string]*int    `yaml:"StatusChecks"`
}

func ReadConfig(fn string) (*Config, error) {
	fh, err := os.Open(fn)
	if err != nil {
		return nil, err
	}

	dec := yaml.NewDecoder(fh)
	conf := &Config{}
	err = dec.Decode(conf)
	return conf, err
}

func notify(conf *Config, b []byte) {
	if len(b) >= 1 {

		if conf.RocketChatURL != "" {
			err := checkup.SendRocketChatAlert(conf.RocketChatURL, string(b))
			if err != nil {
				fmt.Fprintln(os.Stderr, string(b))
				fmt.Fprintf(os.Stderr,
					"When sending webhook for rocketchat: %s\n", err)
			}

		}
		if conf.DiscordURL != "" {
			err := checkup.SendDiscordAlert(conf.DiscordURL, string(b))
			if err != nil {
				fmt.Fprintln(os.Stderr, string(b))
				fmt.Fprintf(os.Stderr,
					"When sending webhook for discord: %s\n", err)
			}
		}
	}
}

func checkCerts(conf *Config) {
	msg := &bytes.Buffer{}
	for host, port := range conf.CheckCerts {
		if port == nil {
			port = &conf.DefaultCertPort
		}

		conn, err := checkup.CertExpiresSoon(
			host,
			*port,
			time.Duration(conf.CertWindow)*time.Hour*24)
		if err != nil {
			fmt.Fprintf(msg, "%s:%s --> %s\n", host, *port, err)
			continue
		}
		conn.Close()
	}

	notify(conf, msg.Bytes())
}

func checkStatus(conf *Config) {
	msg := &bytes.Buffer{}

	for url, code := range conf.StatusChecks {
		if code == nil {
			code = &conf.ExpectedStatusCode
		}
		err := checkup.HttpStatusOK(url, *code)
		if err != nil {
			fmt.Fprintf(msg, "Checking: %s, %v\n",
				url, err)
		}
	}

	notify(conf, msg.Bytes())
}

func main() {
	fl := flag.NewFlagSet("checkup", flag.ExitOnError)

	confFn := fl.String("c", "config.yml", "Configuration file path")

	_ = fl.Parse(os.Args[1:])

	conf, err := ReadConfig(*confFn)
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}

	checkCerts(conf)
	checkStatus(conf)

}