// notifyr sends and reads notifications on the homelab's ntfy bus, so
// any agent can alert a human and check recent infra alerts the same
// way. See doc/tool-parity.md §3.3.
package main

import (
	"flag"
	"fmt"
	"os"
	"sort"
	"strings"

	"gitea.brasse-pc.eu/brasse/agent-tools/notifyr/notify"
)

var version = "dev"

const usage = `notifyr - ntfy client for agents (send and read notifications)

Usage:
  notifyr send --msg "text" [--topic T] [--title X]
               [--priority min|low|default|high|urgent] [--tags a,b]
  notifyr read [--topic T] [--since 10m|2h|all] [--limit N]
  notifyr topics                    list known topics (from the config)
  notifyr version

Config: ~/.config/notifyr/config.json (created on first run; override
path with NOTIFYR_CONFIG). Holds server URL, optional token, the
default topic and the known-topics table.

Examples:
  notifyr send --topic ci-fel --title "Build failed" --msg "agent-tools arm64: FAIL" --priority high
  notifyr read --topic pi5-server-fel --since 2h     # what has alerted lately?
`

func main() {
	if len(os.Args) < 2 {
		fmt.Print(usage)
		os.Exit(2)
	}
	cfgPath := notify.ConfigPath()
	switch os.Args[1] {
	case "send":
		cmdSend(cfgPath, os.Args[2:])
	case "read":
		cmdRead(cfgPath, os.Args[2:])
	case "topics":
		cmdTopics(cfgPath)
	case "version", "--version", "-v":
		fmt.Println("notifyr", version)
	case "help", "--help", "-h":
		fmt.Print(usage)
	default:
		die("unknown command %q — run 'notifyr help'", os.Args[1])
	}
}

func cmdSend(cfgPath string, args []string) {
	fs := flag.NewFlagSet("send", flag.ExitOnError)
	topic := fs.String("topic", "", "topic (default: default_topic from config)")
	title := fs.String("title", "", "notification title")
	msg := fs.String("msg", "", "message text (required)")
	priority := fs.String("priority", "", "min|low|default|high|urgent or 1-5")
	tags := fs.String("tags", "", "comma-separated tags/emoji shortcodes")
	fs.Parse(args)
	cfg, err := notify.LoadConfig(cfgPath)
	if err != nil {
		die("%v", err)
	}
	if *topic == "" {
		*topic = cfg.DefaultTopic
	}
	var tagList []string
	if *tags != "" {
		tagList = strings.Split(*tags, ",")
	}
	if err := notify.New(cfg.Server, cfg.Token).Send(*topic, *title, *msg, *priority, tagList); err != nil {
		die("%v", err)
	}
	fmt.Printf("sent to %s/%s\n", cfg.Server, *topic)
}

func cmdRead(cfgPath string, args []string) {
	fs := flag.NewFlagSet("read", flag.ExitOnError)
	topic := fs.String("topic", "", "topic (default: default_topic from config)")
	since := fs.String("since", "12h", "how far back: 10m, 2h, unix timestamp or all")
	limit := fs.Int("limit", 0, "print at most N (newest) messages")
	fs.Parse(args)
	cfg, err := notify.LoadConfig(cfgPath)
	if err != nil {
		die("%v", err)
	}
	if *topic == "" {
		*topic = cfg.DefaultTopic
	}
	msgs, err := notify.New(cfg.Server, cfg.Token).Read(*topic, *since, *limit)
	if err != nil {
		die("%v", err)
	}
	if len(msgs) == 0 {
		fmt.Printf("no messages on %s since %s\n", *topic, *since)
		return
	}
	for _, m := range msgs {
		fmt.Println(notify.Format(m))
	}
}

func cmdTopics(cfgPath string) {
	cfg, err := notify.LoadConfig(cfgPath)
	if err != nil {
		die("%v", err)
	}
	names := make([]string, 0, len(cfg.Topics))
	for n := range cfg.Topics {
		names = append(names, n)
	}
	sort.Strings(names)
	for _, n := range names {
		mark := "  "
		if n == cfg.DefaultTopic {
			mark = "* "
		}
		fmt.Printf("%s%-18s %s\n", mark, n, cfg.Topics[n])
	}
	fmt.Fprintln(os.Stderr, "(* = default topic)")
}

func die(format string, args ...interface{}) {
	fmt.Fprintf(os.Stderr, "notifyr: "+format+"\n", args...)
	os.Exit(1)
}